An optical coupling arrangement has a first transition region having a plurality
of first segmented waveguides and a plurality of transverse segments of alternating
indices of refraction with at least some of the transverse segments traversing
the first segmented waveguides. The first segmented waveguides are formed by core
segments in some of the transverse segments. The arrangement may also have a second
transition region having a plurality of second segmented waveguides each aligned
with a respective one of the first segmented waveguides. The arrangement is manufactured
with a high production yield and is used in an optical coupling device for combining/splitting
optical signals to reduce the insertion loss. The optical coupling device is also
used in other devices such as Mach-Zehnder devices and arrayed waveguide grating demultiplexers/multiplexers.
