Optical Phaselock Receiver with Multi-Gigahertz Signal Bandwidth

We have built a balanced PINFET receiver for homodyne detection of multigigabit-per-second, pilot-carrier PSK optical signals. A new circuit design is described which employs two separate signal amplification paths. A wideband, HEMT-based transimpedance circuit is provided for the demodulated data, while a DC-coupled, JFET- based circuit forms a phase detector for the carrier-recovery phaselock loop. Using narrow-line 1.51microns semiconductor lasers, we have employed this receiver to phaselock a local oscillator to a 295 pW pilot carrier with 8degrees rms phase error.