Abstract

In the standard architecture for optical communications receivers there are typically three basic elements, a photodetector, a pre-amplifier, and a filter. If the signal is frequency multiplexed, there must be an additional mixing stage to separate the different incident optical channels. Sensitivity and gain are most critical for these elements since the signal is weakest and most susceptible to noise at the receiver front end. In commercial receivers, the photodetector and mixer are separate from the pre-amplifier and must be integrated by hybrid techniques. Interconnections between the pre-amplifier and the other components frequently require complex matching networks or interconnection schemes which introduce unwanted noise while reducing reliability. We have designed and tested a high sensitivity p-i-n/JFET, monolithically integrated photoreceiver which incorporates a p-i-n photodiode and a voltage tunable transimpedance preamplifier for 1.3-1.55 pm optical fiber communication. This design allows us to monolithically mix an optical signal with an electrical signal for use in applications such as frequency demultiplexing or coherent detection. Comparison of our results with alternative mixer technology indicates good efficiency with low signal distortion.

© 1993 Optical Society of America