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 (Δn), therefore control of side lobe magnitude may be achieved by controlling the distribution of Δn. The distribution of Δn 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 Δn.

Disclosed are optical interrogation apparatus that can produce lens-free images using an optoelectronic sensor array to generate a holographic image of sample objects, such as microorganisms in a sample. Also disclosed are methods of detecting and/or identifying microorganisms in a biological sample, such as microorganisms present in low levels. Also disclosed are methods of using systems to detect microorganisms in a biological sample, such as microorganisms present in low levels. In addition or as an alternative, the methods of using systems may identify microorganisms present in a sample and/or determine antimicrobial susceptibility of such microorganisms.

A beam deflection layer includes: a first selective polarization conversion-splitter that splits first color light in an incident light beam into 1A color light and 1B color light having different polarization directions from each other; a first beam deflector that deflects the 1A first first color light in the light beam from the 1A first selective polarization conversion-splitter, a first selective polarization converter that converts polarization directions of the 1A first first color light and the 1B second first color light in the light beam from the 1A first beam deflector, and a 1B second beam deflector configured to deflect the 1B second first color light in the light beam from the first selective polarization converter. The first color light, the 1A color light, and the 1B color light each have a first wavelength band.

A dual-image projection apparatus includes a light source, a spatial light modulator including a first modulation module and a second nodulation module, and a Fourier lens. The spatial light modulator is positioned at a front focal plane of the Fourier lens. The first modulation module modulates light from the light source through the Fourier lens to reproduce a first 2D holographic image and the second modulation module modulates the light through the Fourier lens to reproduce a plurality of second 2D holographic images. The dual-image projection apparatus further includes a first light-diffusing film to display the first 2D holographic image to produce a first virtual image and a plurality of second light-diffusing films to respectively display the plurality of second 2D holographic images sequentially in a rate to produce a 3D virtual image.

There is provided a holographic projector comprising a hologram engine and a controller. The hologram engine is arranged to provide a hologram comprising a plurality of hologram pixels. Each hologram pixel has a respective hologram pixel value. The controller is arranged to selectively-drive a plurality of light-modulating pixels so as to display the hologram. Displaying the hologram comprises displaying each hologram pixel value on a contiguous group of light-modulating pixels of the plurality of light-modulating pixels such that there is a one-to-many pixel correlation between the hologram and the plurality of light-modulating pixels.

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.

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.

There is provided a holographic projector comprising a hologram engine and a controller. The hologram engine is arranged to provide a hologram comprising a plurality of hologram pixels. Each hologram pixel has a respective hologram pixel value. The controller is arranged to selectively-drive a plurality of light-modulating pixels so as to display the hologram. Displaying the hologram comprises displaying each hologram pixel value on a contiguous group of light-modulating pixels of the plurality of light-modulating pixels such that there is a one-to-many pixel correlation between the hologram and the plurality of light-modulating pixels.

A replicator assembly includes reflective, transmissive, and transparent elements. The reflective element receives and reflects a hologram of a HUD system. The transmissive element includes a partially transmissive portion that receives a reflection of the hologram from the reflective element, outputs N replications of the hologram, and reflects N−1 replications of the hologram. The partially transmissive portion is implemented as a continuous transmission neutral density filter across different phase regions. The phase regions of the partially transmissive portion correspond respectively to the N replications. N is an integer greater than or equal to 2. The reflective element reflects the N−1 replications of the hologram. The transparent element is disposed between the reflective and transmissive elements and guides the N replications of the hologram between the reflective and transmissive elements. The reflective, transmissive and transparent elements are implemented as a replicator and collectively provide the N replications of the hologram.

This application relates to a see-through head-mounted display using recorded substrate-guided holographic continuous lens (SGHCL) and a microdisplay with narrow spectral band source or laser illumination. The high diffraction efficiency of the volume SGHCL creates very high luminance of the virtual image.