Abstract: An apparatus, system, and method for a hologram recording system include a recording medium, a light source, and optical elements. The recording medium is configured to record a hologram. At least one light source is configured to provide a writing beam. The optical elements are positioned in a light path of the writing beam and are configured to condition the writing beam to record the hologram at least partially in the volume. The optical elements may include at least one toric optical element and a mirror. The toric optical element may be configured to subtract a quadratic phase from a wavefront of the writing beam, and the mirror may be configured to subtract a linear phase from the wavefront of the writing beam.

Abstract: An apparatus, system, and method for a waveguide system may be used to support eye tracking in a head mounted display (HMD). The waveguide system may be positioned in a user's field of view and within a lens assembly of the HMD to capture light that is reflected from an eye. The waveguide system may include a waveguide, a first diffraction grating, and a second diffraction grating. The first diffraction grating may be configured to in-couple light of a first wavelength into the waveguide, and the second diffraction grating may be configured to in-couple light of a second wavelength. The first and second diffraction gratings operate together to detect light reflections from an eyebox region.

Abstract: An apparatus, system, and method for a waveguide system may be used to support eye tracking in a head mounted display (HMD). The waveguide system may be positioned in a user's field of view and within a lens assembly of the HMD to capture light that is reflected from an eye. The waveguide system may have a number of multi-directional gratings configured to direct light to an out-coupling grating. The multi-directional gratings include first and second in-coupling diffraction gratings disposed in a waveguide. The first and second in-coupling diffraction gratings are oriented to direct incident light in multiple directions within the waveguide towards the out-coupling diffraction grating.

Abstract: An apparatus, system, and method for a waveguide system may be used to support eye tracking in a head mounted display. The waveguide system may be positioned in a user's field of view and within a lens assembly of an HMD to capture light that is reflected from an eye. The waveguide system may include a waveguide, a first diffraction grating, and a second diffraction grating. The first diffraction grating may be configured to in-couple light into the waveguide from an eyebox region. The first diffraction grating may be a rolled diffraction grating having slanted grating planes that receive light from a larger surface area and direct the light onto a smaller surface area. The second diffraction grating may receive the light from the first diffraction grating in the waveguide and may be configured to out-couple the light from the waveguide onto an image sensor.

Abstract: An apparatus, system, and method for a waveguide system may be used to support eye tracking in a head mounted display (HMD). The waveguide system may be positioned in a user’s field of view and within a lens assembly of the HMD to capture light that is reflected from an eye. The waveguide system may have a number of multi-directional gratings configured to direct light to an out-coupling grating. The multi-directional gratings include first and second in-coupling diffraction gratings disposed in a waveguide. The first and second in-coupling diffraction gratings are oriented to direct incident light in multiple directions within the waveguide towards the out-coupling diffraction grating.

Abstract: An apparatus, system, and method for a waveguide system may be used to support eye tracking in a head mounted display (HMD). The waveguide system may be positioned in a user’s field of view and within a lens assembly of the HMD to capture light that is reflected from an eye. The waveguide system may include a waveguide, a first diffraction grating, and a second diffraction grating. The first diffraction grating may be configured to in-couple light of a first wavelength into the waveguide, and the second diffraction grating may be configured to in-couple light of a second wavelength. The first and second diffraction gratings operate together to detect light reflections from an eyebox region.

Abstract: A flow conduit includes surface-enlarging members for cooling fluid in the flow conduit. The surface-enlarging members include cooling blades that extend outwards and downwards from the surface of the flow conduit.