A hologram that includes a formation layer and a reflection layer that are laminated. The formation layer has an optical phase modulation structure on a first interface in contact with the reflection layer. When reference light emitted from a point light source enters through a second interface different from the first interface of the formation layer, the entirety or part of an image to be reconstructed by the optical phase modulation structure is reconstructed as spatial information on the point light source side relative to the second interface.

A method for three-dimensional imaging of a sample (302) comprises: receiving (102) interference patterns (208) acquired using light-detecting elements (212), wherein each interference pattern (208) is formed by scattered light from the sample (302) and non-scattered light from a light source (206; 306), wherein the interference patterns (208) are acquired using different angles between the sample (302) and the light source (206; 306); performing digital holographic reconstruction applying an iterative algorithm to change a three-dimensional scattering potential of the sample (302) to improve a difference between the received interference patterns (208) and predicted interference patterns based on the three-dimensional scattering potential; wherein the iterative algorithm reduces a sum of a data fidelity term and a non-differentiable regularization term and wherein the iterative algorithm includes a forward-backward splitting method alternating between forward gradient descent (108) on the data fidelity term and backward gradient descent (110) on the regularization term.

To provide an authentication device and method for a security medium including a reflective volume hologram, capable of easily performing authentication determination and a security medium including the reflective volume hologram.

An authenticity determination device 1 for a security medium 10 including a reflective volume hologram 2 includes a light source L disposed on the front surface side of the reflective volume hologram 2 so that light emitted therefrom is incident on the reflective volume hologram 2, a first observation device 11 disposed in a pre-designed diffraction direction of the reflective volume hologram 2, and a second observation device 12 disposed in a direction other than the pre-designed diffraction direction of the reflective volume hologram 2. Light including a pre-designed diffraction wavelength is emitted from the light source L to be incident on the reflective volume hologram 2, and at this time, when the light amount observed in the first observation device 11 is larger in the diffraction wavelength than in other wavelengths, and the light amount observed in the second observation device 12 is smaller in the diffraction wavelength than in other wavelengths, it is determined that the reflective volume hologram 2 is genuine.

A system for generating holographic images or videos comprising a camera array, a plurality of processors, and a central computing system. A method for generating holographic images can include receiving a set of images and processing the images.

A digital holographic apparatus includes a first hologram generating unit that generates a first hologram by causing first object light in a first observation direction to interfere with first reference light, the first object light being generated by irradiating an observation object with light having a first wavelength, the first reference light being derived from the light having the first wavelength; a second hologram generating unit that generates a second hologram by causing second object light in a second observation direction that differs from the first observation direction to interfere with second reference light, the second object light being generated by irradiating the observation object with light having a second wavelength, the second reference light being derived from the light having the second wavelength; a first image capturing unit that captures the first hologram; and a second image capturing unit that captures the second hologram.

A vehicle such as a helicopter may scan a scene using a transmitter mounted on a rotating part like a rotor and a receiver mounted on a body of the vehicle. Based on a Doppler shift caused by the rotation of the rotating part, patterns may be recorded and used to develop a holographic image of the scene.

There is disclosed herein a method of light detection and ranging. The method comprises a first step of illuminating a scene with a first light pattern and monitoring for first light return from the scene with an array of detection elements. The method comprises a second step of obtaining first point cloud data from first parts of the scene where the first light return exceeds a first threshold value. The method comprises a third step of determining a second light pattern by reducing, such as substantially zeroing, the intensity of the first light pattern in the areas wherein first point cloud data was obtained. The method comprises a fourth step of illuminating the scene with the second light pattern and monitoring for second light return from the scene with the array of detection elements.

A holographic projector comprising a spatial light modulator arranged to display a hologram of a light pattern for projection and to spatially-modulate light, in accordance with display, to form a holographic reconstruction, wherein the holographic reconstruction is spatially-separated from the spatial light modulator. If the holographic projection is operating properly, the formed holographic reconstruction should correspond to the light pattern. The holographic projector also comprises a detector array comprising a plurality of light detection elements arranged to detect light corresponding to a respective plurality of positions of the holographic reconstruction and to provide a respective plurality of output signals related to light detection, and a fault detection circuit arranged to compare one or more of the plurality of output signals from the respective plurality of light detection elements with one or more of a plurality of expected signals based on the light distribution of the light pattern.

According to an embodiment, a holographic microscope comprises a light source, an optical system splitting light emitted from the light source into an object and a reflective mirror and inducing interference between light reflected by the object or transmitted through the object and light reflected by the reflective mirror, a first image sensor receiving the interference light and sensing interference information for the interference light, a second image sensor receiving the light reflected by the object or transmitted through the object and sensing information for the received light, and an image processor deriving a shape of the object based on the interference information sensed by the first image sensor and the information sensed by the second image sensor.

An apparatus and method are introduced to produce a hologram of an object from electromagnetic radiation, such as incoherent light, received from the object. The electromagnetic radiation is received by a receiving assembly and transformed into a plurality of co-linear co-propagating beams with different focal distances. The interference of the plurality of beams is enabled by projecting components of each beam along a common polarization direction. The interference patterns thus formed are recorded and then processed to form the hologram of the object.