High-Performance III-V Photodetectors on Silicon for Integrated Optical Receivers

The demand for higher bandwidth in aerospace and military communications calls for innovative approaches to improve the performance and efficiency of optical receivers.ĀHistorically, GaAs or InGaAs PIN photodiodes have been used in short-distance multimode fiber links; however, their limitations in terms of speed and sensitivity have become bottlenecks for achieving data rates beyond 10 Gbps. Alternative devices such as avalanche photodiodes (APDs) or uni-traveling carrier detectors (UTCs) are now being explored to circumvent these limitations.Ā Beyond photodetector device structures, achieving faster data rates also introduces challenges with regard to packaging complexity and assembly tolerances in order to mitigate parasitic losses between optical and electronic components. For example, wire-bonds, interconnects, and other passive elements introduce signal degradation as frequencies increase. Therefore, an ideal solution for next generation receivers is integration of III-V photodiodes directly with CMOS ICs.Ā Such architectures can simultaneously optimize electro-optic performance, eliminate parasitics, increase mechanical robustness, and minimize size and cost. This proposal demonstrates a path toward fully integrated receiver modules compatible with wafer scalable CMOS manufacturing.