(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I'm taking an introduction course in optics and I came across this exercise which I can't find how to solve:

"Two light pulses with different wave lengths 500 and 600 nm is sent in to a 1 km long fiber.

n(610 nm) = 1.399, n(600 nm) = 1.400, n(510 nm) = 1.448, n(500) = 1.45.

When will the two pulses come out of the fiber relative to each other?"

(Hopefully the translation is OK..)

2. Relevant equations

I suspect that I might need to use group velocity (http://en.wikipedia.org/wiki/Group_velocity), but this has not been taught in the class so far, so perhaps there is an easier way to tackle the problem??

3. The attempt at a solution

Nothing that has ended up embarrassingly wrong... :/

Thanks in advance!

BR

/Manu

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Velocity in fiber optics cable

**Physics Forums | Science Articles, Homework Help, Discussion**