Method for light ray steering

Abstract

Techniques and assemblies for light ray steering are described. A method includes receiving solar rays onto a surface of an electro-optic prism. The electro-optic prism includes a first electrode positioned on a first substrate, a second electrode positioned on a second substrate, and an electro-optic material positioned between the first and second electrodes. The first electrode includes multiple substantially parallel linear electrodes. The method further includes applying multiple voltages to some or all of the substantially parallel linear electrodes to generate a refractive index gradient across the electro-optic prism. The method further includes controlling the refractive index gradient so that the solar rays exit the electro-optic prism in a direction substantially normal to a light focusing element, and utilizing the light focusing element to focus the solar rays on a solar energy collector.

1 . A method comprising: 
 (a) receiving solar rays onto a surface of an electro-optic prism comprising: 
 (i) a first electrode positioned on a first substrate, wherein the first electrode comprises a plurality of substantially parallel linear electrodes,  
 (ii) a second electrode positioned on a second substrate, and  
 (iii) an electro-optic material positioned between the first electrode and the second electrode;  
   (b) applying a plurality of voltages to at least some of the plurality of substantially parallel linear electrodes to generate a refractive index gradient across the electro-optic prism;    (c) controlling the refractive index gradient so that the solar rays exit the electro-optic prism in a direction substantially normal to a light focusing element; and    (d) utilizing the light focusing element to focus the solar rays on a solar energy collector.    
   
   
       2 . The method of  claim 1 , wherein the solar energy collector comprises a photovoltaic device.  
   
   
       3 . The method of  claim 1 , wherein the electro-optic material comprises a liquid crystal material.  
   
   
       4 . The method of  claim 3 , wherein the liquid crystal material is a cholesteric liquid crystal.  
   
   
       5 . The method of  claim 3 , wherein the liquid crystal material is a nematic liquid crystal.  
   
   
       6 . The method of  claim 1 , wherein the electro-optic material positioned between the first electrode and the second electrode is of substantially uniform thickness.  
   
   
       7 . The method of  claim 1 , further comprising: 
 (e) receiving the solar rays on a static fixed power prism;    (f) utilizing the static fixed power prism to steer the solar rays in a first direction; and    (g) utilizing the electro-optic prism to steer the solar rays in a second direction.    
   
   
       8 . The method of  claim 1 , further comprising: 
 (e) receiving the solar rays on a static fixed power prism;    (f) utilizing the static fixed power prism for coarse steering of the light rays in a first direction;    (g) utilizing the electro-optic prism for fine steering of the light rays in the first direction.    
   
   
       9 . The method of  claim 1 , wherein the light focusing element comprises a Fresnel lens.  
   
   
       10 . A method comprising: 
 (a) receiving solar rays as the sun moves across the sky;    (b) applying voltages to an electro-optic prism to (i) control the refractive index of the electro-optic prism and (ii) steer the solar rays in a direction substantially normal to a surface of a light focusing element, wherein the electro-optic prism comprises a layer of electro-optic material with a substantially uniform thickness;    (c) utilizing the light focusing element to focus the steered solar rays on a photovoltaic device.    
   
   
       11 . The method of  claim 10 , wherein the electro-optic material comprises a liquid crystal material.  
   
   
       12 . The method of  claim 11 , wherein the liquid crystal material is a cholesteric liquid crystal.  
   
   
       13 . The method of  claim 11 , wherein the liquid crystal material is a nematic liquid crystal.  
   
   
       14 . The method of  claim 10 , further comprising: 
 (d) receiving the solar rays on a static fixed power prism;    (e) utilizing the static fixed power prism to steer the solar rays in a first direction; and    (f) utilizing the electro-optic prism to steer the solar rays in a second direction.    
   
   
       15 . The method of  claim 10 , further comprising: 
 (d) receiving the solar rays on a static fixed power prism;    (e) utilizing the static fixed power prism for coarse steering of the light rays in a first direction; and    (f) utilizing the electro-optic prism for fine steering of the light rays in the first direction.    
   
   
       16 . The method of  claim 10 , wherein the light focusing element comprises a Fresnel lens.  
   
   
       17 . The method of  claim 10 , wherein said receiving step comprises receiving the solar rays as the sun moves across the sky from a first solar position to a second solar position and then from the second solar position to a third solar position, and wherein 
 (i) the solar rays from the first position of the sun and the third position of the sun are directed in directions not substantially normal to the surface of the light focusing element, and    (ii) the solar rays from the second position of the sun are directed in the direction substantially normal to the surface of the light focusing element.    
   
   
       18 . A method comprising: 
 (a) receiving solar rays as the sun moves across the sky from a first solar position to a second solar position and then from the second solar position to a third solar position, wherein 
 (i) the solar rays from the first solar position of the sun and from the third solar position of the sun are directed in directions not substantially normal to a receiving surface of a light focusing element, and  
 (ii) the solar rays from the second solar position of the sun are directed in a direction that is substantially normal to the receiving surface of the light focusing element;  
   (b) controllably steering the solar rays from the first solar position using an electro-optic prism to steer the solar rays in the direction substantially normal to the receiving surface of the light focusing element;    (c) controllably steering the solar rays from the third solar position using the electro-optic prism to steer the solar rays in the direction substantially normal to the receiving surface of the light focusing element; and    (d) utilizing the light focusing element to focus the steered solar rays on a photovoltaic device.    
   
   
       19 . The method of  claim 18 , wherein: 
 (i) the electro-optic prism comprises 
 (A) a first electrode positioned on a first substrate, wherein the first electrode comprises a plurality of substantially parallel linear electrodes,  
 (B) a second electrode positioned on a second substrate, and  
 (C) an electro-optic material positioned between the first electrode and the second electrode; and  
   (ii) controllably steering the solar rays using the electro-optic prism comprises applying a plurality of voltages to at least some of the plurality of substantially parallel linear electrodes to generate a refractive index gradient across the electro-optic prism.    
   
   
       20 . The method of  claim 19 , wherein the electro-optic material comprises a liquid crystal material.