InGaAsP photodiodes

InGaAsP photodiodes are finding wide applications in long wavelength fiber-optical communication systems. Particular requirements that these detectors must satisfy include low capacitance, high speed, and low noise capabilities. High-purity InGaAsP materials are necessary to meet these requirements. Low-noise detectors also require low reverse dark current. For avalanche diode applications, the electron and hole impact ionization coefficients are important parameters. In this paper we review recent work including LPE growth of high-purity InP and InGaAs, studies of the tunneling component of the dark current, and measurements of the impact ionization coefficients and excess noise factor in InGaAsP photodiodes.