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.

Example embodiments relate to methods and imaging systems for holographic imaging. One embodiment includes a method for holographic imaging of an object. The method includes driving a laser using a current which is below a threshold current of the laser. The method also includes illuminating the object using illumination light output by the laser. Further, the method includes detecting an interference pattern formed by object light, having interacted with the object, and reference light of the illumination light.

The present disclosure relates to improved holographic reconstruction device and a method. In one aspect, the present disclosure relates to improved holographic reconstruction device and method that can measure a digital hologram regardless of optical characteristics of an object to be measured, by an all-in-one type system integrating a transmissive system that measures an object transmitting light and a reflective system that measures an object reflecting light.

A holographic optical element and a method for producing the same are disclosed herein. In some embodiments, a method includes illuminating a first surface of a photopolymer resin layer, where the photopolymer resin layer comprises a photopolymer resin, illuminating a second surface of the photopolymer resin layer through a retardation layer disposed in the second surface, wherein the second surface is opposite the first surface, and recording an interference pattern in the photopolymer resin layer, wherein the interference pattern is created by interference between the first parallel laser beam and the second parallel laser beam. The holographic optical element is produced using a retardation layer to prevent an unwanted interference pattern from being formed in the process of recording an interference pattern in a photopolymer resin layer.

A light source device connected to an optical fiber and emit light from the optical fiber, the device includes: a plurality of laser light sources to respectively emit light at different wavelengths; a current source to supply a drive current with a superimposed alternating-current component to each laser light source; a light source control section to selectively switch the laser light sources by controlling the current sources; a plurality of optical systems disposed in optical paths of the respective laser light sources to reflect the light from the respective laser light sources to an incident end of the optical fiber and to reflect return light reflected on the incident end to the respective laser light sources; and a return light adjustment section to adjust an amount of the return light to continuously spread a spectrum of the light emitted from the optical fiber.

A projection system that facilitates the use of in-situ detection of a change in wavelength, thereby enabling appropriate compensation or corrections to be applied on the fly to improve the quality of the image in the primary image region. In-situ detection in this manner can allow wavelength changes due to both temperature fluctuations and hardware variations to be compensated for simultaneously, thereby reducing the time and expense for end of line hardware testing, and removing the need to perform in-situ mapping of the wavelength as a function of temperature. In this way, the quality of the image provided to a user can be improved in a simpler, more efficient manner.

A multi-image display apparatus includes a light source configured to emit a first wavelength light, a second wavelength light, and a third wavelength light, a spatial light modulator configured to modulate the first wavelength light, the second wavelength light, and the third wavelength light to form a first image including a first color holographic image, a second color holographic image, and a third color holographic image, a polarization selective lens configured to focus the first image having only a first polarization component and transmit a second image having only a second polarization component without refraction, the second image being provided to the polarization selective lens along a different path from the first image, wherein chromatic aberration of the polarization selective lens is offset by adjusting a depth of the first color holographic image, the second color holographic image, and the third color holographic image.

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.

A control device includes a processor. The processor acquires positional information indicating a position of an observation target. The processor sets, from among a plurality of irradiation positions, a required irradiation position, which is an irradiation position corresponding to the position of the observation target indicated by the positional information and is an irradiation position required for obtaining a plurality of the interference fringe images that are sources of a super-resolution interference fringe image having a resolution exceeding a resolution of an imaging element. The processor causes a light source to emit an illumination light from the required irradiation position by controlling an operation of the light source, and causes the imaging element to outputs the interference fringe image at each required irradiation position.

An illumination device for illuminating a spatial light modulator device. Sub-holograms are used for encoding a hologram into the spatial light modulator device. The Illumination device includes at least one light source for emitting light for illuminating the spatial light modulator device and a beam shaping unit. The beam shaping unit provides a flat-top plateau-type distribution of an absolute value of a complex degree of mutual coherence of the light in a plane of the spatial light modulator device to be illuminated. The flat-top plateau-type distribution of the absolute value of the complex degree of mutual coherence has a shape that is at least similar to a shape of the largest sub-hologram used for encoding of object points into the spatial light modulator device.