A TAPERED RIB WAVEGUIDE

摘要

A tapered rib waveguide tapering from a large, multi-mode optical waveguide to a smaller, single-mode optical waveguide, the tapered rib waveguide comprising two portions (4, 5) formed of the same material: a lower portion (4) which tapers laterally from the large waveguide to the smaller waveguide and an upper portion (5) formed on the lower portion (4), which tapers to a point (or other form of termination), the dimensions of the two portions (4, 5) being such that substantially all of a fundamental mode propagated in the large multi-mode waveguide is coupled to the smaller, single-mode waveguide.