Recently, broadband networks using multichannel wavelength division multiplexing (WDM) technologies, either for wavelength routing or for service segregation, have attracted much attention. 1 In such networks, tunable filters or optical receivers are of great interest2-4; a large wavelength-tuning range and fast wavelength-selection time are desired for such tunable receivers. One way to perform wavelength selection as schematically shown in Fig. 1, is to use a novel optoelectronic integrated circuit (OEIC) receiver with an array of photodetectors and an off-chip wavelength demultiplexer. The OEIC receiver performs optical detection, electronic switching, and signal amplification. Optical signals at different wavelengths transmitted through a single-mode fiber are demultiplexed by a WDM component and coupled into an array of photodetectors. Each detector in the receiver will be activated only when its electronic switch is turned on externally. When a detector is enabled, the wavelength is selected, and the detected signal is then amplified by an on-chip preamplifier. The speed of wavelength selection has the potential to be fast because of the small resistance-capacitance time constant that is achievable in the switching circuit. In addition, any WDM demultiplexer in the 1.1-1.6 μm spectral range can be used with the OEIC receiver, allowing a large wavelength selection range, flexible passbands, and channel spacings.
© 1991 Optical Society of AmericaPDF Article