1. Jun 8, 2010

blorpinbloo

1. The problem statement, all variables and given/known data
Electric field for a single pulse of a laser (operating at central wavelength of 800nm):
Code (Text):

E = E0e^(-(t^2/2a^2))e^(iwt)
(the a is sigma and w is omega)

Derive an expression for the spectral intensity (irradiance)

3. The attempt at a solution
One way I know to calculate irradiance is the time average of the poynting vector: (1/u0)*ExB
But that would involve taking the time average of e^(-(t^2)) which is non-integrable.

I've also seen the function E integrated over an area, then squared to give an irradiance formula, but then again I run into problems with that function that's difficult to integrate. Any suggestions?