Experimental investigation of stability enhancement in semiconductor lasers with optical feedback

The stability enhancement of laser output power for the change of external cavity position in semiconductor lasers with optical feedback is observed b y experiment. The relaxation oscillation frequency which plays an important role in the dynamics of the nonlinear system is also investigated as a fun ction of the external cavity length. The period of the stability enhancemen t along the position of the external cavity is exactly coincident with the length corresponding to the relaxation oscillation frequency of the solitar y laser. The experimental results are compared with theoretical and excelle nt coincidence between the two is found.