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Kim, Jung-Won 1976. "Toward single-cycle optical pulses". Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32336.
Pełny tekst źródłaIncludes bibliographical references (p. 143-151).
Single-cycle optical pulses, the never-before-achieved regime, have a great potential for attosecond science and phase-sensitive nonlinear optics. To achieve single-cycle optical pulses by active synchronization, three major steps are required. Firstly, two very stable and broadband mode-locked lasers with overlapping spectra are necessary. Secondly, a tight timing synchronization with timing jitter under one-tenth of the synthesized pulsewidth has to be implemented. Finally, the carrier-envelope offset frequency lock between two lasers completes the coherent pulse synthesis process. In this thesis, the major ideas, techniques, and experimental results for single-cycle optical pulse synthesis are presented. A broadband Cr:forsterite laser mode-locked by a semiconductor saturable absorber is designed and implemented. The output spectrum spans from 1080 nm to 1500 nm range, and has a 3-dB bandwidth of 90 nm. This is the broadest spectrum from a prismless Cr:forsterite laser to our best knowledge, and corresponds to a sub-20 fs Fourier-transform limited pulsewidth. A new broadband output coupler is designed to optimize the output spectrum of an octavespanning Ti:sapphire laser. The resulting combined spectrum covers 1.5 octave from 600 nm to 1500 nm and has a strong overlap in 1100 to 1200 nm range, which enables a strong beat-note signal between the two lasers. A tight timing synchronization between the two lasers is achieved by balanced cross-correlation. The resulting timing jitter is 300 attoseconds, which is less than one-tenth of the synthesized pulsewidth.
(cont.) For a high-quality pulse synthesis, an ultra-broadband 50:50 beam splitter, a bandpass filter beam splitter, and a tapping beam splitter are designed with optical thin-film multilayer structures. A novel scheme for synchronization of an RF-signal to the pulse train of a mode-locked laser is proposed. Currently the isolation of cross-talk between two locking loops for repetition rate and carrier-envelope phase is under investigation, and it is expected to generate true single- cycle optical pulses in the near future. Future work will include full characterization of the synthesized pulses with SPIDER (spectral phase interferometry for direct electric-field reconstruction) and novel phase-sensitive nonlinear optic experiments.
by Jung-Won Kim.
S.M.
Ališauskas, Skirmantas. "Infrared Few-Cycle Pulse Optical Parametric Amplifier". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101001_145118-06284.
Pełny tekst źródłaDisertacijos darbo tikslas – suformuoti ir parametriškai stiprinti kelių optinių ciklų trukmės impulsus infraraudonojoje srityje Šioje disertacijoje buvo tirtos dvi moduliuotosios fazės („čirpuotų“) impulsų parametrinio stiprinimo sistemos, stiprinančios ypač plataus spektro impulsus 800 nm bei 1,5 μm srityse. Pirmoji sistema skirta tirti galimybę didinti lazerinės spinduliuotės vidutinę galią keliais pluoštais kaupinamame parametriniame stiprintuve; antroji sistema skirta kelių optinių ciklų trukmės stabilios fazės impulsų formavimui 1,5 μm srityje. Disertacijoje aprašomas I tipo parametrinis stiprintuvas, kurio 2-oji pakopa buvo kaupinama dviem arba trimis nepriklausomų lazerinių šaltinių pluoštais. Nustatyta, kad parametrinį stiprintuvą kaupinant keliais pluoštais stebimas naujų erdvinių komponentų atsiradimas, kuriuos sąlygoja parametrinė pakopinė difrakcija, o tai mažina bendrą sistemos energetinio keitimo efektyvumą.. Darbo metu pademonstruota galimybė mažinti parametrinės difrakcijos sąlygotus nuostolius parametriniame stiprintuve derinant kampus tarp kaupinimo pluoštų. Taip pat pristatomas alternatyvus būdas formuoti didelės energijos (kelių dešimčių milidžaulių) kelių optinių ciklų trukmės stabilios fazės impulsus 1,5 μm srityje. Būdas paremtas sąlyginai siauro spektro 1,5 μm srityje stiprinimu II tipo KTP kristale bei spektro plėtra inertinėse dujose po stiprinimo. 4 pakopų parametriniame stiprintuve pasiekta iki šiol didžiausia 12,5 mJ impulso energija 1,5 μm... [toliau žr. visą tekstą]
Huang, Shu-Wei Ph D. Massachusetts Institute of Technology. "High-energy sub-cycle optical waveform synthesizer". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/75634.
Pełny tekst źródłaCataloged from PDF version of thesis.
Includes bibliographical references (p. 147-157).
Over the last decade, the control of atomic-scale electronic motion by optical fields strong enough to mitigate the atomic Coulomb potential, has broken tremendous new ground with the advent of phase controlled high-energy few-cycle pulse sources. In particular, broadband optical parametric chirped pulse amplifier (OPCPA) has been investigated intensively in recent years to enable studies of novel strong-field physics phenomena such as high-harmonic generation (HHG) and strong-field ionization. Further investigation and control of these physical processes ask for the capability of waveform shaping on sub-cycle time scales, which requires a fully phase-controlled multiple-octave-spanning spectrum. To date, no single laser source can support a bandwidth of more than an octave. Coherent synthesis of pulses with different spectra, or wavelength multiplexing, presents a route towards obtaining a multi-octave spanning laser spectrum. The benefit of this approach lies in its modular design and scalability in both bandwidth and pulse energy. However, it was only recently laser scientists were able to successfully demonstrate coherent synthesis of two lasers albeit at low energy and high repetition rate. Achieving high pulse energy requires synthesis of low repetition rate pulses, which is a challenge because of the environmental perturbations typifying high-energy amplifiers. The technological advancements towards the ideal source for study and control of such strong-field physics are the focus of this thesis. The background reviews on femtosecond Ti:sapphire oscillators, carrier-envelope phase stabilization, chirped pulse amplifier, broadband OPCPAs, and HHG are given in Chapter 1. Chapter 2 starts with a discussion on the various properties of OPCPA which lends itself to the ideal building module for high-energy pulse synthesis. Then it is followed by a comprehensive optimization study and experimental results of broadband OPCPAs at different spectral ranges. In chapter 3, the first high-energy sub-cycle waveform synthesizer is presented. It is the prototype of a class of novel optical tools for atto-second control of strong-field physics experiments. Novel technologies that enable such a waveform synthesizer are described in details. At the end of the chapter, work towards the construction of a large-scale waveform synthesizer is included. Finally, the thesis is concluded by introducing some possible future directions.
by Shu-Wei Huang.
Ph.D.
He, Dong. "Efficient cycle algorithms for capacitated optical network design". Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/26919.
Pełny tekst źródłaSiddiqui, Aleem 1977. "Few-cycle and cavity-enhanced optical parametric amplification". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/79494.
Pełny tekst źródłaCataloged from PDF version of thesis.
Includes bibliographical references (p. 179-185).
Optical parametric amplifiers have emerged as important optical sources by extending the properties of few-cycle laser sources, which exist only in materials with sufficiently large gain bandwidths, to wide array of spectral ranges. The work reported in this thesis relates to two areas for the continued development of optical parametric amplification based sources. First, we present a white light seeded, carrier-envelope stable, degenerately pumped OPA producing near tranform-limited sub 7 fs , 3 [mu]J pulses at the driver wavelength from a long pulse, non-CEP stable Ti:sapphire regenerative amplifier. Problems to the spectral phase jump at the driver wavelength, 800 nm, were avoided by using a near infrared OPA to produce white light continuum down to 800 nm where the spectral phase is smooth. Secondly, enhancement cavities are used in conjunction with parametric amplifiers resulting in a new technique entitled, cavity-enhanced optical parametric chirped-pulse amplification (C-OPCPA). C-OPCPA increases the capabilities of nonlinear crystals and can allow continued scaling of parametric amplifier systems to high repetition rate. This work contains the first theoretical and experimental investigation of C-OPCPA. Numerically, passive pump pulse shaping of the intracavity pump power is shown to enable octave spanning gain. Experimentally, a first proof-of-principle experiment demonstrates a 78 MHz C-OPCPA with more than 50% conversion with under 1 W of incident pump power. A comparison to a single pass system shows improvements in the C-OPCPA of orders of magnitude in conversion efficiency and 3 fold increase in phase matching bandwidth in 10 and 20 mm periodically poled lithium niobate phase matched for parametric amplification with 1030 nm pump wavelength and a 1550 nm signal wavelength. A Yb-fiber laser based CPA system producing up to 5 W of 500 fs pulses comprises the pump source, and a Er-fiber laser the signal.
by Aleem Mohammad Siddiqui.
Ph.D.
Laban, Dane Edward. "Highly Nonlinear Optical Phenomena with Few-Cycle Light Pulses". Thesis, Griffith University, 2014. http://hdl.handle.net/10072/365337.
Pełny tekst źródłaThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Physical Sciences
Science, Environment, Engineering and Technology
Full Text
Bates, Philip Kevin. "Optical parametric chirped pulse amplification in the few-cycle regime". Thesis, Imperial College London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445345.
Pełny tekst źródłaKrogen, Peter Ra. "A novel few-cycle optical source in the mid-infrared". Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93067.
Pełny tekst źródłaCataloged from PDF version of thesis.
Includes bibliographical references (pages 43-45).
In this thesis, I designed, simulated, and implemented a novel optical pulse generation system which is shown to be able to generate exceptionally short optical pulses in the mid-infrared, tunable from 2-4[mu]m with pulse widths as low as 1.5 optical cycles at 3.5[mu]m (18fs). Energies as high a 1[mu]J were achieved, representing a peak power of roughly 100MW, at a 1kHz repetition rate, with excellent beam quality. The system was based on adiabatic difference frequency generation in an aperiodically polled lithium niobate crystal of an amplified, mode-locked Ti:Sapphire laser system.
by Peter Ra Krogen.
S.M.
Krogen, Peter Ra. "A novel single-cycle optical source in the mid-infrared". Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105945.
Pełny tekst źródłaThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 90-106).
In this thesis, I demonstrate the generation of single-optical-cycle pulses in the mid-infrared, which are generated using adiabatic difference frequency in an aperiodically polled lithium niobate crystal. The input pulses were generated in amplified Ti:Sapphire laser system, the construction of which is covered in detail, along with complete characterization of the generated pulses. The generated pulses have a bandwidth spanning (1.8-4.5[mu]m), energy in excess of 1[mu]J at a 1kHz repetition rate, and are compressed to within 15% of their Fourier transform limited duration of 10fs, which is 1.1 optical cycles at their central wavelength of 2.6[mu]m, and represents a peak power well in excess of 100MW. Furthermore, intrinsic to the design of the system is the ability to shape both the spectral amplitude and phase of the generated pulses, which makes this source immediately suitable for applications requiring shaped pulses.
by Peter Ra Krogen.
Ph. D.
Hallberg, Oskar. "Simulation and optimization of a multi-TW few-cycle optical parametric synthesizer". Thesis, Umeå universitet, Institutionen för fysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-142100.
Pełny tekst źródłaRipin, Daniel Jacob 1973. "A few-cycle Cr⁴⁺:YAG laser and optical studies of photonic crystals". Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8291.
Pełny tekst źródłaIncludes bibliographical references (p. 261-279).
A prismless Cr4+:YAG laser was used to generate 20 fs pulses at 1450 nm with a bandwidth of 190 nm FWHM. Intracavity group velocity dispersion was compensated with double-chirped mirrors. Pulse spectrum was observable from 1140 to >1700 nm. Broadband saturable Bragg reflectors were designed and used to ensure self-starting of 35 fs pulses in the ultrafast Cr4+:YAG laser or to generate picosecond pulses tunable from 1400 to 1525 nm. The mirrors were a 7-pair GaAs/AlxOy quarter-wave dielectric stack, and the absorber consisted of a InGaAs quantum well centered in a half-wave InP layer. Transmission was measured through a photonic bandgap crystal microcavity resonant near 1550 nm. Cavity quality factors as high as 360 were observed for cavities with a modal volume of only 2([lambda]/2n)3. Photonic crystals were used to enhance the total emission of a light emitting diode at 980 nm by 8-fold. At particular wavelengths, collected photoluminescence enhancements larger than 100 were observed.
by Daniel Jacob Ripin.
Ph.D.
Wan, Hui [Verfasser], i Jörg [Akademischer Betreuer] Wrachtrup. "Nonlinear optical microspectroscopy with few-cycle laser pulses / Hui Wan ; Betreuer: Jörg Wrachtrup". Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2017. http://d-nb.info/1156611520/34.
Pełny tekst źródłaRidente, Enrico [Verfasser], i Ferenc [Akademischer Betreuer] Krausz. "Few-cycle optical waveforms for transient molecular fingerprinting / Enrico Ridente ; Betreuer: Ferenc Krausz". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2021. http://nbn-resolving.de/urn:nbn:de:bvb:19-285410.
Pełny tekst źródłaVaupel, Andreas. "High Energy, High Average Power, Picosecond Laser Systems to Drive Few-Cycle OPCPA". Doctoral diss., University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5881.
Pełny tekst źródłaPh.D.
Doctorate
Optics and Photonics
Optics and Photonics
Optics
Wall, Simon. "Photo-induced dynamics in complex materials probed with femtosecond x-rays and few cycle optical pulses". Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.510258.
Pełny tekst źródłaCulver, Mary Evans. "Applications of chlorophyll a fluorescence in bio-optical models of phytoplankton biomass and productivity / by Mary Evans Culver". Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/10966.
Pełny tekst źródłaFavier, Marine. "Vers un instrument commercial pour la mesure des rapports isotopiques par Optical Feedback Cavity Enhanced Absorption Spectroscopy". Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY106.
Pełny tekst źródłaThe study of stable isotopes has led to many important advances in science, such as, for example, the determination of the timing of the oxygenation of Earth’s atmosphere using sulfur isotopes [1] and the quantification of the exchanges of carbon between the atmosphere and other reservoirs (biosphere, oceans) from the analysis of the 13C/12C isotope ratio [2].The conventional method to measure such isotopic ratios is by means of isotope ratio mass spectrometry (IRMS). About ten years ago, commercial instruments appeared that enabled the measurement of isotopic ratios using infrared spectroscopy of small molecules in the gas phase of interest for environmental studies (notably water and carbon dioxide). However, for some applications these instruments are not well adapted, for example, because they require too much material, or too expensive, or not able to measure isotopes in question. This is in particular the case for sulfur isotopes.During this work two prototype instruments were developed for the analysis of isotopic ratios by means of Optical Feedback Cavity Enhanced Absorption Spectroscopy (OFCEAS). The first targets the 13C/12C isotopic ratio in atmospheric air samples containing between 200 and 500 ppmv of CO2.The lowest concentration of this range is typical of paleo-air trapped in bubbles in ice cores, whereas the higher concentrations are encountered in modern air samples. For this instrument we have shown, through a detailed and systematic study, the effect of pressure, temperature, and optical interference fringes on the measurement of the isotopic ratio. Mitigating these sources of errors has led to a performance characterized by a precision of 0.2‰ in 2 minutes on measurements at a concentration of about 280 ppmv and a precision of 0.05‰ when alternatingly referencing the sample measurement to that of a standard material in a measurement cycle with duration of 2h for one sample.The second instrument is the first of its kind being able to analyze the 33S/32S and 34S/32S ratios through near-infrared spectroscopy on H2S gas. Sulfur compounds, such as sulfate, are easily converted to H2S, but this is not the case for SF6 or SO2, which are the common gases used in the conventional IRMS method. The instrument was demonstrated by performing static measurements on three isotopically different samples of H2S – nitrogen mixtures. These local standard materials were synthesized by us, and shown to have relative enrichment levels of 0‰, 42.6‰ and 83.6‰ for 34S/32S, and 0 ‰, 2.81‰, and 5.39‰ for 33S/32S by IRMS analyses. Our laser spectrometer measurements agree to within 1‰ with the calibrated IRMS values. The precision obtained after averaging three 12-minute measurements is 0.08‰ for both isotopic ratios
Wang, Yicheng [Verfasser]. "Passive mode-locking of 2-μm solid-state lasers : Towards sub-10 optical cycle pulse generation / Yicheng Wang". Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1147758271/34.
Pełny tekst źródłaBrown, Andrew Gavin. "Measurement and modelling of combustion in a spark ignition engine". Thesis, Brunel University, 1991. http://bura.brunel.ac.uk/handle/2438/5143.
Pełny tekst źródłaTalisa, Noah Brodzik. "Laser-Induced Damage and Ablation of Dielectrics with Few-Cycle Laser Pulses". The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1609243476481238.
Pełny tekst źródłaBäcklund, Tomas. "Development and validation of a system for clinical assessment of gait cycle parameter in patients with idiopathic normal pressure hydocephalus". Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-82891.
Pełny tekst źródłaJargot, Gaëtan. "High-repetition rate CEP-stable few-cycle OPCPA sources in the short wavelength infrared/mid-infrared". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLO020.
Pełny tekst źródłaAbstract : The generation of carrier envelope phase (CEP) stable few-cycle pulses in the SWIR/Mid-IR using optical parametric chirped pulse amplification (OPCPA) at high repetition rate is of great interest for several applications in ultrafast dynamics. During this thesis the work was primarily focused on the development of OPCPA sources for attosecond science. We present an OPCPA operating at 2.1 µm delivering 19.5 fs pules duration with an energy of 31 µJ at 10 kHz with a RMS energy stability of 0.54 %. An original architecture using an all-inline difference frequency generation stage allows performances beyond the state of the art in terms of CEP stability. We report RMS CEP fluctuations of 107 mrad RMS measured shot-to-shot over four hours. On another hand, the development of a high repetition rate (125 kHz) OPCPA coupled with an innovative nonlinear compression scheme is described. The OPCPA provides pulses centered at 1.55 µm, with a pulse duration of 63 fs with an energy of 19 µJ after compression. Then a nonlinear compression stage based on a soliton dynamics in a multipass cell is implemented. The periodic propagation inside the cell allows to retain the temporal nonlinear effects, while the spatial nonlinear effects are washed out by the distributed nature of the nonlinearity over a large number of passes. We report the self-compression of 63 fs pulse at 1.5 µm down to 22 fs with an energy of 14 µJ
Schröder, Birgit Eva. "Spatial and temporal dynamics of the terrestrial carbon cycle : assimilation of two decades of optical satellite data into a process-based global vegetation model". Phd thesis, Universität Potsdam, 2007. http://opus.kobv.de/ubp/volltexte/2008/1759/.
Pełny tekst źródłaIn der vorliegenden Arbeit wird anhand der Kombination eines dynamischen globalen Vegetationsmodells mit einer Zeitreihe von 21 Jahren optischer Satellitendaten eine realistische Abschätzung der terrestrischen Quellen und Senken von CO2 ermöglicht. Grundlage des hier vorgestellten neuen Modells stellt das dynamische globale Vegetationsmodell LPJ dar, ein prozessorientiertes Vegetationsmodell, das basierend auf ökophysiologischen Grundlagen die Vegetationsverteilung und -dynamik, Störungen (z.B. Feuer) und den Kohlenstoff- sowie den Wasserkreislauf modelliert. Die Kopplung des LPJ-DGVM erfolgte mit einer Zeitreihe globaler AVHRR-fPAR Daten (fPAR – Anteil photosynthetisch aktiver Strahlung), für den Zeitraum 1982 bis 2002 in einer räumlichen Auflösung von 0.5°. Als Ergebnis liegt nun eine globale raum-zeitliche Verteilung aller relevanten Kohlenstoffflüsse vor: Nettoprimärproduktion, Bodenrespiration, Nettoökosystemproduktion, durch Feuer und Ernte emittierter Kohlenstoff, sowie der in Biomasse und Boden gespeicherte Kohlenstoff. Verglichen mit dem Originalmodell haben sich durch die Einspeisung der Satellitendaten alle relevanten Kohlenstoffkomponenten verringert und zeigen nun bessere Übereinstimmung mit Literaturwerten. Die geringeren Kohlenstoffflüsse resultieren aus einer Kombination verschiedener Effekte: geringere Vegetationsbedeckung, Berücksichtigung der landwirtschaftlichen Nutzfläche, realistischere Abbildung der Saisonalität, Veränderung der Vegetationsverteilung und Verschiebung der Artenzusammensetzung. Die globalen Kohlenstoffflüsse werden mit dem vorgestellten Modell realistischer abgebildet als mit Ansätzen, die nur die potentiell natürliche Vegetation simulieren. Insbesondere die Quellen- und Senkendynamik unterliegt vielfältigen Prozessen, die mit einem Modell, dass auch die Bodenrespiration prozessorientiert berücksichtigt, verlässlich geschätzt wird.
Wittmann, Emanuel [Verfasser], i Eberhard [Akademischer Betreuer] Riedle. "Taming optical parametric amplification : stable few cycle pulses at 210 to 10000 nm from Ti:Sapphire and Yb-based lasers / Emanuel Wittmann ; Betreuer: Eberhard Riedle". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2019. http://d-nb.info/1206877715/34.
Pełny tekst źródłaOuillé, Marie. "Génération d'impulsions laser proches du cycle optique en durée pour l'interaction laser-matière relativiste à haute cadence". Electronic Thesis or Diss., Institut polytechnique de Paris, 2022. http://www.theses.fr/2022IPPAE007.
Pełny tekst źródłaThis experimental thesis was essentially conducted at Laboratoire d’Optique Appliquée in Palaiseau (France), on a laser system capable of delivering near-single-cycle duration pulses containing a few mJ of energy at 1kHz repetition rate: the Salle Noire 2. This laser is a Titanium:Sapphire double CPA system with a nonlinear filter in between (based on the crossed polarized wave generation effect) for temporal contrast enhancement, followed by a stretched-flexible hollow-core-fiber based post-compression stage. Using this system, we study laser-matter interaction in the relativistic regime at high repetition rate. We can, on one hand, in gas jets, accelerate electrons in the wakefield of the laser up to several MeVs; and on the other hand, by interacting with plasma mirrors, generate high order harmonics which are associated to bright attosecond pulses in the time domain. Despite the technological prowess in these experiments, the properties of the XUV and electron beams thus generated remain scarcely compatible with the main applications downstream. Following up on previous works in Salle Noire 2, the objective of this thesis was to obtain beams with stable properties, which was achieved by making the laser system more stable and reliable, as well as implementing a fast carrier-envelope phase control loop. By varying the carrier-envelope phase of the laser pulses, we could generate XUV continua/isolated attosecond pulses by forming a relativistic-intensity temporal gate at the surface of the plasma mirror, and also produce electron beams exhibiting stable energy and angle of emission, by controlling the electron injection within the plasma accelerator. Additionally, different regimes of interaction with plasma mirrors were experimentally investigated, such as wakefield acceleration of electrons in long plasma density gradients, and the acceleration of protons on the target’s front side (onto which the laser impinges) along the target no rmal direction, in order to measure new observables (electron energy spectra, proton beam divergence) and thus gain deeper insights into the laser-plasma dynamics
Gervais, Martin. "Housing and optimal taxation in life-cycle economies". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0006/NQ42520.pdf.
Pełny tekst źródłaWei, Yu-Feng 1970. "Concurrent design for optimal quality and cycle time". Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8859.
Pełny tekst źródłaIncludes bibliographical references (p. 113-116).
Product and manufacturing system design are the core issues in product development and dominate the profitability of a company. In order to assess and optimize the product and manufacturing system design, an objective evaluation framework is needed. Despite the many existing tools for product and manufacturing system design, there is a missing link between the product design and the production performances under system variability. The goal of the thesis is to explore and understand the interactions among part design and tolerancing, processes and system variability, and system control decision, then provide an integrated model to assess the total cost in a system. This model will be used to aid part design, tolerancing, batching, as well as strategy analysis in process improvement. A two-stage modeling approach is used to tackle the problem: quality prediction and production prediction. The quality prediction model projects the process variations into the output quality variations at each manufacturing stage, then predict the yield rate from the stochastic behavior of the variations and the tolerance. The production prediction model projects the demand rate and variability, processing times and variability, yield rates and batch-sizes into the manufacturing cycle time and inventories. After the performances are predicted through the previous two models, concurrent optimization of part design, tolerance, and batch-sizes are achieved by varying them to find the minimum cost. A case study at Boeing Tube shop is used to illustrate this approach. The result shows that the costless decisions in part design, tolerancing, and batch- sizes can significantly improve the system performance. In addition, conducting them separately or without using the system performance as the evaluation criteria may only lead to the local optima.
by Yu-Feng Wei.
Ph.D.
Kapp, Konrad Phillip. "Optimal cycle dating of large financial time series". Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/17767.
Pełny tekst źródłaWeber, Tom. "Optimal timing of phase resolved cell cycle progression". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2015. http://dx.doi.org/10.18452/17253.
Pełny tekst źródłaSelf-reproduction is one of the distinguishing marks of living organisms. The cell cycle is the underlying process by which self-reproduction is accomplished in single-celled organisms. In multi-cellular organisms, the cell cycle is in addition indispensable for other vital processes, including immune reactions. In this thesis a method is developed that allows to estimate the time it takes for a dividing cells to complete the CC phases. Knowledge of the CC phase durations allows to predict, for example, how fast a population of proliferating cells will grow in size, or how many new cells are born per hour in a given tissue. In Chapter 1 of this thesis, a cell cycle model with delays and variability in the completion times of each phase is developed. Analytical solutions are derived to describe a common experimental technique used for cell cycle analysis, namely pulse labeling with bromodeoxyuridine (BrdU). Comparison with data shows that the model reproduces closely measured cell cycle kinetics, however also reveals that some of the parameter values cannot be identified. This problem is addressed in Chapter 2. In a first approach, the framework of D-optimal experimental designs is employed, in order to choose optimal sampling schemes. In a second approach, the prevailing protocol with a single nucleoside is modified by adding a second nucleoside analog pulse. Both methods are tested and the results suggest that experimental design can significantly improve parameter estimation. In Chapter 3, the model is applied to the germinal center reaction. A substantial influx of cells into the dark zone of germinal centers is predicted. Moreover the wide-held view of rapid proliferation in germinal centers, appears, under this model, as an artifact of cell migration.
Ališauskas, Skirmantas. "Kelių optinių ciklų trukmės impulsų parametrinis stiprinimas infraraudonojoje srityje". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101001_145146-49682.
Pełny tekst źródłaMain objective of this thesis is to generate and amplify few cycle pulses in the infrared region. In this thesis, two approaches were introduced for few cycle pulse parametric amplification at 800 nm and 1.5 μm. First approach is dedicated for prospects for increasing average power of OPCPA via multi-beam pumping; the second approach is dedicated for generation of carrier-envelope-phase (CEP) stable high energy (up to tens of millijoules) few-cycle pulses at 1.5 μm. An experimental investigation of two or three beams-pumped OPCPA system based on type I BBO crystal is presented. The 2nd OPA stage was pumped by two or three pump beams derived from independent Nd:YAG laser amplifiers. The efficiency of interaction was shown to be comparable to that of single-beam pumped OPA and diminishes only slightly due to cascaded parametric diffraction of interacting waves. The effect was observed and its impact on efficiency of parametric amplification process was shown to decrease at larger intersecting angles of pump. In the prospect, the use of multiple lasers for OPA pumping has an appeal for increasing the repetition rate and consequently the average power of an ultrashort pulse laser system. Finally, the concept and realization of hybrid system based on type II KTP OPCPA and filamentation are described. A CEP-stable 1.5 μm OPCPA system with pulse energies up to 12.5 mJ after 4 OPA stages is demonstrated. Furthermore, self-compression of CEP-stable 2.2 mJ, 74.4 fs, 1.57 μm input... [to full text]
Marchesini, Camilo. "Optimal Monetary Policy, Macroprudential Instruments, and the Credit Cycle". Thesis, Uppsala universitet, Nationalekonomiska institutionen, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-388488.
Pełny tekst źródłaO'Loughlin, R. L. "Optimal design of organic refrigerant reverse cycle absorption air conditioning systems /". Title page, contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09ENS/09enso52.pdf.
Pełny tekst źródłaTaylor, Tracy A. "Optimal Control and Its Application to the Life-Cycle Savings Problem". VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4288.
Pełny tekst źródłaYekoladio, Peni Junior. "Thermodynamic optimization of sustainable energy system : application to the optimal design of heat exchangers for geothermal power systems". Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/31615.
Pełny tekst źródłaDissertation (MEng)--University of Pretoria, 2013.
Mechanical and Aeronautical Engineering
unrestricted
Ju, Min. "Optimisation de la protection des réseaux optiques de nouvelle génération". Thesis, Avignon, 2018. http://www.theses.fr/2018AVIG0226/document.
Pełny tekst źródłaNetwork survivability is a critical issue for optical networks to maintain resilience against network failures. This dissertation addresses several survivability design issues against single link failure and large-scale disaster failure in optical networks. Twoclassic protection schemes, namely pre-configured Cycles (p-Cycle) protection and path protection, are studied to achieve high protection capacity efficiency while taking intoaccount the equipment cost, power consumption and resource usage. These survivable network design problems are first formulated by mathematical models and then offered scalable solutions by heuristic algorithms or a decomposition approach.We first consider single link failure scenario. To cut the multi-line rates transponderscost in survivable Mixed-Line-Rate (MLR) optical networks, a distance-adaptive andlow Capital Expenditures (CAPEX) cost p-cycle protection scheme is proposed withoutcandidate cycle enumeration. Specifically, path-length-limited p-cycles are designed touse appropriate line rate depending on the transponder cost and transmission reach.A Mixed Integer Linear Programming (MILP) model is formulated to directly generate the optimal p-cycles with the minimum CAPEX cost. Additionally, Graph Partitioning in Average (GPA) algorithm and Estimation of cycle numbers (EI) algorithm are developed to make the proposed MILP model scalable, which are shown to be efficient.Regarding the power consumption in survivable Elastic Optical Networks (EONs),power-efficient directed p-cycle protection scheme for asymmetric traffic is proposed.Owing to the advantage of distinguishing traffic amount in two directions, directedp-cycles consume low power by allocating different Frequency Slots (FSs) and modulation formats for each direction. An MILP model is formulated to minimize total power consumption under constraints of directed cycle generation, spectrum assignment,modulation adaptation and protection capacity allocation. To increase the scalability, the MILP model is decomposed into an improved cycle enumeration and a simplified Integer Linear Programming (ILP) model. We have shown that the directedp-cycles out perform the undirected p-cycles in terms of power consumption and spectrum usage.In order to improve the spectrum usage efficiency in p-cycle protection, a SpectrumShared p-cycle (SS-p-cycle) protection is proposed for survivable EONs with and without spectrum conversion. SS-p-cycles permit to reduce spectrum usage and Spectrum Fragmentation Ratio (SFR) by leveraging potential spectrum sharing among multiplep-cycles that have common link(s). The ILP formulations are designed in both cases of with and without spectrum conversion to minimize the spectrum usage of SS-p-cycleswhich can obtain the optimal solution in small instance, and a time-efficient heuristic algorithm is developed to solve large-scale instances. Simulation results show that SSp-cycles have significant advantages on both spectrum allocation and defragmentation efficiency, and the spectrum conversion does help SS-p-cycle design to acquire better spectrum utilization
Bodnar, Nathan. "Phase-locking Stability of a Quasi-single-cycle Pulse". Master's thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5606.
Pełny tekst źródłaM.S.
Masters
Optics and Photonics
Optics and Photonics
Optics; International
El-khawas, Ihab N. "The optimal design of buildings : a life-cycle approach to energy efficiency /". The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487948158626783.
Pełny tekst źródłaZhang, Xiaoying. "Contrast improvement of few-cycle pulses". Thesis, Umeå universitet, Institutionen för fysik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-165565.
Pełny tekst źródłaParks, Geoffrey Thomas. "Optimal in-core nuclear fuel cycles under integral constraint". Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304442.
Pełny tekst źródłaSALMAN, RAMIZ. "Identification of common economic cycles using optimal multivariate filters". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2022. http://hdl.handle.net/10281/394321.
Pełny tekst źródłaThis thesis includes two essays that are focused on developing multivariate filter approaches to be used for extracting common cyclical components where the common components can be used as an estimator of a business cycle. The first chapter aims to develop an optimal multivariate filter in order to extract common cyclical components of macroeconomic indicators. The filter allows macroeconomic series to be modeled as a phase shifted version of a coinciding business cycle (BC) while keeping other time series components such as the stochastic trend and idiosyncratic shocks intact (i.e. they are individually specified for each series). Earlier studies of Rünstler (2004), Valle e Azevedo et al. (2006) have applied phase shift in the form of a delay parameter when specifying lead-lag cycles. However, the lead-lag relationship is defined by rotating the baseline cycle which leads to loss of information. This deficiency is especially important if one considers working in continuous time. Therefore, this paper improves on the former technique by allowing a more flexible phase shift mechanism on the original BC. This in turn should lead to more realistic estimates and filters considering that the underlying data is generated through a continuous time framework. The study starts by presenting a structure for bi-variate time series system and then extends to model to incorporate a structure for three time series and beyond. Kalman filter and smoothing recursions are applied to compute the smoothed cycle estimates and to construct the likelihood function. Using simulated data, we test both model specifications by carrying out a grid search of the initial delay parameter to see the likelihood behavior as the parameter moves into fractional neighborhoods. Afterwards, applying the methodology to a set of EU countries and macroeconomic indicators; the study aims to shed light to the presence of cyclical heterogeneity at country level economic activity for major EU member states. A second empirical study provides analysis on how the model can be implemented for assigning a lead/lag ordering to three main economic indicators of a single country. The second chapter implements a multivariate non-parametric filtering approach; the Vertical Multivariate Singular Spectrum Analysis (V-MSSA) of Hassani and Mahmoudvand (2013) and Golyandina et al. (2013). to be applied for identifying a common economic cycle indicator. The methodology is a data-driven procedure that can decompose a time series into many sub components. By exploiting this ability of the SSA, the paper aims to first extract cyclical components based on frequency characteristics and then follow by choosing only common cyclical component pairs with-in the business cycle frequency spectrum. These components will then be aggregated for constructing an EU region wide Business cycle indicator. The chapter outlines each steps of the algorithm that will eventually identify the SSA filter to act as a band-pass filter. The study then proceeds with simulation based data where the common cycle can be controlled and extracted a priori as a benchmark to the SSA-based filter estimates. The study follows with an empirical analysis similar to the framework set in Valle e Azevedo et al. (2006) with the aim to identify a Euro region business cycle indicator. The SSA based filter estimate is compared with Euro region economic activity indicators; the EuroCoin and the quarterly GDP growth rate of the EU area. Our results presents evidence of a successful alternative for tracing the cyclical position of the EU economy from a much smaller data set. Moreover, the constructed indicator also could serve as an unobserved proxy for a monthly growth cycle. A further analysis is also conducted to reveal whether the SSA based approach can be considered as an alternative to parametric filtering methods by providing results of common cycle extraction using Unobserved component model alternatives.
Jacquet, Maxime J. "Negative frequency at the horizon : scattering of light at a refractive index front". Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/11780.
Pełny tekst źródłaGong, Liying. "Optimal spatial sampling of infrastructure condition a life-cycle-based approach under uncertainty /". Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1155273960.
Pełny tekst źródłaShin, Hyun. "Life-Cycle Cost-Based Optimal Seismic Design of Structures with Energy Dissipation Devices". Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/40399.
Pełny tekst źródłaPh. D.
Kox, Stephan. "Remote sensing of the diurnal cycle of optically thin cirrus clouds". Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-151170.
Pełny tekst źródłaHemmer, Michaël. "Few-cycle pulses amplification for attosecond science applications modeling and experiments". Doctoral diss., University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4920.
Pełny tekst źródłaID: 029809569; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (Ph.D.)--University of Central Florida, 2011.; Includes bibliographical references (p. 218-230).
Ph.D.
Doctorate
Optics and Photonics
Enes, Aaron R. "Shared control of hydraulic manipulators to decrease cycle time". Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37251.
Pełny tekst źródłaDuineveld, Sijmen [Verfasser], i Burkhard [Akademischer Betreuer] Heer. "Solving Life Cycle Models, Optimal Age-Dependent Unemployment Insurance, and Adaptive Beliefs in a Real Business Cycle Model / Sijmen Duineveld ; Betreuer: Burkhard Heer". Augsburg : Universität Augsburg, 2019. http://d-nb.info/1190564904/34.
Pełny tekst źródłaZeng, Shuo. "Understanding diatomic molecular dynamics triggered by a few-cycle pulse". Diss., Kansas State University, 2015. http://hdl.handle.net/2097/19165.
Pełny tekst źródłaPhysics
Brett D. Esry
In strong field physics, complex atomic and molecular motions can be triggered and steered by an ultrashort strong field. With a given pulse as an carrier-envelope form, E(t) = E₀(t) cos(ωt + φ), we established our photon-phase formalism to decompose the solution of a time-dependent Schrödinger equation in terms of photons. This formalism is further implemented into a general analysis scheme that allows extract photon information direct from the numerical solution. The φ-dependence of any observables then can be understood universally as an interference effect of different photon channels. With this established, we choose the benchmark system H₂⁺ to numerically study its response to an intense few-cycle pulse. This approach helps us identify electronic, rovibrational transitions in terms of photon channels, allowing one to discuss photons in the strong field phenomena quantitatively. Furthermore, the dissociation pathways are visualized in our numerical calculations, which help predicting the outcome of dissociation. Guided by this photon picture, we explored the dissociation in a linearly polarized pulse of longer wavelengths (compared to the 800 nm of standard Ti:Saphire laser). We successfully identified strong post-pulse alignment of the dissociative fragments and found out that such alignment exists even for heavy molecules. More significant spatial asymmetry is confirmed in the longer wavelength regime, because dissociation is no longer dominated by a single photon process and hence allowed for richer interference. Besides, quantitative comparison between theory and experiment have been conducted seeking beyond the qualitative features. The discrepancy caused by different experimental inputs allows us to examine the assumptions made in the experiment. We also extend numerical studies to the dissociative ionization of H₂ by modeling the ionization.
Hyyti, Janne Juhani. "Ultrafast Nonlinear Nano-Optics via Collinear Characterization of Few-Cycle Pulses". Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19410.
Pełny tekst źródłaThe ultrashort laser pulse characterization method “interferometric frequency-resolved optical gating” (iFROG) is extended. Both second- and third harmonic generation (SHG and THG) are separately employed as the optical nonlinearity. An iFROG measurement represents an inverse problem, where the electric field amplitude and phase of the underlying laser pulse can only be reconstructed by an iterative algorithm. In this work, a mathematical formalism for both the SHG and THG variants of iFROG is developed and combined with an evolutionary optimization algorithm to create a novel pulse retrieval algorithm for iFROG. While iFROG was originally conceived solely for pulse characterization, the technique can equally well be applied for spectroscopic purposes. By replacing the nonlinear medium in iFROG with an object of study, say a nanostructure, and characterizing a known pulse again such that the sample affects the harmonic generation process, the response of the object can be deciphered with sub-femtosecond precision. As no previous solution for the THG variant exists, the presented retrieval algorithm allows iFROG to be exploited in the study of ultrafast third-order nonlinear effects for the first time. The spectroscopic capability of iFROG is put to test by studying three differing physical systems, each consisting of nanostructures resting on dielectric substrates. Subjecting these specimen to few-cycle near-infrared pulses, a rich variety of nonlinear optical phenomena is observed. In ZnO nanorods, the power dependence of multiphoton-absorption induced luminescence is measured and found to be connected to a localization of the optical near-field. A three-photon resonance in a thin film of titania and a localized surface plasmon resonance in Au nanoantennas both lead to a finite lifetime of the induced material polarization. The THG-iFROG method is harnessed to measure the ultrafast temporal dynamics of these systems at the nanometer and few-femtosecond scales.
de, Medeiros Rocha Caroline Thennecy. "Optimization of p-cycle protection schemes in optical networks". Thèse, 2009. http://hdl.handle.net/1866/3671.
Pełny tekst źródłaNetwork survivability is a very interesting area of technical study and a critical concern in network design. As more and more data are carried over communication networks, a single outage can disrupt millions of users and result in millions of dollars of lost revenue. Survivability techniques involve providing some redundant capacity within the network and automatically rerouting traffic around the failure using this redundant capacity. This thesis concerns the design of survivable optical networks using p-cycle based schemes, more particularly, path-protecting p-cycles, in link failure scenarios. Our study focuses on the placement of p-cycle protection structures assuming that the working routes for the set of connection requests are defined a priori. Most existing work carried out on p-cycles concerns heuristic algorithms or methods suffering from critical lack of scalability. Thus, the objective of this thesis is twofold: on the one hand, to propose scalable models and solution methods enabling to approach larger problem instances and on the other hand, to produce optimal or near optimal solutions with mathematically proven optimality gaps. For this, we rely on the column generation technique which is suitable to solve large scale linear programming problems. Here, column generation is used as an intelligent way of implicitly enumerating promising cycles to be part of p-cycle designs. At first, we propose mathematical formulations for the master and the pricing problems as well as the first column generation algorithm for the design of survivable networks based on path-protecting p-cycles. The resulting algorithm obtains better solutions within reasonable running time in comparison with existing methods. Then, a much more compact formulation of the pricing problem is obtained. In addition, we also propose a new hierarchical decomposition method which greatly improves the efficiency of the whole algorithm and allows us to solve larger problem instances. As for integer solutions, two heuristic approaches are proposed to obtain good solutions. Next, we dedicate our attention to a systematic comparison of p-cycles and classical shared protection schemes. We perform an accurate comparison by using a unified column generation framework to find provably good results. Afterwards, our study concerns an empirical evaluation of directed and undirected link- and path-protecting p-cycles under asymmetric traffic scenarios. We show how much additional protection cost results from employing bidirectional systems in such scenarios. Finally, we investigate a column generation formulation for the design of p-cycle networks under availability requirements and obtain the first lower bounds for the problem.