Data analysis of the FSR/TSM measruement last week.
1. FSR was measured with "the golden arches" technique.
FSR = 263.0686 MHz +/- 900Hz
Lcav = 1.1396 m --> 7.6 mm too long! (nominal 1.132m)
2. Transverse mode spacings for the vertical and horizontal modes were measured.
TMS/FSR = 0.219366 (V) / 0.220230 (H) (Predicted value with the current cavity length 0.2196/0.2202 very close!)
We want to make this to be ~0.219 (~3% less)
With the current parameters, the 19th-order lower sideband make the coincident resonance.