Flexible, ultra-thin, hybrid absorptive-reflective thin-film filters and methods of making the same

Abstract

A hybrid optical filter includes a plurality of film layers laminated to one another. This renders the filter flexible enough to be bendable and to implement a combination of at least two different wavelength-dependent optical filtering properties in a single hybrid optical filter. Two or more of the optical filtering properties may be caused by interference-based blocking of different ranges of wavelengths of light. Additionally or alternatively, at least one of the optical filtering properties may be an absorptive blocking of a first range of wavelengths of light and at least another one of the optical filtering properties is an interference-based blocking of a second range of wavelengths of light. The first range of wavelengths and the second range of wavelengths may overlap to provide for customized ranges of blocked wavelengths.

What is claimed: 
     
         1 . A hybrid optical filter comprising: a plurality of film layers laminated to one another, at least one of the film layers being a polymer film layer, the hybrid optical filter implementing a combination of at least two different wavelength-dependent optical filtering properties in a single hybrid optical filter. 
     
     
         2 . The hybrid optical filter of  claim 1 , wherein at least one of the optical filtering properties is an absorptive blocking of a first range of wavelengths of light and at least a second one of the optical filtering properties is an interference-based blocking of a second range of wavelengths of light. 
     
     
         3 . The hybrid optical filter of  claim 2 , wherein the interference-based blocking of the second range of wavelengths forms a steeper spectral second blocking flank than a spectral first blocking flank of the absorptive blocking of the first range of wavelengths. 
     
     
         4 . The hybrid optical filter of  claim 3 , wherein spectral first blocking flank extends over a range of wavelengths blocked by the interference based blocking. 
     
     
         5 . The hybrid optical filter of  claim 2 , wherein at least a third one of the optical filtering properties is an interference-based blocking of a third range of wavelengths of light, wherein the first range, the second range, and the third range differ from one another. 
     
     
         6 . The hybrid optical filter of  claim 1 , wherein at least two of the optical filtering properties are interference-based blocking of a first range of wavelengths of light and interference-based blocking of a second range of wavelengths of light, wherein the first and the second ranges are offset from one another. 
     
     
         7 . The hybrid optical filter of  claim 6 , wherein the first range of wavelengths and the second range of wavelengths overlap. 
     
     
         8 . The hybrid optical filter of  claim 1 , wherein at least one film layer of the plurality of film layers is an absorptive filter layer and at least another one film layer of the plurality of film layers is an interference filter layer. 
     
     
         9 . The hybrid optical filter of  claim 8 , wherein the at least one interference filter layer is at least two interference filter layers and the at least one absorptive filter layer is arranged between two of the at least two interference filter layers. 
     
     
         10 . The hybrid optical filter of  claim 1 , wherein at least one film layer of the plurality of film layers is both an absorptive filter and an interference filter. 
     
     
         11 . The hybrid optical filter of  claim 1 , wherein at least one outermost layer of the plurality of film layers is a clear, transparent protective layer. 
     
     
         12 . The hybrid optical filter of  claim 1 , wherein the plurality of film layers comprises at least two interference filter layers and at least two absorptive filter layers, wherein the interference filter layers and the absorptive filter layers are arranged in an alternating order. 
     
     
         13 . A method of making a hybrid optical filter comprising at least two polymer film layers in a single ultra-thin filter, the method comprising the step of:
 laminating at least two polymer film layers together using an index-matched liquid or adhesive layer in between them to reduce total internal reflection at an interface between individual filter layers,   wherein the hybrid optical filter implements at least two different wavelength-dependent optical filtering properties and at least one of the at least two polymer film layers is an optical filter film.   
     
     
         14 . The method of  claim 13 , wherein the at least two polymer film layers include one outermost film layer that is a clear, transparent protective film layer.