Mode-locked and noise characteristics of Gaussian apodized fiber grating laser

Abstract

The noise and mode-locking phenomena of a hybrid soliton pulse source (HSPS) utilizing Gaussian apodized fiber Bragg grating is described. The HSPS is modeled by a time-domain solution of the coupled-mode equations including spontaneous emission noise. Relative intensity noise (kilN) is calculated using numerical solutions of these equations. It is found that with and without noise near transform limited pulses are only generated over a limited frequency range even if system is properly mode-locked over a wide frequency range around the fundamental mode-locking frequency. If transform limited pulses are not obtained at the fundamental frequency, there is no noise peak in the PIN spectrum at this frequency.