Diffractional losses in corner reflectors

We present the analysis of fundamental losses of optical power in dielectrical corner reflectors, which are now planned to replace spherical mirrors in the next generation of large-scale Earth-based gravitational wave detectors. The mechanism of losses is diffractional scattering of light beam used in Fabry-Perot resonator on the edge of corner reflector. We show that Goos-Haenchen shift of totally reflected light beam significantly increases the value of losses. Diffractional losses set the lower limit for the resonator Q-factor that can be achieved if all other sources of energy dissipation are excluded