| 摘要 |
PURPOSE:To reduce the number of parts to be used and to miniaturize apparatuses to be assembled in an optical demultiplexer/multiplexer, by putting rod lenses mounted with optical fibers on the inclined surfaces of a pentagonal prism with interference film filters between the lenses and optical fibers and providing a filter and total reflection mirror at the base of the prism. CONSTITUTION:Of quadruple light rays having wavelengths lambda1-lambda4 which are inputted from an optical fiber 25 and become parallel light rays after passing through a rod lens 28, the light having the wavelength lambda1 is reflected by an interference film filter 29 and outputted to an optical fiber 26. The light of the wavelength lambda2 of the remaining light rays is reflected by a filter 40 and outputted to an optical fiber 30. Moreover, the light having the wavelength lambda3 out of the light rays passing through the filter 40 is reflected by a filter 37 and outputted to an optical fiber 32 and the light of the wavelength lambda4 is reflected by a total reflection mirror 38 and outputted to an optical fiber 33. The transmittance of the interference film filter is 90% and the remaining undesirable light rays are filtrated by filters 27b, 35, and 36a. Therefore, the number of constituting parts and points at which optical axis adjustment is made are reduced and, as a result, the number of assembling processes is reduced and apparatuses to be assembled in this optical demultiplexer/multiplexer can be miniaturized. |
