67 results about "Multiple diffraction" patented technology

An apparatus and method for performing rapid, high-resolution polycrystalline crystallographic texture analysis, by calculating an Orientation Distribution Function (ODF) from partial pole figures obtained from x-ray diffraction measurements on large samples, e.g., 200 millimeter diameter wafers. The measurement apparatus includes a 2-D area x-ray detector and a collimated x-ray source arranged in a specific, fixed spatial relationship dependant on the properties of the sample to be measured, and also includes a particular wafer motion assembly. The wafer motion assembly includes three mutually orthogonal rectilinear translation stages, and a phi rotation stage mounted thereon, as an uppermost motion stage, with its range restricted to 180° of rotation. theta-2theta and χ motions are eliminated, and the close deployment of the x-ray source and area detector to the measuring spot on the wafer is such that the detector covers a sufficient range of 2theta and χ to capture multiple diffraction arcs in each frame. The invention employs a new and advantageous texture analysis protocol to determine ODF from the severely truncated pole figures thus obtained, through comparison of experimental ODF figures with calculated ones. The resulting system is fast, accurate, amenable to automation, and does not require highly skilled personnel to operate.

A spectrometer is designed capable of effectively covering the full desired spectral range using an array of multiple diffraction gratings arranged in gradually differentiated angles to diffract certain sub-range of photon wavelengths to the target detectors without relying on mechanically changing gratings or use of any moving parts. The optically subdivided spectral analysis results are then electronically integrated to accurately yield the desired full range spectral measurement at a speed compatible to the limit of optical and digital analyzers' speed of the measuring system without manual adjustment and/or mechanical movement delays.

The invention discloses a measuring system which comprises a light source module, an illuminating module, an imaging module and a detecting module arranged in sequence along the light propagation direction, wherein the light source module is used for emitting a light beam; after the light beam enters the illuminating module, an illuminating beam is emitted to illuminate a mark on the surface of a substrate, then after the illuminating beam is reflected and diffracted by the mark, emergent light with multiple diffraction orders are formed; the detecting module comprises a detecting grating and a light intensity detector, the light with multiple diffraction orders becomes incident light to enter into the detecting grating after passing through the imaging module, the detecting grating carries out secondary diffraction on the incident light so as to form light beams with multiple diffraction orders to form interference patterns on the light intensity detector; wherein the light with multiple diffraction orders is subjected to phase modulation through moving the substrate or the detecting grating so as to obtain the information of phase difference of the light with multiple diffraction orders, and then according to the information of phase difference, the three-dimensional position information of the substrate is obtained, thereby realizing alignment, focusing and leveling measurement on the substrate.

The invention disclosed here teaches methods to fabricate and utilize a non-dispersive holographic wavelength blocker. The invention enables the observation of the Raman signal near the excitation wavelength (˜9 cm⁻¹) with the compactness of standard thin film/holographic notch filter. The novelty is contacting several individual volume holographic blocking notch filter (VHBF) to form one high optical density blocking filter without creating spurious multiple diffractions that degrade the filter performance. Such ultra-narrow-band VHBF can be used in existing compact Raman instruments and thus will help bring high-end research to a greater number of users at a lower cost.

One or more non-zero diffraction orders are selected, and these selected one or more zero or non-zero diffraction orders are selected for eliminating or obtaining corresponding zero or non-zero diffraction order terms or interference term from measurements from a periodic target using an optical metrology tool. The periodic target has a pitch, and the measurements contain a zero diffraction order and one or more non-zero diffraction order terms. Using the optical metrology tool, an incident beam is directed to positions on the target, and the measurements are obtained from the target in response to the incident beam. The measurements are processed to eliminate or obtain each zero or non-zero diffraction order term or interference term associated with each selected zero or non-zero diffraction order, resulting in a processed metrology signal. The positions are shifted from each other so as to cause the zero or non-zero diffraction order term or interference term corresponding to each selected zero or non-zero diffraction order to be eliminated or obtained.

The invention relates to a nanometer-level automatic focusing system for projection lithography, comprising a light path, an image processing module and a circuit control module. The light path comprises a collimated light beam, two grating marks, four lenses, a silicon wafer stage and a CCD (Charge Coupled Device) image detector, wherein a collimated light beam vertically illuminates one grating mark, carries out glancing incidence imaging on the surface of the silicon wafer stage along the optic axes of the first lens and the second lens, is projected on the tested surface of the silicon wafer stage and undergoes mirror reflection; a grating image is reimaged on the focal plane of the fourth lens through the third lens and the fourth lens; and the image of one grating mark is superposed with the two grating marks by a fixed gap, undergoes multiple diffraction, forms amplified Moire interference fringes on the surface of the grating and then is imaged on the CCD image detector. The image processing module is used for processing images to extract a phase difference and further calculate a defocusing amount; and then, the circuit control module is used for judging the defocusing condition of the surface of the silicon wafer stage to further control the movement of the silicon wafer stage so that the surface of the silicon wafer stage reaches an optimal focal plane position.

In a device for measuring the complete polarization state of light over a spectral bandwidth, an optical input signal (41) with wavelengths of light within a spectral band is incident on two or more diffraction gratings (42, 44, 46, 48), or incident from at least two directions on one or more diffraction gratings (72, 74), and the intensity is measured as a function of wavelength for at least four of the diffraction spectra produced by the grating(s). The polarization state of light is then calculated as a function of wavelength over the spectral bandwidth from the intensity measurements.

An improved optical system is provided for diffusing light uniformly over a wide angle, including, a diffractive element for diffracting light received by the system in multiple diffraction orders, and a diffusing element which diffuses the diffracted light. The diffractive element provides diffracted light having an angular distribution of intensities over the diffraction orders which is correlated to the power spectrum of the diffusing element such that the system produces a predetermined intensity distribution of diffused light. The diffraction period of the diffractive element is selected such that the angular separation between the zeroeth and first diffraction orders is approximately one-half the angular extent of the full-width-at-half-maximum of the power spectrum of the diffusing element. The strengths of the diffraction orders are selected such that the combination of diffused light from each diffractive order provides uniformity in the intensity of the diffused light from the system.

A method and system for evaluating an object that has a repetitive pattern. Illumination optics of an optical unit are adapted to scan a spot of radiation over a repetitive pattern that includes multiple regularly repeating structural elements that are optically distinguishable from their background, generating a diffraction pattern that includes multiple diffraction lobes. Collection optics are adapted to focus radiation from the repetitive pattern onto a detector. The focused radiation includes a single diffraction lobe while not including other diffraction lobes. A grey field detector generates detection signals, responsive to the focused collected radiation. The optical unit is adapted to maintain, at a detection surface of the grew field detector, a radiation pattern that includes a first radiation pattern component resulting from the repetitive pattern and a second radiation pattern component resulting from a defect; wherein the first radiation pattern component is stronger than the second radiation component.

The invention discloses a micro hybrid light splitting device, which is characterized by comprising a substrate, wherein the substrate is provided with an arrayed waveguide grating, a reflecting mirror array, a prism assembly and a photoelectric detector array, wherein the arrayed waveguide grating is provided with an input optical fiber and n output waveguides; the reflecting mirror array is positioned on the substrate, and is provided with n reflecting mirror bodies which correspond to the output waveguides respectively; the prism assembly is arranged in the emitting area of the reflecting mirror array, and is used for splitting n strands of light rays from the reflecting mirror array into m strands respectively, and outputting; the photoelectric detector array is arranged at the back stage of the prism assembly. In the scheme, the prism assembly is taken as a back stage element of the arrayed waveguide grating working at multiple diffraction orders, so that light signals of multiple diffraction orders output by the output waveguides of the arrayed waveguide grating can be further dispersed longitudinally to form a light spot array on a focal plane where the photoelectric detector array is positioned, and the light signals are converted into digital signals through the photoelectric detector array. The device can be used for realizing light splitting in a wide wavelength range at a high wavelength resolution in a small volume.

The invention discloses a two dimension displacement measurement device which uses a double frequency laser and a diffraction grating, and relates to an ultra precise displacement measurement technology and an optical grating displacement measurement system. The two dimension displacement measurement device which uses the double frequency laser and the diffraction grating is composed of a scale grating and a reading head, wherein the reading head comprises a double frequency laser light source, a Z direction interference component, a scan light splitting grating component, an X direction detection component, a Z direction detection component and a signal processing component. The two dimension displacement measurement device which uses the double frequency laser and the diffraction grating is based on a Michelson interferometer theory, a multiple diffraction grating interference theory and an optics beat frequency theory, can achieve simultaneous measurement for X direction displacement and Z direction displacement, has the advantages of being compact in structure, strong in interference resisting ability, and low in demand for backward zero order diffraction intensity of the scale grating, decoupling the X direction measurement and the Z direction measurement and the like, can achieve nanometer level or even higher lelvel measurement resolution, and can be used in displacement measurement multiple in freedom degree and high in accuracy.

The invention refers to a real-time latent-image self-monitoring method in the course of making a holographic grating. It uses arbitrary interference recording light beam of the light intensity acting on the grating as the real-time sub-image self-monotiring incident light beam, and when the ratio of the wavelength of the incident light beam and the period of the grating lambda/d<2/3, the gratinghas multiple diffraction levels, it real-time self-monitors the light beam outside the system collimated and photoelectricly multiplied in the transmission direction of self-diffractions Ir2 and Ir1 of arbitrary level sub-image, or real-timely self-monitors the autocollimating level returning according to the original route filtered, collimated and photoelectricaly multiplied.

The invention discloses a blazed grating based beam deflection angle amplifying unit. The blazed grating based beam deflection angle amplifying unit includes beam deflection angle amplifying subunits;each beam deflection angle amplifying subunit includes two blazed gratings; if an incident angle of a beam incident on the blazed grating is i0, the diffraction angle of the diffracted light containing the main energy of the beam is Theta 0; an included angle between the two blazed gratings is Theta0-i0, so that the incident beam can be diffracted back and forth between the two blazed gratings for multiple times, and the incident angle and the diffraction angle of the incident light are identical in the two blazed gratings. The incident angle i0 and the diffraction angle Theta0 are adjusted,so that the deflection amount of the diffracted light is larger than the deflection amount of the incident light when the incident light is deflected, and multiple diffraction amplifications of the deflection amount of the incident light can be realized. The method can achieve multiple diffraction amplifications of the deflection amount of the incident light.

Methods and systems for measuring structural and material characteristics of semiconductor structures based on wavelength resolved, soft x-ray reflectometry (WR-SXR) at multiple diffraction orders are presented. WR-SXR measurements are simultaneous, high throughput measurements over multiple diffraction orders with broad spectral width. The availability of wavelength resolved signal information at each of the multiple diffraction orders improves measurement accuracy and throughput. Each non-zero diffraction order includes multiple measurement points, each different measurement point associated with a different wavelength. In some embodiments, WR-SXR measurements are performed with x-ray radiation energy in a range of 10-5,000 electron volts at grazing angles of incidence in a range of 1-45 degrees. In some embodiments, the illumination beam is controlled to have relatively high divergence in one direction and relatively low divergence in a second direction, orthogonal to the first direction. In some embodiments, multiple detectors are employed, each detecting different diffraction orders.

The invention discloses an integrated diffraction grating type high stability laser displacement sensor. The sensor includes a sensor body, wherein the sensor body includes a collimation module of a laser diode, a diffraction grating, a diaphragm, a filter, an imaging lens and a CMOS linear image sensor, the laser diode collimation module of the laser displacement sensor emits a collimation beam,the beam is diffusely reflected by a surface of a detected object, passes through the diaphragm and the imaging lens and is then split into multiple diffraction spots by the special transmission typediffraction grating, displacement of the detected object is reversed through utilizing each diffraction spot, solved multiple displacement data are subjected to averaging or median value processing, and the actual displacement of the detected object can be obtained. Compared with a conventional laser triangle range finding sensor, the displacement of the detected object is solved through utilizingthe information of the multiple diffraction spots in the case of measuring the displacement once, influence of environmental factors such as noise is reduced, and the stability of the measured data is effectively improved.

The invention relates to a design method of a high-numerical-aperture short-focal-length step phase position type thick FZP. The step phase position type FZP is equivalent to multiple diffraction screens based on a multi-screen diffraction theory, the diffraction effect in a step phase position type FZP body is considered, a diffraction field of the whole FZP is formed by superposing diffraction fields of multiple equivalent diffraction fields, a vector diffraction theoretical formula is formed, the step phase position type FZP can be designed and diffraction field distribution can be analyzed according to a vector diffraction theory. By adopting the design method, a computing result can be basically consistent to a time domain finite difference simulated result, and the high-numerical-aperture short-focal-length step phase position type thick FZP can be simply and effectively designed.

A combined dammam grating is made by combination of N dammam gratings which meet grating period matching conditions. The grating is obliged to meet the period matching conditions. If the nth dammam grating is an even grating, the dn is required to meet the grating period strict matching condition that 2 sin - 1 (mn lambada/dn) + sin - 1 (2 lambada/dn) = sin - 1 (lambada/dn - 1); if the nth dammam grating is an odd grating, the dn is required to meet the grating period strict matching condition that 2 sin - 1 (mn lambada/dn) + sin - 1 (lambada/dn) = sin - 1 (lambada/dn - 1); and the dn is the period of the nth dammam grating, mn is order of edge diffraction of the nth dammam grating, n is a positive integer and belongs to N, and lambada is incident laser wavelength. By means of the combined dammam grating, beam splitting quantity and beam splitting angle which a single dammam grating can not achieve under same processing conditions can be achieved in terms of incident light multiple diffractions. The combined dammam grating has the advantages that the usage is convenient, cost is low, light spot and light intensity are uniform, and the like. Application range of dammam gratings can be greatly extended, and the combined dammam grating is expected to be widely applied in fields of precision measurement, machine vision, aerospace and the like.

The present invention is directed to methods for creating pseudo-holographic images viewable under different selected angles on optical storage devices and other photosensitive surfaces. The present invention also discloses novel optical storage devices with super-imposed pseudo-holographic images. Generally, a photosensitive surface is exposed with multiple diffraction patterns creating super-imposed pseudo-holographic images. These diffraction patterns create super-imposed images on the photosensitive surfaces, which can be read by either a human or a computer.