Light velocity....

[androz]

Hi,

There is a question that I can't figure out.

What's the difference between signal and group velocity for a light pulse ?

What I understood so far is that the signal velocity is the velocity of the first detectable photon and the groupe velocity is the velocity of the pulse peak.

Am I right ????

[Gonzolo]

There are definitions here :

http://www.uni-koeln.de/~abb11/workshop/announce4.html

Group velocity is what it has always been : domega/dk. Signal velocity seems to be a little more delicate to define.