| 摘要 |
PROBLEM TO BE SOLVED: To provide a diffraction grating and a wavelength multiplexer/demultiplexer which have light converging characteristics and small light loss and can be made small-sized, and a wavelength multiplex signal optical transmission module which uses them. SOLUTION: A diffraction grating 5 comprises a plurality of grating grooves 10 formed on a cylindrical surface, and each grating 10 is in an arcuate shape and the centers of arcs are positioned in array on the circumferential surface of the cylinder in the circumferential direction. Consequently, the same light converging characteristic with a concave diffraction grating which has the same radius of curvature and the same grating constant can be obtained. Thus, the diffraction grating and the wavelength multiplexer/demultplexer which have the light converging characteristics and small light loss and can be made small-sized, and the wavelength multiplex signal optical transmission modules using them can be obtained. COPYRIGHT: (C)2004,JPO |
