# Homework Help: Resonance frequency of confocal resonator

1. Apr 4, 2012

### semc

1. The problem statement, all variables and given/known data
A symmetrical confocal resonator has a length d=30cm, and the medium has refractive index n=1. Determine the frequency spacing $\nu$F and the displacement frequency ($\Delta\varsigma$/$\pi$)$\nu$F. Determine all the resonance frequencies that lie within the band 5*1014$\pm$2*109Hz. $\Delta\varsigma$= $\varsigma$(z1)-$\varsigma$(z2) where z1 and z2 are the position of the mirrors

2. Relevant equations
$\nu$F=c/2d

3. The attempt at a solution
I can only find the resonance frequency. How can I get the phase shift $\Delta\varsigma$ from the length of the resonator?