Light-induced optical waveguide uptapers

Abstract

Permanent uptapers have been produced in a UV-cured epoxy by a self-induced waveguide, created by exposure to cw 532-nm light. The photorefractive effect in this material produces high-quality, low-loss waveguides, which adiabatically taper to give spot sizes of as much as 50 μm diameter. The waveguides can be used at 1550 nm to form low-cost beam expanders with separations of a few millimeters.