摘要 |
An optical device includes a core sandwiched between two clads. The core includes a planar waveguide layer with ridges protruding into one of the clads, forming a ridge waveguide structure that guides the propagation of light in the core. The core dimensions satisfy the following conditions: the ridge width is less than the total core height; the ridge height is less than the ridge width; the thickness of the planar waveguide layer is equal to or less than one-fourth of the total core height. Dimensions satisfying these conditions can be selected to provide polarization independent operation. The ridges may be arranged to define a pair of optical waveguides forming a Mach-Zehnder interferometer, an optical wavelength filter, or various other optical devices. |