Integrated optical silicon photodiode array

Abstract

We consider device design, fabrication, and operation of integrated optical photodiode arrays in which p-i-n junction photodiodes are formed in silicon. A SiO₂ layer on silicon serves as the effective substrate for a KPR waveguide. Light is coupled from the waveguide at the detector region either through the evanescent field or by multiple refraction into the detector. The waveguide–photodiode structure is designed so that nearly 100% of the incident optical energy can be absorbed in the photodiode junction depletion region. A device quantum efficiency of 80% is measured compared to a theoretical value of 93%.