Photodetector working

P-type semiconductor region on the light receiving side and an N-type semiconductor region on the substrate side (see Fig. 1). P-layer and N-layer, so-called because it has no mobile carriers.

Avalanche photodiodes are photodiodes with structure optimized for operating with high reverse bias, approaching the reverse breakdown voltage. This allows each photo-generated carrier to be multiplied by avalanche breakdown, resulting in internal gain within the photodiode , . Nonlinearity: The RF-output is limited by the nonlinearity of the photodetector .

Sometimes it is also called as photo-detector , a light detector, and photo-sensor.

These diodes are particularly designed to work in reverse bias condition, it means that the P-side of the photodiode is associated with the negative .

It consists of built-in lenses, optical filters, and has small or large surface areas. The junction uses an illumination window with an anti-reflect coating. AP Technologies are the UK representatives for Adaptive Lighting, AUREA Technology, Fibotec, Fox Group, IMM Photonics, LDX Optronics, Lumex, Opto Diode Corporation, Oxxius, QD Laser, SensL Technologies, Sensor Electronic Technology and Vertilon. Operating under reverse bias they use avalanche breakdown to give gain.

A look at how various photodetector characteristics affect optical measurements. The construction and working of photodiode is almost similar to the normal p-n junction diode. PIN (p-type, intrinsic and n-type) structure is mostly used for constructing the photodiode instead of p-n (p-type and n-type) junction structure because PIN structure provide fast response time. PIN photodiodes are mostly used in . The PIN diode comprises of three regions, namely P-region, I -region and N-region. The intrinsic region in the diode is in . Photodetection in semiconductors works on the general principle of the creation of electron-hole pairs under the action of light.

The FET input op-amp prevents the loading of the photodiode and the voltage at the output is proportional to the current in the photodiode. So long as the photodiode response to the light is linear, the output voltage is proportional to the light falling on the photodiode. In general, the higher the reverse voltage, the higher the gain. A quick description of the basics fundamentals of photodetectors. Photodetectors are sensors which absorps light and convert it in electric current.

Semiconductor photodiodes are made of silicon, germanium, GaAs, InGaAs, etc. The detector is electrically reverse-biased. In contrary, LEDs and Lasers are forward-biased to emit light).