We present hybrid silicon evanescent photodetectors that utilize silicon waveguides and offset AlGaInAs quantum
wells. The light in the hybrid waveguide is absorbed by the AlGaInAs quantum wells under reverse bias. The first demonstrated photodetector had an internal quantum efficiency of >90 % over the 1.5 μm wavelength regime. This detector structure has the same structure as silicon evanescent lasers and amplifiers leading to easy integration for power monitors and preamplified receivers. A pre-amplified receiver implementing a hybrid silicon evanescent amplifier and a hybrid silicon evanescent waveguide photodetector is also presented in this paper. The integrated device operates at 1550 nm with a responsivity of 5.7 A/W and a receiver sensitivity of -17.5 dBm at 2.5 Gb/s.