Abstract

Periodic poling of LiNbO₃ to achieve quasi-phase matching for non-linear frequency conversion has generated a great deal of interest due to the fact that it allows the use of a large non-linear coefficient and eliminates walk-off effects. Combining such material with a waveguide geometry to increase average pump intensities is a promising route to the realisation of various compact non-linear devices based on harmonic¹ or parametric² generation. Here we present the first fabrication of a PPLN planar waveguide by direct bonding. This technique, which has previously been used to fabricate laser waveguides³, is based on the precision polishing of bulk material to waveguide dimensions. Hence the full non-linearity of the bulk PPLN should be maintained while offering versatility in the fabrication of exotic waveguide structures.

© 1998 IEEE