| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive diffractive optical device with high accuracy which has an excellent structure with respect to the manufacture, which can significantly reduce reflection on the grating face and which can maintain high diffraction efficiency, and to provide an optical appliance having the above diffractive optical device. SOLUTION: The diffractive optical device has a first diffractive optical part 2 having a phase type diffraction grating 6 and a second diffractive optical part 3 having a phase type diffraction grating 7 made of a different material from that of the first diffraction optical part 2, and the surface of the second diffractive optical part 3 has a structure of minute recesses and projections which is smaller than the wavelength to be used. |
