| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical transmission device provided with an optical planar waveguide provided with transmission characteristics independent of a temperature without using a temperature control device for preventing the shift of the center frequency of the waveguide and the optical transmission device by passive control to the thermal effect of the planar optical waveguide. SOLUTION: A substrate 16 supports a base material 13 and an optical core part 14, a control material 22 is adhered to the lower part of the substrate and the thermal expansion coefficients of the control material 22 and the substrate 16 are different. Corresponding to the rise and decline of an ambient temperature, the control material 22 is thermally expanded and contracted by a rate different from the substrate 16, non-planar substrate distortion transmitted to the optical core part 14 is generated and thus, the temperature dependency of an optical path length inside the optical core part 14 is opposed. In this case, the control material 22 is provided with the thermal expansion coefficient larger than the one of the substrate 16, compression force to the optical core part 14 is generated and the thermal expansion of the optical core part 14 is opposed. |
