Beam shaping optical structures

Abstract

A near-eye optical element includes one or more light sources and an optical structure. The one or more light sources emit beams. The optical structure includes an optically transparent material disposed over emission aperture(s) of the light source(s). The optical structure includes one or more facets that diverge or provide a tilt angle to the beams.

What is claimed is: 
     
         1 . A near-eye optical system comprising:
 a light source having an emission aperture, wherein the light source is configured to emit a beam through the emission aperture; and   an optical structure including an optically transparent material disposed over the emission aperture, wherein the optical structure includes:
 a first facet formed in the optically transparent material; and 
 a second facet formed in the optically transparent material, wherein the first facet is configured to diverge the beam in reflection, and wherein the second facet is configured to diverge the beam in transmission through the second facet. 
   
     
     
         2 . The near-eye optical system of  claim 1 , wherein a reflective layer is disposed on the first facet to reflect the beam toward the second facet. 
     
     
         3 . The near-eye optical system of  claim 1 , wherein the first facet is a concave facet, and wherein the second facet is a concave facet. 
     
     
         4 . The near-eye optical system of  claim 1 , wherein the second facet includes a plurality of curvatures formed in a surface of the second facet to diverge the beam in transmission. 
     
     
         5 . The near-eye optical system of  claim 1 , wherein an angle of the first facet with respect to the beam incident on the first facet allows the first facet to rely on total internal reflection (TIR) to reflect the beam to the second facet. 
     
     
         6 . The near-eye optical system of  claim 1 , wherein at least one of the first facet or the second facet is substantially a flat surface. 
     
     
         7 . The near-eye optical system of  claim 1 , wherein at least one of the first facet or the second facet is spherical. 
     
     
         8 . The near-eye optical system of  claim 1 , wherein the beam is a near-infrared wavelength. 
     
     
         9 . The near-eye optical system of  claim 1 , wherein the light source includes a vertical-cavity surface-emitting laser (VCSEL). 
     
     
         10 . The near-eye optical system of  claim 1  further comprising:
 a camera configured to image reflections of the beam reflecting off of an eye to generate an image, wherein the camera is configured to image a near-infrared wavelength range of the beam and reject light wavelengths outside the near-infrared wavelength range. 
 
     
     
         11 . A near-eye optical system comprising:
 a plurality of light sources configured to emit a beam out of an emission aperture of the light source;   a transparent optical layer including a plurality of prisms formed in the transparent optical layer, wherein the prisms are aligned over the emission apertures of the light sources, and wherein each prism includes:
 a first facet formed in the transparent optical layer; and 
 a second facet formed in the transparent optical layer, wherein the beam exits the second facet as an exit beam, and wherein a tilt angle of the exit beam increases as a particular prism in the plurality of prisms gets closer to an outside boundary of the transparent optical layer. 
   
     
     
         12 . The near-eye optical system of  claim 11 , wherein the first facet is angled to reflect the beam to exit the second facet as the exit beam. 
     
     
         13 . The near-eye optical system of  claim 12 , wherein a reflective layer is disposed on the first facet to reflect the beam toward the second facet. 
     
     
         14 . The near-eye optical system of  claim 11 , wherein an angle of the first facet with respect to the beam incident on the first facet allows the first facet to rely on total internal reflection (TIR) to reflect the beam to the second facet. 
     
     
         15 . The near-eye optical system of  claim 11 , wherein the plurality of light sources are near-infrared light sources. 
     
     
         16 . The near-eye optical system of  claim 11 , wherein the second facet includes a plurality of curvatures formed in a surface of the second facet to diverge the beam in transmission. 
     
     
         17 . A near-eye optical system comprising:
 a plurality of light sources configured to emit a beam out of an emission aperture of the light source;   a transparent optical layer including a plurality of prisms formed in the transparent optical layer, wherein the prisms are aligned over the emission apertures of the light sources, and wherein each prism includes:
 a first facet formed in the transparent optical layer; and 
 a second facet formed in the transparent optical layer, wherein the beam exits the second facet as an exit beam, and wherein a beam divergence angle of a given light source in the plurality of light sources increases as the given light source gets closer to an outside boundary of the transparent optical layer. 
   
     
     
         18 . The near-eye optical system of  claim 17 , wherein a tilt angle of the exit beam increases as a particular prism in the plurality of prisms gets closer to an outside boundary of the transparent optical layer. 
     
     
         19 . The near-eye optical system of  claim 17 , wherein the first facet is angled to reflect the beam to exit the second facet as the exit beam. 
     
     
         20 . The near-eye optical system of  claim 17 , wherein the plurality of light sources are near-infrared light sources.