Optical phase processing in a scattering medium

Abstract

An optical phase processing system for a scattering medium. A first beam has a direction and a wavefront and the first beam is configured to enter a holographic recording medium. A scattering medium is illuminated by a signal beam generating at least one scattered beam. An interference pattern is recorded from the at least one scattered beam and the first beam. A second beam is generated in a direction opposite to the direction of the first beam, the second beam having a wavefront and a phase substantially opposite to a phase of the wavefront of the first beam, and the second beam is configured to enter the holographic recording medium. The second beam and the interference pattern interact to generate at least one reconstructed beam having a phase substantially opposite to a phase of the at least one scattered beam, and the at least one reconstructed beam is configured to be viewable through the scattering medium.

1 . An apparatus to reduce optical scattering, the apparatus comprising:
 a first beam having a direction and a wavefront;   the first beam configured to enter a holographic recording medium;   a scattering medium illuminated by a signal beam thereby generating at least one scattered beam;   an interference pattern recorded from the at least one scattered beam in the presence of the first beam;   a second beam generated substantially in a direction opposite to the direction of the first beam;   the second beam having a wavefront and a phase substantially opposite to a phase of the wavefront of the first beam;   the second beam configured to enter the holographic recording medium;   the second beam and the interference pattern interacting to generate at least one reconstructed beam having a phase substantially opposite to a phase of the at least one scattered beam; and   the at least one reconstructed beam configured to be viewable through the scattering medium.   
   
   
       2 . The apparatus of  claim 1 , wherein the holographic recording medium is one of a photorefractive crystaland a Lithium Niobate. 
   
   
       3 . The apparatus of  claim 1 , wherein the scattering medium includes a material selected from the group consisting of:
 a biological tissue;   a gas having one or more particles;   one or more nanoshells;   a scatterer;   material responding to light, and   optically absorptive material.   
   
   
       4 . The apparatus of  claim 3 , wherein an interference pattern is recorded by a forward scattered signal beam through the scattering medium in the presence of the first beam, the at least one scatterer is illuminated by the at least one reconstructed beam, the signal beam is configured to pass through the holographic recording medium so as to reach the at least one scatterer, an interference pattern is recorded by a back scattered light beam from the at least one scatterer and the at least one scatterer is illuminated by the at least one reconstructed beam. 
   
   
       5 . The apparatus of  claim 1 , wherein a change in the interference pattern consequent to a change in a positional relationship between the scattering medium and the holographic recording medium indicates one of an inhomogeneity in the scattering medium and an extent of scattering in the scattering medium, the inhomogeneity indicates at least a biological condition and the extent of scattering indicates at least one of a frequency of scattering and a thickness of scattering sample. 
   
   
       6 . The apparatus of  claim 1 , wherein the interference pattern is recorded partly owing to at least one of a plurality of scattered beams diverted from the holographic recording medium, and wherein the at least one of a plurality of scattered beams is configured to be at least one of a beam bypassing reconstruction and a beam prevented from reaching a detector. 
   
   
       7 . The apparatus of  claim 1 , wherein the interference pattern indicates an information representing the scattering medium, the information is at least one of an encryption information included in one or more scattering media and an encryption key included in one or more scattering media, and wherein the information is processed by the scattering medium, the scattering medium allowing the information to reach an element selected from the group consisting of:
 a viewer, and   a detector.   
   
   
       8 . A method of processing optical scattering in a scattering medium, comprising:
 generating at least a first matrix representing a transfer function of a first scattering medium;   generating at least a second matrix representing a transfer function of an absorptive material;   generating a matrix representing an input electric field;   calculating a matrix representing an output electric field by multiplying the first matrix, the second matrix, the inverse of the first matrix, and a conjugate of the matrix representing an input electric field; and   amplifying the transfer function of the absorptive material by processing the matrix representing the output electric field.   
   
   
       9 . The method of  claim 8 , wherein the calculating the matrix representing the output electric field comprises multiplying a third matrix representing a transfer function of a second scattering medium, the second matrix representing the absorptive material sandwiched between the first scattering medium and the second scattering medium, the first matrix, and the matrix representing an input electric field, and wherein the calculating the matrix representing the output electric field comprises raising the second matrix to a power of a number of times the input electrical field is applied to the first scattering medium if the number is odd. 
   
   
       10 . The method of  claim 8 , wherein the calculating the matrix representing the output electric field comprises raising the second matrix to a power of a number of times the input electrical field applied to the first scattering medium if the number is even. 
   
   
       11 . A method to reduce optical scattering, the method comprising:
 generating a first beam having a direction and a wavefront;   configuring the first beam to enter a holographic recording medium;   illuminating a scattering medium by a signal beam;   generating at least one scattered beam;   recording an interference pattern from the at least one scattered beam in the presence of the first beam;   generating a second beam substantially in a direction opposite to the direction of the first beam;   subjecting the second beam to have a wavefront and a phase substantially opposite to a phase of the wavefront of the first beam;   configuring the second beam to enter the holographic recording medium;   causing the second beam and the interference pattern to interact to generate at least one reconstructed beam having a phase substantially opposite to a phase of the at least one scattered beam; and   rendering the at least one reconstructed beam to be viewable through the scattering medium.   
   
   
       12 . The method of  claim 11 , wherein the generating at least one scattered beam includes at least one of responding optically and absorbing optically, the scattering medium is selected from the group consisting of:
 a gas having one or more particles,   a biological tissue, and   one or more nanoshells, the illuminating the scattering medium further comprises including at least one scatterer and the recording the interference pattern further includes transmitting the signal beam through the scattering medium in the presence of the first beam.   
   
   
       13 . The method of  claim 12 , wherein the including the at least one scatterer further comprises illuminating by the at least one reconstructed beam and wherein the illuminating a scattering medium by a signal beam further comprises configuring the signal beam to pass through the holographic recording medium so as to reach the at least one scatterer. 
   
   
       14 . The method of  claim 13 , further including recording an interference pattern by a reflection from the at least one scatterer. 
   
   
       15 . The method of  claim 14 , further including illuminating the at least one scatterer by the at least one reconstructed beam. 
   
   
       16 . The method of  claim 11 , further including assessing an inhomogeneity in the scattering medium by a change in a reconstructed beam reaching a viewer, consequent to a change in a positional relationship between the scattering medium and the holographic recording medium. 
   
   
       17 . The method of  claim 16 , wherein the assessing the inhomogeneity comprises indicating a biological condition. 
   
   
       18 . The method of  claim 16 , wherein the assessing the inhomogeneity comprises rendering the at least one reconstructed beam detectable by a detector. 
   
   
       19 . The method of  claim 16 , wherein the assessing the inhomogeneity comprises one of indicating an inhomogeneity in the scattering medium and indicating an extent of scattering in the scattering medium. 
   
   
       20 . The method of  claim 11 , wherein the recording the interference pattern further includes recording partly owing to at least one of a plurality of scattered beams getting diverted from a recording medium. 
   
   
       21 . The method of  claim 20 , wherein the recording partly further includes diverting at least one of a plurality of reconstructed beams from a detector. 
   
   
       22 . The method of  claim 11 , wherein the recording the interference pattern further includes indicating an information representing the scattering medium. 
   
   
       23 . The method of  claim 22 , wherein the indicating the information further includes indicating an encryption information. 
   
   
       24 . The method of  claim 22 , wherein the indicating the information further includes processing by a method selected from the group consisting of:
 viewing, and   detecting.   
   
   
       25 . The method of  claim 23 , wherein the indicating an encryption information further comprises indicating an encryption key for one or more scattering media.