A Monolithic Integrated Waveguide Photodetector.

An InGaAs photodetector for detection in the 1.0micron-1.5micron wavelength range has been integrated at the end of and above a ridge waveguide in InP. The waveguides were in n-:InP/n+:InP and had an average propagation loss of 3 dB/cm at 1.15microns. The reflection losses were 3 dB and the coupling loss was 2 dB. The photodetector was an InGaAs photoconductor lattice matched to InP and exhibited a bias dependent optical gain of up to 2.5 with a unity gain quantum efficiency of 49% at 1.15microns. The speed of the photoconductor was found to be bias dependent varying from 10 ns to 150 ns rise/fall times.