| 摘要 |
PURPOSE:To decrease the loss in a light guide by projecting a CO2 laser beam to a light guide film from the opposite face thereof and scanning the same to form two pairs of paired parallel grooves, then forming the part sandwiched by these parallel grooves as the light guide. CONSTITUTION:The CO2 laser beam 18 is projected onto the light guide film 13 which is a work on a silicon substrate 11 from the opposite surface thereof. Then, the laser beam 18 transmits the substrate 11 and is absorbed in the film 13 to heat the laser-irradiated part locally to a high temp. The film 13 in the laser-irradiated part is then selectively etched by an etching soln. 14 having thermal reactivity. The paired parallel grooves 21, 22 are then worked by scanning of the laser beam 18, by which the part sandwiched by the grooves 21, 22 is formed as the light guide 23. The side faces of the formed light guide are worked to smooth surfaces if the scanning by the laser beam 18 is continuously executed in this case. The decrease of the loss in the light guide is thereby permitted. |
