Shu-Ying YE¹ and Junji OHTSUBO^2,*

¹Graduate School of Electronic Science and Technology, ²Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu, 432-8561 Japan

(Received April 10, 1998; Accepted July 1, 1998)

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

Key words : semiconductor laser, optical feedback, chaos, relaxation oscillation, linear stability analysis

* ohtsubo@eng.shizuoka.ac.jp