| 摘要 |
PURPOSE: To produce an optical waveguide which is less deformed and exhibits a good polarization characteristic by removing the upper part of an upper clad layer, which part has a large fluctuation width in refractive index, thereby molding the upper clad layer to have an adequate thickness. CONSTITUTION: The upper clad layer 31 is subjected to etching to remove the upper part thereof. The upper clad layer 31 is molded to have an adequate thickness corresponding to silicon, which is a substrate material, and the quartz glass formed on a substrate. As a result, the fluctuation width in refractive index along the thickness direction of the upper clad layer 31 is sufficiently lowered. Namely, the silicon wafer 1 is cut and divided into chips and thereafter, the chips are immersed into an HF-NH4 F soln. to carry out the wet etching of the quartz glass layer, i.e., waveguide layer, on the chip. As a result, the upper clad layer 31 on the chip is removed over the entire surface and the upper part thereof and the layer thickness is made to be about 30μm. |
