title: Perturbed open resonators.
abstract: The resonant frequencies and diffraction losses of two-mirror open resonators which depart somewhat from an ideal configuration are evaluated by a perturbative technique. Detailed results are derived and discussed for flat mirrors of rectangular or circular aperture with a parabolic phase perturbation as well as flat-roof and conical systems with large apex angle.
authors.forename: S R
authors.initials: SR
authors.lastname: Barone