DESIGN OF LOW-TIMING-JITTER, STABLE PICOSECOND OPTICAL-PULSE SOURCE USING AN UNCOOLED GAIN-SWITCHED FABRY-PEROT SEMICONDUCTOR LASER WITH EXTERNAL CONTINUOUS-WAVE LIGHT INJECTION

摘要

This paper presents the design of a low-timing-jitter, stable picosecond optical-pulse source, which is based on a low-cost, uncooled Fabry-Perot (FP) semiconductor laser in the gain-switching operation. The wavelength of the designed laser can be tuned from 1538 to 1554 nm under the condition of external continuous-wave (CW) light injection. The relationship between injection light power and timing jitter or between injection light power and pulse width of this gain-switched laser is studied experimentally. Our results show that the optical pulses with widths about 28 and 19 ps at the repetition frequencies of 2.5 and 5 GHz, respectively, are produced by an uncooled gain-switched FP semiconductor laser with timing jitter ≤600 fs, when the injection power and wavelength of an external CW light are appropriately chosen. The use of a 500-m dispersion-compensation fiber can easily compress the optical pulses from 26 to 7.7 ps. Moreover, the stability of an uncooled gain-switched FP laser is experimentally investigated, and a stable optical-pulse train at 5 GHz can be feasibly produced over 7 h of continuously working.