Patent ID: 7973998
Filing Date: 2011-07-05
Classification: G02B,G02F

Abstract:
1. A multilayer dielectric optical structure, for selectively reflecting a predetermined wavelength, comprising: a transparent substrate; a plurality of alternating first layers and second layers on the substrate, wherein the first layers comprise a first optical material having a first optical axis and a first refractive index along the first optical axis, and wherein the second layers comprise a second optical material having a second optical axis and a second refractive index along the second optical axis below a characteristic transition temperature (Tc) and a third refractive index above the Tc, wherein the second optical material includes a liquid crystal material having an isotropic-to-ordered state transition temperature between 15 and 35 degrees Celsius, wherein the first and second optical axes are substantially parallel and the first and second refractive indices are substantially equal, and wherein the third refractive index differs from the second refractive index and from the first refractive index; and wherein the optical thickness of each of the first layers is equal to ¼ times the predetermined wavelength and the optical thickness of each of the second layers is equal to ¼ times the predetermined wavelength when the temperature is above the Tc.