| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive method for manufacturing an optical waveguide in which generation of voids is securely prevented, the degree of freedom for selecting materials and dopants to be used is made greater and moreover the loss of signal light is reduced by removing residual internal stresses in respective film forming layers. SOLUTION: For example, glass to which dopant is not added is accumulated by forming a core and a clad layer by a flame deposition method and applying heating/pressurizing treatment. Residual internal stresses in the core and an upper clad layer are removed and moreover voids are closed by applying heating/pressurizing treatment even if the voids are generated because glass does not penetrate into the recessed part or the like. Thus, usable kind of materials for the core and the upper clad layer and dopant is increased and the degree of freedom for selection is improved. |
