Patent ID: 6204957
Filing Date: 2001-03-20
Classification: G02F

Abstract:
A second harmonic wave-generating element for generating a second harmonic wave from a fundamental wave, comprising an optical waveguide layer made of first epitaxial material having a fundamental composition of K.sub.3 Li.sub.2-X (Nb.sub.1-Y Ta.sub.Y).sub.5+X O.sub.15+Z, an underclad part made of second epitaxial material having a fundamental composition of K.sub.3 Li.sub.2-X+A (Nb.sub.-Y-B Ta.sub.Y+B).sub.5+X-A O.sub.15+Z, an overclad part made of third epitaxial material having a fundamental composition of K.sub.3 Li.sub.2-X+C (Nb.sub.1-Y-D Ta.sub.Y+D).sub.5+X-C O.sub.15+Z and formed on and contacting the optical waveguide layer, wherein X=0.006 to 0.5, Y=0.00 to 0.05, A=0.006 to 0.12, B=0.005 to 0.5, C=0.006 to 0.12, D=0.005 to 0.5, X-A.gtoreq.0, X-C.gtoreq.0, .vertline.A-C.vertline..ltoreq.0.006, and .vertline.B-D.vertline..ltoreq.0.005).