An optical mode transformer. The optical mode transformer features a low
index core, a high index core having a first tapered region, with the high
index core embedded within the low index core and with the low index core
serving as a cladding for a waveguide defined by the high index core
embedded in the low index core, and a cladding layer surrounding the low
index core, with the cladding layer including one or more materials with
different refractive indices than those of the low index core and high
index core.
