P-polarizer with large z-axis refractive index difference
Assignee3M Innovative Properties Company
InventorsAndrew T. Ruff, James M. Jonza, Timothy J. Hebrink, Laurence R. Gilbert
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Abstract
A multilayer optical polarizing film has optical layers whose refractive indices substantially match along orthogonal in-plane x- and y-axes, and that mismatch along a z-axis by at least 0.1 and in some cases by at least 0.15. The film has substantially no reflection bands at normal incidence, and for obliquely incident light has at least one reflection band, for p-polarized light only, that monotonically increases and that shifts to shorter wavelengths as the incidence angle increases.
Claims15
A polarizing film, comprising alternating layers of at least a first and second material, the alternating layers defining a coordinate system with mutually orthogonal x- and y-axes extending parallel to the layers and with a z-axis orthogonal to the x- and y-axes, the alternating layers having a refractive index difference along the x- and y-axes of no more than 0.02, the alternating layers also having a refractive index difference along the z-axis of at least 0.1, wherein a repeat unit in the film comprising a first alternating layer of the first material and a second alternating layer of the second material has a sum of an optical thickness of the first alternating layer and an optical thickness of the second alternating layer of 200 nm to 350 nm.
A polarizing film comprising at least one repeat unit, wherein the repeat unit comprises a first alternating layer of at least a first material and a second alternating layer of at least a second material, wherein the alternating layers define a coordinate system with mutually orthogonal x- and y- axes extending parallel to the layers and a z-axis orthogonal to the x- and y-axes, the alternating layers having:
- (1) a refractive index difference along the z-axis of 0.1 or greater,
- (2) a refractive index difference along the x-axis of up to 0.02, and
- (3) a refractive index difference along the y-axis of up to 0.02;
- and
- wherein a repeat unit in the film has a sum of an optical thickness of the first alternating layer and an optical thickness of the second alternating layer of 200 nm to 350 nm.
Dependencies are inferred from the claim text.