Abstract

An optical wavelength division multiplexing (WDM) transmission system is attractive because of its potential to exploit the wide bandwidth of optical fibers. A tunable narrowband wavelength filter is a key device in a high capacity WDM system. Bistable diode laser amplifiers (BDLAs) based on an intensity-induced refractive-index change can be used as tunable, regenerative, nonlinear narrowband wavelength filters.¹ Here, the operation is based on the strong dependence of the switching power on the wavelength detuning of the signal wavelength with respect to one of the Fabry-Perot resonances of the BDLA.² The advantage of the BDLA as a nonlinear filter is that it can not only provide a narrow filter bandwidth with gain but can also perform pulse reshaping and thresholding on the selected signal, all in one step. We have studied the filtering characteristics of a bistable diode laser amplifier in a two-channel experiment. Bit-error-rate vs channel separation measurements were performed at 140 Mbit/s with a return-to-zero data format. Good performance is obtained with 12-GHz channel separation.

© 1991 Optical Society of America