| The short answer is yes. Aside from tiny losses like tunnelling, scattering from vacuum excitations and thermally-generated fields, etc., a perfect optical cavity will store light indefinitely. No laser required, only light of the appropriate wavelength and phase. The combination of Fabry-Perot cavities and power-recycling in the optics of the LIGO gravitational wave observatory "gains" a ~100 W laser up to a few megawatts. If a cavity is formed in free space, like LIGO, then careful attention to vacuum is required to prevent loss. ULE clock reference cavities have quality factors that are much higher, and need no vacuum, as the light propagates entirely within a glass substrate. Edit: I should add that the "tiny losses" mentioned at the outset are precisely what prevent you from making a "perfect cavity". As the quality of a cavity/oscillator increases, the number and deviousness of loss mechanisms does too. This is especially the case at frequencies that are low compared to those at which an experimenter can iterate. For HN, consider building a host that can run uninterrupted for 10^12 seconds (30,000 years). |