Disclosed herein are systems and techniques related to virtual image projection systems. In some examples, the system may include a scanning mirror arrangement for receiving a light beam and reflecting the light beam to a projection surface and a dynamic optical lens for focusing the light beam at a focal plane so that the light beam reflected from the projection surface is collimated or diverging enabling the projected image to be perceived as a virtual image.

There is provided a metasurface structure including a plurality of sub-wavelength structures operable to manipulate optical signal/radiation to which metasurface structure is exposed to or irradiated with. The plurality of sub-wavelength structures is arranged such that the metasurface structure is operable to display a first image based on image data embedded or encoded by the sub-wavelength structures when the metasurface structure is exposed to or irradiated with a first optical signal/radiation, and the metasurface structure is operable to display a second image based on image data embedded or encoded by the sub-wavelength structures when the metasurface structure is exposed to or irradiated with a second optical signal/radiation different from the first optical signal/radiation. The first image includes an optical-printing image and the second image includes one or more holographic images.

Systems, devices, and methods for side lobe control in holograms are described. The magnitude of the side lobes of a hologram depends on the distribution of refractive index modulation (n), therefore control of side lobe magnitude may be achieved by controlling the distribution of n. The distribution of n may be controlled by replicating a hologram from a master with two reference beams, where the wavelength and angle of each reference beam, the playback angle of the master hologram, and the thickness of the master hologram, the copy holographic recording medium (HRM), and the recording substrate are carefully chosen to achieve a pattern of meta-interference within the HRM that matches the desired distribution of n.

Systems, devices, and methods for side lobe control in holograms are described. The magnitude of the side lobes of a hologram depends on the distribution of refractive index modulation (n), therefore control of side lobe magnitude may be achieved by controlling the distribution of n. The distribution of n may be controlled by replicating a hologram from a master with two reference beams, where the wavelength and angle of each reference beam, the playback angle of the master hologram, and the thickness of the master hologram, the copy holographic recording medium (HRM), and the recording substrate are carefully chosen to achieve a pattern of meta-interference within the HRM that matches the desired distribution of n.

Systems, devices, and methods for side lobe control in holograms are described. The magnitude of the side lobes of a hologram depends on the distribution of refractive index modulation (n), therefore control of side lobe magnitude may be achieved by controlling the distribution of n. The distribution of n may be controlled by replicating a hologram from a master with two reference beams, where the wavelength and angle of each reference beam, the playback angle of the master hologram, and the thickness of the master hologram, the copy holographic recording medium (HRM), and the recording substrate are carefully chosen to achieve a pattern of meta-interference within the HRM that matches the desired distribution of n.

A holographic sporting/combat optic may be mounted to weapon. To control the optical path at the holographic recording level, the holographic sporting/combat optic uses a single glass carrier with a holographic optical element for collimating mounted on one side and a second holographic optical element for projecting a reticle image mounted on an opposing side of the carrier. In some cases, the holographic optical elements may be implemented by emulsions disposed on opposing surfaces of the carrier. In this way, the holographic sporting/combat optic simplifies the manufacturing process while improving accuracy.

A holographic sporting/combat optic may be mounted to weapon. The sporting/combat optic includes a holographic optical element that projects a composite reticle image having at least two reticle elements. The first reticle element projects into the optical viewing window in response to light having a first wavelength; whereas, the second reticle element projects into the optical viewing window in response to light having a second wavelength which differs from the first wavelength. By selectively turning on and off different light sources, the reticle elements can be selectively projected into the optical viewing window of the sporting/combat optic.

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 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 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.