High Bandwidth Optoelectronic Data Interfaces for Satellites

A highly efficient optoelectronic (OE) interface is an essential element for satellite data interfaces. The emphasis is on high speed, low power and radiation-hardening. Key to the performance is the transponder subsystem consisting of the photoreceiver (detector , TIA and decision circuit), the clock and data recovery (CDR) circuit consisting of phase detector and voltage controlled oscillator (VCO) to form a phase-locked-loop, clock synthesis and a deserializer/deserializer circuit. Current technology dissipates several watts to achieve 40GB/s and finds it extremely difficult to achieve low jitter with known VCO circuit designs. OPEL proposes a new approach based upon optoelectronic integration that employs an optical thyristor combined with integrated complementary electronics and bipolars. The thyristor is a four terminal laser/detector/switch with optical and electrical thresholding. The thyristor integration produces a new OE oscillator (OEO) with extremely low pulse jitter achieved with optical path delay. Phase detectors, photoreceivers, serializers, deserializers and clock synthesis are all implemented in thyristor logic to achieve a total power of less than 100mW at 40GB/s operation. The single chip transponder is implemented in a 4mm2 chip of rad-hard GaAs. The phase II effort will produce the first fully functional single chip transponder operating at 1310nm and 40GB/s.