transfer matrix method (tmm) has been applied to analyze characteristics of semiconductor laser optical amplifiers. the input signal is sinusoidal modulating wave and we do not assume the modulating bias signal as well. we have shown that the distoration arises from gain modulation at low modulation frequencies, but in microwave modulation frequencies, the gain takes an average value and the re...

This article introduces a new variant on the popular optimization method, simulated annealing, herein called modified discrete-state simulated annealing. A guide in practical implementation of simulated tempering is also provided. The algorithms are tested in the design of an ideal collector for a travelling wave tube amplifier. keywords: simulated annealing, simulated tempering, travelling wav...

ACI = Adjacent Channel Interferences APSK = Amplitude Phase Shift Key BER = Bit Error Rate DPD = Digital Predistortion DTH = Direct To Home EQ = EQualization FIR = Finite Impulse Response GW = Gate Way HPA = High Power Amplifier IBO = Input Back-Off IMUX = Input ISI = Inter-Symbol Interference L-TWTA = Linearized Travelling Wave Tube Amplifier LS = Least Squares OBO = Output Back-Off OMUX = Out...

In this paper, we investigate performance improvements in 10 Gbit/s dispersion supported transmission (DST) systems by partial chirp compensation due to self phase modulation in a travelling wave semiconductor optical amplifier (TWA) used as a booster amplifier. For an unsaturated gain of 20 dB, the system performance is improved by 1.14 dB at 204 km, and by 4.13 dB at 253 km SMF. The improveme...

The compression wave cochlear amplifier (CW-CA) model is introduced for the first time. This is the first cochlear amplifier model that is soundly based on the physiology of the inner ear and neural centres. The CW-CA, which is assumed to be driven by the basilar travelling wave (TW), includes outer hair cell (OHC) motility and neural signal transmissions between the hair cells and the central ...

Substantial power scaling of a travelling-wave femtosecond optical parametric amplifier, pumped near 800 nm by a 1 kHz Ti:sapphire laser amplifier, is demonstrated using monoclinic BiB(3)O(6) in a two stage scheme with continuum seeding. Total energy output (signal plus idler) exceeding 1 mJ is achieved, corresponding to an intrinsic conversion efficiency of approximately 32% for the second sta...

Traditional distributed amplification techniques have allowed for high gain and bandwidth at the expense of low efficiency. The decreased efficiency is primarily due to the existence of an actively loaded artificial transmission line as the output, resulting in backward wave propagation. Using the same traditional input line distributed techniques to achieve high bandwidth, this research has ex...

The theory of a parametric travelling-wave amplifier is developed, including the pumping wave explicitly. Particular reference is made to two characteristics of such amplifiers which theories assuming a constant pumping-wave amplitude fail to predict. The first arises from ohmic attenuation in the line, and limits the useful length of line to a length of the order of (ot\a.i)~l, where <xi and 0...