| 摘要 |
PROBLEM TO BE SOLVED: To provide diffraction grating and a manufacturing method therefor capable of reducing reflected light, improving production efficiency and manufacturing the diffraction grating simply and at a low cost, and to provide an optical pickup which has the diffraction grating and can standby output information of a record carrier. SOLUTION: This manufacturing method for diffraction grating for diffracting light of a wavelength λ with a wavelength entering vertically to a resin substrate 1 comprise: a first process of providing photopolymer layers 2, 3 closely adhering to the surfaces 1a, 1b of the resin substrate 1, a second process of forming projecting and recessed patterns rectangular in section extending in one direction along the surfaces 1a, 1b by stampers 4, 5 on the surfaces 1a, 1b of the photopolymer layers 2, 3, and a third process of hardening the photopolymer layers 2, 3. In this method, the composition and film thickness of the photopolymer layers 2, 3 provided in the first process are set so as to satisfy the relation 2nd=λ/2 where (d) is the film thickness and the (n) is the index of refraction of the projecting parts 2a, 3a of the hardened photopolymer layers 2, 3. |
