| 摘要 |
PROBLEM TO BE SOLVED: To provide a diffraction grating having high diffractive efficiency over a wide wavelength band in a resonance region and suitable also for manufacturing a replica. SOLUTION: The diffraction grating has a sine wave shaped groove sectional shape and its groove bottom part is specified to have a flat shape. In a wavelength region from the near-infrared band over the infrared band where a groove period and a wavelength are nearly equal to each other, the diffraction grating functions as a grating having spectroscopic performance more excellent (highly efficient with good balance in a wide wavelength band) than that of conventional holographic grating and a conventional echellette grating and when the replica is manufactured, since the force generated when the grooves are engaged with each other is weak because the aspect ratio of the groove is low and a releasing agent is satisfactorily spread to the groove bottom because the groove bottom is large, a defect, such as groove faulting is hardly generated at the time of parting. COPYRIGHT: (C)2004,JPO&NCIPI
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