Methods for Fabricating Optical Waveguides

Abstract

Mastering systems and methods of fabricating waveguides and waveguide devices using such mastering systems are described. Mastering systems for fabricating holographic waveguides can include using a master to control the application of energy (e.g. a laser, light, or magnetic beam) onto a liquid crystal substrate to fabricate a holographic waveguide into the liquid crystal substrate. Mastering systems for fabricating holographic waveguides in accordance with embodiments of the invention can include a variety of features. These features include, but are not limited to: chirp for single input beam copy (near i.e. hybrid contact copy), dual chirped gratings (for input and output), zero order grating for transmittance control, alignment reference gratings, 3:1 construction, position adjustment tooling to enable rapid alignment, optimization of lens and window thickness for multiple RKVs simultaneously, and avoidance of other orders and crossover of the diffraction beam.

What is claimed is: 
     
         1 . A method for recording holograms, the method comprising:
 providing a waveguide cell comprising a layer of polymer dispersed liquid crystal mixture sandwiched between two substrates;   providing a master grating;   emitting at least one recording beam toward the master grating, wherein upon interaction with the master grating, a portion of the at least one recording beam is diffracted towards the waveguide cell; and   recording at least one volume grating within the waveguide cell using interferential exposure formed from at least the diffracted portion of the at least one recording beam.   
     
     
         2 . The method of  claim 1 , wherein the master grating comprises an amplitude grating. 
     
     
         3 . The method of  claim 2 , wherein the master grating comprises a chirped grating. 
     
     
         4 . The method of  claim 3 , wherein the recorded volume grating contains a rolled K-vector. 
     
     
         5 . The method of  claim 1 , wherein the recorded volume grating contains a multiplexed grating. 
     
     
         6 . The method of  claim 1 , wherein the master grating comprises three separate gratings. 
     
     
         7 . The method of  claim 6 , wherein the three separate gratings are designed to record an input grating, a fold grating, and an output grating. 
     
     
         8 . The method of  claim 6 , wherein the at least one volume grating comprises three volume gratings. 
     
     
         9 . The method of  claim 8 , wherein the at least one recording beam comprises three recording beams. 
     
     
         10 . The method of  claim 1 , wherein the interferential exposure is formed from the zero order beam and diffracted portion of only one recording beam. 
     
     
         11 . A system for recording holographic gratings, the system comprising:
 a waveguide cell comprising a layer of polymer dispersed liquid crystal mixture sandwiched between two substrates;   a master grating;   a light source configured to emit at least one recording beam toward the master grating, wherein upon interaction with the master grating, a portion of the at least one recording beam is diffracted towards the waveguide cell and at least one volume grating is recorded within the waveguide cell through interferential exposure formed from at least the diffracted portion of the at least one recording beam.   
     
     
         12 . The system of  claim 11 , wherein the master grating comprises an amplitude grating. 
     
     
         13 . The system of  claim 12 , wherein the master grating comprises a chirped grating. 
     
     
         14 . The system of  claim 13 , wherein the recorded volume grating contains a rolled K-vector. 
     
     
         15 . The system of  claim 11 , wherein the recorded volume grating contains a multiplexed grating. 
     
     
         16 . The system of  claim 11 , wherein the master grating comprises three separate gratings. 
     
     
         17 . The system of  claim 16 , wherein the three separate gratings are designed to record an input grating, a fold grating, and an output grating. 
     
     
         18 . The system of  claim 16 , wherein the at least one volume grating comprises three volume gratings. 
     
     
         19 . The system of  claim 18 , wherein the at least one recording beam comprises three recording beams. 
     
     
         20 . The system of  claim 11 , wherein the interferential exposure is formed from the zero order beam and diffracted portion of only one recording beam.