Reflection bistable etalons with absorbed transmission

A reflection bistable etalon with absorbed transmission (BEAT), based on a thermal/refractive optical nonlinearity, has been experimentally demonstrated. In such a device the dominant absorption is placed outside the optical cavity, thus permitting independent optimisation of finesse, optical absorption and cavity length. Considerable reduction in switch powers, when compared to the current generation of bistable nonlinear interference filters, should consequently be possible. The demonstration BEAT device operated near 833 nm wavelength with a critical switch power of less than 4 mW. © 1986.