1.3µm Operation of GexSi1-x/Si strained-layer superlattice avalanche photodetectors

Avalanche photodetectors are key components in the implementation of high bit-rate optical fiber communications. GaInAs and Ge avalanche photodiodes considered for optical communications systems operating near 1.3 m suffer from an excess noise factor near the theoretical maximum. At the other extreme, Si avalanche photodetectors (APDs) have an excess noise factor near the absolute minimum. Unfortunately, the optical response of Si APDs is limited to shorter wavelengths, far below 1.3-1.5pm optimum spectral region for optical fiber transmission.