11 results about "Phase grating" patented technology

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.

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 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 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.

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.

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 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.