All-silicon sub-Gb/s telecom detector with low dark current and high quantum efficiency on chip

TL;DR

This paper presents a silicon-based telecom photodetector with high quantum efficiency and extremely low dark current, leveraging high-Q photonic crystal nanocavities and two-photon absorption for efficient operation at sub-Gb/s speeds.

Contribution

The work introduces a fully silicon integrated telecom detector with high-Q nanocavities achieving low dark current and enhanced quantum efficiency at low input power.

Findings

Dark current measured at only 15 pA

Quantum efficiency reaches about 10% at low power

Photo-current enhancement exceeds 100,000 times

Abstract

We demonstrate channel selective 0.1-Gb/s photo-receiver operation at telecom wavelength using a silicon high-Q photonic crystal nanocavity with a laterally integrated p-i-n diode. Due to the good crystal property of silicon the measured dark current is only 15 pA. The linear and nonlinear characteristics are investigated in detail, in which we found that the photo-current is enhanced of more than 100,000 due to the ultrahigh-Q (>100,000). With the help of two-photon absorption, which is visible at a surprisingly low input power of 10 nW, the quantum efficiency of this device reaches about 10%.