| 摘要 |
PURPOSE:To make a thin film waveguide having the refractive index higher than the refractive index of a substrate usable as an element for an optical circuit having the functions of optical synthesis, demultiplexing and deflection by forming said waveguide on both surfaces of the substrate. CONSTITUTION:A substrate 11 is ultrasonically cleaned and is then dried in ethanol vapor. Titanium films 13 are deposited on both surfaces of the substrate 11 by a vapor deposition method with an electron beam. The films are subjected to thermal diffusion; thereafter, the substrate 11 is moved into another furnace and is cooled slowly down to a room temp. Thin film waveguides 12 having the refractive index higher by about 0.01 than the refractive index of the substrate 11 are formed by such treatment. The luminous flux L consisting of a laser beam or the like is made incident to the waveguide 12a through an incident prism 14 and is emitted from an exit prism 16. If AC electric power is supplied to a comb-shaped electrode 15 in this stage, a surface acoustic wave is excited in the waveguide 12a and the flux L under propagation in the waveguide 12a is deflected by a Bragg diffraction. The photoswitching element which can change the deflection angle of the flux L when the frequency of the AC current is changed is realized. |
