| 摘要 |
PURPOSE:To form partial polarization inversion regions to prevent the generation of an optical damage or a fluctuation in the refractive index in optical waveguides by partially heating the heat absorbing film on a substrate to a Curie point or above, then lowering the temp. of the film to room temp. to generate a polarization inversion. CONSTITUTION:The heat absorbing film 2 or the pattern part of the heat absorb ing film is provided on the substrate consisting of a ferroelectric material in at least the range where the partial polarization inversion regions 4 are to be formed. This substrate is heated up to the temp. right below the Curie point and further, the regions of the heat absorbing film 2 of the range where the partial polarization inversion regions 4 are to be formed, i.e., the partial heating regions 3, are heated partially to the Curie point or above; thereafter, the temp. of the substrate 1 is lowered. Since the ferroelectric material has a pyroelectric effect, the regions partially heated by a laser beam at the time of the temp. fall are subjected to the polrization inversion. The partial polarization inversion regions 4 which do not exert adverse influence are formed as the optical waveguides if the heat absorbing film 2 is removed and washed by suitable treating liquids. |
