Mode-locked and noise analysis of external cavity semiconductor lasers

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 (RIN) is calculated using numerical solutions of these equations. It is found that 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, output pulse is not more affected from the noise at this frequency. It is also found that noise reduction is possible by using these gratings.