| 摘要 |
PURPOSE:To permit change of an optical path with a large angle by adhering silicone tightly to another material having smaller temp. coefft. of refractive index than silicone, and changing at least the temp. of the silicone with a temp. changing means. CONSTITUTION:When a heater 15 is ON, silicone rubber 14 is heated and a large difference of refractive index is generated between waveguides 12, 13. In this case, the area heated by the heater 15 is so wide as compared to the area of the silicone rubber 14 that a part of the waveguides 12, 13 is also included in the heated area, but the change of the refractive index of the waveguides 12, 13 are negligible as compared to the change of the refractive index of the silicone rubber 14. Therefore, almost all of the light l11 is reflected totally at the boundary face of the waveguide 12 and the silicone rubber 14 even if the light is incident with a small angle of incidence, and proceeds as light l13 through the waveguide 13. By this method, the optical path is changed with a large angle. |
