| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical waveguide device in which a polarization dependent loss is reduced by controlling the generation of strain in a core area. SOLUTION: In a method for manufacturing the optical waveguide device, an under clad layer 2 and a core layer 3 are deposited on a quarts substrate 1 and further a cap layer 4 whose refractive index is equal to that of the under clad layer 2 is deposited on the core layer 3 successively under the same value of high frequency power by the use of a plasma CVD(chemical vapor deposition) device. After the core area is formed, an over clad layer 5 is deposited on the quartz substrate 1 in which the core area is formed. When the over clad layer 5 is deposited, an output value of high frequency power is gradually raised from the output value of high frequency in the deposition of the under clad layer 2 or the like. Thus, since the core area is encircled by a silicon oxide film having about the same density, strain is not exerted on the core area. Then, the generation of strain in the core area is controlled and the polarization dependent loss is reduced. |
