| 摘要 |
PURPOSE:To make the length of optical path shorter, to make the size smaller and to realize lower loss, by disposing spherical lenses and a thin optical sheet relatively. CONSTITUTION:When light (solid line arrow) is inputted from a terminal A, the light is made into parallel rays with a spherical lens 4A. Part thereof is reflected by a thin optical sheet 5 for branching to a terminal B side, and the remaining part transmits through a terminal C and is thus branched. The respective rays are outputted from an optical fiber 1 through spherical lenses 4B, 4C. Conversely, when the light is inputted from terminals B and C, the rays are coupled to the terminal A in the route opposite to the above-mentioned route. The input light (dotted line arrow) from the terminal C is branched to the terminals A, D by the effect similar to the above-mentioned effect, and conversely, the input light from the terminals A and D is coupled to the terminal C, thus the device is a bidirectional optical branching and coupling filter in terms of function. The optical branching and coupling filter of variaous branching ratios is realized by changing the branching ratio of the sheet 5. |
