Disclosed are methods and systems for displaying images, and for implementing volumetric user interfaces. One exemplary embodiment provides a system comprising: a light source; an image producing unit, which produces an image upon interaction with light approaching the image producing unit from the light source; an eyepiece; and a mirror, directing light from the image to a surface of the eyepiece, wherein the surface has a shape of a solid of revolution formed by revolving a planar curve at least 180 around an axis of revolution.

A phase-modulated optical component for the visible spectrum is provided and is capable of producing images in three primary colors. The phase-modulated optical component is primarily structured by a plurality of aluminum nanorods that are arranged in several two-dimensional arrays to form a plurality of pixels. The nanorods can yield surface plasmon resonances in red, green and blue light. By tuning the nanorod size in the arrays, the wavelength-dependent reflectance thereof can be varied across the visible spectrum, thereby realizing wavelength division multiplexing operations for the phase-modulated optical component.

An optical reflective device referred to as a skew mirror, having a reflective axis that need not be constrained to surface normal, is described. Examples of skew mirrors are configured to reflect light about a constant reflective axis across a relatively wide range of wavelengths. In some examples, a skew mirror has a constant reflective axis across a relatively wide range of angles of incidence. Exemplary methods for making and using skew mirrors are also disclosed. Skew mirrors include a grating structure, which in some examples comprises a hologram.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, an optical device includes: a first optically diffractive component including a first diffractive structure configured to diffract a first color of light having a first incident angle at a first diffracted angle, a second optically diffractive component including a second diffractive structure configured to diffract a second color of light having a second incident angle at a second diffracted angle, a first reflective layer configured to totally reflect the first color of light having the first incident angle and transmit the second color of light, and a second reflective layer configured to totally reflect the second color of light having the second incident angle. The first reflective layer is between the first and second diffractive structures, and the second diffractive structure is between the first and second reflective layers.

The present invention features new waveguide layouts for input, redirection (expansion), and output holograms that minimize cross talk between colors and allow all three colors to reside in a single waveguide. The use of multiple incoupling holograms that diffract different colors of light in different directions, or along different paths, through a waveguide substrate advantageously provides for a reduction of cross-talk between the colors of a holographic image. In a square-shaped design, red, green, and blue input and output holograms approximately overlay on top of each other. The green redirection hologram is laterally separated from the red and blue redirection holograms. Using this square-shape design, the light beams for the three colors are separated into two paths propagating from input to output holograms.

An imaging module of a projection device generates a multi-color image such that a first color sub-image with a first wavelength and a second color sub-image with a second wavelength are generated. Deflection efficiency curves for a specified angular range about a specified viewing angle are set such that a first efficiency ratio for the specified angular range is constant. The imaging module is actuated such that when the multi-color image is generated, a first brightness ratio of the brightness of the first color sub-image to the brightness of the second color sub-image is inversely proportional to the a efficiency ratio such that different deflection efficiency curves are compensated for and such that the viewer can perceive the multi-color image as a true-color virtual image at viewing angles from the specified angular range.

Examples include imaging one or more objects contained inside a droplet. A method includes generating at least one hologram of the one or more objects contained in the droplet by using in-line lens-free imaging. The at least one hologram includes at least one artifact that is caused by the droplet and that affects the at least one characteristic of the one or more objects contained in the droplet. The method includes at least partially removing the at least one artifact or the cause of the at least one artifact. The method further includes generating an image, after or during removing the at least one artifact or the cause of the at least one artifact. The image includes the one or more objects. The method also comprises recognizing the at least one characteristic of the one or more objects based on the image.

The present method includes a data acquisition process and tomographic image generation processes. In the data acquisition process, holograms of an object light and so forth are acquired for each light with a wavelength by changing the wavelengths of the illumination light, off-axis spherical wave reference light, and inline spherical wave reference light. In the tomographic image generation process, a reconstructed light wave of the object light and a reconstructed light wave of the illumination light on a reconstruction surface are generated from these holograms. A reconstruction light wave with adjusted phase is added up for each wavelength to generate a tomographic hologram. From this, an accurate and focused tomographic image without distortion can be generated.

The present disclosure relates to apparatuses and methods for performing in-line lens-free digital holography of objects. At least one embodiment relates to an apparatus for performing in-line lens-free digital holography of an object. The apparatus includes a point light source adapted for emitting coherent light. The apparatus also includes an image sensing device adapted and arranged for recording interference patterns resulting from interference from light waves directly originating from the point light source and object light waves. The object light waves originate from light waves from the point light source that are scattered or reflected by the object. The image sensing device comprises a plurality of pixels. The point light source comprises a broad wavelength spectrum light source and a pinhole structure. The image sensing device comprises a respective narrow band wavelength filter positioned above each pixel that filters within a broad wavelength spectrum of the point light source.

Disclosed are methods and systems for displaying images, and for implementing volumetric user interfaces. One exemplary embodiment provides a system comprising: a light source; an image producing unit, which produces an image upon interaction with light approaching the image producing unit from the light source; an eyepiece; and a mirror, directing light from the image to a surface of the eyepiece, wherein the surface has a shape of a solid of revolution formed by revolving a planar curve at least 180 around an axis of revolution.