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US 7,255,914 B2Granted
Variable refractive index polymer materials
AssigneeCase Western Reserve University
InventorsJames S Shirk, Eric Baer, P. Anne Hiltner
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Abstract
A new class of composite polymer films where the refractive index can be varied by simple compressive or extensive forces. The films are comprised of alternating layers of an elastomer and a glassy polymer or two different elastomers. When the layer spacing is much less than the wavelength of the probe light, these materials behave as effective medium composites. The layer thickness of the elastomer component and thus the effective index of the composite can be varied by compression, tension or shear.
Claims20
A multilayer structure comprising,
- a plurality of at least two alternating layers A and B represented by formula (AB)x, where x=2n, and n is in the range of from 4 to 15;
- wherein layer A is comprised of component (a) and layer B is comprised of component (b);
- said alternating layers are comprised of different polymers exhibiting differences in the index of refraction and in the elastic moduli;
- wherein said differences in the index of refraction are between 0.05 and 4 units;
- wherein the layer thickness of said layer A and B are less than one quarter of the wavelength of interest;
- wherein said multilayer polymer structure behaves as an effective medium and wherein said structure exhibits a single refractive index;
- wherein said effective medium polymeric materials are transparent;
- and
- wherein the refractive index of said multilayered structure effective medium material can be varied by tensile, compressive or shear force.
6 more elements
Dependencies are inferred from the claim text.