Relative intensity noise in mode-locked fiber grating external cavity lasers

Abstract

Relative intensity noise (RIN) of a mode-locked hybrid soliton pulse source (HSPS) utilizing a linearly chirped Gaussian apodized fiber Bragg grating (FBG) is reported by using coupled-mode equations including spontaneous emission noise. It is found that linear chirp rate in FBGs is required for obtaining near transform-limited pulses over a wide frequency range from mode-locked HSPS with and without noise. It is also found that RIN reduction is possible by selecting a suitable apodized function and linear chirp rate.