| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive reflecting optical device in which the fluctuation of optical performance can be made small, and reflection characteristics can be made satisfactory by constituting a reflecting surface by using a fine lattice structure having pitches smaller than wavelength to be used by a prescribed rate. SOLUTION: A reflection fine lattice structure 3 is provided on the surface of a plane glass substrate 2 in a plane mirror 1. In this reflection fine lattice structure 3, fine metallic layer islands 4 are one-dimensionally or two- dimensionally arranged on the surface of the plane glass substrate 2 with pitches p so that reflectivity can be made uniform. Also, the size (s) of the metallic layer island 4 within the plane is made sufficiently smaller than wavelength to be used. Also, an interval (p) between the metallic layer islands 4 is made sufficiently smaller than the wavelength. In this case, at the time of using a laser beam whose wavelength is 0.63μm radiated from an He/Ne laser, it is desired that the size (s) and pitch (p) of the metallic layer island 4 is smaller than the wavelength by a prescribed rate, for example, it is almost 1/100-1/10 or 0.005μm-0.1μm.
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