# Wave-partical duality and Huygens–Fresnel principle

1. Jun 28, 2010

Hi all!

Couple days ago my friend asked me about the following. He said:
[PLAIN]http://img685.imageshack.us/img685/2886/dualism.png[/CENTER] [Broken]

I have explained it to him in this way. The meaning of the quantum theory of light is NOT that we consider the light as being a gas of particles with energy $$\hbar \omega$$ and momentum $$\hbar \mathbf{k}$$, but rather that an exchange of energy and momentum between light and matter is done by small pieces -- quanta. In this particular problem we calculate the propagation of the light as it was a wave (Huygens–Fresnel principle in rigorous Kirchhoff formulation allows us to do this almost preсisely), but when the light reaches the point P, we interpret the intension of the light as the probability of finding a photon at this point.

Am I right?

Thanks.​

Last edited by a moderator: May 4, 2017
2. Jun 29, 2010