High-power Dual-fed Traveling Wave Photodetector Circuits in Silicon Photonics

We demonstrate multiple-stage dual-illuminated traveling wave photodetectors in silicon photonics for high-power and high-speed applications. Dual-illumination of each photodetector doubles the optical channels, boosting DC and RF power handling capability. Traveling wave architecture ensures large bandwidths. Using the silicon photonics process, these photodetector circuits achieve a DC saturation current of 112 mA with a 3-dB bandwidth of 40 GHz at 0.3 mA. Peak continuous-wave RF power is generated up to 12.3 dBm at 2 GHz and 5.3 dBm at 40 GHz. High speed broadband data signals are detected with eye amplitudes of 2.2 V and 1.3 V at 10 Gb/s and 40 Gb/s, respectively. A theoretical analysis is presented for design tradeoffs of the multiple-stage photodetector circuits based on the bandwidth and power requirements.