Patent attributes
A laminated wave plate of the present invention includes a first wave plate having a phase difference of Γ1 and a second wave plate having a phase difference of Γ2 with respect to a wavelength λ, the first wave plate and the second wave plate being bonded together so that an optical axis of the first wave plate and an optical axis of the second wave plate intersect each other to function as a quarter-wave plate as a whole, the laminated wave plate comprising following equations from (1) to (6): Γ1=360×(n1+1) . . . (1); Γ2=90×(2×n2+1 . . . (2); ΔΓ1=(Γ12a−Γ11a)/(λ12−λ11) . . . (3); ΔΓ2=(Γ12b−Γ11b)/(λ12−λ11) . . . (4); cos 2θ1=1−(1−cos ΔΓ2)/{2×(1−cos Δθ1)}. . . (5); and θ2=45°±5°. . . (6), wherein θ1 is an optic axis orientation of the first wave plate, θ2 is an optic axis orientation of the second wave plate, and each of λ11≦λ≦λ12, n1, and n2 is a natural number starting from 1.
