The effects of Lorentz-violating operators of nonrenormalizable dimension in
optical resonate cavities are studied. Optical-frequency experiments are shown
to provide sensitivity to nondispersive nonbirefringent violations that is many
orders of magnitude beyond current constraints from microwave cavities.
Existing experiments based on Fabry-Perot and ring resonators are considered as
illustrations.Comment: 9 pages, REVTe