WAVELENGTH PLATE AND OPTICAL DEVICE

摘要

A wavelength plate, wherein first birefringent layer and second birefringent layer are laminated such that in-plane directions of optical axes of first birefringent layer and second birefringent layer cross each other, wherein the wavelength plate satisfies formulae (1), (2), (3), and (4), and wherein at least one of first birefringent layer and second birefringent layer is obliquely-deposited birefringent layer formed by oblique deposition,;Δn1×t1=λ/2  (1);1.7≦(Δn1×t1)/(Δn2×t2)≦2.7  (2);5°≦θ1≦30°  (3);(2θ1+35°)≦θ2≦(2θ1+50°)  (4)where Δn1 represents birefringence of first birefringent layer, Δn2 represents birefringence of second birefringent layer, t1 represents a film thickness of first birefringent layer, t2 represents a film thickness of second birefringent layer, θ1 represents angle between optical axis of first birefringent layer and incident linearly polarized light, θ2 represents angle between optical axis of second birefringent layer and incident linearly polarized light, and λ represents a predetermined value in a range of wavelengths of incident light.

主权项

1. A wavelength plate, comprising:
a first birefringent layer; and a second birefringent layer, the first birefringent layer and the second birefringent layer being laminated such that an in-plane direction of an optical axis of the first birefringent layer and an in-plane direction of an optical axis of the second birefringent layer cross each other, wherein the wavelength plate satisfies formulae (1), (2), (3), and (4) below, and wherein at least one birefringent layer of the first birefringent layer and the second birefringent layer is an obliquely-deposited birefringent layer formed by oblique deposition,
Δn1×t1=λ/2  (1)1.7≦(Δn1×t1)/(Δn2×t2)≦2.7  (2)5°≦θ1≦30°  (3)(2θ1+35°)≦θ2≦(2θ1+50°)  (4) where Δn1 represents birefringence of the first birefringent layer, Δn2 represents birefringence of the second birefringent layer, t1 represents a film thickness of the first birefringent layer, t2 represents a film thickness of the second birefringent layer, θ1 represents an angle between the optical axis of the first birefringent layer and incident linearly polarized light, θ2 represents an angle between the optical axis of the second birefringent layer and incident linearly polarized light, and λ represents a predetermined value in a range of wavelengths of incident light.