|
The guiding characteristics of a grating waveguide is presented
for the general case of oblique incidence. The formulation of
the three-dimensional boundary-value problem is carried out
rigorously, taking into account the hybrid nature of the guided
modes. First of all, the TE and TM modes in each constituent
region of the waveguide structures are investigated. Secondly,
the TE and TM modes are coupled by the surfaces of the grating,
resulting in new physical effect of extra stop bands. Numerical
results are obtained extensively to illustrate the new physical
effect, and to evaluate the effect of grating profiles.
|