| 摘要 |
PURPOSE:To efficiently perform transmitting and reflecting operation by forming a multilayered film filter including only a core layer or part of buffer layers and covering the periphery with the buffer layer and a clad layer which have low refractive indexes. CONSTITUTION:Many films which include only the section of the core layer 13 or the sections of the buffer layers 11 and 12 and differ in refractive index are formed on a substrate 10 in the middle of the light propagation direction of the waveguide consisting of the buffer layers 11 and 12, core layer 13, and clad layer 14, thus forming the multilayered film 15. The constitution of the films of this multilayered filter 15 is different among a low-pass filter type, a band-pass filter type, a band-rejection type, and a high-pass type filter, but any type of multilayered film filter 15 is surrounded with a 1st buffer layer 11 and clad layer 14. Consequently, the waveguide type optical fiber which has low loss and desired filter characteristics is obtained. |
