MICROWAVE TRANSMISSION BY DIRECTLY MODULATING AN ULTRA-LONG DOPED FIBER EXTERNAL CAVITY SEMICONDUCTOR LASER

摘要

Direct modulation of an external cavity semiconductorlaser is usually limited to relatively low frequencies dueto the cavity round trip time. This limits the applicationsfor most long cavity lasers. With a saturable absorberinside the cavity, direct modulation can be implementedat multiples of cavity round-trip frequency. In this paper,experimental results are presented on the directmodulation response of an ultra-long doped fiber externalcavity semiconductor laser (DFECL). The DFECL can bedirectly modulated at 22 multiples of the cavity round-tripresonant frequency. At 2.4GHz, a ~10 MHz bandwidthmodulated microwave signal is transmitted by thisDFECL. The results indicate that the ultra-long DFECLcan be directly modulated usefully at a high frequency.