23 results about "Phase grating" patented technology

The present disclosure provides a real-time holographic system and a real-time optical reconstruction method, which relate to the field of holographic technology. The system comprises: a first laser, adapted to generate nanosecond pulse light; a first beam splitter, adapted to split the nanosecond pulse light into reference light and detection light, the detection light being incident on an object to be measured and generating object light having information about the object to be measured; a reconstruction light timing module, adapted to generate reconstruction light having timed femtosecond pulse information; a dichroic mirror, adapted to generate combined light based on the incident reference light and reconstruction light; a holographic dry plate, adapted to receive the combined light and object light, so that the reference light and object light in the combined light interfere on the holographic dry plate to form a phase grating, thereby recording optical information; and a multi-frame imaging module, adapted to receive the reconstruction light and form a diffraction wave based on the phase grating, thereby reading the optical information with a time resolution of the order of picoseconds.

This invention discloses a quartz crystal Y-type optical beamsplitter capable of nonlinear frequency conversion in the deep ultraviolet band, belonging to the field of optoelectronic device technology. It includes a quartz crystal with a Y-type ridge waveguide structure on its surface. The Y-type ridge waveguide structure includes an input arm, the end of which is connected to the beginning of two branch arms. Each branch arm is connected to an output arm parallel to the input arm. One output arm contains a periodic phase grating structure arranged along the light transmission direction of the quartz crystal. The periodic phase grating structure is composed of several single-cycle femtosecond laser-modified regions and several unmodified regions arranged periodically. The Y-type optical beamsplitter disclosed in this invention integrates optical beam splitting and nonlinear frequency conversion functions, allowing for the low-loss output of both a fundamental ultraviolet beam and a deep ultraviolet frequency-doubled beam from an input fundamental ultraviolet light beam.

This invention discloses an infrared optical frequency conversion element and a converter and laser using the same. It employs a nonlinear optical polycrystalline transparent ceramic. The nonlinear optical polycrystalline transparent ceramic has periodically distributed processed and unprocessed regions along the light transmission direction. The processed and unprocessed regions have different refractive indices, forming a phase grating with a periodically distributed refractive index. The processed regions provide the phase difference between the fundamental frequency light, signal light, and difference frequency light, and these processed regions do not exhibit nonlinear optical effects. This invention enables difference frequency laser output in the infrared band by adding a periodic phase method to the nonlinear optical polycrystalline ceramic to achieve optical frequency conversion.

The application discloses a high-transmittance and high-uniformity geometric phase grating element prepared by using femtosecond pulse near-field normalization, a method and application thereof, and belongs to the technical field of laser processing. The application utilizes the principle of femtosecond laser pulse near-field normalization to perform uniform processing in fused quartz, induces a new type of high-transmittance and high-uniformity birefringence structure, controls the change of the slow axis direction, thereby preparing a high-efficiency geometric phase grating with adjustable period, and realizes edge detection by using the light splitting characteristics of the geometric phase grating. The application is applied to optical image edge detection by using an innovative processing technology, solves the limitations of a traditional birefringence structure in transmittance and uniformity, and provides a solution with better performance and lower cost for the field of optical image edge detection.

The invention discloses a radio frequency carbon dioxide laser fast switch control method based on acousto-optic modulation, which is applied to a radio frequency carbon dioxide laser and comprises the following steps: initializing system monitoring and parameter configuration; loading a driving signal to generate effective light; comprising the following steps: applying a driving signal to an acousto-optic modulator by using a control module, and exciting ultrasonic waves to form a phase grating in the acousto-optic modulator; enabling a laser beam output by the laser resonant cavity to enter the phase grating at a Bragg angle to form deflected effective light; outputting laser and performing feedback optimization; comprising the steps that laser is output, characteristic parameters of the output laser are monitored, and when it is monitored that the characteristic parameters of the current output laser are lower than target values of the characteristic parameters of the laser, a control module is used for selecting PID control to optimize driving signals; cutting off the driving signal and absorbing invalid light; comprising the steps that when laser output needs to be closed, a control module is used for stopping an acousto-optic modulator from applying a driving signal, and laser output is stopped. According to the invention, the requirements of high-precision and high-speed laser processing can be met.

A system may include a lateral shearing interferometer. The lateral shearing interferometer may enable measuring a surface profile of a sample, such as the pattern wafers, using reflected light from the sample. The reflected light may be reflected at a grazing incidence angle. A controller may receive images from the lateral shearing interferometer and measure the surface profile. The controller may measure the surface profile by reconstructing a phase of the reflected light from the images. The controller may reconstruct the phase using spatial reconstruction or time-domain reconstruction. The gratings may allow the controller to measure the edge roll-off in one or two dimensions. The controller may also calibrate the grazing incidence angle and determine refractive indices of thin-films on the sample. The controller may also perform full measurements of the surface profile using line beams, rectangular beams, or full-sample beams.

The application discloses a continuous medium coherent array edge emitting semiconductor laser and a preparation method thereof. The laser comprises a conductive substrate, an epitaxial layer formed on the upper surface of the conductive substrate, a rear-end optical medium waveguide area and a front-end optical medium waveguide area located on both sides of the epitaxial layer. The upper surface of the epitaxial layer is provided with a one-dimensional array ridge waveguide area. A rear-end phase grating layer is etched on the rear-end optical medium waveguide area, and a front-end phase grating layer is etched on the front-end optical medium waveguide area. A P-face electrode is arranged on the upper surface of the one-dimensional array ridge waveguide area, an N-face electrode is arranged on the lower surface of the conductive substrate, a high-reflection film is arranged on the end surface of the rear-end phase grating layer, and an anti-reflection film is arranged on the end surface of the front-end phase grating layer. The laser of the application can realize in-phase mode lasing without the selection of supermodes by external optical elements, and the optical field has an ultra-narrow divergence angle in the slow-axis direction of the far field, so that the coupling efficiency of the array semiconductor laser and the optical fiber is greatly improved.

The application discloses a two-dimensional array pulse self-synchronization wafer laser structure, which comprises an inner resonant cavity composed of a first reflecting layer, a saturable absorber, a wafer array gain medium and a second reflecting layer, and an outer resonant cavity composed of a phase grating structure layer and a third reflecting layer, and the inner resonant cavity and the outer resonant cavity form a composite resonant cavity; a pump light source emits pump light which is injected into the composite resonant cavity through a pump module, passes through the wafer array gain medium multiple times, and generates array oscillation laser in the inner resonant cavity; simultaneously, the saturable absorber absorbs and modulates the array oscillation laser, starts and maintains the array pulse operation; the array laser pulse enters the outer resonant cavity through the second reflecting layer, the phase grating structure layer causes the array pulse laser to be coupled, the array pulse laser returns to the inner resonant cavity through the third reflecting layer to be mutually injected, modulated and locked, the array pulse laser is synchronously operated in the composite resonant cavity, the collective mode laser pulse is formed, and the self-synchronized high-energy coherent array pulse output is realized.

A displacement phase modulator is provided for high power laser phase modulation processing, manufacturing and communication applications. In one embodiment, the displacement phase modulator includes multiple two dimensional (2D) modulators arranged in columns and rows on a substrate surface to form a array having multiple pixels along a longitudinal axis. Each pixel includes multiple 2D modulators in one or more adjoining columns and has a long axis transverse to the longitudinal axis of the array. The 2D modulators in each pixel are electrically coupled to receive a common input signal and to operate in unison to modulate a phase of light reflected therefrom in response to the input signal. In some embodiments, the 2D modulators include a faceplate with raised elongated reflective elements to form a blaze profile or a phase grating, operable to diffract an incident light into at least two diffraction orders. Other embodiments are also disclosed.

The application discloses a single-phase grating X-ray microscopic imaging system based on two-stage amplification, which comprises a geometric amplification system, an optical amplification system and a detector; the geometric amplification system comprises an X-ray light tube, a plurality of capillary tubes, a phase grating and a scintillator; the optical amplification system amplifies a fluorescent signal to obtain a fluorescent amplified signal, separates the fluorescent amplified signal from a first modulation signal, and obtains the fluorescent amplified signal; and the detector receives the fluorescent amplified signal. The application uses the plurality of capillary tubes to focus X-rays to realize geometric amplification, uses a scintillator coupled lens imaging system to realize optical amplification, uses two-stage amplification to realize high-resolution microscopic imaging, realizes high resolution without relying on a high-coherence X-ray beam, uses the light source segmentation characteristics of the plurality of capillary tubes, uses only one phase grating to modulate an object, acquires multi-modal information, and does not need two absorption gratings required by a traditional X-ray phase contrast system, thereby greatly improving system light flux and imaging contrast.

The application discloses an optical diffraction tomography imaging device and method based on an integrated quantitative phase imaging camera, and mainly solves the technical problems of mechanical vibration, poor stability, low measurement precision, limited imaging field of view and the like of the current optical diffraction tomography device. The application realizes multi-angle rotary illumination without mechanical movement by loading a blazed phase grating with different directions and periods of pixel numbers on a reflective liquid crystal spatial light modulator; uses the integrated quantitative phase imaging camera to record the point array interference diagram of a non-marked transparent sample under different illumination angles, then processes the four-wave shearing interference point array diagram by using a Fourier transform method, and inversely calculates the light field complex amplitude distribution of the sample under different illumination angles; finally, based on the optical diffraction tomography principle, the three-dimensional refractive index distribution of the sample is quantitatively reproduced from the obtained multi-angle complex amplitude sequence, the micro three-dimensional structure distribution inside the transparent sample is observed without marking, and high-precision three-dimensional imaging is realized.

The application discloses a preparation method of a reflective curved fork surface grating. The grating prepared by the method is a pure phase grating and can be used for generating perfect vortex light (POV). A high-order Bessel Gaussian beam is interfered with a Gaussian beam to expose a photosensitive material on a substrate, wherein the high-order Bessel Gaussian beam is generated by a reflective pure phase liquid crystal spatial light modulator (SLM), and after development and metal film plating, the reflective curved fork surface grating is prepared. When a Gaussian light of a base mode is used for irradiation, the POV can be obtained on a far field or a lens focal plane in a first-order diffraction direction. The method for obtaining the POV by using the reflective curved fork surface grating has the advantages of a higher damage threshold, a wider working wavelength range and a higher conversion efficiency, and has the advantages of simple structure, low cost and mass production, and has an important prospect in generation of high-power POV and can be used in the fields of optical manipulation and optical processing.

The application relates to the field of semiconductor measurement technology, and particularly provides a system and method for measuring a deep trench etching structure in a 3D NAND, aiming at improving a traditional CD-SAXS measurement unit, designing a phase grating on an optical path before probe light is incident on a measured sample, and based on Talbot effect and fractional Talbot effect, the distance between the phase grating and the measured sample is designed as Talbot distance or fractional Talbot distance; the probe light is modulated through the phase grating, so that the probe light intensity distribution irradiated to the sample presents a bright and dark stripe distribution related to the grating structure period and duty cycle; then, through an alignment mechanism, the bright stripe of the incident light beam is aligned to the deep trench etching structure region in the 3D NAND to be measured, and the dark stripe is aligned to the memory hole structure region, so that the light intensity incident to the deep trench etching structure part is enhanced, the light intensity incident to the memory hole part is weakened, and the difficulty of extracting the deep trench nanostructure scattering signal from the total scattering signal is reduced.

The invention provides a pre-deflection angle adjusting wavelength selection switch device and a use method, the pre-deflection angle adjusting wavelength selection switch device comprises a light receiving and transmitting end, a grating assembly, a deflection element, a phase grating and a light switching engine which are sequentially arranged along a light path, and a transmitting end emergent light signal in the light receiving and transmitting end is received by the grating assembly and is divided into a plurality of light signals with different wavelengths; the optical signals with different wavelengths are emitted to the phase grating through the deflection element, and the deflection angles of the optical signals with different wavelengths are changed through the deflection element, so that the grating periods corresponding to the optical signals with different wavelengths are consistent; a phase grating on the light switching engine divides each light signal with different wavelengths into diffracted light of different times, the diffracted light is returned to a light receiving and transmitting end along a light path, and part of the diffracted light of a preset level is received by a corresponding receiving end in the light receiving and transmitting end; the grating periods corresponding to the optical signals with different wavelengths are consistent, so that the diffracted light with different wavelengths and the same level converges, and crosstalk caused by divergence of the diffracted light with the same level is avoided.

The invention provides a multi-view-field display. The multi-view-field display comprises a display module, a circular polarization module and an interrogation Latrinamm-Beryer phase grating. The display module is used for providing initial display light with linear polarization. The circular polarization module is used for adjusting initial display light from the display module into first circularly polarized light and second circularly polarized light. The interrogation Latrinamm-Beryer phase grating is disposed in front of the circular polarization module and includes a liquid crystal material. And the alignment orientation of the liquid crystal material is periodically changed along the light splitting direction to form a plurality of grating units. The interrogation Laynaum-Beryer phase grating adjusts the first circularly polarized light and the second circularly polarized light into first display light emitted towards the first light emitting direction and second display light emitted towards the second light emitting direction. The first light-emitting direction and the second light-emitting direction are diverged relative to each other in the light splitting direction.

A wavelength selective switch apparatus with pre-tilt angle adjustment, and a method for using same. The apparatus comprises a optical transceiving end (1), a grating assembly (2), a deflection element (3), a phase grating (4) and an optical switching engine (5), which are sequentially arranged along a optical path, wherein an optical signal emitted by a transmitting end (11) in the optical transceiving end (1) is received by the grating assembly (2) and divided into a plurality of optical signals of different wavelengths, the optical signals of different wavelengths are transmitted to the phase grating (4) through the deflection element (3), and tilt angles of the optical signals of different wavelengths are changed by means of the deflection element (3), such that the optical signals of different wavelengths correspond to the same grating period; and the phase grating (4) on the optical switching engine (5) divides each of the optical signals of different wavelengths into diffracted light of different orders, and returns same to the optical transceiving end (1) along the optical path, wherein some diffracted light of a preset order is received by a corresponding receiving end (12) in the optical transceiving end (1). Since optical signals of different wavelengths correspond to the same grating period, diffracted light of the same order but different wavelengths converges, thereby preventing crosstalk caused by divergence of the diffracted light of the same order.

The invention discloses a synchronous equivalent multi-wavelength microscopic interference measuring method based on incident angle modulation, and belongs to the technical field of measuring instruments. According to the method, under the condition of a single-wavelength light source, multiple groups of interference wavelengths are equivalently constructed by modulating an illumination incident angle, so that the interference measurement range is expanded, and the phase reconstruction precision is improved. According to the system, a blazed phase grating is loaded by using a spatial light modulator, a plurality of illumination light beams with different incident angles are synchronously generated by regulating and controlling different diffraction orders, so that interference signals corresponding to equivalent wavelengths are formed on the surface of a sample, and interference information of each channel is synchronously acquired through polarization regulation and control. The system does not need multiple light sources or a wide-spectrum light source, is simple in structure, is good in measurement synchronism, is large in measurement range, is high in stability, and is high in anti-interference capability.

The application discloses a system and method for generating stable interference fringes by using a pure phase reflective liquid crystal spatial light modulator, and the system comprises a light source module, a laser collimation filtering and beam expanding module, a pure phase reflective liquid crystal spatial light modulator (SLM) control module and a CCD image acquisition module. The system can generate stable double-hole light spots by loading a gray-scale gradual phase grating on the SLM, replaces the method for generating double-hole light spots by using a photoetching mask in a traditional physical optical interference experiment, and can achieve the final result without the aid of other devices, and is simple and convenient to operate. In addition, compared with traditional interference systems such as a Talbot-Green system and a Mach-Zehnder system, the output interference fringes will not vibrate, and the calculation of the post-stripe movement amount is not affected, and the system has the characteristics of stable operation, flexible control and accurate calculation.

The application discloses a kind of based on the fast switch control method of radio frequency carbon dioxide laser of acoustooptic modulation, it is applied to radio frequency carbon dioxide laser, comprising: initialization system monitoring and parameter configuration;Load driving signal generation effective light;Including using control module to apply driving signal to acoustooptic modulator, excitation ultrasonic wave is formed phase grating in acoustooptic modulator;Make laser resonant cavity output laser beam with Bragg angle incidence phase grating, form deflected effective light;Output laser and feedback optimization;Including: output laser and monitor the output laser characteristic parameter, in monitoring current output laser characteristic parameter is lower than laser characteristic parameter target value, then using control module selects PID control optimization driving signal;Cut off driving signal and absorb invalid light;Including in need to close laser output, using control module to stop acoustooptic modulator to apply driving signal, stop output laser.The application can meet the demand of high-precision, high-speed laser processing.

A system may include a lateral shearing interferometer. The lateral shearing interferometer may enable measuring a surface profile of a sample, such as the pattern wafers, using reflected light from the sample. The reflected light may be reflected at a grazing incidence angle. A controller may receive images from the lateral shearing interferometer and measure the surface profile. The controller may measure the surface profile by reconstructing a phase of the reflected light from the images. The controller may reconstruct the phase using spatial reconstruction or time-domain reconstruction. The gratings may allow the controller to measure the edge roll-off in one or two dimensions. The controller may also calibrate the grazing incidence angle and determine refractive indices of thin-films on the sample. The controller may also perform full measurements of the surface profile using line beams, rectangular beams, or full-sample beams.

This invention discloses a three-dimensional dynamic shape measurement device and method based on four-wave shearing interferometry projection, belonging to the field of three-dimensional shape measurement technology. The device includes a four-wave shearing interferometry fringe projection system, an image acquisition system, a computer, a test object, and a reference background plate. The projection system consists of two sets of interchangeable components. The optical interferometry projection system includes a laser diffraction component, a converging lens, a two-dimensional phase grating, and a four-aperture plate. The laser diffraction component generates spherical waves, which are converged and then diffracted through the two-dimensional phase grating. After filtering by the four-aperture plate, the four beams shear and interfere with each other to form a four-wave shearing interferometry image, which is projected onto the test object on the reference background plate. The image acquisition system acquires the interferogram and processes it with the computer to obtain the object's height information. This invention utilizes instantaneous shearing interferometry technology, requiring only a single image after calibration to complete the measurement, achieving true dynamic measurement. Furthermore, the accuracy is improved through optimized calibration and algorithms.

The application provides a kind of based on retina projection's augmented reality display system, including collimating light source, image display, 4f optical system, phase grating, focusing eyepiece and half mirror.The collimating light source is used to provide collimating illumination light;The image display is used to load the virtual image that needs to be presented in augmented reality display;The 4f optical system is composed of two optical lenses, the distance between two optical lenses is equal to the sum of the focal length of two optical lenses, its main function is used to converge and collimate light;The phase grating is at the focal point position in the middle of 4f optical system, can form multiple parallel light by diffraction with 4f optical system combining a parallel light;The focusing eyepiece is used to converge multiple parallel light formed by 4f optical system and phase grating into multiple view points at the pupil of human eye;The half mirror is used for virtual-real fusion, forms augmented reality display effect.

The disclosed system may include a display; a lens; and a diffractive optical element, where the diffractive optical element includes at least one Pancharatnam-Berry phase grating and is configured to increase a fill factor of the display when the lens is used to magnify the display. Various other apparatuses, systems, and methods are also disclosed.