| 摘要 |
PURPOSE:To adjust the stress birefringence value of an optical waveguide by denaturing the surface of a substrate nearby a core part by laser light irradiation as to a circuit formed by arranging a clad layer and a single-mode optical waveguide, which is embedded therein and provides optical propagating operation, on the substrate. CONSTITUTION:The silicon substrate l is irradiated with the laser beam 24 from a YAG laser light source 23 along the ring-shaped optical waveguide 2 and the denaturing of the irradiated part of the silicon substrate l progresses. For the purpose, while an XY moving table 22 is moved, the irradiation with the laser beam 24 is carried on to form a denatured area 11. At the same time, tunable DFB semiconductor laser light is guided in a sample 21 as diagnostic light from an input fiber 3b and the resonance wavelength characteristic of signal light which is guided out of an output fiber 4b is monitored; and the irradiation with the beam 24 is stopped when the resonance peaks of TE polarized light and TM polarized light are completely put over lapped, and then the polarization dependency of a ring resonator can completely be removed to enable easy polarization characteristic control. |
