885 results about "Laser interference" patented technology

The invention discloses an anti-counterfeiting structure for driving card. The marked pattern composed of microstructure is set on the plastic packaged film of the card. The said marked pattern comprises at least three pattern area. A first pattern area is composed of sub-wavelength structure raster of orientated orthogonal structure and the double vision channel forms single color effect. A second pattern area is composed of light spot with body shape of square. The light spot shape of the pattern edge is determined by the outer outline of the pattern, with gliding property. The interference fringes are set in the light point. A third pattern area is composed of bar speckle microstructure, with oriented achromatization effect for white light reflection. The vision character of pattern is notable, easy to recognize in public places and conveniently and quickly distinguish the card. At the same time, the structure data is computed using rigid coupled wave. The said microstructure is produced using electron beam or laser interference optical lithography, and the means is advanced and the difficulty of technique is high with high safety.

A surface microstructure is superimposed on the surface of a replication mould such as an injection moulding tool insert by laser interference exposure of a mask pattern and etching or electroplating the additional microstructure. The technique enables the post-processing of planar and non-planar replication moulds with additional microstructure to improve the functionality and value of the moulded components. A major area of application is an anti-reflection surface for injection moulded polymer optical components, achieved by the superposition of submicrometer anti-reflection grating structure onto injection moulding tool inserts.

The invention relates to a system and a method for achieving cross-scale 3D (three dimension) printing by adopting a micro-nano composite periodic structure interference light source generated by a multi-beam laser interference technology, belonging to improvement on the existing 3D printing method. The system comprises an image acquisition data processing module (1), a PC control center (2), a laser (3), a beam splitting system (4), a 3D printing platform (5), a printing material (6) and a CCD microscopic imaging system (7). Original 3D printing speed and resolution are improved, a micro-nano composite structure material of a printed object is directly formed, and the system and the method belong to a high-speed large-area efficient micro-nano composite structure 3D printing technology.

The invention discloses an absolute gravity measuring system and measuring method as well as a falling method of a free-falling body. The absolute gravity measuring system comprises a free-falling body device, a laser interference measuring device and a vibration isolation platform, wherein the free-falling body device is used for realizing free-falling motion of a falling object; the laser interference measuring device is used for measuring displacement generated during the free-falling motion of the falling object, and can realize accurate calibration of a measuring beam in a vertical direction by adopting a simplified structure; and the vibration isolation platform is arranged between the laser interference measuring device and the ground and is used for isolating influence of ground vibration on measurement. The absolute gravity measuring system has the beneficial effects that free-falling motion of the falling object is realized by adopting an elastic falling member suspension method, vibration influence of a motor drive system on the free-falling body device is reduced, and the accuracy of the gravity measuring result is improved; meanwhile, the zero crossing point (ZCP) feature of an interference fringe signal is computed by computer software so as to eliminate possible measurement deviation caused by a hardware circuit.

The invention provides a rapid measuring and error compensation method for linearity error of a linear guide rail, and aims at solving the problems of small measurement method, large error and complex data treatment in the prior art. The method comprises the steps of measuring and acquiring a plurality of data points on the linear guide rail through a laser interference instrument; analyzing the linearity measurement result for the data of the acquired points through a linearity data analyzing module in an XD laser measurement system so as to obtain the linearity error of the guide rail. With the adoption of the method, the mounting error, environmental error, delay error and the error caused by thermal expansion of a measured object in measuring can be analyzed; an error correcting model is built.

The invention discloses a laser tracker-based machine tool error dynamic compensation method. A laser tracker is adopted to perform dynamic tracking detection; and the method is suitable for being used in laboratory environments with strictly controlled temperature and humidity and can also be used in workshop site environments with severer conditions. Laser interference ranging, photoelectric detection, precision machinery, a computer and a control and modern numerical value calculation theory are integrated by the laser tracker; a space moving object is tracked and spatial three-dimensional coordinates of an object are measured in real time; and the method has the characteristics of high precision, high efficiency, real-time tracking measurement, quickness and convenience in mounting, easiness in operation and the like. A machine tool is dynamically monitored and compensated in real time based on a laser tracker measurement result; error measured by using the scheme is total error obtained after all system errors and random error are superposed; and thus, all error values can be dynamically compensated in real time by the scheme, the system precision of the machine tool is greatly improved, and a detection device of the machine tool is simplified.

The invention relates to a system for producing various vector beams, in particular to a system for producing various vector beams, which has no need of special devices, low cost, high conversion efficiency and easy realization. The system comprises a cat eye cavity laser and a laser interference part, wherein, the cat eye cavity laser is used for outputting various transverse modes, and the structure of the cat eye cavity laser comprises a cat eye reverse device composed of a concave mirror, a convex lens or a lens group to serve as a cavity mirror; the laser interference part is used for producing various vector beams for beams output by the cat eye cavity laser via beam splitting, reflecting, beam rotating, coherent combination and the like. Various vector beams can be produced by adjusting space between the concave mirror and the convex lens or the lens group in the cat eye reverse device, adjusting phase position of two beams after beam splitting and adjusting intensity. The invention can only utilize one system to produce various vector beams, and can be widely used in the fields of optical manipulation, optical imaging, information transmission, quantum optics, laser machining and the like.

A method and apparatus is provided for determining thickness of films or layers during chemical-mechanical planarization / polishing (CMP) of a semiconductor substrate or wafer in situ. The method may be used to determine end-point during CMP especially of oxide films deposited on the substrate or wafer. In one embodiment, the method includes: a) capturing images of the surface of the substrate using high speed imaging; b) performing pattern recognition on the captured images; c) selecting one of the captured images based on the pattern recognition; and d) converting the selected image into a thickness measurement. In one form, the high speed imaging comprises a high speed camera, while in another form, the high speed imaging comprises a conventional camera and a laser pulse or flash tube. In yet another embodiment, reflective laser interference patterns of the substrate are captured and analyzed for interference pattern changes that can signal a practical end-point.

The invention relates to method and system for manufacturing a self-cleaning surface structure by adopting a laser interference photolithography technology. The method is characterized in that a plurality of coherent laser beams are combined by using a laser interference photolithography system, weakness modulation is carried out on light intensity distribution in an interference field, redistributed laser energy after modulation is used for ablating the surface of optics materials, and a micron-size or nanoscale dense cylindrical or conical anaglyph structure is generated within a large area range, thereby obtaining a super-hydrophobic film, greatly lowering the viscous phenomenon, benefiting to attachments including dusts, liquid and the like on the surface of the materials detaching from the surface of the materials and fulfilling a self-cleaning function. Without external materials, the self-cleaning fine structure generated on the surface of the materials is more stable and durable and can continuously regulate the period and the size from the nanoscale to the micron size by regulating an incidence angle of the interference photolithography system to enable dual structure of nanometer, micro and micro nanometer to become possible.

The invention belongs to the field of biomimetic micro-manufacturing technology and particularly relates to a method for preparing a biomimetic colour super-hydrophobic coating on a transparent polymer material by multi-beam interference photoetching technology, which comprises the following steps: building a laser multi-beam interference system, spirally coating a solidifiable or degradable material on a substrate, solidifying the solidifiable material or degrading the degradable material through laser interference photoetching and obtaining a microstructural array after developing; and then modifying a low-surface energy material on a microstructure, and obtaining the biomimetic colour super-hydrophobic coating by the multi-beam interference photoetching technology on the substrate. The method of the invention can overcome the shortcomings of the traditional preparation method, allows the surface of the material to display various colours and plays a role of very good decoration effect because the regular structure scatters and diffracts incident light, and promotes the super-hydrophobic surface to develop to a simplified and practical surface.

The invention relates to a high repetition frequency jamming-resistant laser encoding method. Due to the threat of high repetition frequency laser active jamming to the laser semi-active homing guidance, aiming at a tunable laser generating nanosecond level pulse width, the invention provides the encoding of pulse width and pulse amplitude by directly clipping with an electro-optical switch; the phase difference generated by static double refraction is compensated by an orthorhombic KTP (potassium titanium oxide phosphate) crystal; the delay and the error can be reduced due to the synchronous control of a pockels cell power supply; the laser encoding, the pulse width encoding and the pulse amplitude modulation are combined with one another, so that the PAWM (puto amo window manager) encoding which not only can resist the laser angle deception jamming but also can resist the high repetition frequency jamming can be formed; and the method of high repetition frequency jamming resistance is improved on a guidance head, so that a novel laser encoding system can be formed, wherein the system is suitable for the aspects such as tracking, guidance, positioning, collimation, photo-communication APT (arbitrage pricing theory) technology, and photoelectronic warfare.

The present invention relates to a method for antimissile protection of vehicles having a very short response time with practically no false alarms and not requiring the use of means such as decoys or conventional laser jammers, while providing the best possible protection. It is characterized in that at least one curtain of plasma filaments is created between these vehicles and the probable launch point of these missiles, this curtain being intended to blind the target-seeking device of the missiles.

The invention discloses multi-beam semiconductor laser interference nanoimprinting technology and system which adopt the following principle that the required two or more bundles of coherent lights can be obtained by using semiconductor pulse laser through beam splitting, the coherent lights are subjected to coupling, beam expansion and reshaping and redistributed on the surface of material by using the light intensity in an interference field to form a periodical interference pattern. When the system is used for imprinting, a photosensing material can be directly subjected to the interference exposure and then etching without masking. By using an optical fiber beam splitting device as a light splitter, the complicity of a light path is greatly reduced, and the system is more stable and reliable; in addition, the selection from two light beams to a plurality of light beams is more flexible and convenient.

The invention provides methods and apparatuses for vision therapy procedures using laser interference patterns for relieving eye strain. One of the methods provided controls a speckle pattern in such a manner that an interesting visual stimulus is created which attracts and retains a viewer's attention and forces the eye to adjust to distance vision. This stimulates relaxation of the ciliary muscles of the viewer's eyes and contributes to the relief of eye strain. Another method provides electronically generated holograms for exercising eye muscles in order to relieve eye strain. The present invention provides further methods and apparatuses which may be used in a computer user's workplace.

The invention discloses a multifunction three-dimensional displacement and topography laser interferometry system, belonging to the technical fields of photo mechanics, engineering material, structural member deformation, displacement testing, topography measurement and the like. The invention consists of a laser device, a image collecting and shooting system, a light split coupler, a light split photoswitch, a DC electrical source controller, a three-dimensional laser interference optical path system, a loading charging floor for putting test pieces, a bracket adjusting system, a computer and the like. The laser interferometry system can realize high-precision measurement of u, v and w displacement fields, and displacement measurement sensitivity can reach wavelength magnitude; the laser interferometry system has two displacement measurement modes of digital holography and electronic speckle pattern interferometry, and also has the mode of digital holographic measurement of surface topography. The invention can realize the adjustment of degrees of freedom on multiple directions by using the bracket adjusting system, brings convenience for system imaging and measurement adjustment, and has the characteristics of convenient use, compact structure, high measurement precision and the like; because the system is provided with a phase shifting device, the displacement measurement precision of the system of the invention can reach nanometer magnitude after phase shifting treatment.

The invention belongs to the technical field of optical precision detection, and relates to a bilateral misalignment differential confocal detection method and device for the free-form curve topography, which can be used for nano-precision detection of the free-form curve topography. The device comprises an active air floating vibration isolation spring, an air floating vibration isolation base, an X-direction air floating guide rail, a gantry, a bilateral misalignment laser confocal fixed-focus trigger measurement system, a laser interference displacement measuring mirror group, a Y-directionair floating guide rail, a Z-direction air floating guide rail, a free-form surface sample attitude adjustment device, a reference flat-crystal attitude adjustment device and a laser interferometer.By the way of contour measurement of a gantry structure coordinate measuring machine (CMM), in combination with the high-precision planar flat crystal as a reference reflecting mirror, the influence of the straightness of the X-direction and Y-direction air floating guide rails on the high-precision detection of the surface contour of the free-form surface is reduced, so that the 21 errors of theCMM are reduced. A spherical air floating table with a three-point support structure is used to adjust the attitude of a free-form surface part to be tested, and the high-precision detection of the contour of the free-form surface part is realized.

The invention relates to the field of 3D topography measurement. An embodiment of the invention provides a speckle structure light projection module group and a 3D depth camera, wherein the speckle structure light projection module group comprises: an array light source for emitting a laser beam corresponding to a first spot pattern, a collimating lens for modulating the laser beam into a collimated beam corresponding to the first spot pattern, and a holographic optical element for modulating and expanding the collimated beam to form a second spot pattern and projecting the second spot patternto a scene object to be tested; the holographic optical element is produced via laser interference exposure processing. Thus, the holographic optical element processed via the laser interference exposure processing is used, ghost line interference problems can be prevented, and stray background light is reduced; in addition, laser interference processing can be more efficient and less expensive than etching processing.

The invention relates to an SPR (surface plasmon resonance) phase measurement method for measuring thickness of a nano metal film. The method comprise the steps of 1, establishing a standard curve graph of the variation of a phase variation difference of a TM polarized wave and a TE polarized wave with the thickness of the metal film, and obtaining a corresponding fitting formula, 2, obtaining a coating interference fringe image of a film coating area of a prism SPR sensor, 3, obtaining an interference fringe image of a non-film coating area of the prism SPR sensor, 4, comparing and calculating the images obtained in Step 2 and Step 3, and obtaining the phase variation difference of the TM polarized wave and the TE polarized wave in the film coating area, and 5, substituting a calculated result in Step 4 into the fitting formula of the standard curve graph in Step 1, and obtaining a value of the thickness of the metal film. The SPR phase measurement method has the benefits that phase modulation is conducted on the TM polarized wave and the TE polarized wave by laser interference, so that non-contact, high-precision and convenient-to-operate measurement of the thickness of the nano metal film can be achieved.

The invention relates to a method and a device for measuring a self-referenced spectral interference femtosecond laser pulse in real time. In the method, firstly, laser is divided into three beams and two beams of laser are focused and irradiated on a non-linear transparent optimal medium to generate two beams of first-order self-diffraction light; any one beam of self-diffraction light is used as a reference laser pulse, the reference laser pulse is collinear with a third beam of laser pulse in space and is regulated to be coincident with the third beam of laser pulse, and a laser interference spectrum can be obtained by regulating delay time; and the interference spectrum is measured, so that a laser spectrum and a spectral phase can be obtained by inverse calculation through a self-referenced spectral coherence method, and thus, the width and the shape of the laser pulse can be measured. In the invention, an SRSI (self-referenced spectral interferometry) method and an FROG (frequency-resolved optical gating) method and the advantages thereof are combined; and the method and the device have the characteristics of high speed, simpleness and convenience and are suitable for singleshot measurement, real-time measurement and monitoring of the widths and the shapes of femtosecond laser pulses with different pulse widths and different wavelengths.

The invention discloses a laser interference displacement measuring system. The laser interference displacement measuring system comprises a laser device, a polarizer, an depolarization beam splitting prism, a polarization beam splitting prism, 1 / 4 wave plates, a pyramid mirror, plane reflectors and a photoelectric detector. Measuring light enters the mobile pyramid mirror, and the light path change of the light reflected back in the original path caused by displacement of the pyramid mirror is four times that of the displacement of the pyramid mirror. In the design of the laser interference displacement measuring system, the measuring light enters and exits the mobile pyramid mirror twice along the same direction by utilizing the polarization optical principle, and an octuple path relation between the displacement of the pyramid mirror and the change of light path difference between the measuring light and reference light is achieved, thereby realizing optical octuple subdivision measurement of the displacement. The laser interference displacement measuring system has the advantages of high measurement resolution and accurate measuring result, is convenient and simple in structural installation, is low in cost, and is wide in application range.

The invention discloses a double-vacuum cavity type fall control absolute gravity meter and an application method. The double-vacuum cavity type fall control absolute gravity meter comprises a horizontal substrate, a double-vacuum cavity fall control system, a laser interference system, a vibration isolating system, a rubidium atomic clock and an upper computer, wherein the double-vacuum cavity fall control system is located on the horizontal substrate, the laser interference system is located under the horizontal substrate, and the vibration isolating system is located under the laser interference system. According to the double-vacuum cavity type fall control absolute gravity meter, a fall prism is located in a small vacuum cavity, the vacuum degree can be lower than 10-6 Pa, the remnant molecule resistance is reduced, and the measurement error is lowered. A fall control power source linear ultrasonic motor is small in volume, precision in location, small in vibration and capable of effectively reducing the volume of the vacuum cavity and lowering the vacuum cavity design difficulty and vacuum degree maintaining cost, and moreover, the vibration is smaller when the linear ultrasonic motor jacks up the falling body towards the upside and releases the falling body towards the downside, and the measurement error caused by vibration is effectively reduced.

The invention relates to a surface plasma resonance (SPR) phase measuring device for measuring the thickness of a nanometer metal film. The SPR phase measuring device comprises a laser, a collimation lens, a first polarizer, a prism-type SPR sensor, a plane reflector, an interference system, a second polarizer, a couple charged device (CCD) camera and a computer 10, wherein the laser, the collimation lens and the first polarizer stay on the same optical axis, and the second polarizer and the CCD camera are placed on the same optical axis; the laser emitted by the laser enters the prism-type SPR sensor after passing through the collimation lens and the first polarizer, after being reflected through the plane reflector to the interference system, the reflection light passes through the second polarizer, an interference image is received by the CCD camera, and then the obtained interference image is recorded by the computer. The SPR phase measuring device has the beneficial effects that the structure is simple, convenience in operation can be realized, the error caused by a light path is inhibited by adopting a laser interference-based SPR phase modulation method and adopting the same light path to measure a coating area and a non-coating area of the prism-type SPR sensor in the measuring process, and high measurement precision can be realized.

The invention provides a low non-linear error and low temperature drift two-frequency laser interference device, comprising a first polarization splitting prism, a second polarization splitting prism located on a light path of transmitted light of the first polarization splitting prism; a third polarization splitting prism located on a light path of transmitted light of the first polarization splitting prism; a first quarter-wave plate, the second polarization splitting prism located between the first quarter-wave plate and the first polarization splitting prism; at least a first prism of corner cube deposited in parallel to one side of the second polarization splitting prism; a second quarter-wave plate located one end of the third polarization splitting prism. The invention uses a plurality of polarization splitting prisms cascaded and path length in the interference device of measuring light path and reference light path. Therefore the device has low non-linear error and low temperature drift.

A method for preparing a colorful three-dimensional hologram based on holographic polymer dispersed liquid crystal gratings comprises: first, in a 441.6 nm laser interference field, preparing with holography a holographic master (7) which stores the reflected (or transmitted) light wave information (amplitude and phase) of an object captured; then using an object light (6) to irradiate the holographic master at a Bragg angle to generate a diffraction light (8); and using the diffraction light and a reference light (10) to simultaneously irradiate a holographic base board (9) comprising a photosensitizer, a co-initiator, a monomer capable of free radical polymerization , and a liquid crystal so that, when total optical paths of the two laser beams reaching the holographic base board are equivalent to each other, optical coherence occurs between the two laser beams on the holographic base board, thereby obtaining a colorful three-dimensional hologram based on holographic polymer dispersed liquid crystal gratings from which an image of the captured object can be observed in the sunlight.

The invention relates to a laser ultrasonic detection device and belongs to the technical field of laser ultrasonic detection. The device is composed of a crawling trolley, an optical fiber and an external control console, wherein the crawling trolley comprises a rotational scanning head, rolling wheels and stretching supporting bars, a box body and a fiber interface. A laser ultrasonic excitation source, a laser interference detection system and a data process system can be carried on the crawling trolley. Ultrasound is excited to generate on detected surfaces by lasers led into the trolley by the optical fiber or emitted by the laser ultrasonic excitation source carried on the crawling trolley. Ultrasonic signals are detected by the laser interference detection system carried on the crawling trolley and data are transmitted to the external control console for display by the data process system. The external control console is capable of monitoring the states of the trolley and controlling the trolley to conduct detection. The device of the invention is capable of conducting laser ultrasonic detection to pipelines on the problems of inwall surface damages, defects inside pipeline walls and the like. The device also has fast surface-scanning speed and high detection efficiency and is very practical.

The invention provides a high-precision double star laser interference dynamic distance measuring ground simulation device which at least comprises a vibration-isolation system, a vacuum system, a light source system, an interferometer, a first horizontal moving system, a second horizontal moving system, a phase detection system and a data analyzing system. The vibration-isolation system is used for isolating and filtering outside vibration noise and reducing the vibration noise of a system. The vacuum system is used for reducing thermal noise brought by temperature fluctuation of the system. The light source system is used for providing two laser beams which are high in stability and high in frequency stabilization. The interferometer is used for generating three paths of heterodyning interference signals which have the identical arm length and simulating satellite orbit dissociating motion information and scientific signal information caused by gravitational waves or a gravitational field or the like. The first horizontal moving system is used for simulating scientific signals caused by gravitational waves or a gravitational field or the like. The second horizontal moving system is used for simulating satellite orbit dissociating signals. The phase detection system is used for carrying out phase detection on interference signals, collecting phase information and carrying out inversion displacement. The data analyzing system is used for estimating dynamic distance measuring precision of an interfering system and extracting scientific signals from mixed signals. The high-precision double star laser interference dynamic distance measuring ground simulation device can achieve ground simulation of high-precision double star laser interference dynamic distance measuring.

An apparatus for measuring an object's surface shape that obtains complex amplitude at a plurality of positions substantially in the directions of the optical axis of the light reflected by the object and calculates the first surface shape of the object by the depth-from-focus principle. On the other hand, using the phase data of the complex amplitude, the apparatus can measure a micro shape in the sub-fringe order by ordinary laser interference measurement. The first surface shape data are applied to a region including a step of a height greater than ½ of the light's wavelength and second surface shape data are applied to the other region.

The invention discloses a large-area manufacturing method and a processing system for the surfaces of micrometer and nanometer structures with tunable periods and tunable morphologies. A laser interference processing method is a widely applied micrometer and nanometer processing means, but is limited and only can be used for realizing intensity distribution of interference fields with fixed periods and fixed morphologies, accordingly, micrometer and nanometer structures processed by the laser interference processing method have single morphologies and are poor in tenability, and requirements on processing multifunctional surfaces in specific designs cannot be met. The large-area manufacturing method and the processing system have the advantages that the large-area manufacturing method and the processing system aim to overcome the bottleneck of the traditional laser interference processing technology, a wave-front modulation device is used for precisely controlling wave-front phases and vibration amplitudes of beams on the basis of the original multi-beam laser interference processing system, so that preliminarily designed target intensity distribution of interference light fields can be realized, and the large-area micrometer and nanometer structures with the variable periods and the variable morphologies can be finally processed; an effective way can be provided for manufacturing the large-area surfaces of non-periodic and diversified structures on a large scale.