A fiber-integrated semiconductor ring laser for 10 GHz optical timing extraction

An optical short pulse source with a high repetition rate is important in high speed optical switching and optical time-division-multiplexing (OTDM). Among various potential techniques of generating optical short pulses, active modelocking, especially harmonically mode-locked erbium-doped fiber laser (EDFL) is one of the most attractive methods for gigahertz repetition rate pulses. However, EDFL requires the configuration of long cavity length to obtain sufficient gain from the EDFA. Thus, inevitable instability of the output pulses is induced from even a small environmental perturbation, such as thermal fluctuations and acoustic vibrations that affect the fiber laser. In the paper, 10 GHz actively mode-locked fiber-integrated semiconductor ring laser is implemented, which shows good short-term amplitude and total cavity length is considerably shortened minimizing the impact of an environmental perturbation compared with the EDFL.