Patent classifications
G03H2270/21
SYSTEMS, DEVICES, AND METHODS FOR APERTURE-FREE HOLOGRAM RECORDING
Systems, devices, and methods for aperture-free hologram recording are described. The apertures typically used for hologram recording create unwanted secondary holograms by diffracting light. Aperture-free hologram recording eliminates these unwanted secondary holograms. Aperture-free hologram recording includes applying a mask to the holographic recording medium. The mask controls the size of the recorded hologram like an aperture but does not create unwanted secondary holograms. Hologram fringes are only present in the desired recording area and a thin boundary region. The mask may be present during recording, or the mask may be used to pre-bleach the holographic recording medium. Pre-bleaching the holographic recording medium renders a portion of the holographic recording medium insensitive to light, the hologram is recorded in the light-sensitive portions of the holographic recording medium.
SYSTEMS, DEVICES, AND METHODS FOR APERTURE-FREE HOLOGRAM RECORDING
Systems, devices, and methods for aperture-free hologram recording are described. The apertures typically used for hologram recording create unwanted secondary holograms by diffracting light. Aperture-free hologram recording eliminates these unwanted secondary holograms. Aperture-free hologram recording includes applying a mask to the holographic recording medium. The mask controls the size of the recorded hologram like an aperture but does not create unwanted secondary holograms. Hologram fringes are only present in the desired recording area and a thin boundary region. The mask may be present during recording, or the mask may be used to pre-bleach the holographic recording medium. Pre-bleaching the holographic recording medium renders a portion of the holographic recording medium insensitive to light, the hologram is recorded in the light-sensitive portions of the holographic recording medium.
SYSTEMS, DEVICES, AND METHODS FOR APERTURE-FREE HOLOGRAM RECORDING
Systems, devices, and methods for aperture-free hologram recording are described. The apertures typically used for hologram recording create unwanted secondary holograms by diffracting light. Aperture-free hologram recording eliminates these unwanted secondary holograms. Aperture-free hologram recording includes applying a mask to the holographic recording medium. The mask controls the size of the recorded hologram like an aperture but does not create unwanted secondary holograms. Hologram fringes are only present in the desired recording area and a thin boundary region. The mask may be present during recording, or the mask may be used to pre-bleach the holographic recording medium. Pre-bleaching the holographic recording medium renders a portion of the holographic recording medium insensitive to light, the hologram is recorded in the light-sensitive portions of the holographic recording medium.
Holographic substrate-guided wave-based see-through display
A holographic substrate-guided wave-based see-through display has a microdisplay, capable of emitting light in the form of an image. The microdisplay directs its output to a holographic optical element, capable of accepting the image from the microdisplay, and capable of transmitting the light. The holographic optical element couples its output to an elongate substrate, capable of accepting the light from the holographic optical element at a first location, and transmitting the light along a length of the substrate by internal reflection to a second location, the elongate substrate being capable of transmitting the accepted light from the second location. The substrate couples out what it receives to a transparent holographic optical element, capable of accepting the light transmitted from the substrate and transmitting it to a location outside of the holographic optical element as a viewable image.
Methods and Apparatus for Compensating Image Distortion and Illumination Nonuniformity in a Waveguide
Typical waveguides rely on total internal reflection between the outer surfaces of substrates, which can make them highly susceptible to beam misalignment caused by nonplanarity of the substrates. In the manufacturing of the glass sheets commonly used for substrates, ripples can occur during the stretching and drawing of glass as it emerges from a furnace. Although glass manufacturers try to minimize ripples using predictions from mathematical models, it is difficult to totally eradicate the problem from the glass manufacturing process. Typically, these beam misalignments manifest themselves as image distortions and non-uniformities in the output illumination from the waveguide. Many embodiments of the invention are directed toward optically efficient, low cost solutions to the problem of controlling output image quality in waveguides manufactured using commercially available substrate glass and to the problem of compensating the image distortions and non-uniformity of curved waveguides.
OPTICAL ARTICLE WITH A HOLOGRAPHIC WAVEGUIDE
An optical article including a substrate, and a holographic waveguide covering at least part of the substrate and including two main surfaces, at least one of them conforming to a surface of the substrate, and at least first and second zones that are configured so that light incoming on one of the first and second zones is at least partially guided towards the other of the first and second zones.
SYSTEMS, DEVICES, AND METHODS FOR HOLOGRAPHIC OPTICAL ELEMENTS
Systems, devices, and methods for holographic optical elements are described. A holographic optical element includes a first layer of holographic material and a second layer of holographic material. The first layer of holographic material includes a first hologram responsive to light in a first waveband and a second hologram responsive to light in a second waveband. The second layer of holographic material includes a third hologram responsive to light in a third waveband and may include a fourth hologram responsive to light in a fourth waveband. The first, second, third, and fourth wavebands are distinct and may comprise light of red, blue, green, and infrared wavelengths, respectively. Distribution of the three or four holograms on two layers of holographic material allows each hologram to have an index modulation of greater than 0.016, a diffraction efficiency of greater than 15%, and an angular bandwidth of greater than 12.
SYSTEMS, DEVICES, AND METHODS FOR HOLOGRAPHIC OPTICAL ELEMENTS
Systems, devices, and methods for holographic optical elements are described. A holographic optical element includes a first layer of holographic material and a second layer of holographic material. The first layer of holographic material includes a first hologram responsive to light in a first waveband and a second hologram responsive to light in a second waveband. The second layer of holographic material includes a third hologram responsive to light in a third waveband and may include a fourth hologram responsive to light in a fourth waveband. The first, second, third, and fourth wavebands are distinct and may comprise light of red, blue, green, and infrared wavelengths, respectively. Distribution of the three or four holograms on two layers of holographic material allows each hologram to have an index modulation of greater than 0.016, a diffraction efficiency of greater than 15%, and an angular bandwidth of greater than 12.
SYSTEMS, DEVICES, AND METHODS FOR HOLOGRAPHIC OPTICAL ELEMENTS
Systems, devices, and methods for holographic optical elements are described. A holographic optical element includes a first layer of holographic material and a second layer of holographic material. The first layer of holographic material includes a first hologram responsive to light in a first waveband and a second hologram responsive to light in a second waveband. The second layer of holographic material includes a third hologram responsive to light in a third waveband and may include a fourth hologram responsive to light in a fourth waveband. The first, second, third, and fourth wavebands are distinct and may comprise light of red, blue, green, and infrared wavelengths, respectively. Distribution of the three or four holograms on two layers of holographic material allows each hologram to have an index modulation of greater than 0.016, a diffraction efficiency of greater than 15%, and an angular bandwidth of greater than 12.
Holographic display
A display device includes an optical sensor configured to image a user eye, an image source configured to provide image light, a holographic film including a plurality of holograms, and a controller. Each hologram is recorded with a same reference beam but recorded differently so as to differently diffract image light received from the light source. The controller is configured to determine, via the optical sensor, a position of the user eye, and adjust, based on the determined position of the user eye, a state of the holographic film such that a particular hologram of the plurality of holograms diffracts image light to the position of the user eye.