Browsing by Author "Xia, GQ"

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Dynamics of optical backward-injection-induced gain-depletion modulation and mode locking in semiconductor optical amplifier fiber lasers
(2004-05-17)
Lin, GR
;
Liao, YS
;
Xia, GQ
;
光電工程學系
;
Department of Photonics
The optical gain-depletion-induced mode-locking dynamics of a semiconductor optical-amplifier-based fiber ring laser (SOAFL) backward injected by a purely sinusoidally modulated or digitally encoded distributed-feedback laser diode are theoretically and experimentally demonstrated. The effect of gain depletion and waveform on the mode-locked pulse width, pulse shape, and power of the SOAFL are interpreted from theoretical simulations. The shortest pulse width of 12 ps can be generated from an optically sinusoidal-wave-modulated SOAFL. By backward injecting the SOAFL with a digitally encoded optical signal of adjustable duty cycle, one can observe the optimized gain depletion time of 400-600 ps required for mode locking the SOAFL. (C) 2004 Optical Society of America.
Effects of gain shift and wavelength dependence of semiconductor light amplifiers on picosecond optical pulses
(2004-02-01)
Wu, ZM
;
Xia, GQ
;
Lin, GR
;
光電工程學系
;
Department of Photonics
By introducing the gain shift and wavelength dependence of semiconductor light amplifiers (SLAs) into the theoretical model that describes the dynamic process of picosecond optical pulses passing through SLAs, the influence of the gain shift and wavelength dependence on temporal distributions of amplified pulses was studied numerically. The results show that, in order to model accurately the temporal shape of the amplified picosecond pulse by the SLA, the gain shift and wavelength dependence of the SLA should be taken into consideration.
Rising and falling time of amplified picosecond optical pulses by semiconductor optical amplifiers
(2003-11-01)
Xia, GQ
;
Wu, ZM
;
Lin, GR
;
光電工程學系
;
Department of Photonics
After adopting the theoretical model that includes several physical mechanisms such as the position- and time-dependent carrier lifetime, the gain saturation caused by the depletion of carrier density owing to the stimulated emission, the gain compression induced by the intraband process of carrier heating and spectral hole burning, the gain asymmetry and shift, both the rising and falling time of amplified picosecond optical pulses by the semiconductor optical amplifiers (SOAs) have been investigated numerically. The results show that with the increase of the bias current of SOAs or the length of SOAs, the rising time will decrease and the falling time increase; the input pulse with a large peak power will accelerate the rising time shortening and the falling time lengthening; the gain compression has an obvious influence on the rising and falling time for several picosecond width input pulses and gives approximately no effect for the input pulses in the tens of picosecond range; the gain asymmetry and shift affects the rising and falling time. (C) 2003 Elsevier B.V. All rights reserved.
Studies on the amplified picosecond optical pulse by semiconductor light amplifiers using an improved model
(2004-02-01)
Xia, GQ
;
Wu, ZM
;
Lin, GR
;
光電工程學系
;
Department of Photonics
After presenting an improved theoretical model that describes the dynamic process of optical pulses amplification by the semiconductor light amplifiers (SLAs), both the rising and falling time of amplified picosecond optical pulses by the SLAs have. been investigated numerically. The results show that with the increase of the bias current of SLAs, the rising time will decrease and the falling time increase; the input pulse with a large peak power will accelerate the rising time shortening and the falling time lengthening; the gain compression has an obvious influence on the rising and falling time for several picosecond-width input pulses and gives approximately no effect on the input pulses in the tens of picosecond range; the gain asymmetry and shift strongly affect the rising and falling times.
Studies on the amplified picosecond optical pulse by semiconductor light amplifiers using an improved model
(2004-02-01)
Xia, GQ
;
Wu, ZM
;
Lin, GR
;
交大名義發表
;
National Chiao Tung University
After presenting an improved theoretical model that describes the dynamic process of optical pulses amplification by the semiconductor light amplifiers (SLAs), both the rising and falling time of amplified picosecond optical pulses by the SLAs have. been investigated numerically. The results show that with the increase of the bias current of SLAs, the rising time will decrease and the falling time increase; the input pulse with a large peak power will accelerate the rising time shortening and the falling time lengthening; the gain compression has an obvious influence on the rising and falling time for several picosecond-width input pulses and gives approximately no effect on the input pulses in the tens of picosecond range; the gain asymmetry and shift strongly affect the rising and falling times.