[OPTICAL REVIEW Vol. 6, No. 4 (1999) 365-371]

Relaxation Oscillation Enhancement and Coherence Collapse in Semiconductor Lasers with Optical Feedback

Shinsuke FUKUCHI, Shu-Ying YE and Junji OHTSUBO*

Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu, 432-8561 Japan

(Received January 20, 1999; Accepted February 17, 1999)

The dynamic characteristics of a semiconductor laser with optical feedback are strongly dependent on the injection current and the reflectivity and position of the external feedback reflector. We investigated the relaxation oscillation enhancement and coherence collapse state of the laser oscillation based on the laser rate equations. It is well known that laser output power jumps with increase of the injection current due to external mode transition. But here for the first we time demonstrate the existence of a chaotic scenario within successive laser power jumps. The results calculated by numerical simulations based on the rate equations are compared with those of the experiments and good coincidence between them is found.

Key words : semiconductor laser, optical feedback, chaos, relaxation oscillation, coherence collapse