Abstract

Simple and robust sources of wavelength-tunable picosecond optical pulses are attractive for future optical-communication schemes that combine wavelength-division and time-division multiplexing. We present a new wavelength-tunable source of picosecond optical pulses based on a gain-switched Fabry-Perot (FP) laser diode. Filtered amplified spontaneous emission (ASE) is used as a novel seed injected into the laser to obtain tunable single-mode operation with what we believe to be the broadest tuning range and the highest side-mode suppression (SMS) at 1550 nm reported to date for a gain-switched pulse source. The injected seed is obtained by passing the output of a broadband ASE source through a narrow-band tunable filter. Enhanced side-mode suppression is achieved by passing the output pulse train through the same filter. The advantages of the method over other methods of producing single-mode emission from gain-switched FP lasers include use of a passive tuning element and, potentially, direct modulation of the laser without timing restrictions.

© 1995 Optical Society of America