LIGHT WAVELENGTH CONVERTER AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED : To provide a light wavelength converter which is improved in efficiency of optical coupling with a laser ray source so as to reduce the energy loss to the irreducible minimum. SOLUTION : A core layer 12 added with rare-earth elements represented by lanthanum series is laminated on a substrate 13 having a lower refractive index than the core layer 12 through a thin film deposition technique, such as a sputtering process, a CVD (chemical vapor deposition) process, an evaporation process or the like. A substrate 14 of the same material with the substrate 13 is laminated on the core layer 12 for the formation of the laminate. The laminate is cut out as wide as prescribed and subjected to lapping. Furthermore, substrates 15 and 16 are bonded to the cut surfaces of the laminate so as to form an optical waveguide having a structure composed of the core layer 12 and the clad layers (substrates 13 to 16) covering the core layer 12. Furthermore, optical film mirrors M1 and M2 are formed on the end faces of the optical waveguide, respectively.