| 摘要 |
PURPOSE:To obtain an optical multiplexer and demultiplexer which facilitates an assembly adjustment and is sized small by arranging plural hemisperic lenses on two planes of optical glass bulk linearly in contact so that their centers face each other, and forming interference filters at the contacting parts. CONSTITUTION:When light beams lambda1-lambdan from hemispheric lenses 5 having no interference film filter 3 interposed are incident, the incident light lambda1 among the lambda1-lambdan is transmitted through the 1st interference film filters 3-1 of the hemispheric lens 5 on the opposite surface on the same axial line with the hemispheric lens 5. Other light beams lambda2-lambdan are reflected by the interference film filter 3-1 to reach the 2nd interference film filter 3-2, where the lambda2 is transmitted whereas other light beams lambda3-lambdan are reflected by the interference film filter 3-3 to reach the 3rd interference filter 3-3. Then, the lambda3 is transmitted through the interference filter 3-3, and thus the incident light beams lambda1-lambdan are demultiplexed successively. They are multiplexed in the opposite order of the demultiplexing. The angle theta of incident to the interference film filter 3-1 is determined by the thickness (t) of the optical glass bulk and the radius R of the hemispheric lenses 5 and theta=tan<-4>R/t. |
