Ultrashort Optical Pulses

1. Sep 22, 2012

johnroberts

If an ultrashort optical pulse has a complex wavefunction with central frequency corresponding to a wavelength = 585 nm and a Gaussian envelope of RMS width of 6 femtoseconds, how can I calculate how many optical cycles are contained in the pulse width?

2. Relevant equations

3. The attempt at a solution
Not too sure where to begin. I don't understand how a width can be measured in seconds. If it had been provided as a length, I would assume that one needs to simply divide that length by two times the wavelength to get the amount of cycles.

2. Sep 22, 2012

voko

When you say of something "in two minutes drive from here", you refer to a distance in terms of time.

3. Sep 22, 2012

johnroberts

So then I suppose I can multiply it by the speed of light to get a distance, and then divide accordingly to get the answer?

4. Sep 22, 2012

voko

That sounds right. The only issue is that with this sort of duration one cannot really talk of a particular frequency, but I guess that's what the problem wants you to neglect.

5. Sep 22, 2012

johnroberts

Sounds good. Thanks for the help.