| 摘要 |
PURPOSE:To efficiently branch the rays of different wavelength bands and to increase the multiplicity by installing a multiplex interference film filter before diffraction with a diffraction grating, and branching waves at every wavelength band. CONSTITUTION:If optical fibers 10-20 arrayed in accordance with the number of wavelengths and a transmission optical fiber 1 are placed on the focal plane of a lens, the rays of different wavelengths lambda11-lambda20 propagating in the fiber 1 are emitted from the fiber 1, after which they are made into parallel rays by a lens 2, and these parallel rays are made incident to a multiplex interference film filter 3. The wavelengths lambda11-lambda15 and lambda16-lambda20 are in different wavelength bands, and if the filter 3 which allows the transmission of the rays of the wavelengths lambda11-lambda15 and reflects the rays of the wavelengths lambda16-lambda20 is selected, the rays of the wavelengths lambda11-lambda15 transmit through the filter 3 and are made incident to a reflection type diffraction grating 4. Thereby, the rays of different wavelength bands are branched efficiently and the multiplicity is increased. |
