Resonant-cavity enhanced (RCE) separate absorption and multiplication (SAM) avalanche photodetector (APD)

We report a highly-efficient and wavelength-selective separate absorption and multiplication (SAM) avalanche photodiode (APD) with a thin (500 /spl Aring/) absorbing layer. The improved characteristics of the photodetector were obtained by placing the absorption and multiplication layers in a Fabry-Perot cavity. An external quantum efficiency of 77% was achieved with a spectral linewidth of less than 4 nm and an avalanche gain of more than 50. Noise measurements indicate that the impact ionization coefficient for electrons is larger than that for holes.