Abstract

This article highlights recent developments in high-speed photodiodes and their role in efficient data transmission. Design considerations and state-of-the-art performances are presented for waveguide-integrated and vertically illuminated photodiodes. PIN, Uni-traveling carrier (UTC), and avalanche photodiodes (APD) are reviewed in terms of sensitivity and 3-dB bandwidth. Further, a metric for a proper comparison of avalanche photodiodes is proposed. Current performance limitations are described and an outlook for the photodiode material platforms is given.