Photodetector

Photomultiplier (side view)

CCD

Photodiode

Phototransistor

Photoresistor

As a photodetector, and the light sensor or optical detector, photoelectric sensor, electronic components are called to convert light of the photoelectric effect, using an electrical signal, or a point dependent on the incident radiation, electrical resistance. The term also means applications are called that have integrated such a radiation- measuring device. The term light refers in optoelectronics not only to visible light but also to invisible infrared light and ultraviolet radiation.

An optoelectronic sensor can signal gathering be: (for example exposure meters) or integrated into an imaging measurement method in which the light- receptive surface in individual areas (pixels) is divided, so that - produce an electrical image - in interplay with a lens and a camera electronics leaves. Developments already underway in the direction of complex Sehapparate for robotics and medical applications.

Photodetectors that use the outer photoelectric effect, inter alia:

• Photocells
• Photomultiplier (fast, lowest light levels down to single photons)
• Microchannel plate photomultiplier (same principle as in the photomultiplier, but with even better time resolution )

Photodetectors that use the internal photoelectric effect, among other things:

• CMOS sensors (eg digital cameras and video cameras)
• CCD sensors (eg digital cameras and video cameras, scanners, spectrometers, fax machines )
• Photodiodes ( faster than visible light sensor and the infrared and ultraviolet, usually made ​​of silicon, but also other semiconductor materials )

• Pin photodiodes ( inter alia, at the end of fiber optic cables and a receiver in remote control )
• Avalanche photodiodes (for very low light intensities up to individual photons, like PIN photodiodes, but with internal amplification by the avalanche effect )
• Position Sensitive Device (PSD, position-sensitive large-area PIN photodiode)
• MSM photodiodes ( metal - metal Semikonduktor - photodiodes, in principle composed of two Schottky diodes)

• Phototransistors (typically made ​​of silicon, higher signal than photodiodes, however, slower than)
• Photoresistor (slow, inter alia, for measuring light, twilight switches, light meter )