Abstract

There has been a growing interest in densely spaced incoherent wavelength-division-multiplexed (WDM) optical communications systems as an alternative to coherent (heterodyne) systems. Recent work has reported an MQW-DBR laser simultaneously functioning as a local oscillator and photodetector/mixer in a coherent (heterodyne) system[1]. In this work we demonstrate the potential of a broadly tunable multiple-quantum-well (MQW) DBR laser geometry to perform as a complete narrow-band tunable incoherent receiver. Biased just below threshold, the device simultaneously integrates the functions of a tunable filter, resonant optical amplifier, photodetector, and if desired, an FSK discriminator. Using identical devices for both an FSK transmitter and an FSK receiver, we demonstrate transmission at speeds up to 250 Mb/s with a preliminary sensitivities in the ~-30 dBm range for 10⁻⁹ BER. Speed is limited by the transmitter FM response, and independent speed measurements indicate a receiver bandwidth of at least 1.7 GHz.

© 1989 Optical Society of America