Abstract: A transparent waveguide, for use in tracking an eye illuminated by infrared light, includes an input-coupler and an output-coupler. The input-coupler includes a stack of electronically switchable diffractive gratings arranged parallel to one another, each of which has a respective lens power that causes each of the gratings in the stack to have a different focal length. Each grating, when turned on, couples received infrared light into the waveguide. A sensor images an eye in dependence on infrared light beams that exit the waveguide at the output-coupler. Images of an eye, obtained using the sensor, are analyzed to determine which one of the electronically switchable diffractive gratings, when turned on, provides a best focused image of the eye or portion thereof. The one of the electronically switchable diffractive gratings, which provides the best focused image of the eye, is used for imaging the eye during eye tracking.

Abstract: A transparent waveguide, which is for use in tracking an eye that is illuminated by infrared light having an infrared wavelength, includes a volume Bragg grating type of input-coupler adapted to receive infrared light having the infrared wavelength and couple the received infrared light into the waveguide. The volume Bragg grating includes a lower boundary and an upper boundary that is closer to the output-coupler than the lower boundary. A k-vector angle of the volume Bragg grating at the lower boundary is greater than a k-vector angle at the upper boundary, with k-vector angles of the volume Bragg grating between the lower and upper boundaries gradually decreasing as distances decrease between grating planes of the volume Bragg grating and the upper boundary. Additionally, the volume Bragg grating preferably has an angular bandwidth that is no greater than 5 degrees.

Abstract: A transparent waveguide, for use in tracking an eye illuminated by infrared light, includes an input-coupler and an output-coupler. The input-coupler includes a stack of electronically switchable diffractive gratings arranged parallel to one another, each of which has a respective lens power that causes each of the gratings in the stack to have a different focal length. Each grating, when turned on, couples received infrared light into the waveguide. A sensor images an eye in dependence on infrared light beams that exit the waveguide at the output-coupler. Images of an eye, obtained using the sensor, are analyzed to determine which one of the electronically switchable diffractive gratings, when turned on, provides a best focused image of the eye or portion thereof. The one of the electronically switchable diffractive gratings, which provides the best focused image of the eye, is used for imaging the eye during eye tracking.

Abstract: A transparent waveguide, which is for use in tracking an eye that is illuminated by infrared light having an infrared wavelength, includes a volume Bragg grating type of input-coupler adapted to receive infrared light having the infrared wavelength and couple the received infrared light into the waveguide. The volume Bragg grating includes a lower boundary and an upper boundary that is closer to the output-coupler than the lower boundary. A k-vector angle of the volume Bragg grating at the lower boundary is greater than a k-vector angle at the upper boundary, with k-vector angles of the volume Bragg grating between the lower and upper boundaries gradually decreasing as distances decrease between grating planes of the volume Bragg grating and the upper boundary. Additionally, the volume Bragg grating preferably has an angular bandwidth that is no greater than 5 degrees.

Abstract: Grating configurations are described for creating time sequenced field of view (FOV) tiles for a waveguide display. Pairings of non-output diffraction gratings and output diffraction gratings are activated to create a number of FOV tiles in a time sequence, for example in a frame update period for the image. Examples of a non-output grating are an input grating and a fold grating. For a set of at least three gratings used to make the pairings, each non-output grating is paired with each output grating. The number of pairings, and so the number of FOV tiles, is equal to a product of the total number of non-output gratings and the total number of output gratings. At least one diffraction grating in the pairing is an active pairing. Also described is a multiplexed diffraction grating including multiplexed K-vectors which increases the overall angular bandwidth for both incidence and diffraction.

Abstract: Grating configurations are described for creating time sequenced field of view (FOV) tiles for a waveguide display. Pairings of non-output diffraction gratings and output diffraction gratings are activated to create a number of FOV tiles in a time sequence, for example in a frame update period for the image. Examples of a non-output grating are an input grating and a fold grating. For a set of at least three gratings used to make the pairings, each non-output grating is paired with each output grating. The number of pairings, and so the number of FOV tiles, is equal to a product of the total number of non-output gratings and the total number of output gratings. At least one diffraction grating in the pairing is an active pairing. Also described is a multiplexed diffraction grating including multiplexed K-vectors which increases the overall angular bandwidth for both incidence and diffraction.

Abstract: A system and method are disclosed for providing uniform color distribution of light emitted from a light source to an eye box in a near eye display (NED). An example of the system and method uses an optical element including two or more waveguides optimized to different colors of the visible light spectrum. The optical element further includes one or more polarization state generators for controlling the polarization of light incident on the waveguides to facilitate coupling of light into a matched waveguide, and to impede coupling of light into unmatched waveguides.

Abstract: A system is disclosed for maintaining the spacing between waveguides in an optical element of a near eye display. Spacing is maintained with spacer elements mounted between adjacent waveguides in the optical element.

Abstract: A system and method are disclosed for providing uniform color distribution of light emitted from a light source to an eye box in a near eye display (NED). An example of the system and method uses an optical element including two or more waveguides optimized to different colors of the visible light spectrum. The optical element further includes one or more polarization state generators for controlling the polarization of light incident on the waveguides to facilitate coupling of light into a matched waveguide, and to impede coupling of light into unmatched waveguides.