A method of and apparatus for creating a second order non-linearity profile
along a waveguide. The method comprises: thermally poling a waveguide
structure to generate a second order non-linearity; placing a mask
adjacent to the waveguide structure; and exposing the waveguide structure
with UV light through the mask to selectively erase the second order
non-linearity along the waveguide structure. The mask may be an amplitude
mask or phase mask. In a preferred embodiment an amplitude mask is used in
combination with an incoherent UV light source to produce selective
erasure of a thermally poled second order non-linearity. Apparatus for
carrying out this method and devices based on waveguide structure
fabricated using the method are also described.
