Coupled contradirectional mode equations are derived that describe Hermite-Gaussian beam interactions in corrugated thin-film waveguides when the grating teeth are curved and/or tilted. Coupling coefficients are evaluated for identical and hybrid modes. The problem of focusing a guided Gaussian beam reflection from a curved grating is discussed. It is shown that the grating curvature should serve to match the phase fronts of the contradirectional Gaussians and the grating should extend axially to include the region where the two beam widths are approximately equal.
|Number of pages||8|
|Journal||Journal of the Optical Society of America|
|State||Published - 1979|