Photodiode (Receiver)

A photodiode is a specialized semiconductor component designed to detect and convert incident light photons into proportional electrical current through the photoelectric effect. In transceiver modules, it serves as the optical receiver that captures modulated light signals from optical fibers and transforms them into electrical signals for further processing by communication systems. These devices operate in reverse bias mode to achieve fast response times and high sensitivity across specific wavelength ranges.

Operates on the photoelectric effect where incident light photons with sufficient energy create electron-hole pairs in the semiconductor's depletion region. Under reverse bias voltage, these charge carriers are swept across the junction, generating a photocurrent proportional to the light intensity. The PIN (p-i-n) structure is commonly used for optimal performance in communication applications.