The illustrative embodiment of the invention is a surface waveguide having
low modal birefringence. The surface waveguide has a composite guiding
region that is sandwiched by a lower cladding layer and an upper cladding
layer, wherein the cladding layers serve to confine propagating light to
the composite guiding region. In accordance with the illustrative
embodiment, the composite guiding region is structured so that it
exhibits a balanced stress configuration, wherein the stress in the
direction that aligns with the T.sub.E polarization mode is substantially
equal to the stress in the direction that aligns with the T.sub.M
polarization mode. The balanced stress configuration results in a surface
waveguide that exhibits very low modal birefringence.