Method and system for configuring a device for correcting the effect of a medium on a light signal, method, device and system for correcting said effect

Abstract

A method and a system is provided for configuring a device for correcting the effect of a medium on a light signal having propagated through the medium, the device including at least one optical element whose phase profiles are individually adjustable. The configuring system and method include propagating a reference signal and a disordered signal obtained at the output of the medium through the correcting device. An interference parameter is measured and optimized by modifying the phase profile of each of the optical elements of the correcting device. A method and a system is also provided for correcting the effect of a medium on a light signal having propagated through the medium.

The invention claimed is: 
     
       1. A method for configuring a device to correct the effect of a medium on a light signal having propagated through said medium, said device comprising at least one optical element a plurality of optical elements whose spatial phase profile is individually adjustable, said method comprising the following steps:
 propagating a first light signal through said medium, said propagating step providing a disordered signal; 
 propagating said disordered signal through said device the optical elements; 
 propagating a second light signal, called reference signal, through said device the optical elements in a propagation direction opposite to a propagation direction of the disordered signal, said reference signal being identical to said first signal to generate an interference signal between said disordered signal and said reference signal; 
 optimizing interference between said disordered signal and said reference signal, said optimizing step comprising the interference signal by repeating at least one iteration of the following steps for at least one optical element: 
 measuring at least one interference parameter between said disordered signal and said reference signal of the interference signal; and 
 modifying the phase profile of at least one optical element depending on said interference parameter. 
 
     
     
       2. The method according to claim  1  27, wherein the step of measuring an interference parameter comprises a step of measuring for each optical element:
 an interference parameter for several zones of each optical element, and/or 
 an interference parameter for each pixel of each optical element, and/or 
 an interference parameter for the whole optical element. 
 
     
     
       3. The method according to  claim 1 , wherein the interference parameter comprises a parameter relative to the intensity of the interference signal obtained by interference of the reference signal and the disordered signal. 
     
     
       4. The method according to  claim 1 , wherein the step of modifying the spatial phase profile of an the at least one optical element comprises modifying the phase delay applied by at least one zone and/or at least one pixel of said optical element to a light signal. 
     
     
       5. The method according to  claim 1 , also comprising a step for phase modulating the reference signal before propagating it through the device the optical elements. 
     
     
       6. The method according to  claim 5 , also comprising a step for measuring an interference visibility parameter between the reference signal and the disordered signal. 
     
     
       7. The method according to claim  1  27, wherein the optimizing step is realised for each optical element of the correcting device one after another. 
     
     
       8. The method according to  claim 1 , also comprising a step of generating the first light signal and the reference signal from a unique light signal. 
     
     
       9. The method according to  claim 8 , comprising a step to modulate spatially the unique light signal. 
     
     
       10. A non-transitory computer-readable medium comprising: instructions to implement the steps of a method according to  claim 1  that, when said computer program is instructions are executed by a computer or by computing means, cause the computer or computing means to correct the effect of a medium on a light signal having propagated through said medium by:
 causing a source to propagate a first light signal through said medium, said propagating step providing a disordered signal; 
 causing said disordered signal to propagate through optical elements whose spatial phase profile is individually adjustable; 
 causing the source to propagate a second light signal, called reference signal, through the optical elements in a propagation direction opposite to a propagation direction of the disordered signal, said reference signal being identical to said first signal to generate an interference signal between said disordered signal and said reference signal; 
 causing at least one optimization module to optimize the interference signal by repeating at least one iteration of the following steps for at least one optical element; 
 measure at least one interference parameter of the interference signal; and 
 modify the phase profile of at least one optical element depending on said interference parameter. 
 
     
     
       11. A device for correcting the effect of a medium on a light signal having propagated through said medium, comprising at least one optical element whose spatial phase profile is individually adjustable and configured according to the method according to  claim 1 . 
     
     
       12. The device according to  claim 11 , wherein at least one optical element is a spatial light modulator or a deformable mirror. 
     
     
       13. A method for correcting the effect of a medium on a light signal having propagated through said medium, said method implementing a device comprising at least one optical element a plurality of optical elements whose phase profile is profiles are individually adjustable, said method comprising:
 a configuration phase for configuring said device according to the method according to  claim 1 , and 
 a correcting phase correcting said signal with said calibrated device. 
 
     
     
       14. The method according to  claim 13 , also comprising at least one adjusting step for adjusting the configuration of the device if changes occur in the medium during the correcting phase. 
     
     
       15. A system for configuring a device for correcting the effect of a medium on a light signal having propagated through said medium, said device comprising at least one optical element whose spatial phase profile is individually adjustable, said system comprising:
 means for propagating a first light signal through said medium, said medium thus providing a disordered signal;   means for propagating said disordered signal through said device;   means for propagating a second light signal, called reference signal, through said device, said reference signal being identical to said first signal;   means for measuring an interference parameter between said disordered signal and said reference signal at the level of each optical element; and   means for modifying the phase profile of at least one of said optical elements to increase said interference parameter.   
     
     
       16. The system according to  claim 15 , also comprising modulation means for modulating the reference signal before propagating said reference signal through the correcting device. 
     
     
       17. The system according to  claim 15 , wherein the measuring means comprise a CCD camera for each optical element. 
     
     
       18. The system according to  claim 15 , wherein the modifying means comprise at least one actuator for each optical element. 
     
     
       19. A system for correcting the effect of a medium on a light signal having propagated through said medium, said system comprising:
 a correcting device comprising at least one optical element whose spatial phase profile is individually adjustable, and   a configuring system according to  claim 15  to configure said device.   
     
     
       20. A method for configuring a device to apply a given deformation to a light signal, said device comprising at least one optical element a plurality of optical elements whose spatial phase profile is profiles are individually adjustable, said method comprising the following steps:
 propagating a first light signal through a medium, said propagating step providing a reference signal; 
 propagating said reference signal through said device the optical elements; 
 propagating a signal to deform second light signal through said device optical elements in a propagation direction opposite to a propagation direction of the reference signal, said signal to deform second light signal being identical to said first reference signal; 
 using the reference signal to apply the given deformation to the second light signal and generating an interference signal between said second light signal and said reference signal;  
 optimizing interference between said reference signal and said signal to deform, said optimizing step comprising said interference signal by repeating at least one iteration of the following steps for at least one optical element: 
 measuring at least one interference parameter between said reference signal and said signal to deform of said interference signal; and 
 modifying the phase profile of at least one optical element depending on said interference parameter. 
 
     
     
       21. A system for configuring a device to apply a given deformation to a light signal, said device comprising at least one optical element whose spatial phase profile is individually adjustable, said system comprising:
 means for propagating a first light signal through a medium, said medium thus providing a reference signal;   means for propagating said reference signal through said device;   means for propagating a signal to deform through said device, said signal to deform being identical to said first signal;   means for measuring an interference parameter between said reference signal and said signal to deform at the level of each optical element; and   means for modifying the phase profile of at least one of said optical elements to increase said interference parameter.   
     
     
       22. A non-transitory computer-readable medium comprising: instructions to implement the steps of a method for configuring a device to correct the effect of a medium on a light signal having propagated through said medium that, when said computer program is instructions are executed by a computer or by computing means, said device comprising at least one optical element whose spatial phase profile is individually adjustable, said method comprising the following steps cause the computer or computing means to apply a given deformation to a light signal by:
 propagating a first light signal through said a medium, said propagating step providing a reference signal; 
 propagating saidcausing the reference signal to propagate through said deviceoptical elements whose spatial phase profiles are individually adjustable utilizing a source; 
 propagatingcausing a signal to deformsecond light signal to propagate through said deviceoptical elements in a propagation direction opposite to a propagation direction of the reference signal utilizing the source, said signal to deformsecond light signal being identical to said firstreference signal; 
 using the reference signal to apply the given deformation to the second light signal and generating an interference signal between said second light signal and said reference signal;  
 optimizingcausing at least one optimization module to optimize said interference between said reference signal and said signal to deform, said optimizing step comprisingsignal by repeating at least one iteration of the following steps for at least one optical element: 
 measuring at least one interference parameter between said reference signal and said signal to deform of said interference signal; and 
 modifying the phase profile of at least one optical element depending on said interference parameter. 
 
     
     
       23. A device for applying a given deformation to a light signal, comprising at least one optical element whose spatial phase profile is individually adjustable and configured according to the following method:
 propagating a first light signal through a medium, said propagating step providing a reference signal;   propagating said reference signal through said device;   propagating a signal to deform through said device, said signal to deform being identical to said first signal;   optimizing interference between said reference signal and said signal to deform, said optimizing step comprising at least one iteration of the following steps for at least one optical element:   measuring at least one interference parameter between said reference signal and said signal to deform: and   modifying the phase profile of at least one optical element depending on said interference parameter.   
     
     
       24. A method for applying a given deformation to a light signal, said method implementing a device comprising at least one optical element whose phase profile is individually adjustable, said method comprising:
 a configuration phase for configuring said device, and   a deformation phase deforming said signal with said calibrated device;   said configuration phase comprising:   propagating a first light signal through a medium, said propagating step providing a reference signal:   propagating said reference signal through said device;   propagating a signal to deform through said device, said signal to deform being identical to said first signal;   optimizing interference between said reference signal and said signal to deform, said optimizing step comprising at least one iteration of the following steps for at least one optical element:   measuring at least one interference parameter between said reference signal and said signal to deform: and   modifying the phase profile of at least one optical element depending on said interference parameter.   
     
     
       25. A system for applying a given deformation to a light signal, said system comprising:
 a deformation device comprising at least one optical element whose spatial phase profile is individually adjustable; and   a configuring system to configure said device, said configuring system comprising:   means for propagating a first light signal through a medium, said medium thus providing a reference signal;   means for propagating said reference signal through said device;   means for propagating a signal to deform through said device, said signal to deform being identical to said first signal;   means for measuring an interference parameter between said reference signal and said signal to deform at the level of each optical element; and   means for modifying the phase profile of at least one of said optical elements to increase said interference parameter.   
     
     
       26. The method of claim 1, wherein each optical element is separated from another optical element by free space propagation and a lens.  
     
     
       27. A method for configuring a device to correct the effect of a medium on a light signal having propagated through said medium, said device comprising a plurality of optical elements whose spatial phase profile is individually adjustable, said method comprising the following steps:
 propagating a first light signal through said medium, said propagating step providing a disordered signal;   propagating said disordered signal through the optical elements;   propagating a second light signal, called reference signal, through the optical elements, said reference signal being identical to said first signal to generate an interference signal between said disordered signal and said reference signal, wherein said reference signal is propagated through each optical element in a propagation direction opposite to the propagation direction of the disordered signal; and   optimizing the interference signal by repeating at least one iteration of the following steps for at least one optical element:
 measuring at least one interference parameter of the interference signal; and 
 modifying the phase profile of at least one optical element depending on said interference parameter.  
   
     
     
       28. A method for configuring a device to correct an effect of a medium on a light signal having propagated through the medium, the device comprising a plurality of optical elements whose spatial phase is individually adjustable, the method comprising:
 propagating a disordered signal and a reference signal through the optical elements in opposite directions to generate an interference signal between the disordered signal and the reference signal, the disordered signal comprising a first light signal having propagated through the medium, the reference signal comprising a second light signal identical to the first light signal;   optimizing the interference signal by performing at least one iteration of the following steps for at least one optical element:
 measuring at least one interference parameter of the interference signal; and 
 modifying the phase profile of the at least one optical element depending on the interference parameter.  
   
     
     
       29. A method for configuring a device to apply a given deformation to a light signal, said device comprising a plurality of optical elements whose spatial phase profiles are individually adjustable, said method comprising the following steps:
 propagating a first light signal through a medium, said propagating step providing a reference signal;   propagating the reference signal through the optical elements;   propagating a second light signal through said optical elements, said second light signal being identical to said reference signal, wherein said reference signal is propagated through each optical element in a propagation direction opposite to the propagation direction of the second light signal;   using the reference signal to apply the given deformation to the second light signal and generating an interference signal between said second light signal and said reference signal;   optimizing said interference signal by repeating at least one iteration of the following steps for at least one optical element:
 measuring at least one interference parameter of said interference signal; and 
 modifying the phase profile of at least one optical element depending on said interference parameter.  
   
     
     
       30. The method according to claim 20, wherein the step of modifying the phase profile of the at least one optical element comprises modifying the phase delay applied by at least one zone and/or at least one pixel of said optical element to a light signal.  
     
     
       31. The method according to claim 20, further comprising a step for phase modulating the reference signal before propagating it through the optical elements.  
     
     
       32. The method according to claim 20, further comprising a step of generating the reference signal and the second light signal from a unique light signal.  
     
     
       33. The method according to claim 32, further comprising a step to modulate spatially the unique light signal.  
     
     
       34. The method of claim 20, wherein each optical element is separated from another optical element by free space propagation and a lens.