25 October 2004 Linewidth of mode combs of passively and actively mode-locked semiconductor laser diodes
Author Affiliations +
We derive the Schawlow-Townes linewidth of mode-locked lasers, and discuss how the timing jitter affects the linewidth in passively/actively mode-locked laser diodes (MLLD's). The linewidth of longitudinal modes of MLLD's is much broader than the Schawlow-Townes linewidth due to the linewidth enhancement factor of the gain medium, and its characteristics depend on whether the laser is mode-locked passively or actively. For the case of active mode-locking, the detuning of the modulation frequency from the natural cavity frequency broadens the linewidth. In the experiment, we measure the linewidth of 10-GHz external cavity MLLD's and investigate the correlation with the noise characteristics of timing jitter and amplitude noise of the pulse train. The experimental results agree well with theoretical predictions.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yuichi Takushima, Yuichi Takushima, Hideyuki Sotobayashi, Hideyuki Sotobayashi, Matthew E. Grein, Matthew E. Grein, Erich P. Ippen, Erich P. Ippen, Hermann A. Haus, Hermann A. Haus, } "Linewidth of mode combs of passively and actively mode-locked semiconductor laser diodes", Proc. SPIE 5595, Active and Passive Optical Components for WDM Communications IV, (25 October 2004); doi: 10.1117/12.580046; https://doi.org/10.1117/12.580046

Back to Top