Effect of spontaneous noise on mode-locked hybrid soliton pulse source utilizing chirped grating

The noise of mode-locked hybrid soliton pulse source (HSPS) with linearly chirped grating is analyzed by couple-mode equations including spontaneous emission noise. Relative intensity noise (RIN) is calculated using numerical solutions of these equations. It is shown that a noise peak in the RIN spectrum locates at the resonance frequency and this peak is a little broad. In this range noise affects the operation of device, so transform limited pulses are not obtained. It is also shown that RIN value is low in the mode-locking range except approximately at the resonance frequency.