Understanding the Single Photon in Double Slit Experiments

Click For Summary

Discussion Overview

The discussion revolves around the concept of single photons in the context of double slit experiments, exploring how single photons are defined, methods for generating them, and the implications for experimental setups. The scope includes theoretical and experimental aspects of quantum mechanics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions how a single photon is defined and what methods exist to fire them controllably.
  • Another participant asserts that a "tick" in a detector, such as a photomultiplier tube, indicates the detection of a single photon.
  • There is a request for clarification on whether there is a known method to fire a single photon from a source.
  • A participant confirms that single photons can indeed be fired and that this is how double slit experiments are conducted.
  • One suggested method for achieving single photon emission involves using a dim light source with neutral density filters to reduce the photon rate.
  • A later reply mentions that there are established schemes for producing single photons on demand, providing a link to a resource for further information.

Areas of Agreement / Disagreement

Participants express differing views on the methods for generating single photons, with some asserting that it is possible while others seek clarification on the mechanisms involved. The discussion remains unresolved regarding the specifics of photon generation techniques.

Contextual Notes

Limitations include potential assumptions about the definitions of photons and the effectiveness of various methods for generating single photons, which are not fully explored in the discussion.

Phymath
Messages
183
Reaction score
0
when performing a double slit experiment using photons it is said that if you fire individual photons that over time as more photons are fired the interference pattern starts to appear. My question is how do they define a single photon? what is the method that they can fire one photon at a time controllably so? how do they define a photon?
 
Physics news on Phys.org
One "tick" in their detector (a photomultiplier tube or something) is a single photon. That's what particle *are*. They are things that come into your detector and go "tick!"
 
so just to clarify there is no known way to fire a single photon from a source?
 
Yes, they can fire single photons. That is how they do the experiments you are talking about.
 
Easiest way is to get a dim light source and then put neutral density filters (welding mask glass is good) in front of it until you are only getting a few photons / sec. You can confirm this by pointing the detector direcly at the source without any sllits.
You can of course add more filters to reduce the rate until you are convinced there is only one photon in the system at once.
 
Phymath said:
so just to clarify there is no known way to fire a single photon from a source?

There are already many schemes that produce single photon on demand. See, for example

http://physics.nist.gov/Divisions/Div844/facilities/cprad/PhotonSource.htm

Zz.
 
Last edited by a moderator:

Similar threads

  • · Replies 15 ·
Replies
15
Views
1K
  • · Replies 3 ·
Replies
3
Views
967
  • · Replies 33 ·
2
Replies
33
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 36 ·
2
Replies
36
Views
9K
  • · Replies 32 ·
2
Replies
32
Views
4K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 20 ·
Replies
20
Views
2K