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

We demonstrate channel selective 0.1-Gb/s photoreceiver 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 photocurrent is enhanced of more than 10(5) due to the ultrahigh-Q (Q similar or equal to 10(5)). With the help of two-photon absorption, which is visible at a surprisingly low input power of 10(-8) W, the quantum efficiency of this device reaches similar to 10%. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3357427]