## Some relations for cavities

### Cavity Enhancement with absorption losses input coupler and absorption losses in the cavity

The enhancement U is calculated by

U=(1-IC-AIC)/(1-sqrt(R^N*IC*T))^2

(All parameters are related to the power and not to the field)

### Cavity finesse with absorption losses in the cavity

The finesse F is calculated by

F=pi*sqrt(sqrt(R^N*IC*T))/(1-sqrt(R^N*IC*T))

(All parameters are related to the power and not to the field)

### Mode jumping of a doubling cavity (410 nm -> 205 nm)