Photo-induced dichroic polarizers and fabrication methods thereof

Abstract

The present invention provides a method of forming a polarizing material comprising exposing a layer of dichroic material to activating light illumination to provide an ordered structure with a distinguished absorption axis and thus photo-induce polarization, and fixing the induced polarization by polymerisation of the dichroic layer. The present invention also provides novel polarizing formed thereby. By selectively exposing regions of the dichroic material to differing activating radiation, different regions with different polarization axes can be created. The polarizing material can also be provided with a coating or coatings to alter the spectral response, and a stack formed of a plurality if dichroic layers may be provided.

1 .- 12 . (canceled)  
     
     
         13 . A polarizing material comprising a layer of photochemically stable dichroic molecules exhibiting photo-induced anisotrophy upon the absorption of light.  
     
     
         14 . (canceled)  
     
     
         15 . A polarizing material as claimed in  claim 13  wherein said dichroic absorber is selected from the group consisting of: mono-, bis-, tris-, and poly-azo dyes, quinone dyes, mono- and poly-oxyanthraquinone dyes, sulfur-substituted hydroxythio-anthraquinone dyes, aminohydroxy-anthraquinone dyes, anthrapyrimidinone dyes, merocyane dyes, azomethine dyes, polycyclic compounds, benzoquinones, napthoquinones, tolanes, diphenyls, p-nitroanilines, p-nitrosodialkylanilines, dialkylaminostyroles.  
     
     
         16 . (canceled)  
     
     
         17 . A polarizing material as claimed in  claim 13  wherein the polarizing material is provided with a coating of a material selected to alter the spectral response of said material.  
     
     
         18 . A polarizing material as claimed in  claim 17  wherein the selected material is iodine.  
     
     
         19 . A polarizing material according to  claim 13 , wherein said dichroic molecules are formed within a polymer matrix.  
     
     
         20 . A polarizing material according to  claim 19 , wherein the polymer matrix is formed of polymeric materials selected from the group consisting of: polyimide, polyethylene, cellulose acetate, polystyrene, polycarbonate, polyester, polyacrylonitrile, polyacetal, polyacrylamide, polybutadiene, polyvinylalcohol, polymethylmethacrylate, and polyvinylcinnamate