Photolithographically fabricated silicon photonic crystal nanocavity photoreceiver with laterally integrated p-i-n diode

We fabricated a SiO₂-clad all-silicon high-Q integration of p-i-n diode with photonic crystal nanocavity to demonstrate channel selective photoreceiver operation at a speed of 0.1 Gbs^-1 for telecom wavelength light. This SiO₂-clad device is photolithographically fabricated with a fabrication method compatible with that used for a complementary metal-oxide semiconductor, and the structure allows future mass production. The dark current is as small as 37.6 pA, which is possible because of the all-silicon structure clad with SiO₂. As a result of the low noise, the minimum detectable optical power is -20 dBm, while the footprint of this integrated device is a very small 50 μm². The characteristics of this device may allow us to use it as a compact monitoring device for optical networks.