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1
Oulmane, Mourad. "Integrated solutions for timing jitter measurement". Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104524.
Testo completoAbstract (sommario):
In this thesis we present two integrated solutions suitable for measuring the timing jitter of digital signals in SoCs and data acquisition systems (mainly sampling ADCs). The presented methods are also suitable for time measurement in a variety of timing-based metrological applications. The first method is based on the amplification of the time difference to be measured using a time amplifier (TAMP). The result of the amplification is subsequently digitized using a low resolution time-to-digital converter (TDC). The amplifier is based on the principle of virtual charge sharing that allows for continuous, monotonic and symmetric time transfer characteristics. Given its analog nature, the time amplifier has linearity issues in addition to being prone to temperature and process variations and uncertainties. To address these problems, a measurement and calibration method that consists of a dual TAMP arrangement is used to deduce the measured timing quantities without a priori knowledge of the gain of the amplifiers. Also, an empirical and more direct calibration technique suitable for a single-amplifier-based measurement system is presented. In this thesis we implement an amplifier with a measured gain of 228 s/s feeding a TDC of 78 ps of resolution resulting in a timing measurement system of 342.1 fs of nominal resolution.The second method consist of an ADC-based jitter measurement technique in which the jittery signal assumes the role of sampling clock. The novelty in this technique is that it supports arbitrary analog inputs to the ADC as measurement vehicle. The proposed measurement system comprises, in addition to the sampling ADC, an independent back-end digital system to extract jitter timing information. A very important feature of such a digital system is that the jitter-induced magnitude error in each output sample of the ADC is first measured before extracting its associated timing information. Jitter characteristics of the sampling clock are extracted with high accuracy. Indeed, as demonstrated in this thesis, even for an input signal to the ADC with a bandwidth as small as 4.61 MHz, the jitter distribution of a 12.5 MHz sampling clock is extracted with an accuracy of about 3.25 ps.Dans cette thèse, nous présentons deux solutions intégrées pour mesurer les fluctuations dans le timing des signaux numériques, communément appelé “jitter”, et ce dans les systèmes sur puce et les systèmes d'acquisition de données (principalement les CANs). Ces techniques sont aussi employables dans toutes autres applications métrologiques dont le principe de fonctionnement est basé sur la mesure du temps.La première méthode est basée sur l'amplification de la différence de temps à mesurer à l'aide d'un amplificateur de temps (TAMP). Le résultat de l'amplification est ensuite numérisé en utilisant un convertisseur temps-numérique. La conception de l'amplificateur est basé sur le principe de partage virtuel de charge qui permet une courbe de transfert de temps continue, monotone et symétrique. Compte tenu de sa nature analogique, l'amplificateur est limité en termes de linéarité en plus d'être sensible aux variations de température et de processus. Pour résoudre ce problème, une méthode de mesure et d'étalonnage qui consiste en une configuration double-TAMP est utilisée pour déduire les quantités mesurées sans connaissance préalable du gain des amplificateurs utilisés. Aussi, nous présentons une technique empirique pour calibrer un système de mesure comprenant un seul amplificateur. Dans cette thèse, nous implémentons un amplificateur avec un gain mesuré de 228 s/s alimentant un convertisseur temps-numérique de 78 ps de résolution. Effectivement, ceci résulte en un système de mesure de temps d'une résolution nominale de 342,1 fs.La seconde méthode pour mesurer le jitter consiste en une technique de mesure basée sur un CAN à échantillonnage ou le signal dont le jitter est à mesurer assume le rôle d'horloge. La particularité fondamentale de cette technique est qu'elle admet des signaux analogiques arbitraires à l'entrée du CAN. Le système de mesure proposé comprend, en plus du CAN, un bloc digital entièrement indépendant du CAN pour extraire l'erreur de timing associée à chaque échantillon à la sortie du CAN. Une caractéristique très importante de ce bloc est qu'il calcule d'abords l'erreur dans le code de chaque échantillon à la sortie du CAN induite par le jitter avant d'en déduire l'erreur de timing. Dans cette étude, les caractéristiques du jitter de l'horloge d'échantillonnage sont extraites avec une grande précision. Expérimentalement parlant, même pour une bande d'entrée aussi basse que 4,61 MHz, la distribution du jitter d'une horloge d'échantillonnage de 12,5 MHz est extraite avec une précision de l'ordre de 3.25 ps.
2
Onunkwo, Uzoma Anaso. "Timing Jitter in Ultra-Wideband (UWB) Systems". Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10465.
Testo completoAbstract (sommario):
Timing offsets result from the use of real clocks that are non-ideal in sampling intervals. These offsets also known as timing jitter were shown to degrade the performance of the two forms of UWB systems impulse radio and orthogonal frequency division multiplexing (OFDM)-based UWB. It was shown that for impulse radio, timing jitter distorts the correlation property of the transmitted signal and the resulting performance loss is proportional to the root-mean-square (RMS) value of the timing jitter. For the OFDM-based UWB, timing jitter introduced inter-channel interference (ICI) and the performance loss was dependent on the product of the bandwidth and the RMS of the timing jitter. A number of techniques were proposed for mitigating the performance degradation in each form of UWB. Specifically, for impulse radio, the methods of pulse shaping and sample averaging were provided, whereas for OFDM-based UWB, oversampling and adaptive modulation were given. Through analysis and simulation, it was shown that substantial gain in signal power-to-noise ratio can be achieved using these jitter-reduction methods.
3
Sickler, Jason William 1978. "Timing jitter studies in modelocked fiber lasers". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/87855.
Testo completoAbstract (sommario):
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.Also issued in pages.
Includes bibliographical references (p. 107-109).
by Jason William Sickler.
S.M.
4
Tomlin, Toby-Daniel. "Analysis and modelling of jitter and phase noise in electronic systems : phase noise in RF amplifiers and jitter in timing recovery circuits". University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2004. http://theses.library.uwa.edu.au/adt-WU2004.0021.
Testo completoAbstract (sommario):
Timing jitter and phase noise are important design considerations in most electronic systems, particularly communication systems. The desire for faster transmission speeds and higher levels of integration, combined with lower signal levels and denser circuit boards has placed greater emphasis on managing problems related to phase noise, timing jitter, and timing distribution. This thesis reports original work on phase noise modelling in electronic systems. A new model is proposed which predicts the up-conversion of baseband noise to the carrier frequency in RF amplifiers. The new model is validated by comparing the predicted phase noise performance to experimental measurements as it applies to a common emitter (CE), bipolar junction transistor (BJT) amplifier. The results show that the proposed model correctly predicts the measured phase noise, including the shaping of the noise about the carrier frequency, and the dependence of phase noise on the amplifier parameters. In addition, new work relating to timing transfer in digital communication systems is presented. A new clock recovery algorithm is proposed for decoding timing information encoded using the synchronous residual time-stamp (SRTS) method. Again, theoretical analysis is verified by comparison with an experimental implementation. The results show that the new algorithm correctly recovers the source clock at the destination, and satisfies the jitter specification set out by the ITU-T for G.702 signals.
5
Haghighat, Afshin. "Low-jitter symbol timing recovery for M-ary QAM and PAM signals". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0002/MQ39476.pdf.
Testo completo
6
Li, Duo Ph D. Massachusetts Institute of Technology. "Attosecond timing jitter modelocked lasers and ultralow phase noise photonic microwave oscillators". Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/87930.
Testo completoAbstract (sommario):
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 111-119).
Photonic microwave oscillator based on optical frequency comb and ultrastable optical reference cavity represents the state-of-the-art solution to generate X-band microwaves of ultralow phase noise. Such high-quality microwave source enables a range of applications in which frequency stability and timing accuracy are essential to performance. Wide use of this technology, however, requires compact system architecture, low-term stability and low energy consumption, which drive the needs to develop high repetition-rate femtosecond lasers alternative to Ti:sapphire technology, and to explore a feasible means to achieve integrated photonic microwave oscillators. Ultrafast Cr:LiSAF lasers can be directly pumped with low-cost red laser diodes, and the electrical-to-optical conversion efficiency is as high as 10%. High repetition-rate femtosecond Cr:LiSAF lasers are developed with the help of semiconductor saturable absorber technology, efficient dispersion compensation mirror design algorithms, and heat management of the saturable absorber. The I-GHz Cr:LiSAF oscillator generates 55-fs pulses with 110 pJ pulse energy, which represents almost two orders of magnitude improvement in the output peak power over previous results. Timing jitter of 1 00-MHz Cr:LiSAF lasers is measured with a single-crystal balanced optical cross-correlator to be -30 as from 10 kHz to 50 MHz. Pump intensity noise coupled into phase noise through the self-steepening effect proves to be the major noise source. The most recent advance in silicon photonics and wafer-scale three-dimensional integration technology illuminates a pathway toward on-chip photonic microwave oscillators. Phase noise model of the proposed Erbium Silicon Photonics Integrated OscillatoR (ESPIOR) suggests that it is possible to achieve comparable noise performance with the Ti:sapphire-based system, without the need of carrier-envelope-offset frequency detection. A demonstration using fiber-optic components further indicates that it is practicable to realize optical frequency division and microwave readout in the proposed architecture. With the advancement of heterogeneous electronic-photonic integration, it would pave the way for an ultralow-noise microwave source fully integrated in a hybrid photonic-electronic chip on a silicon substrate.
by Duo Li.
Ph. D.
7
Sidorova, Mariia. "Timing Jitter and Electron-Phonon Interaction in Superconducting Nanowire Single-Photon Detectors (SNSPDs)". Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/22296.
Testo completoAbstract (sommario):
Die vorliegende Doktorarbeit beschäftigt sich mit der experimentellen Studie zweier miteinander verbundener Phänomene: Dem intrinsischen Timing-Jitter in einem supraleitendenden Nanodraht-Einzelphotonen-Detektor (SNSPD) und der Relaxation der Elektronenenergie in supraleitenden Filmen. Supraleitende Nanodrähte auf einem dielektrischen Substrat als mikroskopische Grundbausteine jeglicher SNSPDs stellen sowohl für theoretische als auch für experimentelle Studien komplexe Objekte dar. Die Komplexität ergibt sich aus der Tatsache, dass SNSPDs in der Praxis stark ungeordnete und ultradünne supraleitende Filme verwenden, die eine akustische Fehlanpassung zu dem zugrundeliegenden Substrat aufweisen und einen Nichtgleichgewichts-Zustand implizieren. Die Arbeit untersucht die Komplexität des am weitesten in der SNSPD Technologie verbreiteten Materials, Niobnitrid (NbN), indem verschiedene experimentelle Methoden angewandt werden. Als eine mögliche Anwendung der SNSPD-Technologie wird ein Prototyp eines dispersiven Raman-Spektrometers mit Einzelphotonen-Sensitivität demonstriert.This Ph.D. thesis is based on the experimental study of two mutually interconnected phenomena: intrinsic timing jitter in superconducting nanowire single-photon detectors (SNSPDs) and relaxation of the electron energy in superconducting films. Microscopically, a building element of any SNSPD device, a superconducting nanowire on top of a dielectric substrate, represents a complex object for both experimental and theoretical studies. The complexity arises because, in practice, the SNSPD utilizes strongly disordered and ultrathin superconducting films, which acoustically mismatch with the underlying substrate, and implies a non-equilibrium state. This thesis addresses the complexity of the most conventional superconducting material used in SNSPD technology, niobium nitride (NbN), by applying several distinct experimental techniques. As an emerging application of the SNSPD technology, we demonstrate a prototype of the dispersive Raman spectrometer with single-photon sensitivity.
8
Morse, Jonathan Lee. "Femtosecond fiber lasers at 1550 nm for high repetition rates and low timing jitter". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82363.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references.
Femtosecond fiber lasers have become an important enabling technology for advances in many areas including: frequency combs, precise timing distribution, optical arbitrary waveform generation, and high bit rate sampling for analog to digital conversion. Experiments and applications like these put demanding requirements on the source laser oscillator; such as operating near 1550 nm in wavelength, multi-gigahertz repetition rates, sub 100 femtosecond pulse widths, and sub 10 femtosecond timing jitters. This thesis describes the design, fabrication, and characterization of three different iterations of mode-locked laser sources utilizing erbium doped fibers and semiconductor saturable absorbing mirrors to form pulse trains in the 1550 nm wavelength band. The first systems took advantage of a highly doped erbium fiber in a sigma cavity configuration to generate 100 fs pulses at up to a 300 MHz repetition rate through polarization additive pulse mode-locking. At the time, this was the highest fundamental repetition rate to be reported for a fiber cavity in a ring configuration. The next two systems are variations on a linear cavity fiber laser design. In the first, the fiber coupling was achieved through free space optics and the saturable absorbing mirror was also imaged through lenses. Once mode-locked, repetition rates of just beyond 1 GHz were demonstrated with this design; however the laser output was relatively low power. The second version coupled the input and output light through fiber components and coupled the fiber directly to the saturable absorbing mirror. This laser mode-locked in several different states and a study to characterize and understand these states was undertaken. Ultimately, it was understood which conditions minimized the cavity noise and pulse widths thus allowing for the achievement of a 1550 nm, 1 GHz, sub 10 fs jitter, femtosecond fiber laser. This laser is more compact than competing technologies and could be constructed with relatively low cost.
by Jonathan Lee Morse.
Ph.D.
9
Sidorova, Mariia [Verfasser]. "Timing Jitter and Electron-Phonon Interaction in Superconducting Nanowire Single-Photon Detectors (SNSPDs) / Mariia Sidorova". Berlin : Humboldt-Universität zu Berlin, 2021. http://d-nb.info/1226153380/34.
Testo completo
10
Docherty, Andrew Engineering UNSW. "Collision induced timing shifts in wavelength-division-multiplexed optical fiber communications systems". Awarded by:University of New South Wales. Engineering, 2004. http://handle.unsw.edu.au/1959.4/19337.
Testo completoAbstract (sommario):
Long distance repeaterless optical fiber communications systems are currently used to transmit most internet and telephone information worldwide. The growth of photonic telecommunications technology has produced systems with very high bit-rate per fiber, but this still falls short of its potential capacity. Currently systems that are able to transmit even higher bit-rates are being developed utilizing dense wavelength-division-multiplexing (WDM) to maximally utilize the bandwidth potential of optical fibers. One of the most important factors that limits the bit-rate achievable in a such a WDM optical communications system is the cross-talk between channels caused by pulse collisions. In this thesis a consistent mathematical theory is used to analyze the frequency and timing shifts caused collisions between two WDM channels. This theory is applied to the systems currently most promising for next-generation photonic telecommunications; the dispersion managed (DM) soliton and 'quasi-linear' systems. Self-contained formulae are obtained which accurately predict the timing shifts suffered in these systems with a wide range of parameters. These formulae require an order of magnitude less computational time that direct numerical simulations. Several mathematical techniques are introduced to obtain computationally efficient formulae for complete and incomplete collisions in both systems. For complete collisions we use the Poisson sum transform to change the calculation to a sum in the Fourier domain. For incomplete collisions we use asymptotic integration to obtain approximate formulae. For quasi-linear systems we simplify the Laplace method even further to obtain elementary formulae. We show that using a combination of these methods the timing shift for incomplete and complete collisions in a wide range of system configurations can be obtained in comparatively small computational times. We find that for systems with small DM map strength the timing shift from widely separated channels is significant. For quasi-linear systems with large DM map strength this is negligable and the timing shift decreases with the square of the channel frequency separation. We also find the timing shift from closely spaced channels is higher for quasi-linear systems than for DM soliton systems operating at the same average dispersion.
11
Haider, Daniyal. "On-Chip Phase Measurement Design Study in 65nm CMOS Technology". Thesis, Linköpings universitet, Elektroniska Kretsar och System, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-120912.
Testo completoAbstract (sommario):
Jitter is generally defined as a time deviation of the clock waveform from its desired position. The deviation which occurs can be on the leading or lagging side and it can be bounded (deterministic) or unbounded (random). Jitter is a critical specification in the digital system design. There are various techniques to measure the jitter. The straightforward approach is based on spectrum analyzer or oscilloscope measurements. In this thesis an on-chip jitter measurement technique is investigated and the respective circuit is designed using 65 nm CMOS technology. The work presents the high level model and transistor level model, both implemented using Cadence software. Based on the Vernier concept the circuit is composed of an edge detector, two oscillators, and a phase detector followed by a binary counter, which provides the measurement result. The designed circuit attains resolution of 10ps and can operate in the range of 100 - 500 MHz Compared to other measurement techniques this design features low power consumption and low chip area overhead that is essential for built-in self-test (BIST) applications.
12
Strak, Adam. "Timing Uncertainty in Sigma-Delta Analog-to-Digital Converters". Doctoral thesis, Stockholm : Elektronik, dator- och programvarusystem Electronic, Computer, and Software Systems, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4243.
Testo completo
13
Rashed, Atef Mahmoud Khalil. "Performance analysis and improvement of edge emitting semiconductor laser diodes for optical communications". Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390834.
Testo completo
14
Güvenç, İsmail. "Towards practical design of impulse radio ultrawideband systems: Parameter estimation and adaptation, interference mitigation, and performance analysis". Scholar Commons, 2006. http://scholarcommons.usf.edu/etd/2541.
Testo completoAbstract (sommario):
Ultrawideband (UWB) is one of the promising technologies for future short-range high data rate communications (e.g. for wireless personal area networks) and longer range low data rate communications (e.g. wireless sensor networks).Despite its various advantages and potentials (e.g. low-cost circuitry, unlicensed reuse of licensed spectrum, precision ranging capability etc.), UWB also has its own challenges. The goal of this dissertation is to identify and address some of those challenges, and provide a framework for practical UWB transceiver design.In this dissertation, various modulation options for UWB systems are reviewed in terms of their bit error rate (BER) performances, spectral characteristics, modem and hardware complexities, and data rates. Time hopping (TH) code designs for both synchronous (introduced an adaptive code assignment technique) and asynchronous UWB impulse radio (IR) systems are studied. An adaptive assignment of two different multiple access parame
ters (number of pulses per symbol and number of pulse positions per frame)is investigated again considering both synchronous and asynchronous scenarios, and a mathematical framework is developed using Gaussian approximations of interference statistics for different scenarios. Channel estimation algorithms for multiuser UWB communication systems using symbol-spaced (proposed a technique that decreases the training size), frame-spaced (proposed a pulse-discarding algorithm for enhanced estimationperformance), and chip-spaced (using least squares (LS) estimation) sampling are analyzed.A comprehensive review on multiple accessing andinterference avoidance/cancellation for IR-UWB systems is presented.BER performances of different UWB modulation schemes in the presence of timing jitter are evaluated and compared in static and multipath fading channels, and finger estimation error, effects of jitter distribution, and effects of pulse shape are investigated. A unified performance analysis app
roach for different IR-UWB transceiver types (stored-reference, transmitted-reference, and energy detector) employing various modulation options and operating at sub-Nyquist sampling rates is presented. The time-of-arrival (TOA) estimation performance of different searchback schemesunder optimal and suboptimal threshold settings are analyzed both for additive white Gaussian noise (AWGN) and multipath channels.
15
Ardey, Abhijeet. "On-Chip Optical Stabilization of High-Speed Mode-locked Quantum Dot Lasers for Next Generation Optical Networks". Doctoral diss., University of Central Florida, 2014. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/6240.
Testo completoAbstract (sommario):
Monolithic passively mode-locked colliding pulse semiconductor lasers generating pico- to sub-picosecond terahertz optical pulse trains are promising sources for future applications in ultra-high speed data transmission systems and optical measurements. However, in the absence of external synchronization, these passively mode-locked lasers suffer from large amplitude and timing jitter instabilities resulting in broad comb linewidths, which precludes many applications in the field of coherent communications and signal processing where a much narrower frequency line set is needed. In this dissertation, a novel quantum dot based coupled cavity laser is presented, where for the first time, four-wave mixing (FWM) in the monolithically integrated saturable absorber is used to injection lock a monolithic colliding pulse mode-locked (CPM) laser with a mode-locked high-Q ring laser. Starting with a passively mode-locked master ring laser, a stable 30 GHz optical pulse train is generated with more than 10 dB reduction in the RF noise level at 20 MHz offset and close to 3-times reduction in the average optical linewidth of the injection locked CPM slave laser. The FWM process is subsequently verified experimentally and conclusively shown to be the primary mechanism responsible for the observed injection locking. Other linear scattering effects are found to be negligible, as predicted in the orthogonal waveguide configuration. The novel injection locking technique is further exploited by employing optical hybrid mode-locking and increasing the Q of the master ring cavity, to realize an improved stabilization architecture. Dramatic reduction is shown with more than 14-times reduction in the photodetected beat linewidth and almost 5-times reduction in the optical linewidth of the injection locked slave laser with generation of close to transform limited pulses at ~ 30 GHz. These results demonstrate the effectiveness of the novel injection locking technique for an all-on-chip stability transfer and provides a new way of stabilizing monolithic optical pulse sources for applications in future high speed optical networks.Ph.D.
Doctorate
Physics
Sciences
Physics
16
Slavinskis, Nerijus. "Trumpų impulsų kokybės moduliacijos išilgai diodais kaupinami kietojo kūno minilazeriai: generavimas, charakterizavimas ir panaudojimas". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110630_134132-74098.
Testo completoAbstract (sommario):
Disertacija skirta diodais kaupinamų kietojo kūno lazerių su aktyviąja ir pasyviąja kokybės moduliacija generacijos dinamikos detalesnei skaitmeninei analizei, lazerio impulsų laikinių ir erdvinių parametrų charakterizavimui ir sukurtų minilazerių panaudojimo galimybių demonstracijai. Generacijos dinamikos detalesniai skaitmeniniai analizei, darbe pristatomas sukurtas bėgančiųjų bangų modelis, kuriame atsižvelgiama ne tik į daugelį procesų vykstančių lazerio aktyviajame elemente, bet ir į rezonatoriaus konfigūraciją bei kaupinimo šaltino parametrus. Pateikiami skaitinio modeliavimo rezultatai demonstruojantys šio modelio privalumus lyginant su dažniausiai naudojamu taškiniu lazerio modeliu. Naudojant taškinį lazerio modelį yra nagrinėjama generuojamų impulsų laikinio tirtėjimo problema pasyvios kokybės moduliacijos lazeriuose ir pasiūlyti mažinimo būdai naudojant skirtingus kaupinimo būdus. Darbe taip pat pateiktas naujas, antraisiais momentais pagrįstas, pluošto charakterizavimo judančiu peiliu metodas. Nagrinėjamos lazerių impulsų spūdos galimybės tetrachlorido CCL4 skystyje ir pademonstruota, kad naudojant užkrato signalą galima gauti trumpesnius (< 60 ps) ir stabilesnius optinius impulsus. Darbe pademonstruotos sukurtų minilazerių pritaikymo galimybės: aprašomas netiesinio lūžio rodiklio kvarciniame stikle matavimas Z-skenavimo metodu ir gautų duomenų apdorojimo procedūra įskaitant naudojamų impulsų erdvinę ir laikinę formą; aprašomi eksperimentai, kuriuose sukurti... [toliau žr. visą tekstą]The dissertation is dedicated to the detailed numerical modelling of generation dynamics of actively and/or passively Q-switched diode laser longitudinally pumped solid-state lasers, characterization of spatial and temporal laser properties and for the demonstration of application possibility of created minilasers. A detailed theoretical model for the description of generation dynamics using travelling wave approach is presented. In this model more parameters of active laser medium, pump sources and resonator architecture are taken into account. In this thesis the results which show the principal difference between results obtained using the laser travelling wave model and point laser model are presented. Using point laser model the problems of generated pulse timing jitter in passively Q-switched lasers are described and its lowering possibilities using different pumping methods are suggested. In this thesis new, based by the second order moment, laser beam characterisation by knife-edge method is presented. Also laser pulse compression possibilities in tetrachloride CCL4 medium are described. It is showed that using seed signal it is possible to obtain shorter (< 60 ps) and more stable optical pulses. In this thesis application possibilities of created minilasers are presented: the experimental results of the Z-scan measurements obtained using pulses with different pulse shapes for fused silica are presented; also experiments, in which, created minilasers for paper cleaning... [to full text]
17
Slavinskis, Nerijus. "Short pulse q-switched longitudinally diode pumped solid state minilasers: generation, characterization and application". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110630_134119-87467.
Testo completoAbstract (sommario):
The dissertation is dedicated to the detailed numerical modelling of generation dynamics of actively and/or passively Q-switched diode laser longitudinally pumped solid-state lasers, characterization of spatial and temporal laser properties and for the demonstration of application possibility of created minilasers. A detailed theoretical model for the description of generation dynamics using travelling wave approach is presented. In this model more parameters of active laser medium, pump sources and resonator architecture are taken into account. In this thesis the results which show the principal difference between results obtained using the laser travelling wave model and point laser model are presented. Using point laser model the problems of generated pulse timing jitter in passively Q-switched lasers are described and its lowering possibilities using different pumping methods are suggested. In this thesis new, based by the second order moment, laser beam characterisation by knife-edge method is presented. Also laser pulse compression possibilities in tetrachloride CCL4 medium are described. It is showed that using seed signal it is possible to obtain shorter (< 60 ps) and more stable optical pulses. In this thesis application possibilities of created minilasers are presented: the experimental results of the Z-scan measurements obtained using pulses with different pulse shapes for fused silica are presented; also experiments, in which, created minilasers for paper cleaning... [to full text]Disertacija skirta diodais kaupinamų kietojo kūno lazerių su aktyviąja ir pasyviąja kokybės moduliacija generacijos dinamikos detalesnei skaitmeninei analizei, lazerio impulsų laikinių ir erdvinių parametrų charakterizavimui ir sukurtų minilazerių panaudojimo galimybių demonstracijai. Generacijos dinamikos detalesniai skaitmeniniai analizei, darbe pristatomas sukurtas bėgančiųjų bangų modelis, kuriame atsižvelgiama ne tik į daugelį procesų vykstančių lazerio aktyviajame elemente, bet ir į rezonatoriaus konfigūraciją bei kaupinimo šaltino parametrus. Pateikiami skaitinio modeliavimo rezultatai demonstruojantys šio modelio privalumus lyginant su dažniausiai naudojamu taškiniu lazerio modeliu. Naudojant taškinį lazerio modelį yra nagrinėjama generuojamų impulsų laikinio tirtėjimo problema pasyvios kokybės moduliacijos lazeriuose ir pasiūlyti mažinimo būdai naudojant skirtingus kaupinimo būdus. Darbe taip pat pateiktas naujas, antraisiais momentais pagrįstas, pluošto charakterizavimo judančiu peiliu metodas. Nagrinėjamos lazerių impulsų spūdos galimybės tetrachlorido CCL4 skystyje ir pademonstruota, kad naudojant užkrato signalą galima gauti trumpesnius (< 60 ps) ir stabilesnius optinius impulsus. Darbe pademonstruotos sukurtų minilazerių pritaikymo galimybės: aprašomas netiesinio lūžio rodiklio kvarciniame stikle matavimas Z-skenavimo metodu ir gautų duomenų apdorojimo procedūra įskaitant naudojamų impulsų erdvinę ir laikinę formą; aprašomi eksperimentai, kuriuose sukurti... [toliau žr. visą tekstą]
18
El, bassri Farid. "Sources lasers déclenchées nanosecondes : Applications à la spectroscopie Raman cohérente sous champ électrique". Thesis, Limoges, 2014. http://www.theses.fr/2014LIMO0060/document.
Testo completoAbstract (sommario):
Du fait de leur compacité, leur robustesse et leur faible coût, les microlasers impulsionnels nanosecondes constituent des sources particulièrement attractives pour de nombreux systèmes de détection et d'analyse, en particulier les cytomètres en flux ou les dispositifs pour la spectroscopie CARS (Coherent Raman Anti Stokes Scattering). Cependant, ces applications nécessitent des performances améliorées en ce qui concerne la gigue temporelle et la cadence de répétition accessible. Dans sa première partie, cette thèse propose des solutions originales pour atteindre les performances requises à partir de microlasers passivement déclenchés, grâce à la mise en oeuvre d'une cavité hybride couplée, pompée par une onde modulée en intensité. Une cadence de répétition supérieure à 30 kHz avec une gigue demeurant inférieure à 200 ns est atteinte. Le potentiel de microlasers à fibres déclenchés par modulation du gain pour monter en cadence est aussi évalué, montrant que des impulsions à faible gigue, à une cadence de plus de 2 MHz peuvent être produites. Enfin, la dernière partie est consacrée à la mise au point et à l'exploitation d'un nouveau système de spectroscopie CARS assisté par une excitation électrique haute tension. Ce dispositif, réalisé à partir d'un microlaser amplifié, permet de s'affranchir du bruit de fond non résonnant des mesures et de réaliser une analyse spectroscopique fine de la réponse de différents milieux d'intérêt sous champ continu ou impulsionnel, pouvant conduire à une nouvelle méthode de microdosimétrie de champ. Diverses applications, dont la granulométrie à l'échelle micro ou nanométrique ou l'identification de marqueurs pour la biologie, sont démontréesThanks to their compactness, robustness and low cost, pulsed nanosecond microlasers are particularly attractive sources for different detection and analysis systems, particularly flow cytometers or devices for CARS (Coherent Anti Raman Stokes Scattering) spectroscopy. However, these applications require reduced time jitter and increased repetition rate. The first part of this thesis proposes novel solutions to achieve the required performance from passively Q-switched microlasers, which are based on an hybrid coupled-cavity and intensitymodulated pump wave. A repetition rate greater than 30 kHz with jitter remaining lower than 200 ns is reached. Pulsed fiber microlasers operating by gain switching are also studied, showing that pulses with low timing jitter, at a repetition rate of more than 2 MHz can be obtained. The last part is devoted to the development and the implementation of a new system of CARS spectroscopy assisted by a high-voltage electrical stimulation. This device, based on an amplified microlaser, allows to substract the non-resonant background noise in the measurements. Thus, a fine spectroscopic analysis of the response of different environments of interest in continuous or pulsed field can be achieved. It may lead to a new method for field microdosimetry. Various applications, including granulometry at the micro or nanometric scale and the identification of markers for biology, are shown
19
Akrout, Akram. "Contribution à l’étude des lasers à verrouillage de modes pour les applications en télécommunications". Thesis, Evry, Institut national des télécommunications, 2009. http://www.theses.fr/2009TELE0023/document.
Testo completoAbstract (sommario):
Ce travail de thèse porte sur l’étude des lasers à verrouillage de modes à bâtonnets quantiques (MLL QD) sur le système de matériau InAs/InP en vue de leur utilisation pour les applications télécoms. Contrairement aux lasers à deux sections, nous exploitons, tout au long de cette thèse, le phénomène du mélange à quatre-ondes qui est à l’origine du verrouillage de modes dans ces structures. Une analyse du « chirp » des impulsions générées par ce type de lasers, ainsi qu’une étude théorique et expérimentale pour le compenser, ont été décrites. En particulier, nous démontrons la compensation du « chirp » linéaire par un filtrage et par une fibre présentant une dispersion adéquate. D’autre part, une compensation du « chirp » d’ordre supérieur est possible en utilisant une fibre à dispersion spécifique. Une étude a été consacrée à la gigue temporelle, un autre paramètre crucial pour la plupart des applications utilisant les MLLs QD. Dans une première étape, nous avons mis en œuvre une technique de mesure par cross-corrélation optique pour caractériser la gigue temporelle des MLLs à haute fréquence de répétition. Contrairement à la technique de mesure par analyse spectrale, celle-ci permet d’effectuer des mesures à des fréquences de répétitions supérieures à 50 GHz et sur une plage de fréquence allant de presque 0 Hz à quelques centaines de MHz. Ensuite, nous avons caractérisé des diodes lasers présentant une largeur de raie RF record d’une valeur de 850 Hz. Une valeur de gigue de 500 fs a été mesurée sur la bande de fréquence [150 kHz-320 MHz]. Cette valeur correspond à une amélioration d’un facteur 25 par rapport à la valeur mesurée sur une structure à base de puits quantiques pour les mêmes bornes d’intégration. Nous avons également présenté une étude de la réduction du bruit de phase des MLLs basée sur l’effet de la réinjection optique. Nous avons ainsi obtenu une amélioration du niveau de bruit de phase d’un facteur supérieur à 15 dB par rapport à la technique optoélectronique standard. Ces résultats mettent en évidence le potentiel des MLL QD pour la génération des impulsions à très faibles gigue temporelle et ouvrent la voie pour la conception des oscillateurs tout-optiques à faible bruit de phase. Enfin, nous présentons la génération d’un peigne de fréquences WDM en utilisant un MLL QD. En utilisant une telle source, nous avons démontré une transmission canal par canal sur une distance de 50 km de fibre SMF à un débit de 10 Gbit/s. Ce résultat de toute première importance permet d’envisager l’utilisation des MLLs QD pour la transmission WDMThis PhD thesis deals with the integration of InP based quantum dash mode locked lasers for use in optical communication systems and microwave optoelectronic applications. The properties of pulse and characterization methods are described as well as requirements for application in communication systems. Experimental and analytic method for pulse “chirp” characterization and compensation are also discussed. In particular, we demonstrate that high order dispersion can be compensated using specific fibre length. The characterization of quantum dash based mode locked lasers, has shown their potential to generate high spectral purity self-pulsating signals, with state-of-the-art spectral linewidth of ~ 850 Hz. Especially, the importance of, and way to reduce high-frequency jitter is discussed. Indeed, a novel method for measurement of high-frequency jitter based on optical cross-correlation technique is implemented. Systematic investigation of 10 GHz passively mode locked laser based on InAs/InP quantum dashes emitting at 1.55 µm have demonstrated a reduced value of timing jitter of 500 fs in the 150 kHz – 320 MHz frequency range. Compared to typical passively mode-locked quantum well laser which exhibit timing jitter in the range 12 ps (150 kHz – 50 MHz), our device demonstrates an approximately 25 times improvement in timing jitter. Concerning microwave optoelectronic applications, we demonstrate that a low phase noise oscillator can be obtained using a QD MLL integrated in an optical self injection loop without any opto-electronic or electro-optic conversion. A significant reduction of the -3 dB linewedith as low as 200Hz was obtained thanks to optimised tuning of the optical external cavity length. The phase noise has been reduced from -75dBc/Hz to a level as low as -105dBc/Hz at an offset of 100kHz. This yields to ultra low timing jitter and shows the potential to fabricate simple, and yet low noise oscillators based on semiconductor lasers without any high frequency electronics, photodetector or modulator. Finally, we report, for the first time, error-free transmission of 8 WDM channels over 50 km long single mode fiber at 10 Gbit/s using comb-generation in a quantum dash based mode locked laser. Such good performance paves the way for the use of mode locked-lasers in WDM transmission and allows considering such a solution in an integrated WDM transceiver
20
Akrout, Akram. "Contribution à l’étude des lasers à verrouillage de modes pour les applications en télécommunications". Electronic Thesis or Diss., Evry, Institut national des télécommunications, 2009. http://www.theses.fr/2009TELE0023.
Testo completoAbstract (sommario):
Ce travail de thèse porte sur l’étude des lasers à verrouillage de modes à bâtonnets quantiques (MLL QD) sur le système de matériau InAs/InP en vue de leur utilisation pour les applications télécoms. Contrairement aux lasers à deux sections, nous exploitons, tout au long de cette thèse, le phénomène du mélange à quatre-ondes qui est à l’origine du verrouillage de modes dans ces structures. Une analyse du « chirp » des impulsions générées par ce type de lasers, ainsi qu’une étude théorique et expérimentale pour le compenser, ont été décrites. En particulier, nous démontrons la compensation du « chirp » linéaire par un filtrage et par une fibre présentant une dispersion adéquate. D’autre part, une compensation du « chirp » d’ordre supérieur est possible en utilisant une fibre à dispersion spécifique. Une étude a été consacrée à la gigue temporelle, un autre paramètre crucial pour la plupart des applications utilisant les MLLs QD. Dans une première étape, nous avons mis en œuvre une technique de mesure par cross-corrélation optique pour caractériser la gigue temporelle des MLLs à haute fréquence de répétition. Contrairement à la technique de mesure par analyse spectrale, celle-ci permet d’effectuer des mesures à des fréquences de répétitions supérieures à 50 GHz et sur une plage de fréquence allant de presque 0 Hz à quelques centaines de MHz. Ensuite, nous avons caractérisé des diodes lasers présentant une largeur de raie RF record d’une valeur de 850 Hz. Une valeur de gigue de 500 fs a été mesurée sur la bande de fréquence [150 kHz-320 MHz]. Cette valeur correspond à une amélioration d’un facteur 25 par rapport à la valeur mesurée sur une structure à base de puits quantiques pour les mêmes bornes d’intégration. Nous avons également présenté une étude de la réduction du bruit de phase des MLLs basée sur l’effet de la réinjection optique. Nous avons ainsi obtenu une amélioration du niveau de bruit de phase d’un facteur supérieur à 15 dB par rapport à la technique optoélectronique standard. Ces résultats mettent en évidence le potentiel des MLL QD pour la génération des impulsions à très faibles gigue temporelle et ouvrent la voie pour la conception des oscillateurs tout-optiques à faible bruit de phase. Enfin, nous présentons la génération d’un peigne de fréquences WDM en utilisant un MLL QD. En utilisant une telle source, nous avons démontré une transmission canal par canal sur une distance de 50 km de fibre SMF à un débit de 10 Gbit/s. Ce résultat de toute première importance permet d’envisager l’utilisation des MLLs QD pour la transmission WDMThis PhD thesis deals with the integration of InP based quantum dash mode locked lasers for use in optical communication systems and microwave optoelectronic applications. The properties of pulse and characterization methods are described as well as requirements for application in communication systems. Experimental and analytic method for pulse “chirp” characterization and compensation are also discussed. In particular, we demonstrate that high order dispersion can be compensated using specific fibre length. The characterization of quantum dash based mode locked lasers, has shown their potential to generate high spectral purity self-pulsating signals, with state-of-the-art spectral linewidth of ~ 850 Hz. Especially, the importance of, and way to reduce high-frequency jitter is discussed. Indeed, a novel method for measurement of high-frequency jitter based on optical cross-correlation technique is implemented. Systematic investigation of 10 GHz passively mode locked laser based on InAs/InP quantum dashes emitting at 1.55 µm have demonstrated a reduced value of timing jitter of 500 fs in the 150 kHz – 320 MHz frequency range. Compared to typical passively mode-locked quantum well laser which exhibit timing jitter in the range 12 ps (150 kHz – 50 MHz), our device demonstrates an approximately 25 times improvement in timing jitter. Concerning microwave optoelectronic applications, we demonstrate that a low phase noise oscillator can be obtained using a QD MLL integrated in an optical self injection loop without any opto-electronic or electro-optic conversion. A significant reduction of the -3 dB linewedith as low as 200Hz was obtained thanks to optimised tuning of the optical external cavity length. The phase noise has been reduced from -75dBc/Hz to a level as low as -105dBc/Hz at an offset of 100kHz. This yields to ultra low timing jitter and shows the potential to fabricate simple, and yet low noise oscillators based on semiconductor lasers without any high frequency electronics, photodetector or modulator. Finally, we report, for the first time, error-free transmission of 8 WDM channels over 50 km long single mode fiber at 10 Gbit/s using comb-generation in a quantum dash based mode locked laser. Such good performance paves the way for the use of mode locked-lasers in WDM transmission and allows considering such a solution in an integrated WDM transceiver
21
Acremont, Quentin d'. "Étude des propriétés thermiques de librairies d’alliages ternaires en couches minces et mise en évidence du transport non-diffusif par spectroscopie thermique pompe-sonde femtoseconde". Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0665/document.
Testo completoAbstract (sommario):
Durant ces travaux, nous nous sommes intéressés à l’étude des transferts thermiques aux nano-échelles dans les couches minces par spectroscopie pompe-sonde femtoseconde. Dans un premier temps, nous nous sommes intéressés à la mesure haute-cadence de la conductivité thermique d’alliages de Fe-Si-Ge et Ti-Ni-Sn, dans le but d’optimiser leur processus de fabrication et de créer une base de données des propriétés thermiques de ces matériaux. Afin de pouvoir mesurer une grande quantité d’échantillons en un temps réduit, un système de mesure haute cadence entièrement automatisé a été développé et utilisé avec succès. Dans un second temps,ces travaux ont portés sur l’étude du transport thermique dans trois matériaux (Ge, GaAs In-GaAs) par spectroscopie pompe-sonde femtoseconde. Une nouvelle méthode de mesure de la réponse spectrale des nanomatériaux sur une gamme de fréquences allant de quelques centaines de kHz jusqu’au THz a été développée. Les mesures à l’aide de cette méthode ont permis de confirmer la présence d’un régime de transport qualifié de quasi-balistique dans certains matériaux,et une méthode d’extraction de propriétés thermiques à partir de la réponse spectrale mesurée, et prenant en compte ces effets quasi-balistiques, a été développée. L’ensemble des résultats obtenus par ces nouvelles méthodes confirment les travaux précédents décrits dans la littérature. Enfin, la mesure de la réponse spectrale d’un nano-matériau à haute fréquence est en grande partie limitée par la gigue des cavités lasers utilisées par l’expérience. Ainsi, la dernière étape a été de développer un système de mesure de cette gigue et de synchronisation de cavités laser qui pourra permettre de repousser la limite des fréquences mesurables par spectroscopie pompe-sonde femtosecondeIn this work, we studied ultrafast thermal transport at nanoscale in thin films by femtosecond pump-probe thermal spectroscopy. We first developed a high-throughput heterodyne thermoreflectance setup that allows the extraction of thermal properties of a large number of sample in a minimum time, aiming at creating a database of these properties for a large numberof thin film ternary alloys with thermoelectric potential. In the second part of this work, wefocused on the study of thermal transport in three materials : Ge, GaAs and InGaAs. A high resolution phonon spectroscopy setup, along with a spectral reconstruction method allowed usto measure the response of these materials up to several tens of GHz in Fourier domain, which highlighted the presence of non-diffusive thermal transport in InGaAs. Non-diffusive theory,based on Lévy dynamics, allowed us to model this superdiffusion phenomenon and to extract coherent, frequency-independant thermal properties of these materials. Also, high frequency(>GHz) measurements of these spectral responses have shown interesting effects related to the ultrafast thermalisation in transducer-like very thin films. Finally, high-frequency thermal spectroscopy is inherently limited by the intrinsic timing jitter of laser cavities. Thus, the last partof this work was dedicated to developing a timing jitter measurement and active laser synchronisation system in order to increase the signal-to-noise ratio and access higher frequencies in pump-probe thermal spectroscopy experiments
22
Saint-Laurent, Martin. "Modeling and Analysis of High-Frequency Microprocessor Clocking Networks". Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7271.
Testo completoAbstract (sommario):
Integrated systems with billions of transistors on a single chip are a now reality. These systems include multi-core microprocessors and are built today using deca-nanometer devices organized into synchronous digital circuits. The movement of data within such systems is regulated by a set of predictable timing signals, called clocks, which must be distributed to a large number of sequential elements. Collectively, these clocks have a significant impact on the frequency of operation and, consequently, on the performance of the systems. The clocks are also responsible for a large fraction of the power consumed by these systems.
The objective of this dissertation is to better understand clock distribution in order to identify opportunities and strategies for improvement by analyzing the conditions under which the optimal tradeoff between power and performance can be achieved, by modeling the constraints associated with local and global clocking, by evaluating the impact of noise, and by investigating promising new design strategies for future integrated systems.
23
Sahni, Mohamed Omar. "Contribution à l'étude de techniques pour l'affinement spectral de lasers : application aux diodes à blocage de modes destinées aux télécommunications optiques cohérentes". Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S121/document.
Testo completoAbstract (sommario):
Les peignes de fréquences optiques, issus de diodes à blocage de modes, font partie des candidats potentiels pour les réseaux de transmission à multiplexage en longueurs d’onde (WDM). Cependant, les modes composant leur peigne, exhibent généralement des largeurs de raie optiques relativement élevées ( 1-100 MHz), rendant ainsi incompatible leur utilisation sur un réseau WDM employant des formats de modulation avancés d’ordre supérieur. Cette thèse étudie, une solution pour palier à cette limitation. La technique utilisée, dite d’asservissement à correction aval hétérodyne, effectue un traitement du flux lumineux en sortie du laser sans agir sur ce dernier, permettant de réduire le bruit de fréquence présent sur chacune des raies et par conséquent leur largeur de raie optique. Dans une première approche, la technique est appliquée à un laser mono-fréquence. Cela a permis d’une part de valider son fonctionnement et d’autre part d’identifier les limites intrinsèques du dispositif expérimental mis en place. Ainsi, nous démontrons que le niveau de bruit de fréquence minimum permis par notre système, correspond à un spectre optique de largeur de raie optique instantanée de 50 Hz et une largeur de raie de 1,6 kHz pour un temps d’observation de 10 ms. La technique est par la suite appliquée à une diode à blocage de modes actif. Le peigne de fréquences optiques ainsi généré, est composé de 21 modes, ayant tous une largeur de raie optique intrinsèque inférieure à 7 kHz, dont 9 modes sont sub-kHz. Pour un temps d’observation du spectre optique de 10 ms, ces modes exhibent tous une largeur de raie d’environ 37 kHz. Nous démontrons ainsi l’impact de la gigue d’impulsions sur les performances de la technique et nous soulignons l’intérêt d’une telle cohérence, pour le domaine des télécommunications optiques cohérentes (transmissions WDM cohérentes de type m-QAM avec des constellations d’ordre élevé, compatibles avec des débits multi-Tbit/s par raie). En dernier lieu, nous abordons une seconde technique consistant à pré-stabiliser la fréquence d’un laser par asservissement en boucle fermée. Elle repose sur l’utilisation d’un interféromètre à fibre déséquilibré comme référence pour réduire le bruit de fréquence d’un laser, situé particulièrement en basses fréquences. Appliquée à un laser mono-fréquence, elle a permis de réduire son bruit de fréquence technique conduisant ainsi à une nette amélioration de sa largeur de raie intégrée sur 3 ms, de 224 kHz à 37 kHz. Ce premier résultat représente un bon support vers l’exploration du potentiel des diodes à blocage de modes pour des applications métrologiquesOptical frequency combs obtained from mode-locked laser diodes are potential candidates for WDM networks. However, their lines exhibit usually a broad optical linewidth ( 1-100 MHz). Thus their use is incompatible for high order modulation formats WDM based systems. This thesis investigates one solution to overcome this limitation. It consists of using a feed-forward heterodyne technique to reduce the frequency noise of each comb-line and consequently their optical linewidths. In a first approach, the technique is applied to a single-mode laser. This allowed us to validate its proper working and to identify the intrinsic limits of the experimental device set up. The latter analysis enabled us to reveal that the minimum achievable frequency noise level by our system, corresponds to a 50 Hz intrinsic optical linewidth spectrum and a 1,6 kHz optical linewidth based on 10 ms observation time. This technique is then applied to an actively mode-locked laser diode demonstrating, at our system output, a 21-line optical frequency comb with intrinsic optical linewidths reduced to below 7 kHz. It is worth noting that 9 among them, exhibit sub-kHz linewidths. For an observation time of 10 ms, all lines share the same optical linewidth, almost equal to 37 kHz. We thus show that the timing jitter impacts the technique performances. We also highlight the relevance of such coherence level for coherent optical communication. Lastly, we study a laser frequency pre-stabilization technique based on a locking to an unbalanced fiber interferometer. When applied to a single-mode laser, the technique showed a reduction of its technical frequency noise, thus leading to a clear improvement of its integrated optical linewidth from 224 kHz to 37 kHz for 3 ms observation time. This first result provides a good support towards the exploration of mode-locked laser diodes potential for metrological applications
24
Tall, Ndiogou. "Etude et réalisation de circuits de récupération d'horloge et de données analogiques et numériques pour des applications bas débit et très faible consommation". Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4717.
Testo completoAbstract (sommario):
Les circuits de récupération d'horloge et de données sont nécessaires au bon fonctionnement de plusieurs systèmes de communication sans fil. Les travaux effectués dans le cadre de cette thèse concernent le développement de ces circuits avec d'une part la réalisation, en technologie HCMOS9 0,13 μm de STMICROELECTRONICS, de circuits CDR analogiques à 1 et 54 Mbit/s, et d'autre part, la mise en œuvre de fonctions CDR numériques programmables à bas débit. Un circuit CDR fonctionnant à plus bas débit (1 Mbit/s) a été conçu dans le cadre de la gestion d'énergie d'un récepteur ULB impulsionnel non cohérent. Ces deux structures ont été réalisées à l'aide de PLL analogiques du 3ème ordre. Un comparateur de phase adapté aux impulsions issues du détecteur d'énergie a été proposé dans cette étude. Les circuits ont ensuite été dimensionnés dans le but d'obtenir de très bonnes performances en termes de jitter et de consommation. En particulier, les performances mesurées (sous pointes) du circuit CDR à 1 Mbit/s permettent d'envisager une gestion d'énergie efficace (réduction de plus de 97% de la consommation du récepteur). Dans le cadre d'une chaîne de télémesure avion vers sol, deux circuits CDR numériques ont également été réalisés durant cette thèse. Une PLL numérique du second degré a été implémentée en vue de fournir des données et une horloge synchrone de celles-ci afin de piloter une chaîne SOQPSK entièrement numérique. Un circuit ELGS a également mis au point pour fonctionner au sein d'un récepteur PCM/FMClock and data recovery circuits are required in many wireless communication systems. This thesis is about development of such circuits with: firstly, the realization, in HCMOS9 0.13 μm of STMICROELECTRONICS technology, of 1 and 54 Mb/s analog CDR circuits, and secondly, the implementation of programmable digital circuits at low rates. In the aim of an impulse UWB transceiver dealing with video transmission, a CDR circuit at 54 Mb/s rate has been realized to provide clock signal synchronously with narrow pulses (their duration is about a few nanoseconds) from the energy detector. Another CDR circuit has been built at 1 Mb/s rate in a non-coherent IR- UWB receiver power management context. Both circuits have been implemented as 3rd order analog PLL. In this work, a phase comparator suitable for “RZ low duty cycle” data from the energy detector has been proposed. Circuits have been sized to obtain very good performances in terms of jitter and power consumption. Particularly, measured performances of the 1 Mb/s CDR circuit allow to plan an efficient power management (a decrease of more than 97% of the receiver total power consumption). In the context of a telemetry system from aircraft to ground, two digital CDR circuits have also been implemented. A second order digital PLL has been adopted in order to provide synchronous clock and data to an SOQPSK digital transmitter. Also, a digital ELGS circuit has been proposed to work in a PCM/FM receiver. For both CDR structures, the input signal rate is programmable and varies globally from 1 to 30 Mb/s
25
Gouzien, Élie. "Optique quantique multimode pour le traitement de l'information quantique". Thesis, Université Côte d'Azur (ComUE), 2019. http://www.theses.fr/2019AZUR4110.
Testo completoAbstract (sommario):
Cette thèse étudie l’optique quantique multimode, aussi bien du point de vue de la génération que celui de la détection. Elle s’articule autour de trois volets. Nous étudions la génération de lumière comprimée multimode dans une cavité. Pour cela nous considérons la forme la plus générale de hamiltonien quadratique, permettant entre autres de décrire l’utilisation de plusieurs pompes dans un matériau effectuant du mélange à quatre ondes. Une approche combinant fonctions de Green et décompositions de matrices symplectiques est décrite. Cette théorie générique est appliquée à des cas particuliers. Dans un premier temps, des exemples en basse dimension sont donnés. Ensuite, une configuration d’oscillateur paramétrique optique pompé de manière synchrone (SPOPO) est décrite et étudiée ; les résultats obtenus montrent que ce système a un comportement très différent de celui du SPOPO utilisant une non-linéarité d’ordre 2. Ces travaux ouvrent la voie à la réalisation de peignes de fréquences quantiques avec des micro-résonateurs en anneau gravés sur silicium. Un autre problème examiné est celui de prendre en compte l’information temporelle obtenue lors du clic d’un détecteur de photon unique. Pour cela nous utilisons un formalisme multimodal temporel afin d’expliciter les opérateurs décrivant la mesure. Les principaux défauts des détecteurs réels, dont la gigue temporelle, l’efficacité finie et les coups d’obscurité sont pris en compte. L’utilisation des opérateurs est illustrée par la description d’expériences usuelles de l’optique quantique. Enfin, on montre que la lecture du temps de clic du détecteur permet d’améliorer la qualité de l’état généré par une source de photons annoncés. En troisième partie nous présentons un schéma de génération d’intrication hybride entre variables continues et discrètes, pour laquelle la partie discrète est encodée temporellement. Ce schéma est analysé en détail vis-à-vis de sa résistance aux imperfections expérimentalesThis thesis studies multimode quantum optics, from generation to detection of light. It focuses on three main parts. Multimode squeezed states generation within cavity is studied. More specifically, we take into account general quadratic Hamiltonian, which allows describing experiments involving arbitrary number of modes and pumps within a medium performing four-wave mixing. We describe a generic approach combining Green functions and symplectic matrix decomposition. This general theory is illustrated on specific cases. First, low-dimensional examples are given. Then, a synchronously pumped optical parametric oscillator (SPOPO) is described and studied; it shows a very distinct behavior from that of the SPOPO using second order non-linearity. This work opens way to the realization of quantum frequency combs with ring micro-resonators engraved on silicon. Single-photon detectors are described taking into account temporal degrees of freedom. We give positive-valued measurement operators describing such detectors including realistic imperfections such as timing-jitter, finite efficiency and dark counts. Use of those operators is illustrated on common quantum optics experiments. Finally, we show how time-resolved measurement allows improving the quality of state generated by single-photon heralded source. In the third part we propose a protocol for generating a hybrid state entangling continuous and discrete variables parts, for which the discrete part is time-bin encoded. This scheme is aanalysed in detail with respect to its resilience to experimental imperfections
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吳丞騏. "A BIST techniq;ue for timing jitter testing". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/30359286474133695763.
Testo completo
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Tsung-Ta, Lee. "An On-Chip Jitter Timing Measurement Circuits for PLLs". 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0016-0109200613415353.
Testo completo
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Lee, Tsung-Ta, e 李宗達. "An On-Chip Jitter Timing Measurement Circuits for PLLs". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/62432304412470696091.
Testo completoAbstract (sommario):
碩士國立清華大學
電機工程學系
94
This thesis presents an on-chip phase-locked loops (PLLs) jitter timing measurement design that the expected deviation from the specification and the average jitters can be measured. Examining the measured signals whether they conform to the specification, the proposed circuit is operated at every cycle of the PLL’s reference frequency without using an extra sampling clock and provides a robust result and low area overhead. A series of pulses with average length of 100-ps is injected in the proposed circuit, and the test results show about 8% measurement errors. With lower area overhead, the proposed design can measure accumulated jitter and give a warning signal if a clock’s jitter over a specific value. To verify the correctness of the design, the proposed circuit is simulated by HSPICE in a standard 0.18-um CMOS technology.
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Liu, Shang-Cheng, e 劉上誠. "Timing Jitter Reduction of Passively Mode-locked Ti:sapphire Lasers". Thesis, 1997. http://ndltd.ncl.edu.tw/handle/62865152320331982023.
Testo completoAbstract (sommario):
碩士國立交通大學
光電工程研究所
85
In this thesis, we demonstrate a new timing stabilization method based on an optoelectronic harmonic mixer (OEHM) in a phase-locked loop toreduce the timing jitter of passively mode-locked Ti: sapphire lasers. The OEHM replaces the photodiode and RF mixer combination in conventional approaches. The system becomes more flexible and allows the use of low-frequency electronics in the remainder of the phase-locked loop. In the home-made passively mode-locked Ti: Sapphire laser system that use dye as the saturable absorber, the optimal r.m.s. timing jitter of the freerunning laser is 12.6ps. This is calculated from single side-band phase noise spectrum measured from 100 Hz to 10 kHz at a resolution bandwidth of lOHz. 1The r.m.s. timing jitter of the stabilized laser is reduced to 710(100-500Hz), 478fs (500-5kHz), and 93fs (5kHz-IOKHz), espectively. Semiconductor quantum well as saturable absorbers in solid-state lasers can provide sufficiently stable amplitude-modulation to generate ultrafast optical pulses. Those characteristics efficiently reduces amplitude and phase noises of pulse trains. The optimal r.m.s. timing jitter of the free- running laser is 6.8ps, the r.m.s. timingjitter of the stabilized laser is reduced by a factor of about 13dB to 290fs (100-500Hz), 302fs (500-5kHz), and 178fs (5kHz-1OKHz), respectively.
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Chang, Liang-Yao, e 張喨堯. "The Timing Jitter Reduction and Measurement of the Passively Mode-locked Ti:Sapphire Laser". Thesis, 1998. http://ndltd.ncl.edu.tw/handle/60952457391174846991.
Testo completoAbstract (sommario):
碩士國立交通大學
光電工程研究所
86
In this thesis, we demonstrate a new stabllization method based on an optoelectronic harmonic mixer (OEHM) biased by picosecond electrical pulse in a phase-locked loop to reduce and measure the timing jitter of the passively mode-locked Ti: sapphire laer. We stabilize the laser by intermixing harmonics of the electrical pulse with higher harmonics of the laser pulse train. We also demonstrated a new method which detects the phase error signal directly for computation of the r.m.s. timing jitter. The results are in good agreement with the conventional phase noise spectra measurements. The best r.m.s timing jitter for the freee running Ti: sapphire/SSBR laser is 7.24ps. With an optoelectronic phaselocked loop (OEPLL) and intermixing higher harmonics of the laser pulse train with the reference RF sine wave signal, the r.m.s. timing jitter calculated rrom the conventional phase noise spectra is 1.56ps. We then replace. RF sine wave signal with a 1GHz comb generator and the corresponding r.m.s timing jitter is reduced to 1.36ps, 1.26ps, 0.94ps, and 1.33ps when the 11th, 22th 33th, and 45th harmonic of the laser pulse train is used for intermixing. We design a circuit to detect the phase error signal in the time domain directly for computing the r.m.s timing jitter. The dorresponding r.m.s thming jitter is reduced to 524fs, 351fs, and 493fs when the 22th, 33th, and 45th harmonic of the laser pulse was used for intermixing.
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Richter, André [Verfasser]. "Timing jitter in long haul WDM return to zero systems / vorgelegt von André Richter". 2002. http://d-nb.info/964926989/34.
Testo completo
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Wu, Seng-wen, e 吳聖文. "Reducing Timing Jitter Error by Using Self-tuning Based MPI-DLL in UWB Systems". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/68293324950153286216.
Testo completoAbstract (sommario):
碩士國立中山大學
電機工程學系研究所
93
Ultra-Wideband ﹙UWB﹚Communication Technology is one of the potential technologies in indoor wireless communication applications. Because of the property of fine resolution of transmitted signal by UWB, it is powerful on indoor location applications. In the first place, we need to estimate the time of arrival based on the wireless location applications. Whether synchronization between the template signals and received signals affects directly the SNR of the estimator output and decreases the ranging accuracy. Because of the transmitted signal is the type of impulse radio for UWB system, it is more important on the time accuracy of the internal oscillator. In the thesis, we utilize the Delay-Locked Loop ﹙DLL﹚ structure with Self-tuning function to reduce the timing jitter in the internal oscillator. We can improve the stability in the tracking loop and utilize multipath canceller to cancel the multipath interference in the indoor environment. When reaching synchronization between the template signal and received signal by using the tracking loop, we can improve ranging accuracy and increase location precision according to the received signal.
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ZHANG, ZHONG-DAO, e 張仲道. "Use phase lock loop to reduce timing jitter of Nd:YAG CW mode-locked laser". Thesis, 1993. http://ndltd.ncl.edu.tw/handle/87809560913642115565.
Testo completo
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Bray, Adam. "A Low Jitter Analog Circuit for Precisely Correcting Timing Skews in Time Interleaved Analog-to-Digital Converters". Thesis, 2013. http://hdl.handle.net/10012/8053.
Testo completoAbstract (sommario):
Time-interleaved analog-to-digital converters are an attractive architecture for achieving a high speed, high resolution ADC in a power efficient manner. However, due to process and manufacturing variations, timing skews occur between the sampling clocks of the sub ADCs within the TI-ADC. These timing skews compromise the spurious free dynamic range of the converter. In addition, jitter on the sampling clocks, degrades the signal-to-noise ratio of the TI-ADC. Therefore, in order to maintain an acceptable spurious free dynamic range and signal to noise ratio, it is necessary to correct the timing skews while adding minimal jitter.
Two analog-based architectures for correcting timing skews were investigated, with one being selected for implementation. The selected architecture and additional test circuitry were designed and fabricated in a 0.18??m CMOS process and tested using a 125 MSPS 16 bit ADC. The circuit achieves a correction precision on the order of 10???s of femtoseconds for timing skews as large as approximately 180 picoseconds, while adding less than 200 femtoseconds of rms jitter.
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Wang, Chen-Kuang, e 王晨光. "The Improvement of Far-End Crosstalk and Timing Jitter for Coupled Microstrip Line by Using Rectangular Resonators". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/3kmd9y.
Testo completoAbstract (sommario):
碩士國立臺北科技大學
電腦與通訊研究所
99
In the modern generation of digital data transmission, crosstalk is one major source of noise to interfere with signal integrity (SI). Generally, crosstalk can be reduced by adding a guard trace with shorting-vias between the victim and aggressor areas of the circuit. However, the shorting-vias in the guard trace induced the resonance in the frequency domain and the ringing noise in the time domain. We propsed the step guard trace to compensate capacitive coupling between the guard trace and signal trace. Our method offers minumum number of shorting-vias to increase the flexibility on the circuit routing and decrease the ringing noise. The experimental results indicated that the step gaurd trace could reduce near-end crosstalk (NEXT) and far-end crosstalk (FEXT) by 34% and 26% compared to without guard trace in the time domain, respectively. Therefore, in a parallel-terminated interface, the FEXT is more problematic than NEXT since it seriously affects the SI at the receiver side. Since a large number of shorting-vias and resistances reduce the flexibility of the circuit routing and increase cost, we propose a method to reduce the FEXT and timing jitter by using rectangular resonators (RRs) structure. In which, the shorting-via and resistance are not necessary to be used for improving the FEXT and timing jitter. The experimental results indicated that the RRs structure could reduce FEXT and timing jitter by 57% and 18% compared to without guard trace in the time domain, respectively. These experimental results confirmed that our proposed RRs structure not only shows better performance than the alternatives, but also no requires extra components such as terminating resistors or shorting-vias to reduce noise significantly. Accordingly, the new concept and method might be approached to the practical engineering.
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Srinivasan, Venkatesh. "Timing jitter in symmetric load ring oscillators and the estimation of aperture uncertainty in A-D converters". 2002. http://etd.utk.edu/2002/SrinivasanVenkatesh.pdf.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of Tennessee, Knoxville, 2002.Title from title page screen (viewed Oct. 1, 2002). Thesis advisor: Syed K. Islam. Document formatted into pages (vii, 85 p. : ill.). Vita. Includes bibliographical references (p. 68-74).
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Lee, Chuen-Shang, e 李春生. "Measurement and control of the timing jitter of passively mode- locked Ti:sapphire lasers and gain-switched laser diodes". Thesis, 1996. http://ndltd.ncl.edu.tw/handle/68895457609475097994.
Testo completoAbstract (sommario):
碩士國立交通大學
光電工程研究所
84
In this thesis, we have studied the timing jitter of optical pulses generated by a free-running mode-locked Ti:sapphire laser and a gain-switched semiconductor laser diode. In the home-made passively mode-locked Ti:Sapphire laser system, the optimal timing jitter of the free-running is 11.2ps.This is calculated from single side-band phase noise spectrum measured from 100 Hz to 10 kHz at a resolution bandwidth of 10Hz.We also observed that the timing jitter can be strongly affected by the wavelength- selecting slit inside the laser cavity. We also confirm that timing jitter of a self-seeding gain- switched laser diode can be further reduced from 1.3 ps down to 1.1ps by tuning the delay of the optical feedback in a range of 25ps.This is 2-3 order of magnitude larger than the corresponding value of a typical mode-locked laser.By using an optoelectronic phase lock loop,we observe that the timing jitter can be futher reduced from 68ps down to 1.3ps and 0.2ps when the laser is locked to the fundamental and 5th ordered harmonics.On the other hand,the timing jitter of the gain-switched semiconductor laser can be efficiently suppressed form 68ps down to 0.9ps （without feedback）and 0.65ps （with feedback） via the combination of optielectronic phase lock loop of the free-running laser at higher harmonics of a self-seeding gain-switched laser diode.
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Cai, Bo-Wei, e 蔡伯偉. "Study on Relative Timing Jitter between Ultrafast Er- and Yb-Fiber Laser Systems by Hybrid Active-Passive Synchronization". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/99841410131907467043.
Testo completoAbstract (sommario):
碩士輔仁大學
物理學系碩士班
101
In this thesis, we investigate the relative timing jitter between 1 μm and 1.5 μm pulses from the ultrafast Yb- and Er-fiber laser systems under the hybrid active-passive synchronization. First of all, the 1 μm pulses generated from the Yb-fiber laser system are injected into the 1.5 μm mode-locked Er-doped fiber laser. The 1.5 μm pulses will change the center wavelength as well as the group velocity so as to achieve the passive synchronization with the 1 μm Yb-fiber laser system. On the other hand, the slow drift between 1 μm and 1.5 μm pulses resulted from the passive synchronization can be effectively removed by the electronic feedback servo which actively controls the cavity length of the Er-fiber laser via a piezo-transducer. In addition, we utilize the cross-correlation trace and the fluctuation of the sum-frequency-generation signal to measure the relative timing jitter. It is found that the relative timing jitter depends significantly on the relative position between the 1 μm and 1.5 μm pulses when they enter the co-propagating fiber section. This observed phenomenon can be explained theoretically by the pulse dynamics of frequency-modulated mode-locked fiber lasers. The minimum relative timing jitter obtained in our ultrafast Yb- and Er-fiber laser systems with such a hybrid synchronization is 0.8 fs (measurement bandwidth: 1.9 MHz).
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SU, CHIEN-RU, e 蘇建儒. "Comparison between Integral Method and Harmonic Analysis on the Timing Jitter Characteristics of Gain-Switched Semiconductor Laser Diodes". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/69242780278471738029.
Testo completoAbstract (sommario):
碩士國立臺灣大學
光電工程學研究所
100
A theoretical and experimental comparison between two methods of timing jitter calculation in the gain-switched laser diode is made. The integral method utilizes spectral area of the single side-band (SSB) phase noise spectrum to calculate root mean square (rms) timing jitter. Another approach, harmonic analysis, exploits the uppermost noise power in high harmonics to retrieve timing fluctuation instead. Even though both methods have been verified to be accurate, a full comparison has yet to be performed. This thesis will first demonstrate that both amplitude noise and timing jitter fluctuation can be characterized efficiently by implementing two methods with Labview programs. Results show that a consistent timing jitter is found by the integral method (1.1ps) and harmonic analysis (1.25ps) in gain-switched laser diodes with an external cavity scheme. A comparison of the two approaches in noise measurement of diode-pumped Yb:KY(WO4)2 (Yb:KYW) passive mode-locked laser is also discussed, which both give an outcome of 2ps rms timing jitter. The results indicate that either harmonic analysis or integral method can be successfully utilized to calculate timing jitter.