| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical wavelength plate of fine cyclic structure having a desired phase difference. SOLUTION: A dielectric substrate 1 having a refractive index n<SB>1</SB>is coated with an amorphous dielectric medium 2 having a refractive index n<SB>2</SB>larger than the refractive index n<SB>1</SB>, and a rectangular grating 3 is formed on the amorphous dielectric medium 2 by etching. When microcrystal is formed on the amorphous dielectric medium 2 by heat treatment to increase the refractive index n<SB>2</SB>, the magnitudeΔn of structural double refraction becomes large, so that the phase differenceΔΦof a rugged grating pattern by the rectangular grating 3 becomes large without increasing the groove depth D of the rectangular grating 3. COPYRIGHT: (C)2005,JPO&NCIPI |
