RIN of Mode-Locked External Cavity Lasers Utilizing a Sinusoidally Chirped Fiber Bragg Grating

The relative intensity noise (RIN) of a mode-locked hybrid soliton pulse source (HSPS) utilizing a sinusoidally chirped fiber Bragg grating (FBG) is investigated using the time-domain solution of coupled wave equations and rate equations that include both spontaneous noise and carrier density noise. The effect of some laser diode and grating parameters on the RIN of the HSPS is also described. The numerical results indicate that most parameters affect the system operation even in the absence of noise. RIN reduction at the fundamental frequency is possible in a mode-locked HSPS utilizing a sinusoidally chirped, Gaussian-apodized FBG when compared with an HSPS with linearly chirped gratings. Furthermore, it is also shown that an HSPS utilizing a sinusoidally chirped FBG produces shorter pulses with and without noise than linearly chirped gratings.