Integrated quantum well feedback structure

Claim 1

A receiver comprising an amplifier having an input and an output, signal detecting means connected to said input for generating a first current in response to a signal, a feedback circuit connected between said output and said input for generating a second current for balancing said first current generated by said signal detecting means, said feedback circuit comprising: a single integrated semiconductor device including a substrate, a light emitter in the form of a first P-I-N structure formed on said substrate and having a first multiple quantum well active region, and a detector in the form of a second P-I-N structure formed on said substrate and having a second multiple quantum well active region, said first P-I-N structure being forward biased by voltages at the output of said amplifier to emit light, said second P-I-N structure being connected to said input of said amplifier, and means for maintaining a constant reverse bias voltage on said second P-I-N structure to shift an absorption edge of the active region of the second P-I-N structure into a portion of the spectrum wherein the active region of the second P-I-N structure is normally transparent to enable said second P-I-N structure to absorb light emitted by said first P-I-N structure to generate said second current.