Abstract

The rigorous coupled-wave approach has been applied to characterize dielectric waveguide structures containing a spatially periodic modulation in the permittivity. When one of the waves diffracted by the periodic structure is close to one of the allowed modes of the waveguide, so-called guided-mode resonances occur. Under these conditions, efficient energy exchange among the external propagating waves can take place over small ranges in the physical parameters involved, for example, in wavelength, grating thickness, or angle of incidence. Since the resonances do not occur at the same parametric locations for TE and TM polarized input waves, these structures can function as polarizers by effectively reflecting one polarization state and transmitting the other. In this paper, planar and surface-relief types of waveguide grating structures are analyzed and their effectiveness for polarization separation is evaluated.

© 1992 Optical Society of America