Optical filter materials and devices

Abstract

A method of aligning a chiral nematic liquid crystal, the method comprising depositing a first chiral nematic liquid crystal onto a first substrate, positioning a second substrate on top of the liquid crystal to form an initial layer structure and then applying rolling pressure to at least one of the substrates of the initial layer structure to create a final layer structure in which the first chiral nematic liquid crystal is aligned with a helical axis substantially perpendicular to a local plane of the first substrate. Aspects of the invention provide optical filter materials for laser protection applications, LED emission filtering and lighting, augmented reality display coatings.

1 - 20 . (canceled) 
     
     
         21 . A device comprising:
 a display screen providing a window that is transparent to visible light; and   a reflective filter providing one or more reflectivity peaks centered around one or more selected wavelengths corresponding to light from a projector, wherein the reflective filter at least partially overlaps the display screen, wherein the display screen and the reflective filter are configured to reflect the light from the projector at the one or more selected wavelengths to an eye of a user to provide one or more images to eye of the user at the one or more selected wavelengths that appear overlaid over a physical scene viewed through the display screen, wherein the reflective filter comprises:
 one or more chiral nematic liquid crystal photopolymerized layers having helical axes fixed perpendicular to a plane of the display screen. 
   
     
     
         22 . The device of  claim 21 , wherein the reflective filter is disposed on a first side of the display screen, wherein the device further comprises:
 an additional reflective filter disposed on a second side of the display screen opposite the first side and aligned with the reflective filter, wherein the additional reflective filter provides at least one of the one or more reflectivity peaks of the reflective filter.   
     
     
         23 . The device of  claim 21 , wherein at least one of the one or more selected wavelengths is within at least one of a red spectral region, a green spectral region, or a blue spectral region. 
     
     
         24 . The device of  claim 21 , wherein the one or more selected wavelengths comprise at least one of 658 nanometers, 550 nanometers, or 450 nm. 
     
     
         25 . The device of  claim 21 , wherein the one or more chiral nematic liquid crystal photopolymerized layers comprise a single chiral nematic liquid crystal photopolymerized layer, wherein the one or more reflectivity peaks comprise a single reflectivity peak. 
     
     
         26 . The device of  claim 21 , wherein the one or more chiral nematic liquid crystal photopolymerized layers comprise two or more chiral nematic liquid crystal photopolymerized layer, wherein at least one of the two or more chiral nematic liquid crystal photopolymerized layers is left-handed, wherein at least one of the two or more chiral nematic liquid crystal photopolymerized layers is right-handed, wherein the one or more reflectivity peaks comprise a single reflectivity peak. 
     
     
         27 . The device of  claim 21 , wherein the one or more chiral nematic liquid crystal photopolymerized layers comprise two or more chiral nematic liquid crystal photopolymerized layer, wherein the one or more reflectivity peaks comprise two or more reflectivity peaks, each centered around a different one of the one or more selected wavelengths. 
     
     
         28 . The device of  claim 21 , wherein the one or more reflectivity peaks comprise a first reflectivity peak, a second reflectivity peak, and a third reflectivity peak, wherein the one or more chiral nematic liquid crystal photopolymerized layers comprise:
 a first set of one or more chiral nematic liquid crystal photopolymerized layers providing the first reflectivity peak centered around a first selected wavelength of the one or more selected wavelengths;   a second set of one or more chiral nematic liquid crystal photopolymerized layers providing the second reflectivity peak centered around a second selected wavelength of the one or more selected wavelengths; and   a third set of one or more chiral nematic liquid crystal photopolymerized layers providing the third reflectivity peak centered around a third selected wavelength of the one or more selected wavelengths.   
     
     
         29 . The device of  claim 28 , wherein the first selected wavelength is in a red spectral region, wherein the second selected wavelength is in a green spectral region, wherein the third selected wavelength is in a blue spectral region. 
     
     
         30 . The device of  claim 28 , wherein the first selected wavelength is 658 nanometers, wherein the second selected wavelength is 550 nanometers, wherein the third selected wavelength is 450 nanometers. 
     
     
         31 . The device of  claim 21 , wherein the display screen and the reflective filter are configured to be worn by the user as a head mounted system. 
     
     
         32 . The device of  claim 21 , wherein the reflective filter is formed by the steps of:
 depositing a first chiral nematic liquid crystal onto a first substrate, wherein the first chiral nematic liquid crystal contains photopolymerizable moieties, wherein a concentration of the photopolymerizable moieties in the first chiral nematic liquid crystal is selected to fix an orientation of a helical axis of the first chiral nematic liquid crystal when photopolymerized;   positioning a second substrate on top of the first chiral nematic liquid crystal to form an initial layer structure;   applying uniform pressure to at least one of the first substrate or the second substrate of the initial layer structure to create a final layer structure in which the first chiral nematic liquid crystal is uniformly aligned with a helical axis perpendicular to a plane of the first substrate; and   subjecting the final layer structure to at least one of UV or visible light to produce a solid first photopolymerized liquid crystal layer with the helical axis fixed perpendicular to the plane of the first substrate.   
     
     
         33 . The device of  claim 32 , wherein the reflective filter is further formed by the steps of:
 removing one of the first substrate or the second substrate, wherein a remaining one of the first or the second substrate disposed on the first photopolymerized liquid crystal layer is a remaining substrate;   depositing a second chiral nematic liquid crystal onto the first photopolymerized liquid crystal layer;   positioning an additional substrate on top of the second chiral nematic liquid crystal to form the initial layer structure; and   applying uniform pressure to at least one of the remaining substrate or the additional substrate of the initial layer structure to create the final layer structure in which the second chiral nematic liquid crystal is uniformly aligned with a helical axis parallel to the helical axis of the first chiral nematic liquid crystal, wherein a handedness of the second chiral nematic liquid crystal is at least one of a same or opposite of the first chiral nematic liquid crystal.   
     
     
         34 . A device comprising:
 a display screen providing a window that is transparent to visible light;   a projector providing one or more images with light having one or more selected wavelengths; and   a reflective filter providing one or more reflectivity peaks centered around the one or more selected wavelengths, wherein the reflective filter at least partially overlaps the display screen, wherein the display screen and the reflective filter are configured to reflect the light from the projector at the one or more selected wavelengths to an eye of a user to provide one or more images to eye of the user at the one or more selected wavelengths that appear overlaid over a physical scene viewed through the display screen, wherein the reflective filter comprises:
 one or more chiral nematic liquid crystal photopolymerized layers having helical axes fixed perpendicular to a plane of the display screen. 
   
     
     
         35 . The device of  claim 34 , wherein the reflective filter is disposed on a first side of the display screen, wherein the device further comprises:
 an additional reflective filter disposed on a second side of the display screen opposite the first side and aligned with the reflective filter, wherein the additional reflective filter provides at least one of the one or more reflectivity peaks of the reflective filter.   
     
     
         36 . The device of  claim 34 , wherein at least one of the one or more selected wavelengths is within at least one of a red spectral region, a green spectral region, or a blue spectral region. 
     
     
         37 . The device of  claim 34 , wherein the one or more selected wavelengths comprise at least one of 658 nanometers, 550 nanometers, or 450 nm. 
     
     
         38 . The device of  claim 34 , wherein the one or more chiral nematic liquid crystal photopolymerized layers comprise a single chiral nematic liquid crystal photopolymerized layer, wherein the one or more reflectivity peaks comprise a single reflectivity peak. 
     
     
         39 . The device of  claim 34 , wherein the one or more chiral nematic liquid crystal photopolymerized layers comprise two or more chiral nematic liquid crystal photopolymerized layer, wherein at least one of the two or more chiral nematic liquid crystal photopolymerized layers is left-handed, wherein at least one of the two or more chiral nematic liquid crystal photopolymerized layers is right-handed, wherein the one or more reflectivity peaks comprise a single reflectivity peak. 
     
     
         40 . The device of  claim 34 , wherein the one or more chiral nematic liquid crystal photopolymerized layers comprise two or more chiral nematic liquid crystal photopolymerized layer, wherein the one or more reflectivity peaks comprise two or more reflectivity peaks, each centered around a different one of the one or more selected wavelengths. 
     
     
         41 . The device of  claim 34 , wherein the one or more reflectivity peaks comprise a first reflectivity peak, a second reflectivity peak, and a third reflectivity peak, wherein the one or more chiral nematic liquid crystal photopolymerized layers comprise:
 a first set of one or more chiral nematic liquid crystal photopolymerized layers providing the first reflectivity peak centered around a first selected wavelength of the one or more selected wavelengths;   a second set of one or more chiral nematic liquid crystal photopolymerized layers providing the second reflectivity peak centered around a second selected wavelength of the one or more selected wavelengths; and   a third set of one or more chiral nematic liquid crystal photopolymerized layers providing the third reflectivity peak centered around a third selected wavelength of the one or more selected wavelengths.   
     
     
         42 . The device of  claim 41 , wherein the first selected wavelength is in a red spectral region, wherein the second selected wavelength is in a green spectral region, wherein the third selected wavelength is in a blue spectral region. 
     
     
         43 . The device of  claim 41 , wherein the first selected wavelength is 658 nanometers, wherein the second selected wavelength is 550 nanometers, wherein the third selected wavelength is 450 nanometers. 
     
     
         44 . The device of  claim 34 , wherein the display screen, the projector, and the reflective filter are configured to be worn by the user as a head mounted system. 
     
     
         45 . The device of  claim 34 , wherein the reflective filter is formed by the steps of:
 depositing a first chiral nematic liquid crystal onto a first substrate, wherein the first chiral nematic liquid crystal contains photopolymerizable moieties, wherein a concentration of the photopolymerizable moieties in the first chiral nematic liquid crystal is selected to fix an orientation of a helical axis of the first chiral nematic liquid crystal when photopolymerized;   positioning a second substrate on top of the first chiral nematic liquid crystal to form an initial layer structure;   applying uniform pressure to at least one of the first substrate or the second substrate of the initial layer structure to create a final layer structure in which the first chiral nematic liquid crystal is uniformly aligned with a helical axis perpendicular to a plane of the first substrate; and   subjecting the final layer structure to at least one of UV or visible light to produce a solid first photopolymerized liquid crystal layer with the helical axis fixed perpendicular to the plane of the first substrate.   
     
     
         46 . The device of  claim 45 , wherein the reflective filter is further formed by the steps of:
 removing one of the first substrate or the second substrate, wherein a remaining one of the first or the second substrate disposed on the first photopolymerized liquid crystal layer is a remaining substrate;   depositing a second chiral nematic liquid crystal onto the first photopolymerized liquid crystal layer;   positioning an additional substrate on top of the second chiral nematic liquid crystal to form the initial layer structure; and   applying uniform pressure to at least one of the remaining substrate or the additional substrate of the initial layer structure to create the final layer structure in which the second chiral nematic liquid crystal is uniformly aligned with a helical axis parallel to the helical axis of the first chiral nematic liquid crystal, wherein a handedness of the second chiral nematic liquid crystal is at least one of a same or opposite of the first chiral nematic liquid crystal.