13 results about "Grating interferometer" patented technology

The invention relates to a displacement correction and rapid feedback control method based on a grating interference signal. The method comprises the steps that 1, a lower computer outputs a voltage signal for driving a piezoelectric ceramic scanner according to an instruction of an upper computer; 2, the piezoelectric ceramic deforms, so that the grating of the grating interferometer generates corresponding displacement; 3, simultaneously uploading grating interference signals formed by frequency difference on the left side and the right side of the grating to an upper computer and a lower computer; 4, the upper computer and the lower computer carry out correction and calculation on the grating interference signal through an RANSAC-Heydemann algorithm which is jointly corrected by the upper computer and the lower computer, and actual displacement is obtained; and 5, the lower computer performs correction through a PID control model according to the actual displacement to obtain an accurate displacement value for driving the piezoelectric ceramic scanner. According to the invention, a mode of cooperative operation of the upper computer and the lower computer is adopted, the feedback period of the RANSAC-Heydemann grating interference signal correction algorithm is reduced, and the efficient and precise positioning capability of the flat-plate scanner is improved.

The application belongs to the field of grating measurement, and provides an error compensation method for grating interferometer measurement, which comprises the following steps: constructing an angle error function based on the angle error of grating interferometer measurement; constructing a relative displacement error function based on the relative displacement error of grating interferometer measurement; constructing an explicit compensation model based on the angle error function and the relative displacement error function; constructing an implicit compensation model based on the data set formed by the angle error and the relative displacement error; obtaining an explicit accuracy mean value based on the explicit compensation model, and obtaining an implicit accuracy mean value based on the implicit compensation model; when the implicit accuracy mean value is not less than the explicit accuracy mean value, the explicit compensation model is used to compensate the error of the grating interferometer measurement value. The method guarantees the reliability of the selected model by analyzing the consistency of the internal mapping of the model and the physical law, so as to realize high-precision, high-robustness and strong-explainability displacement measurement compensation.

The invention discloses a device for realizing a large-stroke direct traceability type grating interferometer, which belongs to the technical field of precise displacement measurement, and comprises a grating bottom plate, a coherent light source and an optical fiber beam splitter, a plurality of gratings are arranged on the grating bottom plate, and the gratings comprise a first grating, a second grating, a third grating, a fourth grating and a fifth grating; the optical gratings are arranged on the optical grating bottom plate in a staggered manner, the optical gratings are all self-tracing optical gratings, the coherent light source is connected with the optical fiber beam splitter, the output end of the optical fiber beam splitter is connected with two reading heads, the two reading heads are a first reading head and a second reading head respectively, and the other ends of the first reading head and the second reading head are connected with a signal processing unit. The grating bottom plate is driven by the displacement table to perform one-dimensional translation, and the first reading head and the second reading head are fixed. By adopting the device, the problem that an existing large-stroke grating interferometer is difficult to directly trace is solved, and the device has the advantages of range self-calibration splicing, large expansion space and embedded use.

The application discloses a heterodyne six-degree-of-freedom measurement grating interferometer, a first laser head emits laser with a first frequency, and the laser is vertically incident to a measurement grating after passing through a first polarization beam splitter prism, a first quarter-wave plate and a beam splitter prism, and diffraction is generated; after being reflected by a first right-angle prism group, the diffraction light enters the beam splitter prism; a part of diffraction light components are refracted, enter a four-quadrant photodetector group through a lens to perform angle measurement, another part of diffraction light components are transmitted through the beam splitter prism, enter the first polarization beam splitter prism through the first quarter-wave plate, enter a photodetector group through a second polarization beam splitter prism and a polaroid to perform displacement measurement; a second laser head emits laser with a second frequency, diffraction is generated through a reference grating, the diffraction light is parallel and coincides with the laser with the first frequency to enter the photodetector group together. The application realizes sub-nanometer precision, six-degree-of-freedom measurement, low error level and miniaturization.

The invention discloses a self-traceability grating interference type inter-workpiece cosine installation error in-situ detection method, and belongs to the technical field of precision measurement, and the method comprises the steps: depositing self-traceability gratings on two to-be-detected workpieces respectively, and measuring grating interference signals at the same time through two self-traceability grating interferometers which move cooperatively; the period direction of a certain self-traceability grating is adjusted to be consistent with the direction of a motion measuring shaft of a high-precision displacement table, and two reading heads of a self-traceability grating interferometer are ideally installed relative to respective gratings by debugging interference optical signals; along with the displacement of the self-traceability gratings, two reading heads of the self-traceability interferometer respectively collect displacement signals of the two self-traceability gratings at the same time; and the cosine installation error between the workpieces is calculated by comparing the ratio of the number of original signal cycles collected by the two reading heads. By adopting the method, the problem of workpiece cosine installation error in-situ detection is solved, and the method has the advantages of magnitude self-calibration, high measurement precision and environmental interference resistance.

The invention relates to the technical field of projection objective position measurement, and discloses a displacement measurement system and a projection objective. The displacement measurement system comprises a lens mounting seat, three grating interferometers and three one-dimensional plane gratings. The lens mounting base is used for mounting a lens. The three grating interferometers are evenly arranged on the side face of the lens around the optical axis of the lens at intervals. The three one-dimensional plane gratings are in one-to-one correspondence with the three grating interferometers; the one-dimensional plane grating is arranged on the lens mounting seat, and the grid line direction of the one-dimensional plane grating is perpendicular to the movement direction of the lens; the grating interferometer is arranged on the side, away from the lens, of the one-dimensional plane grating and used for measuring the actual position of the lens. The real-time high-precision measurement of the actual position of the lens can be achieved, the purpose of dynamic monitoring is achieved, the change of the position of the lens can be tracked in real time in the operation process of the projection objective, displacement deviation caused by factors such as temperature change and mechanical vibration can be found and corrected in time, and the stability of an optical system of the projection objective is ensured.

The embodiment of the invention provides a pulse electromagnetic wave sensor. The method is applied to the technical field of electromagnetic wave sensing equipment, and comprises the following steps: a vibration suppression base system forms a dynamic anti-phase displacement field, and converts mechanical vibration energy into heat energy for dissipation; the output is a stabilized sensor platform signal; the time sequence coding array system is used for generating a differential photoelectric phase in an inter-wafer unit by an incident pulse electric field signal, converting the phase difference into a light intensity fluctuation sequence through a built-in time grating interferometer, converting the light intensity fluctuation sequence into a time sequence coding electric signal through a high-speed photodiode array, and outputting the time sequence coding electric signal as a photoelectric pulse sequence; the direction demodulation central system directly generates digital readings of azimuth angles and elevation angles through fringe inclination angles and density distribution in an interference pattern, and end-to-end processing from vibration suppression signals to direction evaluation is completed. In this way, the problems that in the prior art, stable operation is unstable in a complex vibration environment, and the precision of analyzing the pulse electromagnetic wave direction needs to be further improved can be solved.

The application belongs to the field of grating measurement, and provides a grating interference displacement measurement method based on a network model, comprising: constructing an input vector of the network model based on measurement parameters of the grating interferometer; constructing a hidden layer transfer function based on a hidden layer nonlinear activation function and the input vector; determining a displacement error compensation value based on an output layer activation function and the hidden layer transfer function; and obtaining a compensated displacement value based on an uncompensated displacement measurement value and the displacement error compensation value. The application proposes physical guided neural architecture learning, realizes data decoupling and structured representation through "independent component coding", and injects prior knowledge as a constraint through "physical rule guidance", so as to realize high-precision, high-robustness, interpretable and physically consistent error modeling and compensation in a data-driven framework.

The invention relates to the technical field of optical engineering, and provides a reflective projection objective position measuring device and adjusting system.The measuring device comprises a measuring unit and a processing unit, the measuring unit comprises three grating interferometers, the three grating interferometers are arranged on the three side faces of a reflector respectively, and the processing unit is connected with the three grating interferometers. The grating interferometer is used for measuring the position information of the reflector and outputting a corresponding measurement signal; and the processing unit is used for receiving the measurement signals output by the three grating interferometers and determining the spatial pose information of the reflector based on the three measurement signals. According to the invention, through the grating interferometers arranged on the three side surfaces of the reflector, the position information of the reflector in multiple directions can be obtained, the processing unit is utilized to process multiple paths of measurement signals, the spatial pose information of the reflector can be solved, the accurate measurement of the position of the reflector is realized, the aberration correction capability and the imaging stability are effectively improved, and the measurement precision is improved. Therefore, the imaging quality of the reflective projection objective lens is improved.

This application belongs to the field of grating measurement and provides an error compensation method for grating interferometer measurement. The method includes: constructing an angle error function based on the angle error measured by the grating interferometer; constructing a relative displacement error function based on the relative displacement error measured by the grating interferometer; constructing an explicit compensation model based on the angle error function and the relative displacement error function; constructing an implicit compensation model based on the dataset formed by the angle error and the relative displacement error; obtaining the explicit accuracy mean based on the explicit compensation model and the implicit accuracy mean based on the implicit compensation model; when the implicit accuracy mean is not less than the explicit accuracy mean, the explicit compensation model is used to compensate for the error in the grating interferometer measurement. This method ensures the reliability of the selected model by analyzing the consistency between the internal mapping of the model and physical laws, thereby achieving high-precision, high-robustness, and highly interpretable displacement measurement compensation.

The application discloses a kind of X-ray grating interferometer spectral characteristic measuring device and measuring method, it is related to nuclear radiation detection technical field, including shielding sleeve, shielding sleeve inside is equipped with energy spectrum probe, the end of shielding sleeve is equipped with non-destructive optical filter, and small hole is opened in non-destructive optical filter;Shielding sleeve is installed on positioning adjusting mechanism;X-ray grating interferometer has analysis grating and X-ray surface detector, and has the ability of scanning acquisition static step curve.It has the advantages of high detection precision, low manufacturing cost, and very convenient operation, can measure the spectral characteristics of various X-ray grating interferometer, the energy segment of measurement is high, can meet the demand of current scientific research and engineering.Compared with the existing method based on photon technology detector, the cost is greatly reduced;By specially designed non-destructive optical filter, the actual sensitive area of energy spectrum probe is constrained, and the degradation of spectral characteristic data caused by angle misalignment and other factors is reduced.

Method (V1, V2) for measuring a transfer function of an optical system (101) comprising a positioning drive (105) and an optical element (104), namely in particular an optical element (101) of a lithography system (1), by means of an interferometer device (102) which is configured to generate two interference signals that are phase-shifted by 90° to each other, wherein the interferometer device (102) is in particular a full reflection interferometer device or a diffraction grating interferometer device, comprising: exciting (S10) at least one oscillation (115) of the optical system (101), changing (S11) a nominal distance (117) between the optical element (104) and the interferometer device (102), measuring (S12) a profile of the actual distance (117) between the optical element (104) and the interferometer device (104) at different Nominal distances (117) during at least one oscillation (115),and determining (S13) the transfer function based on the measured course of the actual distance (117).,