Dichroic optical waveguides and lasers

The transverse structure of modes in optical waveguides and resonators filled with dichroic media is investigated. Two families of Hermite-Gaussian modes, corresponding to two orthogonal polarizations of radiation, are found for transversely one-dimensional field distributions and for approximating the characteristics of the medium by quadratic functions of the transverse coordinate. Angular selectivity is displayed by extraordinary waves and is manifested in a decrease in the increment of the mode upon an increase in the mode number. With account of the absence of deformation in the lowest mode due to selection, this implies that resonators containing dichroic media (including photon crystals) are promising for reducing the angular divergence of laser beams.