| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical demultiplexer for use in narrow-band wavelength multiplex optical communication, which has a high dispersive power of a diffraction grating and copes with change of intervals of converging/image-forming positions and has a high precision and is efficient. SOLUTION: Incident light 11 from an optical fiber 10 is converted to light of parallel rays 12 by a collimator lens 2 and demultiplexed in accordance with wavelengths by a diffraction grating 3 and arrives at the collimator lens 2 again and is converted to convergent light 14 and converged on a photo acceptance element array. Because the converging/image-forming positions of respective channels are arranged at irregular pitches in accordance with wavelengths, signals of the channels can be accurately and efficiently taken out from photo acceptance elements respectively by providing the photo acceptance elements in the converging/image-forming positions respectively. COPYRIGHT: (C)2004,JPO |
