Numerical description of mode switching characteristics of bistable external cavity semiconductor lasers

Based on solution of the rate equation of semiconductor lasers (LDs),the dynamic characteristics of grating tuned bistabe external cavity LDs (ECLDs) have been described. The effects of the tuning angle of the grating on the transient process have been discussed. It is found that a narrow and strong pulse may be observed before the switched off mode dies out when the output of the bistable ECLD jumps up. This phenomenon does not appear in the jump down process. In addition,the ECLD settles down more quickly for the jump up process.