| 摘要 |
PROBLEM TO BE SOLVED: To contrive miniaturization and low cost of an optical demultiplexer by arranging an arbitrary fiber and the center line of the rows of photodetector arrays corresponding to this fiber, each at an equal distance against the optical axis of a collimator lens and a concave mirror-shaped diffraction grating, and thereby combining the use of the diffraction grating with the collimator lens for two inputs or more. SOLUTION: This optical demultiplexer is such that k lines of inputting optical fibers 1 and a k-row/n-column planar photodetector array 4, which has the same number of rows as that of the optical fiber as well as the number of columns corresponding to the n channels of demultiplex number, are arranged each on the front focal surface of a collimator lens 2. Then, a diffraction grating 3 is arranged on the rear focal surface. In addition, the first optical fiber 11 and its corresponding rows 41 of the photodetector array, and also, the k-th optical fiber 12 and its corresponding rows 42 of the photodetector array are disposed each at an axially symmetrical position against the optical axis 21 of the collimator lens. |
