207 results about "Reference beam" patented technology

The invention discloses an automatic calibration method and system for a mining laser gas detector, and relates to the technical field of instrument calibration. The method comprises the following steps: dividing detection beam parameters into measurement beam parameters and reference beam parameters; enabling the measurement light beam parameter to penetrate through the to-be-measured gas area to obtain a measurement signal, and enabling the reference light beam parameter to penetrate through the reference gas chamber to obtain a reference signal; performing photoelectric conversion calculation on the reference signal to obtain a gas concentration detection value; the gas concentration detection value is compared and analyzed with a reference data value according to the central wavelength position of the mining laser gas detector, and a calibration unit is activated according to a comparison result; and automatically correcting the mining laser gas detector, generating a correction parameter set, calculating a measurement signal, and generating a concentration value of the gas to be detected. The technical problems of low calibration efficiency and unstable calibration precision of the mining laser gas detector in the prior art are solved, and the technical effects of realizing automatic calibration of the mining laser gas detector and improving the calibration efficiency and precision are achieved.

The invention relates to the technical field of optical element surface shape dynamic measurement scheme design, in particular to an element surface shape dynamic measurement system based on a metasurface. According to the scheme, polarized light emitted by a laser is split into reference light and test light, the test light passes through a quarter-wave plate twice to realize polarization orthogonalization, and the test light is combined with the reference light to form elliptically polarized light; synchronously capturing component intensities of left-handed / right-handed circular polarized light and orthogonal line polarized light by using a detector, and resolving a phase difference delta in real time by combining a Stokes parameter; environmental interference is eliminated based on a common-path design, a polarization beam-splitting element is omitted, and the architecture is simplified; accurate dynamic measurement of the surface shape of the measured piece is realized by deducting the inherent surface shape error of the system. The system provided by the invention has the advantages of strong anti-interference performance, high measurement efficiency, remarkable cost reduction and the like, and is suitable for precise optical manufacturing and on-line detection scenes.

The invention relates to a reflectivity spectrum obtaining method, an end point detection method and device and a polishing device.The reflectivity spectrum obtaining method comprises the steps that an influence factor distribution curve representing light intensity measured value volatility under different light intensity light source conditions is obtained, a critical light intensity value corresponding to the dominant light source factor is determined based on the influence factor distribution curve, and the critical light intensity value is calculated according to the critical light intensity value. The source light beam is split according to a preset proportion beta to obtain a required measurement light beam and a reference light beam, and the measurement light beam enters a sample to form a reflection light beam; the reflected light intensity is calibrated based on the reference light intensity to generate a target reflected light intensity. And calculating the reflectivity spectrum of the sample based on the target reflection light intensity. Wherein the measuring light beam and the reference light beam have the same light intensity volatility, so that when the reflected light intensity is calibrated based on the reference light intensity, the accuracy and the stability of reflectivity spectrum measurement are effectively improved.

A system for a full-field OCT eye measurement, comprising:—a source (1) of a light beam (2),—a detector (3), preferably in form of a camera,—an interferometer, comprising a reference arm (4) and a sample arm (5),—a beam splitter (6), configured to receive the light beam (2) and to split the light beam (2) into a sample beam (7) and a reference beam (8) and further configured to direct the sample beam (2) to the sample arm (5) and the reference beam (8) to the reference arm (4) respectively, wherein the sample arm (5) is configured for guiding the sample beam (7) through a point on the cornea of a subject's eye (9) into the subject's eye (9) and back to the detector through the beam splitter (6), wherein the reference arm (4) is configured for guiding the reference beam (8) to a mirror (10) and back to the detector (3) through the beam splitter (6), wherein said detector (3) is configured and programmed for comparing the sample beam (7) and the reference beam (8) for detecting diseases of the subject's eye (9). The system is characterized in that it comprises an arrangement for decreasing the intensity of the sample beam (7) passing through the point of the cornea of the subject's eye (9).

This invention relates to an interferometric measurement method and apparatus for large warp wafers, belonging to the field of optical detection and semiconductor measurement technology. The detection light is polarized and birefringently split to form P-beams and S-beams, which are then further divided into P-reference beams, S-silicon beams, S-reference beams, and P-silicon beams, respectively. By adjusting the spatial orientation of the reference mirror and the wafer under test, and using an aperture for spatial filtering, the P-reference beam and S-silicon beam are allowed to enter the subsequent optical path, while the S-reference beam and P-silicon beam are blocked. The S-silicon beam forms a measurement wavefront carrying information about the surface shape of the wafer under test. The P-reference beam is modulated by a deformable mirror to form a modulated reference wavefront similar to the measurement wavefront. The two form a resolvable interference fringe pattern at the camera. A wavefront sensor measures the surface shape information of the deformable mirror, and a calculation system obtains the surface shape information of the wafer under test based on the deformable mirror surface shape information and the relative surface shape change. This invention can reduce the interference fringe density in the detection of large warp wafers, reduce splicing measurement errors, and improve detection efficiency and accuracy.

A laser ranging method and device using the autocorrelation characteristics of light intensity random noise, the method comprising: step S1, a wide spectrum light source emits laser light, which is divided into a first light beam and a second light beam by a ranging probe, and the first light beam is defined as a reference light beam; step S2, the second light beam is emitted to a target object to be measured, and a light beam reflected by the target object to be measured is obtained and defined as a signal light beam; step S3, the reference light beam and the signal light beam are coupled to form a coupled light beam; and step S4, the coupled light beam is processed to obtain absolute distance information of the target object to be measured to the light emitting end surface of the probe. The device obtains absolute distance information of the target object to be measured based on light source intensity noise. The present application has the advantages of high time resolution and high precision measurement.

This invention provides a real-time ranging and positioning system and method based on an extended light source and a fast coincidence measurement algorithm. The real-time ranging system includes: an entangled light source, a first single-photon detector, a time-to-digital converter, a coincidence measurement module, a quantum transceiver module, and a corner mirror. The coincidence measurement module performs real-time coincidence measurement using a fast coincidence measurement algorithm based on the arrival time sequence of the signal beam and the arrival time sequence of the reference beam, obtaining the time difference corresponding to the peak position of the coincidence measurement curve. The distance between the target point and the real-time ranging system is then obtained based on this time difference. Furthermore, this invention splits the signal beam emitted by the light source into multiple signal sub-beams to form an extended light source, effectively reducing the cost of the measurement device while still satisfying quantum positioning measurement requirements.

This application relates to a method, apparatus, and computer-readable storage medium for determining beam distribution. For a beam to be modeled, at least two reference directions are determined based on a measured dose distribution; and a target beam distribution of the beam is determined based on at least two reference beam distributions corresponding to the at least two reference directions. This solves the problem of low beam modeling efficiency, improves the speed of modeling calculation, and is applicable to a wider range of application scenarios.

A system includes an illumination system, an optical system, a detector system, and a processor. The illumination system directs a first illumination beam and a second illumination beam toward the target structure, and directs a first reference beam toward the detector system. The optical system directs the first scattered beam and the second scattered beam from the target structure to the detector system. A detector system captures the interference pattern and outputs a measurement signal. The first scattered beam, the second scattered beam, and the first reference beam generate an interference pattern. The processor analyzes the measurement signal to determine a characteristic of the target structure.

This invention relates to a real-time monitoring device for yarn vibration characteristics based on laser imaging, comprising: a laser for emitting laser light to form a laser beam; a first polarizing beam splitter for orthogonally decomposing the laser beam into a measurement beam and a reference beam according to the polarization state of the laser; a measurement imaging optical path for measuring the yarn under test using the measurement beam and reflecting the measurement beam passing through the area where the yarn under test is located through a reflector to form an echo beam carrying the characteristic information of the yarn under test; a reference illumination optical path for constructing a uniform and stable background illumination reference beam; a beam splitter for combining the echo beam and the background illumination reference beam to obtain a combined beam; an area array camera for acquiring the combined beam; and an image processing system connected to the area array camera for performing image processing on the acquired combined beam to obtain the vibration characteristics of the yarn. This invention can accurately capture and quantify the vertical vibration characteristics of the yarn.

The application provides a wafer warping detection device, a processing device, a method and a storage medium. The detection device comprises a monochromatic light source for providing a detection light beam. At least three half-reflective half-transmissive lenses are used to obtain the detection light beam, reflect it to corresponding mirrors, and then transmit the detection light beam to corresponding optical fibers and the next half-reflective half-transmissive lens. At least three mirrors are respectively used to detect the detection light beam, form a reference light beam, and transmit the reference light beam to corresponding detectors. At least three optical fibers are respectively used to transmit the detection light beam to at least three detection windows, irradiate corresponding measured points of a wafer to be measured through the detection windows, reflect to form an object light beam, and transmit the object light beam to corresponding detectors. At least three detectors are respectively used to collect the reference light beam and the object light beam. A processor is connected to the detectors, and is used to determine distances from each corresponding measured point of the wafer to be measured to a wafer tray surface according to the number of interference fringes in an interference fringe image, and determine the warping of the wafer according to the distances.

The application discloses a method and device of laser ranging technology based on cross-correlation principle, which are used for absolute distance measurement of a target object. The intensity information of a reference light beam and a signal light beam after photoelectric conversion is cross-correlated and demodulated to obtain the transmission time difference between the end surface of a ranging probe and the target surface and the reference light beam, and then the absolute distance is calculated. The application has the advantages of large range, high precision and high frequency response in absolute distance measurement.

The application discloses a kind of ultra-long curvature radius convex spherical surface shape measurement systems, the surface shape measurement system includes interferometer, spherical standard mirror, aberration compensation lens and the convex spherical mirror to be measured in same optical axis, the aberration compensation lens is concave on the side of the convex spherical mirror to be measured;Light beam emitted by interferometer, part is reflected back to interferometer by spherical standard mirror, forms reference beam, another part passes through spherical standard mirror, aberration compensation lens, is irradiated on the convex spherical mirror to be measured, is reflected twice by the convex spherical mirror to be measured, finally, it is back to interferometer by aberration compensation lens, spherical standard mirror, forms test beam;Reference beam and test beam interfere, form interference fringe, obtain the surface shape error of measured surface by analyzing interference fringe.The application solves the problem that the size of detection equipment is large, the cost is high and difficult to realize in prior art for detecting ultra-long curvature radius convex spherical mirror surface shape.

This invention provides a three-dimensional detection system for lubricating oil abrasive particles based on a phase-shifting micromirror, comprising: a light source system, a beam splitter, an abrasive particle imaging system, a phase modulation system, and a detection system; the light source system emits a parallel beam that is incident on the beam splitter; the beam splitter divides the parallel beam into two identical transmitted beams and reflected beams; the reflected beam passes through the abrasive particle imaging system and is incident on the oil abrasive particle detection area, generating a scattered beam that returns to the beam splitter along the original path; the transmitted beam is modulated by the phase modulation system to form a reference beam that returns to the beam splitter along the original path; the reference beam and the scattered beam interfere at the exit position of the beam splitter, forming an interference beam that is then incident on the detection system to obtain interference spectrum information; the amplitude and phase information of the cross-correlation term in the interference intensity expression are extracted from the interference spectrum information to construct a complex function of the interference beam signal, and then a Fourier transform is performed on the complex function to finally obtain a clear three-dimensional reconstructed image of lubricating oil abrasive particles.

A terminal according to one aspect of the present disclosure comprises: a control unit that, when a reference beam used for determining whether or not a condition of a specific event related to a beam report initiated by the terminal is satisfied changes within a time window related to the occurrence of the specific event, controls resetting or continuation of at least one of a counter related to the occurrence of the specific event and the time window; and a transmitting unit that transmits the beam report on the basis of a measurement of the reference beam. According to said one aspect of the present disclosure, communication quality / throughput can be improved.

Disclosed herein is an apparatus and method for optical tomography with extended imaging depth. The apparatus obtains a three-dimensional (3D) optical tomography image of a sample based on interference between reference beam and sample beam that is scattered from or through the sample after being irradiated by a light source, and may include a sample region optical unit for adjusting the depth of a focal plane in the sample while maintaining an optical path length constant by translating the sample by a predetermined length along the optical axis of light incidence for the sample.

The present application relates to the field of optical measurement, and provides a lithography machine interferometer light beam calibration device and method. The lithography machine interferometer light beam calibration device is used for calibrating a measurement light beam of an interferometric measurement system in a lithography machine, and comprises a reference optical element configured to establish an absolute angle reference in a calibration environment; a simulation target having at least one reflecting surface and configured to be detachably placed in the optical path of the measurement light beam during calibration; a reference transmission assembly configured to transmit the absolute angle reference defined by the reference optical element to the reflecting surface of the simulation target; and a diagnostic optical module configured to be detachably installed at the light beam outlet of the interferometric measurement system to receive the measurement light beam reflected by the reflecting surface of the simulation target; the diagnostic optical module interferes the received measurement light beam with an internal reference light beam of the diagnostic optical module, and uses the form of the formed interference fringes as a basis for judging the collimation state of the measurement light beam.

The present disclosure relates to an imaging system including: an objective having an optical axis defining a z-direction; an autofocus illumination module arranged to project, via the objective, a reference beam onto a reflective interface positioned in the field of view of the objective; and an image sensor arranged to image, via the objective, a reflection of the reference beam from the reflective interface. The autofocus illumination module is arranged so that the value of a parameter derivable from an object profile of the reference beam at the objective focal plane is an inflection value in the context of values of the parameter derivable from object profiles of the reference beam at planes corresponding to z-positions either side of the objective focal plane.

An OCT system includes a broadband light source, and a beam splitter that splits the broadband light into a reference beam and an illumination beam. A reference mirror reflects the reference beam. Illumination optics passes the illumination beam and has a reflective surface with an optical power. Collection optics has a transparent region and a reflective surface with an optical power. The collection optics is configured so that the illumination beam is reflected from the reflective surface of the collection optics to the reflective surface of the illumination optics such that the illumination beam is redirected to a surface of a sample at an angle that results in scattering from within the sample that forms a sample beam propagating normal to a surface of the sample and through the transparent region of collection optics and through the transparent region of the illumination optics. An interferometric combiner is configured to interferometrically combine light from the sample beam and the reference beam. A spectrometer is configured to receive the interferometrically combined light from the sample beam and the reference beam and to generate spectral interferometric information. A processor processes the spectral interferometric information to determine information about the sample.

The application discloses a grating beam splitter, an angle measuring device and a method. The lens body of the grating beam splitter has a front surface and a rear surface, an included angle between the front surface and the rear surface is not zero, and the front surface and the rear surface are both grating planes. The application utilizes the grating beam splitter to realize lateral shearing of an incident light beam, two light beams emitted on a light signal collecting unit form an interference image, the interference image is related to the angle of the grating beam splitter relative to the incident light beam, and the measurement of the rotating angle of the grating beam splitter can be realized by demodulating the interference image. The application can realize the precise measurement of the rotation of the element without a reference light beam or a reference benchmark, has a simple structure, is easy to realize, has small error and high precision.

The application relates to the field of optical technology, in particular to a three-coordinate instrument of a real-time feedback system in integrated fluid blade repair, which comprises a workbench for loading a blade to be repaired and a measuring head, the measuring head is connected to a left-right moving slide through a measuring head lifting system, the blade to be repaired is horizontally placed on the workbench; one end of the slide is provided with the measuring head lifting system; the other end of the slide is provided with a cloud platform, and a laser detection system is arranged on the cloud platform; the laser detection system comprises a beam splitter and a grating, the beam splitter divides out a measuring beam and a reference beam with an included angle of 5-15 degrees; the measuring beam and the reference beam are projected to the surface of the blade to be repaired. The three-coordinate instrument of the real-time feedback system in integrated fluid blade repair not only shortens the cycle of the whole repair operation, guarantees the precision, improves the processing efficiency, and avoids the blade to be repaired from being scrapped due to excessive polishing.

This invention provides a multi-channel receiving SLM partition-controlled adaptive optics alignment system and method. The method includes: a beam to be aligned in a perturbed channel is decomposed into a target beam and a reference beam after passing through a beam splitter; a wavefront sensor receives the reference beam, acquires the intensity distribution and phase distribution of the reference beam, and inputs them into a processor; the processor uses a preset SLM multi-zone control algorithm to partition the liquid crystal of the phase-type SLM, and matches each selected zone with each optical receiver one by one, generating a phase hologram for each selected zone and inputting it into the liquid crystal controller; each selected zone of the SLM liquid crystal performs partition alignment and outputs the received target beam; this invention can achieve multi-point focusing, dynamic alignment, and power allocation of the received beam through a single SLM, supports multi-point simultaneous alignment and arbitrary power allocation of a multi-channel receiving UOWC system under dynamic conditions, and has outstanding advantages such as high flexibility, good real-time performance, and strong scalability.

The application discloses a vibration wave measuring system for traditional Chinese medicine shallow needle manipulation analysis, and belongs to the technical field of vibration wave measurement, and specifically comprises the following steps: a first beam splitter in a laser Doppler vibrometer is used to divide outgoing laser into a measuring light beam and a reference light beam, the measuring light beam is vertically focused on the surface of a needle handle, the reference light beam is vertically focused on an adjacent unoperated skin area, after the two light beams are reflected, interference occurs when the light beams return to a probe to form a first interference light signal, meanwhile, a part of the returned reference light beam is separated to interfere with local light of the system to form a second interference light signal, after photoelectric conversion, common-mode background noise is eliminated through a differential amplifier, and finally, a pure needle handle vibration wave is output, and high signal-to-noise ratio non-contact measurement of high-frequency weak vibration signals generated by traditional Chinese medicine shallow needle manipulation is realized.

The application discloses a kind of microcavity optical frequency comb ultra-high repetition frequency precision measurement system and method, solve the existing microcavity optical frequency comb repetition frequency measurement system because of facing electronic device frequency bandwidth bottleneck lead to the problem that measurable range is seriously limited, including optical rough measurement unit, comb tooth processing unit, modulation frequency shift unit, reference equalization unit, beam combination beat frequency unit and microwave precision measurement unit;Optical rough measurement unit is used to measure the repetition frequency of the light beam to be measured, and is divided into measurement beam and reference beam;Comb tooth processing unit is used to filter out target comb from measurement beam;Modulation frequency shift unit is used for electro-optic modulation to target comb;Reference equalization unit is used to control the reference comb power of reference beam to obtain better beat frequency detection effect;Beam combination beat frequency unit is used for optical beam combination beat frequency between target comb and reference comb and is divided into two beams;Microwave precision measurement unit is used to detect the beat frequency signal between target comb and reference comb, to realize the precision measurement of repetition frequency.

This invention relates to the field of grating processing technology, and more particularly to an online method and apparatus for grating marking tool alignment. The online alignment method includes: mounting a standard tool on a tool holder of a marking system; the tool holder is positioned above a fixed plate, and a laser, a beam splitter, a reflector, and a first panel with a first slit are arranged on the fixed plate; the beam splitter splits the laser beam into a first laser and a second laser; the first laser is incident perpendicularly on the reflector to generate a reference beam, and the second laser is incident perpendicularly on the surface of the standard tool to generate a standard detection beam; both the reference beam and the standard detection beam are guided by the beam splitter to the first panel; the first panel is adjusted so that both the reference beam and the standard detection beam completely pass through the first slit; the standard tool is replaced with a marking tool, and the positional relationship between the detection beam and the first slit is observed to complete the alignment. This invention at least helps to reduce the difficulty of alignment and achieve precise online alignment.

The utility model provides a kind of measuring support, comprising: base, the base is used to place on ground;Reference beam, one end of the reference beam is hinged with base;Supporting rod, one end of the supporting rod is hinged with base, the other end of the supporting rod is hinged with reference beam;Universal rod, the universal rod is detachably installed on reference beam;Displacement meter, the displacement meter is detachably installed on universal rod;By adjusting the position of universal rod, the position of displacement meter can be flexibly adjusted, conveniently satisfy the displacement, subsidence, strain, sliding phenomenon of structure such as measuring earth dam, earth dike, side slope under different working conditions.

Method for measuring the frequency of a laser (D1) using a device for frequency stabilization of a laser (D1, D2), comprising a beam path for coupling laser radiation emitted by the laser (D1, D2) onto a frequency-selective element (G1), wherein the frequency-selective element (G1) is temperature-controlled, and the frequency-selective element is a volume Bragg grating, VBG, (G1) with a plurality of grating structures (E) and, prior to coupling the laser radiation into the VBG (G1) via an input facet, a portion of the laser radiation is diverted into a reference beam and the portion of the laser radiation coupled into the VBG (G1) forms a measuring beam, characterized by the fact that An error signal is derived from the intensity of the reference beam and the intensity of the measuring beam after passing through the VBG (G1), the temperature of the VBG (G1) is adjusted via a control loop using the error signal such that a Bragg frequency of the VBG (G1) corresponds to the frequency of the laser (D1) up to an optionally selected, signed frequency difference, and the frequency of the laser (D1) is determined from the set temperature of the VBG (G1) using a known mapping.

The invention belongs to the technical field of optical processing, and relates to a holographic optical element preparation method and system and a double-view-angle head-up display system, and the method comprises the steps: determining a first direction vector in a three-dimensional space according to the design parameters of a reference light beam and a signal light beam relative to a holographic optical element; adjusting the angle of the holographic optical element to enable the holographic optical element to be in a vertical position in the three-dimensional coordinate system; calculating a second direction vector according to the first direction vector and the adjustment angle of the vertical position; adjusting the angle of the holographic optical element again according to the second direction vector to enable the reference light beam and the signal light beam to be in the same plane; and performing exposure interference on the holographic optical element by using the holographic optical element preparation system so as to enable the photosensitive material in the holographic optical element to form a standing wave pattern. The three-dimensional light path structure in the optical element preparation process is converted into the two-dimensional exposure interference through the light beam position conversion method, the preparation complexity is reduced, and the head-up display accuracy is guaranteed.

The application provides a three-dimensional laser scanner electric signal channel delay self-calibration method, calculates the time difference between a transmitting pulse and a receiving pulse through the absolute distance between a target and the transmitting channel and the receiving channel, adds the fixed delay between a reference pulse and the transmitting pulse to the absolute time to obtain the absolute time as a reference; a data processing module sends an instruction to a transmitting module to control the transmitting module to send a pulse laser, and at the same time, the pulse laser sends a reference light beam to an analog amplification module as a reference signal; the pulse laser is irradiated on the target surface through a scanning mechanism, and the diffusely reflected light signal returns to the receiving channel, converges on a photosensitive element on the surface of an analog detection amplification module through the scanning mechanism, and the light signal is output to the data processing module as an electric signal of different channels through the analog detection amplification module; the data processing module compares the electric signal of different channels with the absolute time to calibrate the delay of the electric signal of different channels.

The invention relates to a wafer film thickness measuring device, a wafer film thickness measuring method, wafer polishing equipment and a wafer polishing method. The wafer film thickness measuring device comprises a light source used for providing an illumination source light beam; the light source energy adjusting module is used for adjusting and controlling the light intensity of the source light beam to obtain a modulated light beam with dynamic target light intensity; the beam splitter is used for splitting the modulation light beam to generate a measurement light beam and a reference light beam; the flexible probe is used for transmitting a measurement light beam and a reflection light beam, and the flexible probe moves in a self-adaptive mode in the optical axis direction so that the flexible probe can make contact with a grinding pad transmission window of the wafer polishing equipment in the grinding process; the light detection module is used for collecting a light intensity measurement value of the reference light beam and a light intensity measurement value of the reflected light beam; the processing unit calibrates the light intensity measurement value of the reflected light beam based on the light intensity measurement value of the reference light beam to obtain the light intensity calibration value of the reflected light beam, and determines the film thickness of the wafer based on the light intensity calibration value of the reflected light beam. The film thickness measuring precision is improved, and the service life of the transmission window is prolonged.