High Bandwidth Optoelectronic Data Interfaces for Satellites

Satellite data interfaces require optoelectronics for lower power, higher speed and radiation-hard components. The highest speed function is the transponder consisting of the photoreceiver ( detector , TIA and decision circuit), the clock and data recovery (CDR) circuit consisting of a phase locked loop incorporating a voltage controlled oscillator (VCO) and a deserializer circuit. When implemented with state-of-the-art integrated circuits, the power dissipation is excessively high (typical numbers are 5W at 40GB/s). Achieving low jitter with known VCO circuit designs is very difficult . OPEL proposes a novel solution based upon an optoelectronic thyristor combined with integrated complementary electronics. The thyristor is a four terminal device electronically but it is thresholded optically. The unique ability to perform as both a laser (the on state) and an optical switch (the off state) enables a novel optoelectronic oscillator (OEO) with extremely low pulse jitter associated with optical path delay. By combining the OEO with a second thyristor performing in the role of a phase discriminator, the complete photoreceiver and CDR function are implemented with approximately 15 components and a total dissipation of less than 30mW. This SBIR program will develop the integrated optoelectronic circuit to achieve a fully functional transponder at 40GB/s.