[OPTICAL REVIEW Vol. 6, No. 5 (1999) 399-401]
Low-Frequency Fluctuation and Frequency-Locking in Semiconductor Lasers with Long External Cavity Feedback
Yoshiro TAKIGUCHI,1 Yun LIU2 and Junji OHTSUBO1,*
1Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu, 432-8561 Japan, 2Adaptive Communications Research Laboratories, ATR, 2-2, Hikaridai, Seika-cho, Kyoto, 619-0288 Japan
(Received January 27, 1999; Accepted May 20, 1999)
The properties of low-frequency fluctuations in semiconductor lasers with optical feedback from a long external cavity are experimentally studied. Frequency-locking of the laser light output to the injection current modulation is observed when the modulation frequency approaches the external cavity mode. The modulation frequency for the successful frequency-locking is always less than the external cavity mode frequency and the locking domains as a function of the modulation amplitude is asymmetric with respect to the frequency detuning.
Key words : semiconductor laser, optical feedback, low frequency fluctuation, chaos