Abstract

When a conventional semiconductor laser is driven by nanosecond or subnanosecond electrical pulses its output generally exhibits lasing on several longitudinal modes spanning 20-40 A. To reduce the chromatic dispersion attendant to this bandwidth in fiber-optic systems, a considerable effort has been under way lately to achieve single-longitudinal-mode operation by drastically shortening the cavity length of injection lasers. Instead of the usual 200-400-μm cavity lengths, new etching, or micro cleavage techniques give lengths in the 20- 40-μm range. The wider Fabry-Perot mode spacing generally leads to predominantly single-mode operation because of the limited gain bandwidth. For operation at rates above 1 Gbit/sec, the substantial power in adjacent modes still poses a problem in these lasers.

© 1983 Optical Society of America