摘要 |
An optical waveguide mode transformer has a substrate supporting a high refractive index core layer surrounded by lower refractive index cladding. The core layer includes a wide input waveguide section to accept a multimode, including a fundamental mode, light input. The input waveguide section is coupled to a narrow output waveguide section by a tapered region having a taper length enabling adiabatic transfer of the fundamental mode of the multimode light from the wide input waveguide section to the output waveguide section while suppressing(stripping) other modes of the multimode light input. The narrow output waveguide section supports a single mode light output comprising said fundamental mode. The core layer is contoured to include a localized upstanding ridge intermediate opposite lateral sides of the core layer. The output waveguide section includes a portion having a real index step between the core layer and cladding layers, and advantageously is functional to output a light beam having similar vertical and horizontal divergences.
|