"Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. A photo detector has a p--n junction that converts light photons into current. The absorbed photons make electron--hole pairs in the depletion region. Photodiodes and photo transistors are a few examples of photo detectors. They are the forerunners of any new frontier in optoelectronics. When an unusual spectral range or a new frequency band is explored, firstly photodetectors establish a tool for handling the optical signal, then optical components and laser sources follow"-- Provided by publisher.
Includes bibliographical references and index.