| Summary: | 碩士 === 國立交通大學 === 光電工程研究所 === 85 ===
In this thesis, we demonstrate a new timing stabilization method based on an optoelectronic harmonic mixer (OEHM) in a phase-locked loop toreduce the timing jitter of passively mode-locked Ti: sapphire lasers. The OEHM replaces the photodiode and RF mixer combination in conventional approaches. The system becomes more flexible and allows the use of low-frequency electronics in the remainder of the phase-locked loop.
In the home-made passively mode-locked Ti: Sapphire laser system that use dye as the saturable absorber, the optimal r.m.s. timing jitter of the freerunning laser is 12.6ps. This is calculated from single side-band phase noise spectrum measured from 100 Hz to 10 kHz at a resolution bandwidth of lOHz. 1The r.m.s. timing jitter of the stabilized laser is reduced to 710(100-500Hz), 478fs (500-5kHz), and 93fs (5kHz-IOKHz), espectively.
Semiconductor quantum well as saturable absorbers in solid-state lasers can provide sufficiently stable amplitude-modulation to generate ultrafast optical pulses. Those characteristics efficiently reduces amplitude and phase noises of pulse trains. The optimal r.m.s. timing jitter of the free- running laser is 6.8ps, the r.m.s. timingjitter of the stabilized laser is reduced by a factor of about 13dB to 290fs (100-500Hz), 302fs (500-5kHz), and 178fs (5kHz-1OKHz), respectively.
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