Photoreceiver Based on SiGe Nanostructure on Silicon

To address the Air Force need for a high-speed free-space photoreceiver operating in the near-infrared communications band, Physical Optics Corporation (POC) proposes to develop a new monolithic Silicon/Germanium/CMOS (SIGNMOS) photoreceiver that far exceeds the capabilities of current devices. The SIGNMOS is based on germanium "quantum dust" embedded in a silicon matrix, directly integrated into a CMOS amplification circuit. The device will perform amplified photoreception with a bandwidth of >40 GHz analog and >40 Gbps digital. Unlike current silicon-based high-speed photodetectors, the SIGNMOS will operate with signals between 1.2 and 1.6 micrometers, including the telecommunications bands near 1.31 and 1.55 micrometers. Compared to current InGaAs photodetectors that operate in the communications bands, the SIGNMOS will be less expensive because of its easy integratability with standard silicon-based circuitry. Another advantage over current free-space photodetectors is that the reception area of the SIGNMOS is independent of its bandwidth, so the detector can be large and hence more sensitive. In Phase I POC demonstrated the feasibility of SIGNMOS by physics-based modeling and demonstration of a low-bandwidth prototype. In Phase II POC plans to fabricate a fully operational 40 Gbps photoreceiver and demonstrate it with communication input from a 1.55-micrometer laser modulated at 40 Gbps.