An ultrasonic apparatus (100) for creating a holographic ultrasound field (1) comprises an ultrasound source device (10) being adapted for creating an ultrasound wave, and a transmission hologram device (20) having a transmission hologram (21) and an exposed acoustic emitter surface (22), said transmission hologram device (20) being acoustically coupled with the ultrasound source device (10) and being arranged for transmitting the ultrasound wave through the acoustic emitter surface (22) and creating the holographic ultrasound field in a surrounding space, wherein the acoustic emitter surface (22) is a smooth surface which do not influence the field distribution of the ultrasound wave. Furthermore, a method of creating a holographic ultrasound field in an object (3), wherein the ultrasonic apparatus (100) is used, and applications of the ultrasonic apparatus (100) are described.

An apparatus includes a precursor dispenser for dispensing a precursor material into a workspace, one or more acoustic sources configured to direct acoustic waves towards the workspace to provide acoustic fields that arrange the precursor material in a three-dimensional shape in the workspace, one or more sensors configured to detect a distribution of the precursor material in the workspace, and an electronic controller in communication with the precursor dispenser, the one or more acoustic sources, and the one or more sensors, the electronic controller being programmed to cause the one or more acoustic sources to adjust the acoustic fields to reduce deviations in the distribution of the precursor material from the three-dimensional shape in the workspace.

A phase distribution is calculated such that modulated light has a predetermined intensity distribution on a target plane and displayed on a phase modulation plane, readout light enters the phase modulation plane so as to generate the modulated light. When calculating the phase distribution, a region on the phase modulation plane is divided into N regions A.sub.1 . . . A.sub.N, with sizes set such that integration values of an intensity distribution in the regions are equal to each other. Further, a region on the target plane is divided into N regions B.sub.1 . . . B.sub.N, with sizes set such that integration values of an intensity distribution in the regions are equal to each other. The phase distribution is calculated by obtaining an optical path length from the region A.sub.n to the region B.sub.n, and determining the phase of the region A.sub.n based on the optical path length.

The present disclosure provides methods and systems for the three-dimensional (3D) printing of 3D objects. Methods and systems provided herein may comprise 3D holographic lithography which may enable the 3D printing of various shapes. Methods and systems provided herein may enable high efficiency 3D holographic printing and may avoid, for example, problems zero-order defects. Methods and systems provided herein comprise methods for printing 3D objects with reduced or minimal inconsistency.

A method to form a three-dimensional photonic crystal template with a gradient structure involves irradiating a photoresist composition of a thickness of at least 15 μm from at least four laser beams to yield a periodic patterned with a percolating matrix of mass in constructive volumes of a cured photoresist composition and destructive volumes of voids free of condensed matter where the proportion of constructive volume displays a gradient from the irradiated surface to the substrate after development. For a given light intensity, photoinitiator concentration in the photoresist composition, and a given thickness, by irradiating for a relatively short period, a three-dimensional photonic crystal template displaying a gradient having greater constructive volume proximal the air interface forms and a relatively long irradiation period results in a gradient having greater constructive volume proximal the substrate.

A display device according to an embodiment of the present disclosure includes: a transparent screen; one or more imaging units; and a video projection unit that acquires positional information regarding a predetermined subject included in each of captured images obtained by the one or more imaging units and then irradiates the transparent screen with video light on the basis of the positional information to cause predetermined video to appear on the transparent screen for the subject.

A laser beam irradiation unit of a laser processing apparatus includes a laser oscillator, a condenser lens that condenses a laser beam emitted from the laser oscillator, and a phase modulation element arranged between the laser oscillator and the condenser lens. Individual differences of the condenser lens are prevented by applying, to the phase modulation element, voltages corresponding to a combined pattern of a shape correction pattern which is configured to correct differences between an actual shape and design values of the condenser lens, and an adjustment pattern which is configured to adjust optical characteristics of the laser beam at each processing point.

An apparatus includes a precursor dispenser for dispensing a precursor material into a workspace, one or more acoustic sources configured to direct acoustic waves towards the workspace to provide acoustic fields that arrange the precursor material in a three-dimensional shape in the workspace, one or more sensors configured to detect a distribution of the precursor material in the workspace, and an electronic controller in communication with the precursor dispenser, the one or more acoustic sources, and the one or more sensors, the electronic controller being programmed to cause the one or more acoustic sources to adjust the acoustic fields to reduce deviations in the distribution of the precursor material from the three-dimensional shape in the workspace.

A diffractive optical element, such as a holographic plasma lens, can be made by direction two laser beams so that they overlap in a nonlinear material, to form an interference pattern in the nonlinear material. The interference pattern can modify the index of refraction in the nonlinear material to produce the diffractive optical element. The interference pattern can modify the distribution of plasma for the nonlinear material, which can adjust the index of refraction. A third laser beam can be directed through the diffractive optical element to modify the third laser beam, such as to focus, defocus, or collimate the third laser beam.

An embodiment of the invention relates to a method for carrying out a time-resolved interferometric measurement comprising the steps of generating at least two coherent waves, overlapping said at least two coherent waves and producing an interference pattern, measuring the interference pattern for a given exposure time, thereby forming measured interference values, and analyzing the measured interference values and extracting amplitude and/or phase information from the measured interference values. In at least one time segment, hereinafter referred to as disturbed time segment, of the expo-sure time, the interference pattern is intentionally disturbed or destroyed such that the corresponding measured interference values describe a disturbed or destroyed interference pattern. In at least one other time segment, hereinafter referred to as undisturbed time segment, of the exposure time, the interference pattern is undisturbed or at least less disturbed compared to the disturbed time segment such that the corresponding measured interference values describe an undisturbed or less disturbed interference pattern. The measured interference values that were measured during the entire given exposure time, are filtered, wherein those interference values that were measured during the at least one disturbed time segment, are reduced, suppressed or discarded. The filtered interference values are analyzed and the amplitude and/or phase information is extracted from the filtered interference values.