Novel electrically controlled rapidly wavelength selective photodetection using MSMs

A novel electrically controlled tunable metal-semiconductor-metal (MSM) photodetector is introduced and experimentally demonstrated with 2.5-ns wavelength-switching access time on a GaAs chip for switching between two wavelengths. This detector has a demonstrated 20.1-dB ON/OFF contrast ratio between the selected and the rejected wavelength and can resolve 179-GHz spaced wavelength-division multiplexing channels. In addition, device wavelength switching is achieved with a differential input voltage swing of /spl plusmn/1.65 V. This low bias voltage makes it compatible with complementary metal-oxide semiconductor (CMOS) control electronics for rapid switching.