| 摘要 |
PURPOSE: To provide an optical filter, which eliminates all of stray light penetrating a single mode integrated optical waveguide, and its implementation method. CONSTITUTION: The optical filter consists of an optical single mode, and the mode is supported by a substrate 2, and at least one curve part and two light absorbing materials 8 and 10 are provided along a face parallel with a substrare surface 3. The radius of the curve part is so set that the loss in the curve is so small that it can be ignored with respect to the first light mode and is very large with respect to the second stray light mode, and two light absorbing materials are arranged on both sides of the curve part of a micro waveguide in a specific plane, and side faces of absorbing materials are formed like teeth so that absorbed stray light cannot penetrate the micro waveguide again. |
