| 摘要 |
PURPOSE:To reduce the influence of a modal noise, and to reduce the size of an optical demultiplexer and to facilitate its assembly by branching one input optical line to at least >=3 optical lines, and making them confluent to lines less than the optical lines. CONSTITUTION:For example, a fiber type optical demultiplexer 1D uses 3 optical fibers 11-13; and 1 terminal of the optical fiber 12 and 1 terminal of the optical fiber 13 are welded to the intermediate part of the optical fiber 11 to constitute a demultiplexing part, and the other terminal of the optical fiber 12 is welded to the intermediate part of the optical fiber 13 to constitute a multiplexing part. Further, 1 terminal of the optical fiber 11 is connected to an optical fiber 2A, the other terminal of the optical fiber 11 is connected to an optical fiber 3A, and the other terminal of the optical fiber 13 is connected to an optical fiber 4A. Then, light incident from one optical fiber 2A to the optical demultiplexer 1D is demultiplexed temporarily into three directions, and then light beams in 2 directions are mae confluent in consideration of a combination which improves the balance of light power, thus demultiplexing the light into 2 directions eventually while reducing the influence of a modal noise. |
