Would someone be kind enough to please give physical meanings to these two terms? I have never fully understood their meaning and difference (although I know how to express them mathematically).(adsbygoogle = window.adsbygoogle || []).push({});

If, say, I have a Gaussian-shaped signal in the frequency domain that I am sending through a medium (such as a crystal) in the direction z say and I want to specify where the maximum intensity is as a function of t (it is at z=0 when t=0), am I right in saying that I would use:

t= z/(group velocity)

where the group velocity is obviously evaluated at the frequency of largest intensity.

Any help on this fairly basic matter would be much appreciated.

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# Phase velocity, Group velocity

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