The present invention describes methods and apparatuses for creating superposition shape images by superposed base and revealing layers of lenslet gratings. The superposition shape images form a message recognizable by a human observer or by an image acquisition and computing device such as a smartphone. The superposition shape images may be created by different superposition techniques ranging from 1D moir, 2D moir and level-line moir superposition techniques to lenticular image and phase shift superposition techniques. Moir superposition techniques enable creating superposition shape images at different apparent depth levels. Applications comprise the protection of documents and valuable articles against counterfeits, the creation of eye-catching advertisements as well as the decoration of buildings and exhibitions.

A phase object visualization apparatus includes: an illumination optical system 11 that illuminates a phase object; an image formation optical system 12 that forms an image from light from sample S that corresponds to the phase object; and light blocking unit 10 for blocking light, the light blocking unit 10 being disposed between the sample S and an image plane formed by the image formation optical system 12, and including an aperture at a position decentered from the optical axis of the image formation optical system 12. The position of the aperture is such that an area occupied on the aperture by 0-order diffraction light from the sample S illuminated by the illumination optical system 11 becomes smaller than the total area of the aperture.

A phase object visualization apparatus includes: an illumination optical system 11 that illuminates a phase object; an image formation optical system 12 that forms an image from light from sample S that corresponds to the phase object; and light blocking unit 10 for blocking light, the light blocking unit 10 being disposed between the sample S and an image plane formed by the image formation optical system 12, and including an aperture at a position decentered from the optical axis of the image formation optical system 12. The position of the aperture is such that an area occupied on the aperture by 0-order diffraction light from the sample S illuminated by the illumination optical system 11 becomes smaller than the total area of the aperture.

A dual-modulation projection system (100) includes a light source (102), a phase modulator (104), an amplitude modulator (106), and a controller (110) having temporal lightfield simulation capabilities (114). The phase modulator (104) spatially modulates a lightfield from the light source (102) to generate an intermediate image on the amplitude modulator (106). The amplitude modulator (106) spatially modulates the intermediate image to form a final image. The controller (110) models the phase state of the phase modulator (104) during transitions between phase modulator frames and generates lightfield simulations of the intermediate image during the transition. The controller (110) utilizes the lightfield simulations to generate and provide sets of amplitude drive values to the amplitude modulator (106) at a faster rate than that at which the phase modulator (104) is capable of switching.

A method and system for imaging in degraded visual environments. The system includes a laser that is positioned to transmit a Gaussian beam toward a target object located within the degraded visual environment. An optical receiver is positioned to receive return signals. A helical phase element is positioned between the target object and the optical receiver. The return signals pass through the helical phase element. The helical phase element separates coherent and incoherent light by imparting orbital angular momentum on the coherent returns to form an optical vortex.

A method for measuring a spatial distortion of a target surface (110) of a workpiece (110A). Light is transmitted twice through a reference pattern-generator (104) and impinged upon a workpiece pattern-generator (108). Then, with an optical detector (116), first and second beams formed by the light as a result of interaction with two pattern-generators (104) (106) is acquired to produce a signal characterizing geometry of interference fringes formed at the detector (116) by the first and second beams. Indicia representing at least one of a type and a value of spatial distortion of the target surface (110) is generated and recorded. A system embodying the implementation of the method.

A method for measuring a spatial distortion of a target surface (110) of a workpiece (110A). Light is transmitted twice through a reference pattern-generator (104) and impinged upon a workpiece pattern-generator (108). Then, with an optical detector (116), first and second beams formed by the light as a result of interaction with two pattern-generators (104) (106) is acquired to produce a signal characterizing geometry of interference fringes formed at the detector (116) by the first and second beams. Indicia representing at least one of a type and a value of spatial distortion of the target surface (110) is generated and recorded. A system embodying the implementation of the method.

A new projector design combines one spatial light modulator that affects only the phase of the illumination, and one spatial light modulator that only affects its amplitude (intensity). The phase-only modulator curves the wavefront of light and acts as a pre-modulator for a conventional amplitude modulator. This approach works with both white light and laser illumination, generating a coarse image representation efficiently, thus enabling, within a single image frame, significantly elevated highlights as well as darker black levels while reducing the overall light source power requirements.

A new projector design combines one spatial light modulator that affects only the phase of the illumination, and one spatial light modulator that only affects its amplitude (intensity). The phase-only modulator curves the wavefront of light and acts as a pre-modulator for a conventional amplitude modulator. This approach works with both white light and laser illumination, generating a coarse image representation efficiently, thus enabling, within a single image frame, significantly elevated highlights as well as darker black levels while reducing the overall light source power requirements.

A wavefront measuring device and method obtain wavefront information of an optical system. The method including: irradiating the optical system with a light beam; allowing the light beam passed via the optical system to come into a diffraction grating having periodicity in a first direction; and obtaining the wavefront information based on an interference fringe formed by light beams generated from the diffraction grating. The diffraction grating including: first portions which allow light to pass therethrough; and second portions which shield light, each of the second portions being provided between two of the first portions. A ratio between a width of one of the first portions in the first direction and a width of one of the second portions in the first direction is changed in the first direction, the one of the first portions and the one of the second portions being adjacent to each other.