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Zygarlicki, Jarosław, and Janusz Mroczka. "Method of testing and correcting signal amplifiers’ transfer function using prony analysis." Metrology and Measurement Systems 19, no. 3 (October 1, 2012): 489–98. http://dx.doi.org/10.2478/v10178-012-0042-7.
Abstract This article presents a way of analyzing the transfer function of electronic signal amplifiers. It also describes the possibility of using signal precorrection which improves the parasitic harmonics in the THD (Total Harmonic Distortion) of the amplified signal by correcting linearity of the tested amplifier’s transfer function. The proposed method of analyzing and presenting the transfer function allows to diagnose the causes of generating parasitic harmonics, what makes it a useful tool when designing low distortion amplifier systems, such as e.g. amplifiers in measurement systems. The presented THD correction can be used in e.g. amplifier systems that cooperate with arbitrary generators.
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Kumar, Sunil, and Arun Kr Chatterjee. "Comparative study of different Sense Amplifiers in 0.18um technology." INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 7, no. 3 (June 10, 2013): 615–19. http://dx.doi.org/10.24297/ijct.v7i3.3440.
A comparative study of different types of sense amplifiers [1] using 0.18um technology is presented. The sense amplifiers under considerations are used in SRAM and DRAM cells.The sensing delay of different types of sense amplifiers are evaluated with respect to variation of bitline capacitance. Comparative results are also provided for the variation in delay with respect to power supply. Extensive results based on 0.18um CMOS technology using CADENCE Spectre simulation tools are presented for different architectures of sense amplifiers. From these results it has been proven that if the output of sense amplifier is isolated from the bitline parasitic capacitance then the sensing delay of sense amplifier reduces.
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Sadegh Kazempourfard, Mohammad, Hamid Nadgaran, and Seyed Mahdi Mousavi. "The effects of pump pulse fluence on the output energy and amplified spontaneous emission of a femtosecond regenerative amplifier." Laser Physics 32, no. 1 (December 14, 2021): 015002. http://dx.doi.org/10.1088/1555-6611/ac3ee8.
Abstract In this paper, the effects of pump pulse fluence on the output energy and amplified spontaneous emission (ASE) of a femtosecond regenerative amplifier are investigated. One can easily enhance the output energy of laser amplifiers by increasing their pump fluence. This in turn can increase the ASE and reduce the performance of amplifiers in terms of output beam quality, beam stability, etc. This effect would eventually lead to what is called ‘temporal intensity contrast deterioration’. In this work, it is shown that an optimum state of the pump pulse fluence can indeed optimize the amount of the output energy from a regenerative amplifier without much reducing the performance of the amplifier due to the higher ASE. Temporal gain characteristics were employed to achieve this optimum value for a better design, performance, and maintenance of femtosecond laser amplifiers. The results of the current study can be effectively used in designing a wide range of regenerative amplifiers for femtosecond pulses.
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Borel, Andžej. "DEVELOPMENT AND INVESTIGATION OF INPUT AMPLIFIER FOR THE OSCILOSCOPE." Mokslas - Lietuvos ateitis 12 (January 20, 2020): 1–5. http://dx.doi.org/10.3846/mla.2020.11420.
Digital oscilloscope’s structure has analog signal acquisition circuit, which transforms signal’s amplitude to fit ADC dynamic range. This circuit is commonly called oscilloscope’s vertical or front-end amplifier. Difficulty in designing front-end amplifiers in GHz range largely affects higher frequency range oscilloscope’s price. This work is focused on designing a front-end amplifier using discrete and openly sold components. We propose a design for attenuator, buffer, variable gain circuits. Amplifier’s prototype is designed. Main characteristics of the amplifier were measured. Measured bandwidth is 3 GHz. Amplifier’s gain and attenuation can support vertical scale sensitivity range from 10 mV/div to 1 V/div. Step response distortion is under 10 %. SMD and PTH relay model attenuators were evaluated. In this paper we review oscilloscope’s front-end purpose and structure. We review amplifiers design and provide the results of experimental measurements.
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Kitsios, E. E., and R. F. Boucher. "The Dynamics of Vortex Amplifiers. Part 1: Analytical Model." Journal of Dynamic Systems, Measurement, and Control 107, no. 3 (September 1, 1985): 176–81. http://dx.doi.org/10.1115/1.3140717.
A semi-empirical technique for the dynamic modeling of vortex amplifiers is demonstrated with reference to one particular vortex amplifier geometry. The model parameters are determined explicitly from the amplifier static characteristics and geometry except for two which are estimated from measurements of the amplifier’s dynamic response. The two are time constants associated with the chamber time delay and the vortex rotational inertia. The model is linearized about a working point and is presented in terms of an admittance matrix. The paper is continued in Part 2 where two of the amplifier’s transfer admittances are measured experimentally and compared with the model predictions.
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SUDO, SHOICHI. "PROGRESS IN OPTICAL FIBER AMPLIFIERS." International Journal of High Speed Electronics and Systems 07, no. 01 (March 1996): 1–35. http://dx.doi.org/10.1142/s0129156496000025.
Recent progress in fiber amplifier technology is reviewed. Broad band and high power are currently the key goals in the field of fiber amplifiers in conjunction with amplified system development. Broad-band EDFAs using fluoride-based hosts and high-power EDFAs with powerful pump lasers are described in detail. Recent progress and other requirements for optical amplifiers i.e. high gain, low noise, and high reliability, are all reviewed. The limitations in relation to achievable gain are described as well as the highest gain ever achieved. A method for its reduction are described. In relation to reliability, this paper mainly focuses on fluoride fiber. Recent progress on the main characteristics of 1.3 µm PDFA is reviewed and transmission experiment are described. Several attempts to construct fiber amplifiers operating at 0.8 µm, 1.4 µm, and 1.65 µm are also reviewed. In the field of amplified systems, WDM and remote pumping TDM techniques are a high priority. In particular, various WDM experiments such as long-distance WDM transmission, WDM soliton transmission, and WDM networks are all described in detail.
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Ismail, Khadijah, P. S. Menon, Sahbudin Shaari, Abang Annuar Ehsan, Norhana Arsad, and A. Ashrif A. Bakar. "Link Power Level Improvements in an Amplified 8-Channel CWDM System with Hybrid EDFA-SOA Pre-Amplifier." Applied Mechanics and Materials 799-800 (October 2015): 1361–65. http://dx.doi.org/10.4028/www.scientific.net/amm.799-800.1361.
The link power improvement in a coarse wavelength division multiplexing (CWDM) system which is transmitted using a hybrid erbium-doped fiber amplifier (EDFA) and semiconductor optical amplifier (SOA) scheme as a pre-amplifier, is discussed. The network is designed for amplifying 8 CWDM channels ranging from 1471 nm to 1611 nm. The hybrid amplifiers’ gain measurement is obtained from experimental work with gain peak at 22 dB which is observed at 1531 nm. The amplifiers also caused power increment of 5.06 dB in the transmission link before the signal is split individually at the receiving end. Based on the higher gain peaks and power spectrum at 1531 nm and 1551 nm wavelengths, the proposed amplified link would be useful for the transmission of video applications.
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Sullivan, J. A. "Simplified model for designing large KrF amplifiers." Laser and Particle Beams 11, no. 1 (March 1993): 241–56. http://dx.doi.org/10.1017/s0263034600007084.
A simplified model for determining the performance of large krypton-fluoride laser amplifiers is presented. The model includes a straightforward treatment of the controlling kinetics, an exact solution for energy extraction, and an approximation to amplified spontaneous emission losses; it can be easily programmed to run on personal computers. The inclusion of the controlling basic physics for KrF lasers makes the model ideally suited for the many calculations that are necessary to optimize the design of a specific amplifier. The basic parameters determined in the model are compared to experimental data wherever possible, and the large amplifier performance predictions are compared to the results from the most sophisticated kinetics and a 3-D extraction model that includes a full treatment of losses due to amplified spontaneous emission.
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Mei, Shangming, Yihua Hu, Hui Xu, and Huiqing Wen. "The Class D Audio Power Amplifier: A Review." Electronics 11, no. 19 (October 9, 2022): 3244. http://dx.doi.org/10.3390/electronics11193244.
Class D power amplifiers, one of the most critical devices for application in sound systems, face severe challenges due to the increasing requirement of smartphones, digital television, digital sound, and other terminals. The audio power amplifier has developed from a transistor amplifier to a field-effect tube amplifier, and digital amplifiers have made significant progress in circuit technology, components, and ideological understanding. The stumbling blocks for a successful power amplifier are low power efficiency and a high distortion rate. Therefore, Class D audio amplifiers are becoming necessary for smartphones and terminals due to their power efficiency. However, the switching nature and intrinsic worst linearity of Class D amplifiers compared to linear amplifiers make it hard to dominate the market for high-quality speakers. The breakthrough arrived with the GaN device, which is appropriate for fast-switching and high-power-density power electronics switching elements compared with traditional Si devices, thus, reducing power electronic systems’ weight, power consumption, and cost. GaN devices allow Class D audio amplifiers to have high fidelity and efficiency. This paper analyzes and discusses the topological structure and characteristics and makes a judgment that Class D amplifiers based on GaN amplifiers are the future development direction of audio amplifiers.
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Sullivan, J. A., G. R. Allen, R. R. Berggren, S. J. Czuchlewski, D. B. Harris, M. E. Jones, B. J. Krohn, et al. "KrF amplifier design issues and application to inertial confinement fusion system design." Laser and Particle Beams 11, no. 2 (June 1993): 359–83. http://dx.doi.org/10.1017/s0263034600004961.
Los Alamos National Laboratory has assembled an array of experimental and theoretical tools to optimize amplifier design for future single-pulse KrF lasers. The next opportunity to exercise these tools is with the design of the second-generation NIKE system under construction at the Naval Research Laboratory with the collaboration of Los Alamos National Laboratory. Major issues include laser physics (energy extraction in large modules with amplified spontaneous emission) and diode performance and efficiency. Low cost is increasingly important for larger future KrF single-pulse systems (low cost and high efficiency is important for larger repetitively pulsed applications such as electric power production). In this article, we present our approach to amplifier scaling and discuss the more important design considerations for large single-pulse KrF amplifiers. We point out where improvements in the fundamental database for KrF amplifiers could lead to increased confidence in performance predictions for large amplifiers and address the currently unresolved issues of anomalous absorption near line center and the possibility of diode instabilities for lowimpedance designs. Los Alamos has applied these amplifier design tools to the conceptual design of a 100-kJ Laser Target Test Facility and a 3-MJ Laboratory Microfusion Facility.
Shao, Jin. "Advanced Power Amplifiers Design for Modern Wireless Communication." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc804973/.
Modern wireless communication systems use spectrally efficient modulation schemes to reach high data rate transmission. These schemes are generally involved with signals with high peak-to-average power ratio (PAPR). Moreover, the development of next generation wireless communication systems requires the power amplifiers to operate over a wide frequency band or multiple frequency bands to support different applications. These wide-band and multi-band solutions will lead to reductions in both the size and cost of the whole system. This dissertation presents several advanced power amplifier solutions to provide wide-band and multi-band operations with efficiency improvement at power back-offs.
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Hur, Joonhoi. "A highly linear and efficient out-phasing transmitter for multi-band, multi-mode applications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42823.
There have been many efforts to improve efficiency of transmitter while meeting stringent linearity requirement of modern communication system. Among the technology to enhance efficiency of linear transmitter, the out-phasing technologies, also called the linear amplification with nonlinear components (LINC), is considered as a promising technology. LINC has been studied long times, since it provides excellent linearity with high efficiency by allowing adopt high efficient switch-mode power amplifiers. However, The LINC transmitter has some technical challenges: linearity degradation due to amplitude and phase mismatches, efficiency degradation due to poor combining efficiency, and narrow frequency bandwidth due to output matching network of switching power amplifier.
In this thesis, some state-of-the-art techniques for solving the problems of LINC transmitters are presented. An unbalanced phase calibration technique compensates amplitude/phase mismatches between two parallel paths in the LINC system, and multi-level LINC (MLINC) and an uneven multi-level LINC (UMLINC) structure improve the overall power efficiency. And the reconfigurable Class-D switching PA enables multi-band operation with high efficiency and good linearity. With these techniques, the new multi-band out-phasing transmitter improves the efficiency without sacrificing the linearity performance.
3
Kim, Moonil. "Grid amplifiers." Diss., Pasadena, Calif. : California Institute of Technology, 1993. http://resolver.caltech.edu/CaltechETD:etd-08292007-104142.
Lee, Ockgoo. "High efficiency switching CMOS power amplifiers for wireless communications." Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/37145.
High-efficiency performance is one of the most important requirements of power
amplifiers (PAs) for wireless applications. However, the design of highly efficient CMOS
PAs for watt-level applications is a challenging task. This dissertation focuses on the
development of the design method for highly efficient CMOS PAs to overcome the
fundamental difficulties presented by CMOS technology.
In this dissertation, the design method and analysis for a high-power and highefficiency
class-E CMOS PA with a fully integrated transformer have been presented.
This work is the first effort to set up a comprehensive design methodology for a fully
integrated class-E CMOS PA including effects of an integrated transformer, which is
very crucial for watt-level power applications. In addition, to improve efficiency of
cascode class-E CMOS PAs, a charging acceleration technique is developed. The method
accelerates a charging speed to turn off the common-gate device in the off-state, thus
reducing the power loss. To demonstrate the proposed cascode class-E PA, a prototype
CMOS PA was implemented in a 0.18-μm CMOS process. Measurements show an
improvement of approximately 6% in the power added efficiency. The proposed cascode
class-E PA structure is suitable for the design of high-efficiency class-E PAs while it
reduces the voltage stress across the device.
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Talli, Giuseppe. "Amplified spontaneous emission and gain dynamics in semiconductor optical amplifiers." Thesis, University of Essex, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397730.
Mestrado em Engenharia Electrónica e Telecomunicações Recentemente tem-se feito um esforço no sentido de aumentar a
eficiência em aplicadores de RF, no entanto, o transístor é um
dispositivo intrinsecamente ineficiente. Utilizando amplificadores
paramétricos pode-se teoricamente chegar a 100% de eficiência mesmo
operando em modo linear.
A razão desta elevada eficiência é o dispositivo activo utilizado, já que
os amplificadores paramétricos utilizam uma reactância controlada, que
não consome potência. Esta mudança de elemento activo modifica
completamente o princípio de funcionamento dos amplificadores.
Neste trabalho este tipo de amplificação é estudado, relações e transformações conhecidas são examinadas primeiro para obter propriedades
limite gerais. Depois é feita análise de pequeno sinal para se obterem
outras características importantes. Finalmente, um novo modelo de
grande sinal é derivado e apresentado. Este modelo é capaz de prever
algumas características do amplificador, tal como o AM/AM.
Utilizando o modelo de grande sinal apresentado projecta-se um amplificador, sendo este posteriormente simulado. In recent years a significant effort has been made towards efficiency
increase in RF amplifiers. The transistor is, however, an intrinsically
inefficient device. Parametric amplification can theoretically be 100%
efficient even operating in linear mode.
The reason behind this efficiency is the active device. These amplifiers
forget the transistor to use a controlled reactance, which cannot consume
power. This switch in active element changes the whole principle
of operation of the amplifiers.
In this work this type of amplification is studied. Known relations and
transformations are first examined to obtain general limit properties of
the used elements. Then small-signal analysis is performed to obtain
other important characteristics. Finally, a novel large signal model is
developed and presented. This model is capable of accurately predicting
the non-linear responses of the amplifier, such as the AM/AM.
Using the presented large-signal model, an amplifier is designed and
simulated.
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Al, Tanany Ahmed. "A Study of Switched Mode Power Amplifiers using LDMOS." Thesis, University of Gävle, Department of Technology and Built Environment, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-701.
This work focuses on different kinds of Switch Mode Power Amplifiers (SMPAs) using LDMOS technologies. It involves a literature study of different SMPA concepts. Choosing the suitable class that achieves the high efficiency was the base stone of this
work. A push-pull class J power amplifier (PA) was designed with an integrated LC resonator inside the package using the bondwires and die capacitances. Analysis and motivation of the chosen class is included. Designing the suitable Input/Output printed circuit board (PCB) external circuits (i.e.; BALUN circuit, Matching network and DC
bias network) was part of the work. This work is done by ADS simulation and showed a simulated result of about 70% drain efficiency for 34 W output power and 16 dB gain at 2.14 GHz. Study of the losses in each part of the design elements is also included.
Another design at lower frequency (i.e.; at 0.94 GHz) was also simulated and compared to the previous design. The drain efficiency was 83% for 32 W output power and 15.4 dB Gain.
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Gray, Blake Raymond. "Design of RF and microwave parametric amplifiers and power upconverters." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43613.
The objective of this research is to develop, characterize, and demonstrate novel parametric architectures capable of wideband operation while maintaining high gain and stability. To begin the study, phase-incoherent upconverting parametric amplifiers will be explored by first developing a set of analytical models describing their achievable gain and efficiency. These models will provide a set of design tools to optimize and evaluate prototype circuit boards. The prototype boards will then be used to demonstrate their achievable gain, bandwidth, efficiency, and stability. Further investigation of the analytical models and data collected from the prototype boards will conclude bandwidth and gain limitations and end the investigation into phase-incoherent upconverting parametric amplifiers in lieu of negative-resistance parametric amplifiers.
Traditionally, there were two versions of negative-resistance parametric amplifiers available: degenerate and non-degenerate. Both modes of operation are considered single-frequency amplifiers because both the input and output frequencies occur at the source frequency. Degenerate parametric amplifiers offer more power gain than their non-degenerate counterpart and do not require additional circuitry for idler currents. As a result, a phase-coherent degenerate parametric amplifier printed circuit board prototype will be built to investigate achievable gain, bandwidth, and stability. Analytical models will be developed to describe the gain and efficiency of phase-coherent degenerate parametric amplifiers. The presence of a negative resistance suggests the possibility of instability under certain operating conditions, therefore, an in-depth stability study of phase-coherent degenerate parametric amplifiers will be performed.
The observation of upconversion gain in phase-coherent degenerate parametric amplifiers will spark investigation into a previously unknown parametric architecture: phase-coherent upconverting parametric amplifiers. Using the phase-coherent degenerate parametric amplifier prototype board, stable phase-coherent upconversion with gain will be demonstrated from the source input frequency to its third harmonic. An analytical model describing the large-signal transducer gain of phase-coherent upconverting parametric amplifiers from the first to the third harmonic of the source input will be derived and validated using the prototype board and simulations.
This thesis explores the broadband fibre optical parametric amplifiers (FOPAs) to develop the FOPA ability to provide broadband amplification anywhere in the low-loss transmission window and to make FOPA an enabling technology for future ultra-wide bandwidth high-speed optical communications. A number of techniques have been implemented to demonstrate an exceptionally wide and flat FOPA gain of 10.5±0.5 dB over 102 nm bandwidth on a single side of the FOPA pump. A flat gain spectrum is targeted here because FOPA is prone to large gain variation which has a particularly strong negative impact on amplified signals in FOPA. The FOPA dependence on gain fibre length, pump wavelength and pump power has been experimentally investigated. The parametric gain bandwidth enhancement by a forward Raman gain invoked by the same pump has been demonstrated. Gain spectrum shaping by pump polarisation tuning has been explored and has allowed for a significant gain spectrum flatness improvement. A concept of cascading low gain stages has been introduced as a way to achieve a high gain with low variation across a wide bandwidth. It is envisaged that gain of ~20±1.5 dB over >100 nm can be achieved using this approach. Additionally, a reliance of the FOPA on Erbium doped fibre amplifiers (EDFAs) for pump amplification, which restricts the FOPA operating range, has been addressed by demonstrating a high pump power (>1 W) EDFA-free FOPA for the first time. In this experiment a Raman amplification was used instead of an EDFA to amplify the FOPA pump and thus to grant a required flexibility for FOPA operation anywhere in the low-loss transmission window. In summary, this thesis has demonstrated the FOPA ability to provide an ultra-wide amplification and has highlighted a way towards obtaining an optical gain in arbitrary spectral regions.
Blackburn, James A. "Amplifiers." In Modern Instrumentation for Scientists and Engineers, 37–56. New York, NY: Springer New York, 2001. http://dx.doi.org/10.1007/978-1-4613-0103-5_5.
Graziane, Nicholas, and Yan Dong. "Amplifiers." In Neuromethods, 33–53. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3274-0_3.
Magrab, Edward B. "Amplifiers." In Computer Integrated Experimentation, 87–111. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-95638-6_4.
Huber, David Miles, and Robert E. Runstein. "Amplifiers." In Modern Recording Techniques, 389–95. Edition 9. | New York; London : Routledge, 2017.: Routledge, 2017. http://dx.doi.org/10.4324/9781315666952-13.
Tietze, Ulrich, Christoph Schenk, and Eberhard Gamm. "Amplifiers." In Electronic Circuits, 269–482. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-78655-9_4.
Lewis, Barry, and Tim Strickland. "Amplifiers." In The Electronics Pathway, 144–93. London: Macmillan Education UK, 1996. http://dx.doi.org/10.1007/978-1-349-13300-0_7.
Lipton, Richard J. "Amplifiers." In The P=NP Question and Gödel’s Lost Letter, 195–99. Boston, MA: Springer US, 2010. http://dx.doi.org/10.1007/978-1-4419-7155-5_40.
van de Roer, Theo G. "Amplifiers." In Microwave Electronic Devices, 255–86. Boston, MA: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4615-2500-4_9.
Graziane, Nicholas, and Yan Dong. "Amplifiers." In Neuromethods, 33–53. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2589-7_3.
Laming, R. I., D. N. Payne, F. Meli, G. Grasso, and E. J. Tarbox. "Saturated Erbium-Doped Fibre Amplifiers." In Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oaa.1990.mb3.
It has not been generally appreciated that the erbium-doped fibre amplifier1 (EDFA) has both a saturation output power which increases with pump power, as well as an ability to operate deep in saturation without signal distortion and interchannel crosstalk2. The latter is a consequence of its slow gain dynamics and is quite different from diode-amplifier behaviour3. Most investigations of the gain-characteristics of EDFAs to date have concentrated on the small input signal regime and attempted to obtain high unsaturated gain for low-pump powers4,5, an attribute which is required for an in-line amplifier. By contrast, in this paper we discuss the application of EDFAs as power (post) amplifiers where the input signal is large and the amplifier saturation behaviour outlined above can be exploited. In the highly-saturated regime we have obtained near-quantum-limited differential pump to signal conversion efficiencies, resulting in 47mW (16.7dBm) of amplified signal for only l00mW of pump power at 978nm. Operating in this mode EDFAs are attractive for application as power amplifiers to ease power budget restrictions in point-to-point digital links, video distribution networks6 and LANs.
2
Way, W. I., A. C. Von Lehman, M. J. Andrejco, M. A. Saifi, and C. Lin. "Noise Figure of a Gain-Saturated Erbium-Doped Fiber Amplifier Pumped at 980 nm." In Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oaa.1990.tub3.
Erbium-doped fiber amplifiers (EDFAs) have recently been extensively studied for applications in long-distance transmission[1] [2] and subscriber loop distribution systems[3][4][5]. The noise figure of the fiber amplifier is a parameter that must be considered in these systems to optimize overall system performance. Noise figures of an EDFA pumped at 1480 nm and 980 nm were reported to be near 5 dB[6], and 3 dB[7], respectively. However, these numbers were measured when the amplifiers were operated in the linear region. An EDFA may be operated in the gain saturation region when it is used as a power amplifier in the subscriber loop[3] [5], or when it is one of the latter stages of many cascaded amplifiers in a transmission system. In the latter case, the amplifier gain saturates because of the accumulated amplified spontaneous emission (ASE) noise, which may be due to the finite passband of interstage optical filters, or because there is not enough inter-stage loss to compensate the amplifier gain. Under the above conditions, questions arise as to whether the amplifier noise figure increases while the gain is saturated, and what are the parameters that control this noise figure degradation. The subject of this paper is to examine these questions.
3
Fleming, G. R., A. J. Ruggiero, and N. F. Scherer. "Impulsive Phase Coherent Femtosecond Spectroscopy of Molecular Transients at Repetition Rates in the 100kHz Range." In International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/up.1990.thd3.
We report on the design and characteristics of a 50fs pulsewidth (5nJ/pulse) cavity dumped antiresonant ring femtosecond dye laser1 and a continuously pumped 45ps pulsewidth (100µJ/pulse) all acousto-optically switched Nd:YAG regenerative amplifier2 operating at pulse repetition rates in the tens of kilohertz range. Optically synchronized dye laser amplification to microjoule levels at these repetition rates is also discussed. This range of pulse repetition rates fills the gap between that available with conventional electro-optically switched (1–6kHz) solid state regenerative amplifiers3 or copper vapor laser based amplifiers4 (6-20kHz) and MHz amplifiers based on cavity dumped ion lasers5.
4
Mehuys, D., D. F. Welch, R. G. Waarts, R. Parke, A. Hardy, and W. Streifer. "Modal analysis of monolithically integrated, surface-emitting, master oscillator power amplifiers." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.mk4.
Recently, promising results have been obtained from a monolithically integrated master-oscillator power amplifier (M-MOPA) composed of a single-mode distributed Bragg-reflector (DBR) oscillator and linear chain of amplifiers and surface-emitting output couplers.1 The oscillator output is successively amplified in index-guided amplifiers and is coupled upwards from the wafer surface via detuned second-order DBR's. Coherent output power from this structure is nearly 0.5 W, in contrast to < 100 mW from coupled arrays of grating-surface-emitting oscillators.
5
Jopson, R. M., and G. Eisenstein. "Optical Amplifiers for Photonic Switches." In Photonic Switching. Washington, D.C.: Optica Publishing Group, 1987. http://dx.doi.org/10.1364/phs.1987.fc1.
Although semiconductor optical amplifiers1,2,3,4 hold the promise of allowing lossless switch design, current optical amplifiers have properties that render them unusable in many applications. Two problems currently limiting their use are rapid Fabry-Perot variations in the gain spectra and bidirectionality of the gain. The figure below schematically illustrates the gain spectrum of a semiconductor optical amplifier. It can be seen that the broad (≈70-nm) semiconductor gain spectrum is multiplied by a rapidly varying Fabry-Perot spectrum. (The spacing between the Fabry-Perot peaks in the figure has been increased for illustrative purposes). Semiconductor optical amplifiers are usually made by putting an anti-reflective coating on the facets of a laser diode. It is the residual refectivity of the amplifier facets that causes Fabry-Perot resonances in the gain spectrum. The amplitude of this variation is determined by the product of the amplifier chip gain and facet reflectivity while the optical length of the amplifier waveguide determines the separation between the peaks. Since optical amplifiers typically have Fabry-Perot periods of 1.3 nm, it can be seen that there are actually around 50 Fabry-Perot periods within the material gain bandwidth rather than the 7 illustrated in the figure. While is possible to obtain high gain from an amplifier with strong Fabry-Perot resonances, the use of such an amplifier obviously presents wavelength control problems to the switch designer. Other less obvious problems in amplifiers with strong Fabry-Perot structure are: 1) the locations of the Fabry-Perot peaks are strongly temperature dependent, 2) the location and gain of the peaks are sensitive functions of the bias current of the amplifier, 3) they have more cross-talk and lower saturated output power than amplifiers with a smooth gain spectrum, and 4) the backward reflected gain is comparable to the forward gain. Given these problems, it is unlikely that amplifiers with large Fabry-Perot resonances will be of much use in photonic switching systems.
6
Auge, J., B. Clesca, B. Biotteau, P. Bousselet, A. Dursin, C. Clergeaud, P. Kretzmeyer, et al. "Repeaterless Transmission With 62.9 dB Power Budget Using A Highly Efficient Erbium-Doped Fiber Amplifier Module." In Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oaa.1990.tuc3.
Laser-diode-pumped erbium-doped fiber amplifiers (EDFA) have recently demonstrated all their potential for very long haul transmissions [1]. In-line EDFA application is clearly identified for long undersea links. However, repeaterless transmissions have many applications, especially over 250 km lengths. Compared to direct detection, heterodyne detection allows to achieve a very high receiver sensitivity, increasing the overall link budget [2], Optical amplifiers highly improve this budget, particularly by compensating for the insertion loss of the external phase modulator in DPSK systems. We report a 565 Mbit/s DPSK transmission experiment at 1.532 μm using an EDFA module at the emission, operating in gain saturation regime. Pumped by laser diodes, this optical post-amplifier delivers an amplified output power exceeding +13 dBm, leading to a repeaterless power budget of 62.9 dB. This gives the potentiality to design over 350 km repeaterless links by use of a pure silica core fiber.
7
Rhoads, Jeffrey F., and Steven W. Shaw. "The Effects of Nonlinearity on Parametric Amplifiers." In ASME 2008 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/detc2008-49594.
Mechanical and electromechanical parametric amplifiers have garnered significant interest, as of late, due to the increased need for low-noise signal amplification in resonant micro/nanosystems. While these devices, which are traditionally designed to operate in a linear range, potentially represent an elegant, on-chip amplification solution, it is not readily apparent that this technical approach will suffice in all micro/nanoresonator implementations, due to the scale-dependent nature of a mechanical or electromechanical amplifier’s dynamic range. The present work investigates whether the aforementioned linear dynamic range constraint is truly a practical limitation, by considering the behavior of a representative degenerate parametric amplifier driven within a nonlinear frequency response regime. The work adopts a comparatively simple lumped-mass model for analysis and proceeds with the characterization of pertinent performance metrics, including gain/pump and gain/phase behaviors. Ultimately, the work concludes that parametric amplification can be realized in a nonlinear context, but such implementations generally lead to inferior amplifier performance.
8
Izadpanah, H., A. Elrefaie, W. Sessa, Chinlon Lin, S. Tsuji та H. Inoue. "A Multi-Gb/s Self-Synchronized Optical Regenerator Using a 1.55 μm Traveling-Wave Semiconductor Optical Amplifier". У Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oaa.1990.wc5.
We demonstrate experimentally and by computer simulation that the semiconductor optical amplifiers (SOAs) are capable of performing a variety of optoelectronic (OE) functions useful in fiber-optic networks and optical signal processors at multi-Gb/s rates[1,2]. An example of OE functions obtained is a complete optical regeneration of data pulses which are amplified, retimed, and reshaped in optical domain. In this paper, we present results on a 1.55 μm traveling-wave (TW) SOA optical regenerator with a novel clock recovery circuit for retiming and synchronization. The regenerator operates at a 2.5 Gb/s rate, with a 10 dB fiber-to-fiber gain. In contrast to the 1.31 μm SOA reflective regenerator reported recently[1] at 560 Mb/s, the present amplifier is a packaged 1.55 μm traveling-wave amplifier[3], which operates at much higher bit rate, higher gain, and includes the self-synchronized clock recovery circuit.
9
Mito, Ikuo, та Kenji Endo. "1.48μm and 0.98μm High-Power Laser Diodes for Erbium-Doped Fiber Amplifiers". У Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/oaa.1991.wc1.
The development of erbium-doped fiber amplifiers has recently progressed rapidly. Highly efficient power conversion for 1.48μm wavelength pumping enables a post-amplifier to achieve output power greater than 100mW1). When pumped in 0.98μm wavelength, the erbium-doped fiber amplifiers showed very low noise property2), which permits high receiver sensitivity as a pre-amplifier.
10
Giles, C. Randy. "Signal propagation and noise accumulation in amplified lightwave systems." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.tha4.
Lightwave systems using optical amplifiers as repeaters offer the advantage of ease of capacity enhancement through the use of either high data rates or wavelength-multiplexed channels. Besides optical fiber nonlinearities, potential limitations of such lightwave systems include the effects of optical amplifier saturation and the accumulation of amplified spontaneous emission. Simulations show that transmission at gigabit-per-second rates over transoceanic distances is possible if erbium-doped fiber amplifiers are used as repeaters. The upper limit on amplifier spacing imposed by noise accumulation is approximately 100 km for a 10000 km, 2.5 Gb/s transmission system. Reduced amplifier spacing lowers the total noise and expands the range of signal powers that satisfy the required signal-to-noise ratio and constraints related to optical-fiber nonlinearities. Best noise performance is obtained with distributed amplification in which the transmission fiber is lightly doped with erbium and optically pumped, so that the gain just compensates the loss. Depending on the supervisory methods, amplified lightwave systems might be operated with regulated optical power or might be free-running, a choice that affects the signal power, efficiency, saturation, and noise figure of the fiber amplifier.
Звіти організацій з теми "Amplifiers":
1
Rutledge, David. Grid Amplifiers. Fort Belvoir, VA: Defense Technical Information Center, July 1995. http://dx.doi.org/10.21236/ada300131.
Cheung, Chun-Tung, Blythe Deckman, James J. Rosenberg, and David B. Rutledge. Progress in Grid Amplifiers. Fort Belvoir, VA: Defense Technical Information Center, May 2003. http://dx.doi.org/10.21236/ada413414.
Alaniz, Gabriel. Tuning Broadband Microwave Amplifiers. Office of Scientific and Technical Information (OSTI), September 2003. http://dx.doi.org/10.2172/815637.
Sutton, S., C. Marshall, C. Petty, L. Smith, B. van Wonterghem, and S. Mills. Thermal recovery of NIF amplifiers. Office of Scientific and Technical Information (OSTI), February 1997. http://dx.doi.org/10.2172/562469.
Teegarden, Kenneth J. Fiber Laser Amplifiers and Oscillators. Fort Belvoir, VA: Defense Technical Information Center, September 1993. http://dx.doi.org/10.21236/ada274231.
Kircher, C. J. Tunnelling Hot Electron Transfer Amplifiers. Fort Belvoir, VA: Defense Technical Information Center, October 1993. http://dx.doi.org/10.21236/ada275529.
Delagrange, Arthur D. An Alternative to Operational Amplifiers. Fort Belvoir, VA: Defense Technical Information Center, June 1990. http://dx.doi.org/10.21236/ada237439.
Luhmann, N. C., and Jr. Stable High-Power Harmonic Gyro-Amplifiers. Fort Belvoir, VA: Defense Technical Information Center, September 1994. http://dx.doi.org/10.21236/ada293697.
Bennett, E. F. Induction filtering for proportional counter amplifiers. Office of Scientific and Technical Information (OSTI), March 1989. http://dx.doi.org/10.2172/6276326.
