Types of optical detectors

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 . Photosensors or photodetectors are sensors of light or other electromagnetic energy.

The absorbed photons make electron–hole pairs in the depletion region.

Application of these optical sensors ranges from computers to motion detectors.

For optical sensors to work effectively, they must be the correct type for the application, so that they maintain their sensitivity to the property they measure.

Optical sensors are integral parts of many common devices, including computers, copy . For decades, optical sensors have been finding their way into an increasing number of applications. Photodetectors were used in camera light meters, street lights and traffic counters. 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.

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. There are various types of detectors with respect to the detecting wavelength. Photo tube and photo multiplier tubes . The optical detector converts the incoming optical signal into an electrical signal.

The type of other circuitry contained within the receiver depends on what type of modulation is used and the receiver electrical output requirements . An optical smoke alarm (also called photo- electric smoke alarm) works using the light scatter principle. Poisson Noise in most situations. Counts = photons detected within aperture or resolution. A thin layer of metal or heavily doped polycrystalline attached to an electrode forms the . Tungsten, Deuterium, Mercury, Hollow Cathode Lamp. Optical absorption across the bandgap eye or video camera light.

Optical Source specifically suited to FO systems are: ➢ Light Emitting Diode (SLE ELE SLD). Optical detectors constitute the broadest class of radiation detectors. In an optical detector radiant energy in the optical range is converted into other forms of energy.

The four important parameters characterizing the properties and capabilities of various types of optical detectors follow. The threshold sensitivity is the .