Metamaterial Optical Filter and Methods for Producing the Same

Abstract

A metamaterial optical filter including: a transparent substrate; and a photosensitive polymer layer provided to the transparent substrate, wherein the photosensitive polymer layer is treated using a laser to form a non-conformal holographically patterned subwavelength grating, the holographic grating configured to block a predetermined wavelength of electromagnetic radiation. A system and method for manufacturing holographically patterned subwavelength grating onto the photosensitive polymer layer including: applying a photosensitive polymer layer to a transparent substrate; placing the photosensitive polymer layer between a laser and a mirror; scanning the laser over the photosensitive polymer layer such that a holographic grating is created within the photosensitive polymer layer by interaction between the laser light and light reflected from the mirror; and stacking two or more holographically patterned subwavelength grating layers to form complex metamaterial optical filter stacks.

1 - 25 . (canceled) 
     
     
         26 . A method of manufacturing a metamaterial optical filter configured to block a predetermined bandwidth of electromagnetic radiation at a predetermined angle, the method comprising:
 providing a photosensitive polymer layer disposed between a laser and a mirror; and   scanning the laser over the photosensitive polymer layer such that a holographically patterned subwavelength grating is created within the photosensitive polymer layer by interaction between the laser light and light reflected from the mirror, the holographically patterned subwavelength grating having a spacing dependent on the predetermined bandwidth of electromagnetic radiation; wherein the scanning includes scanning over a first portion of the surface of the photosensitive polymer layer and scanning over a second, different portion of the surface of the photosensitive polymer layer.   
     
     
         27 . The method according to  claim 26 , wherein the scanning includes scanning over successive offset lines across the surface of the photosensitive polymer layer. 
     
     
         28 . The method according to  claim 26 , wherein the scanning includes moving the laser in a longitudinal direction and moving the photosensitive polymer layer in a latitudinal direction. 
     
     
         29 . The method according to  claim 26 , wherein the scanning comprises moving one or more of the laser, the photosensitive polymer layer and the mirror. 
     
     
         30 . The method according to  claim 26 , further comprising thermoforming the photosensitive polymer layer to have a repeatable filter wavelength shift and a filter wavelength pre-compensation of the photosensitive polymer layer such that the thermoformed photosensitive polymer layer meets predetermined requirements. 
     
     
         31 . The method according to  claim 30 , wherein the bandgap of the photosensitive polymer layer before thermoforming is pre-shifted to longer wavelengths in order to counter-balance the shift caused by the thermoforming. 
     
     
         32 . The method according to  claim 31 , wherein the bandgap pre-shift is radially-dependent, with gradually smaller shifting away from a center of the photosensitive polymer layer. 
     
     
         33 . The method according to  claim 26 , wherein the laser is split into separate beams and the beams are directed onto the photosensitive polymer layer at different angles of incidence. 
     
     
         34 . The method according to  claim 26 , wherein the laser comprises a plurality of lasers of different wavelengths that are combined into a single combined beam and the combined beam is directed onto the photosensitive polymer layer at a predetermined angle of incidence, thereby recording notch filters of different wavelengths simultaneously. 
     
     
         35 . The method for manufacturing according to  claim 26 , comprising forming a holographically patterned subwavelength grating in each of a plurality of photosensitive polymer layers, and wherein the plurality of photosensitive polymer layers are combined into a multi-layered metamaterial optical filter stack, comprising at least two or more holographically patterned gratings to allow control of angle, bandgap, optical density and color balance of the multi-layered metamaterial optical filter stack. 
     
     
         36 . The method for manufacturing according to  claim 35 , wherein an adhesive comprising graphene is used to bond the plurality of photosensitive polymer layers of the multi-layered metamaterial optical filter stack. 
     
     
         37 . The method according to  claim 26 , wherein the photosensitive polymer layer is disposed on a substrate and the photosensitive polymer layer disposed on the substrate is placed between the laser and the mirror. 
     
     
         38 . The method according to  claim 26 , wherein the holographically patterned subwavelength grating comprises non-conformal fringes configured to block the predetermined bandwidth of electromagnetic radiation at the predetermined angle. 
     
     
         39 . The method according to  claim 38 , wherein the holographically patterned subwavelength grating of the optical filter is curved in order to increase an effective angle of protection. 
     
     
         40 . The method for manufacturing according to  claim 38 , wherein the holographically patterned subwavelength grating comprises a plurality of gratings, wherein each of the gratings is configured to block a different predetermined bandwidth of electromagnetic radiation. 
     
     
         41 . The method of manufacturing according to  claim 40 , wherein at least one of the plurality of holographically patterned subwavelength gratings of the optical filter is provided to color balance the filter. 
     
     
         42 . The method of manufacturing according to  claim 40 , wherein the plurality of holographically patterned subwavelength gratings of the optical filter are configured to selectively block at least one of approximately 405 nm, 445 nm, 520 nm, 532 nm, 635 nm, 650 nm wavelengths. 
     
     
         43 . The method of manufacturing according to  claim 38 , wherein the photosensitive polymer layer of the optical filter is shaped for a transparent substrate using thermoforming and the photosensitive polymer layer is pre-configured to allow for changes to the photosensitive polymer layer during thermoforming. 
     
     
         44 . The method of manufacturing according to  claim 38 , wherein the photosensitive polymer layer is infused with a dye selected to color balance the filter. 
     
     
         45 . The method of manufacturing according to  claim 38 , wherein the optical filter includes a substrate that contains a dye selected to color balance the filter. 
     
     
         46 . The method of manufacturing according to  claim 38 , wherein the optical filter comprises two or more transparent substrates and the photosensitive polymer layer is positioned between at least two of the two or more transparent substrates. 
     
     
         47 . The method of manufacturing according to  claim 38 , wherein the predetermined angle of the non-conformal fringes is up to 75 degrees below a normal axis of the filter. 
     
     
         48 . The method of manufacturing according to  claim 38 , wherein the optical filter further comprises a transparent substrate and an adhesive bonding the transparent substrate and photosensitive polymer layer wherein the adhesive comprises graphene. 
     
     
         49 . The method of manufacturing according to  claim 38 , wherein the optical filter includes a transparent substrate on which the photosensitive polymer layer is disposed. 
     
     
         50 . The method of manufacturing according to  claim 49 , wherein the transparent substrate is selected from one of the following:
 a window;   eyewear; and   a visor.   
     
     
         51 . A system for manufacturing a metamaterial optical filter, the system comprising:
 a clamp for holding a photosensitive polymer layer applied to a mirror;   a laser; and   a laser transport system for moving the laser relative to the photosensitive polymer layer such that, as the laser moves over a surface of the photosensitive polymer layer, laser light is reflected off of the mirror to create a holographically patterned subwavelength gratings within the photosensitive polymer layer.   
     
     
         52 . The system according to  claim 51 , wherein the laser transport system comprises:
 a carriage for carrying the laser; and   rails provided adjacent the surface of the photosensitive polymer layer such that the carriage movably engages with the rails and is configured to move across the surface of the photosensitive polymer layer.   
     
     
         53 . The system according to  claim 52 , wherein the carriage and rails are configured to move the laser in the longitudinal direction and the clamp is configured to move the photosensitive polymer layer in the latitudinal direction.