Single-longitudinal-mode lasers tend to originate large mode competition noise when they are used for optical disk reading. This kind of noise can be suppressed by feedback of the laser beam, which makes a single-mode laser oscillate with a stable multimode. Whether this technique is practically useful depends on achieving noise suppression with high yield and sufficient stability under a variety of Q-factors of lasers, the percent of feedback light and temperature change. Q-factors and feedback rates of practical systems vary widely.

© 1984 Optical Society of America

PDF Article