| 摘要 |
PURPOSE:To easily and effectively prevent the generation of the light damage of an optical waveguide even when strong light of a relatively short wavelength is made incident. CONSTITUTION:A Peltier element 22 is driven and the element 10 itself is maintained more specifically in a temp. range from 50 to 300 deg.C, more preferably a temp. range from 80 to 150 deg.. The incident light on an incident end 16 from another optical element, such as optical fiber, not shown in Fig., is branched in this state through the inside of the optical waveguide 14 and is introduced from exit ends 18, 20 into another optical elements, such as optical fibers. The element 10 itself is heated to a prescribed temp. at this time and, therefore, the generation of the light damage in the optical waveguide 14 is effectively prevented. |
