Register to reply

How does a photo detector detect?

by einstein2603
Tags: detect, photo
Share this thread:
einstein2603
#1
Apr16-06, 05:30 AM
P: n/a
Please guys I really need your help.

How does a photo detector detect? Can you also tell me where you got the info from.

thanks

einstein2603
Phys.Org News Partner Science news on Phys.org
'Office life' of bacteria may be their weak spot
Lunar explorers will walk at higher speeds than thought
Philips introduces BlueTouch, PulseRelief control for pain relief
Hootenanny
#2
Apr16-06, 05:41 AM
Emeritus
Sci Advisor
PF Gold
Hootenanny's Avatar
P: 9,772
Hello again einstein,

All 'photodetectors' operate using the photoelectric effect (or variants of). Basically, the photoelectric effect can be explained using quantum physics. Have you heard of the wave-particle duality of light? The photoelectric effect was the first source of firm evidence for the particle nature of light. Basically, light can be considered as a massless particle called the photon which has an energy of [itex]E = hf[/itex]. This site is very useful and should have all the information you need. If you have any questions, you can post them here

http://hyperphysics.phy-astr.gsu.edu...on.html#quacon

Regards,
~Hoot
andrevdh
#3
Apr16-06, 12:28 PM
HW Helper
P: 1,471
Basically the photons causes the material that it falls on to become conductive - electrons (or their counterparts - holes) are generated (freed) from their bound states and become part of the sea of free charges that can flow in the material - that is the charge carriers are raised to a higher energy level by absorbing the energy from the photon. This increase in conductivity is sensed as an increase in current through the detector by a circuit connected to it. See for instance http://en.wikipedia.org/wiki/Photodiode


Register to reply

Related Discussions
Limit below which we cannot detect light? General Physics 12
Photo-Source (OLED)& Photo-sensor (pTFT).. Introductory Physics Homework 1
How exactly will LHC detect superpartners? High Energy, Nuclear, Particle Physics 4
Is it possible to remotely detect a nuclear weapon? High Energy, Nuclear, Particle Physics 7
Detect planets through mag field? Astronomy & Astrophysics 2