Reflection of a Gaussian light beam from the surface of a corrugated waveguide

The results are reported of an investigation of the anomalies in the spectral and angular dependences of the reflection of light from the surface of a corrugated waveguide at nearnormal angles of incidence allowing for the interaction of waveguide modes traveling in opposite directions and for the finite dimensions of the incident beam. Practical applications of corrugated waveguides as narrow-band frequency filters and selector devices in laser resonators are considered.