Exploring the Coherence Length and Repeat Length in Wave Packets

[zarrin77]

It says on my homework that:
"A wave packet is like a periodic function with a repeat length of _______."

I am confused by "repeat length" because I understand a wave packet to NOT repeat anywhere. It has a spread x but the peaks are all different heights, so I do not really understand what they are asking?

Your suggestions are very appreciated =)

 

[RedX]

If you really believe what you say and have no fear, put this:

"A wave packet is like a periodic function with a repeat length of infinity."

That sentence is very audacious!

The safe answer would probably go something like, "assuming the coherence length to be sufficiently long, the repeat length is the mean wavelength in the spread" (at least I think that's right - someone do correct me if I'm wrong!).