Optical detectors

Photosensors or photodetectors are sensors of light or other electromagnetic energy. The absorbed photons make electron–hole pairs in the depletion region. An optical smoke alarm (also called photo- electric smoke alarm) works using the light scatter principle.

Photodiodes are designed to detect photons and can be used in circuits to sense light. Phototransistors are photodiodes with some internal amplification.

Note: Reverse current flows through the photodiode when it is sensing light.

Photon detectors may be further subdivided according to the physical effect that produces the detector response.

Some important classes of photon detectors are listed below. The incoming light produces free electrons which can carry electrical current so that the electrical . Consultant, formerly with Honeywell Technology Center. Many photonics applications require the use of optical radiation detectors. Examples are optical radar, monitoring of laser power levels for materials processing, and laser metrology. It does this by generating an electrical current proportional to the intensity of incident optical radiation.

They convert optical signals back into electrical impulses that are used by the receiving end of the fiber optic data, video, or audio link. Detectors perform the opposite function of light emitters. The most common detector is the semiconductor photodiode, which produces current in response to incident light. In this paper, I will review the subjects of optical detectors and optical receivers. I will focus, at times, on the lessons learned while performing my own research and development activities, and on how and . The field of optical detectors is old but nevertheless rapidly developing.

The main drivers for investigation of new optical detectors are the success of semiconductor technology and new applications, which de- mand better properties, lower price, and often miniaturization. Looking for Optical detectors ? Find out information about Optical detectors. Devices that respond to incident ultraviolet, visible, or infrared electromagnetic radiation by giving rise to an output signal, usually electrical. Explanation of Optical detectors.

Analyze the basics characteristics and the principles used in optical sensors. Cryogenic radiometry, initially developed at NPL, is now widely . The signal increases when smoke enters the chamber and light is . Our nanosecond free space optical detectors are ideal for use as general- purpose photodetectors. With Q-switched or cw lasers, their large diameter and DC response makes alignment easy. High speed optical detectors use special photodiodes with high speed electronic circuits to convert fast optical pulses to electrical signals for measurement.

These products are offered in hermetic packages for high reliability and exposure to harsh environmental conditions. The optical hybrids are designed and .