| 摘要 |
PURPOSE:To obtain an optical waveguide of good productivity by providing a phase matching film on the surface of an optical crystal plate of which refractive index dcreases gradually from the front surface of the rear surface. CONSTITUTION:A YIG singla crystal 1 is formed by an epitaxial growth method on a GGG substrate, and such an element which increases the refractive index of the single crystal 1 is diffused in the surface thereof, so that the refractive index is lowered gradually in its thickness direction. A phase matching film 2 consiting of 3-ply construction of SiO2-SiH-SiO2 is provided on the surface. The light beam made incident to the crystal plate 1 is reflected by the film 2 as shown by a broken line, and in the optical crystal plate 1, it is bent to a curved shape and advances. In the film 2, the phase deviation of P and S polarization components does not occur. In the plate 1, the light beam advances in a curved shape and therefore, the phase difference of the polarization components does not occur. Thereby, the optical waveguide of good productivity is obtained. |
