Amplifier-Free Bias-Free Receiver Based on Low-Capacitance Nanophotodetector

The substantial energy dissipation of photoreceivers will obstruct dense photonic-electronic integration in keeping the development of processors and communications on a chip. Nanophotodetectors offer the opportunity to overcome this problem by allowing us to realize an amplifier-free bias-free receiver. Low device capacitance and forward-biased operation are the keys to achieving such a receiver, which can operate with signal light alone, namely without extra electrical energy. A photonic-crystal waveguide combined with an embedded absorber is a good candidate for this purpose, since our simulation reveals that light confinement and carrier depletion in a narrow dimension lead to fast and efficient operation. We also carry out circuit analyses to investigate the receiver performance and compare it with that of a conventional receiver with amplifiers. We show that an amplifier-free bias-free receiver can be expected to offer advantages in terms of energy consumption, signal-to-noise ratio, footprint, and delay.