49 results about "Two beam interference" patented technology

The invention discloses a high-precision optical tiny thrust measurement system based on a two-beam interference principle. The high-precision optical tiny thrust measurement system comprises an engine suspension assembly, a thrust calibration assembly and a thrust measurement optical system. The thrust measurement optical system is used for generating interference fringes; an engine to be measured is hoisted through the engine suspension assembly, weights are placed on a weight disc in the thrust calibration assembly to generate thrust, and the thrust of the engine to be measured is simulated. The thrust is applied to a deformation membrane to enable the deformation membrane to deform, and the number of screwing and unscrewing turns of the interference fringes is changed. The variable quantity of the number of the screwing and unscrewing turns of the interference fringes is counted, and a thrust-counted number curve is generated by a computer to serve as a calibration curve. The number of the screwing and unscrewing turns of the interference fringes can also be changed by the thrust generated by the engine to be measured and is input into the computer after being counted by a counting device, a counted number-time curve is generated, the calibration curve is further used in a cooperation mode, and a thrust-time curve can be obtained. The high-precision optical tiny thrust measurement system has the advantages that sensors needed by measurement are few, the structure is simple, reliability is high, and measurement is accurate.

The present invention discloses a method for fabricating polymeric wavelength filter, which method for forming gratings patterns on the UV polymer involves three processing steps. First, a gratings pattern is holographically exposed using a two-beam interference pattern on a positive photo-resister film. A 20-nm-thick nickel thin film is then sputtered onto the positive photo-resister film to form a nickel mold. This nickel mold on the photo-resister film then can be subsequently used to transfer the final gratings pattern onto a UV cure epoxy polymer. Whereby, a polymer film can be spun coated on the cure epoxy substrate so as to simplify the fabrication process for obtaining a polymer wavelength filter with good aspect ratio of gratings pattern.

The invention relates to a thermo-compensation current sensing head as well as an alternate current measurement method and a system thereof. A current sensing head is placed in a magnetic field generated by alternate current to be measured, and a fiber bragg grating FPI adhered on magnetostrictive material senses ambient temperature and magnetic induction. A light signal emitted by a monochromatic light source enters fiber bragg grating F-P cavity of a fiber bragg grating Fabry-Perot interferometer and forms a similar two beam light interference signal after interference to be output. Cavity length variation amount of the fiber bragg grating F-P cavity of the fiber bragg grating Fabry-Perot interferometer is obtained according to the two beam interference signal, and then alternate current measurement value is obtained according to the cavity length variation amount. And finally, compensation relation between current measurement value and actual value to be measured on temperature is utilized to obtain alternate current actual value. The performance of an original current sensor is improved, preparation technology is relatively simple, and simultaneous measurement of temperature and alternate current can be realized.

The invention discloses a device for measuring clearance between a mask and a silicon chip and leveling the mask and the silicon chip in nanolithography, which is characterized in that a monochromatic plane wave emitted by a light-source laser tube is reflected by a first reflector and then perpendicularly injected into a first mark grating and a second mark grating in a mask marking area, a diffraction light beam B1 transmitted from the first mark grating and reflected by the surface of the silicon chip and a diffraction light beam B2 directly reflected from the second mark grating are deflected by a second reflector and then received by an object glass, and finally converged to the image surface of the object glass and perform two-beam interference, the interference fringes are recorded by a CCD detector, and the clearance measurement & control is realized according to the moving situations of the fringes and the change situations of phases. The invention has the advantages of high measuring sensitivity and strong practical applicability, and has an important significance to the related fields of mask-silicon chip leveling and clearance measurement & control.

A two-beam interference lithography system offers large-area nanopatterning with tunability of pattern periodicities. The tunable feature is achieved by placing two rotatable mirrors in the two expanded beam paths which can conveniently be regulated for the designed pattern periodicities. While the effective interference pattern coverage is mainly determined by the optical coherence length and mirror size, the minimum pattern coverage area is as large as the effective coherence length of the laser and the selected mirror size over a wide range of periodicities.

In accordance with some aspects of the present disclosure, a maskless interferomeric lithography system for fabricating a three-dimensional (3D) photonic crystal using a multiple two-beam-exposures is disclosed. The system can comprise an illumination system comprising an optical arrangement operable to receive radiation from a radiation source and provide three or more tilted two-beam interference pattern exposures to be combined into a three-dimensional pattern; and a substrate operable to be supported by a substrate table, wherein the substrate comprises a photoresist formed on a top surface of the substrate and operable to receive the three-dimensional pattern and wherein means are provided to adjust the position of the substrate in all six mechanical degrees of freedom.

The invention discloses a method for preparing a moth-eye structure for antireflection on the surface of a solar battery, which comprises the following steps: 1, cleaning an epitaxial wafer used by the solar batter; 2, spin-coating photoresist on the epitaxial wafer; 3, prebaking the photoresist to form a sample; 4, carrying out double exposure and development on the sample by two-beam interference exposure equipment to form a two-dimension periodic photoresist mask pattern; 5, carrying out after-baking on the developed sample; 6, performing dry etching on the sample; and 7 removing the photoresist mask pattern in order to complete the preparation of the moth-eye structure.

The invention relates to a testing method of transmission grating-modulated pumping-detection saturated absorption spectrum. The method is characterized in that black/white transmission grating-modulated pump light is used before a sample to generate period matrix intensity distribution grating, replace the traditional grating formed by two beam interference and stimulate the electronic grating with period matrix concentration distribution in the sample; the saturated absorption change of detection light is used to replace the traditional grating diffraction signal intensity change so as to measure the attenuation kinetics of instantaneous electron concentration grating. The method has the advantages of high sensitivity, simple experiment device and the like. The experiment device schematic diagram is shown in the drawing 1 of the abstract and can be used to measure the ambipolar diffusion constant of electron spin; and when an electric field is exerted on the sample along the vertical direction of grating stripe, the ambipolar diffusion constant and mobility of electron spin can be measured at the same time. When 1/4 wave plate 2 and 3 are removed, the ambipolar diffusion constant and mobility of electron charge can be measured. The beneficial effects of the invention can be shown when used in the testing example of GaAs semiconductor.

The invention provides the separation method of the carrier electronic speckle displacement field. The method is: it adds the reference path in the electronic speckle two-beam interference path to make the reference path share by the two beams; it imports the carrier modulation stripe by the deflection object, so the carrier stripe distorts adjusted by the object distortion. The two beams measure the distorting object independently to collect the stripe after the object distortion and get the two frame phase bitmap including the off-face displacement and the in-face displacement component information to separate the in-face displacement field and the off-face displacement field by computing the phase location. The invention can get the high precision measurement result, so it can provide a new way for measuring the deformation field component.

To provide a DFB solid-state dye laser including a grating having Moire interference fringes. A DFB solid-state dye laser element includes: a laser medium containing an organic dye; and a distribution feedback type resonance unit having a third grating including a Moire fringe corresponding to an overlap between a first grating and a second grating formed in different directions. The third grating including a Moire fringe is formed by irradiating a photoresist with a laser for two-beam interference exposure, and then rotating a substrate by a predetermined angle and re-irradiating the substrate with the laser.

The invention relates to a thin film type optical collimator on the basis of surface plasmon polaritons, which is formed by a substrate and a metal grating. The substrate is a glass substrate for bearing the metal grating; and the metal grating is formed by a metal medium alternate film and a metal surface grating structure, wherein the metal medium alternate film is obtained by alternately making a metal thin film and a medium thin film on the substrate by a vacuum hot dip coating technology or a magnetron sputtering technology and the metal surface grating structure is made on the metal medium alternate film by a two-beam interference exposure technology and a stripping technology. The structure changes Gaussian light into planar light by utilizing the metal medium alternate film for the first time and also has capacity of expanding the light beam width; the structure is compact, the size is small and the total thickness of a device is used as a wavelength magnitude; on the basis that the metal medium alternate film which adopts a simple preparation process and is low in cost supports the metal surface grating and conducts light, a metal film with a through hole, which is high in manufacturing cost, is avoided; and the thin film type optical collimator can be integrally made on the end faces of a semiconductor laser, a light emitting diode, an optical fiber or an optical fiber laser, and is used for improving an angle of divergence of a light beam and obtaining collimated light.

A method for evaluating a hologram image recording medium includes: recording continuously a plurality of fine holograms, each being the same in size as an element hologram, on a hologram image recording medium to be evaluated, using either one of a two-beam interference between a reference beam and a signal beam both being a plane wave and a two-beam interference between a reference beam being a plane wave and a signal beam being a spherical wave; reproducing a diffraction image by irradiating the recorded fine hologram with a plane wave; from intensity distribution data based on a captured diffraction image, determining an intensity distribution data array and a diffracted beam intensity I_s, the intensity distribution data array having the same shape and size as those of the fine hologram; and when the diffracted beam intensity I_s takes on the maximum value I_s(_max), determining an SN ratio.

A two-beam interference apparatus may include a wafer stage on which a wafer may be set, a beam splitter to split first laser light into second and third laser light having a beam intensity distribution elongated in a first direction within a surface of the wafer, and an optical system to guide the second and third laser light onto the wafer. The wafer is irradiated with the second laser light from a second direction perpendicular to the first direction, and the third laser light from a third direction perpendicular to the first direction but different from the second direction, to thereby cause interference of the second and third laser light on the wafer. This apparatus increases the accuracy of the two-beam interference exposure.

The coherent interference effect between two beam is used with one light beam delayed by a controllably variable time delay with respect to another analogous beam to obtain a convolutional profile of the oscillatory component of the interference amplitude as a function of the time delay, having a peak value representing the performance clearance between a zero-bit and a one-bit. The convolutional profile is represented by a diamond diagram (DD) of the interference amplitude, within the coherence length. The peak value and the size of DD openings are used for characterizing pulsed optical signals by determining at least one of a predefined set of signal parameters, including signal degradation, optical chromatic dispersion, signal coherence length, type of signal modulation, and signal-to-noise ratio. The two-beam interference effect is optionally provided by a free-space Mach Zehnder interferometer, an integrated Mach Zehnder interferometer, a Michelson interferometer, or combinations thereof.

A position detection apparatus that illuminates diffraction gratings formed on two objects with light from a light source and receives diffracted light from the diffraction gratings to acquire relative positions of the two objects includes: an optical system configured to cause plus n-th order diffracted light and minus n-th order diffracted light from each of the diffraction gratings to interfere with each other, where n is a natural number; a light receiving unit; and a processing unit, wherein the light receiving unit receives a two-beam interference light from each of the diffraction gratings, and wherein the processing unit acquires the relative positions of the two objects by using the two-beam interference light at an area where two-beam interference lights of the diffracted light from the respective diffraction gratings do not overlap each other among the two-beam interference lights of the diffracted light from each of the diffraction gratings.

The invention relates to a method for implementing light emitting diode surface pattern preparation by using two-beam interference for assisting wet etching. The method includes: using a laser interference light path to irradiate a to-be-etched surface of a light emitting diode epitaxial wafer; adjusting the laser interference light path to form a light interference pattern on the to-be-etched surface of the light emitting diode epitaxial wafer; and subjecting the light emitting diode epitaxial wafer to light assisted wet etching by the aid of an existing wet etching method. Structures of different periods can be etched on the LED epitaxial wafer by adjusting angles of two incident laser beams. Compared with existing pattern preparation processes, the method has the advantages of simplicity in operation, low cost and acquisition of better surface patterns and microstructures.

The invention provides a non-destructive and highly-precise refractivity measuring method for miniature optical elements and a detection device thereof. The detection method comprises the following steps: (1) lights emitted by a light source go through a collimating lens and a light gap, then the lights is parallelly incident on a first sample cell and a second sample cell; then the lights go through a convergent lens and are converged on a cylindrical mirror, and two interference fringes vertically arranged can be watched from an observation pipe behind the cylindrical mirror; (2) an optical element to be measured is put into the first sample cell, and the upper interference fringe moves relative to the lower interference fringe; (3) calculating the interference grade through watching the displacement situation of the interference fringes, and finally obtaining the refractivity value of the optical element through formula calculation. The invention utilizes a Rayleigh interferometer, establishes a novel measuring method, and utilizes the two beam interference method's characteristics of high precision, simple structure, and user-friendliness so as to achieve the non-destructive and highly-precise measurement on refractivity of miniature or deformed optical elements.

The invention discloses a two-dimension cosine waveform surface light tripping structure and a solar film cell based on the structure. The two-dimension cosine waveform surface light tripping structure comprises a cell absorption layer. The upper and lower surfaces of the cell absorption layer respectively have a cosine waveform light trapping structure. The provided periodic two-dimension cosine waveform surface light tripping structure can be numerically optimized, and is capable of advancing absorption efficiency to a theory limit, thereby improving cell conversion efficiency greatly. Meanwhile, compared with an existing light tripping structure, the periodic two-dimension cosine waveform surface light tripping structure is more practical in production; and the surface type thereof can be prepared through a simple two-beam interference photoetching method, and the formed area is large, and thus the defects of limited area and unordered structure and the like in an existing light tripping structure preparation method can be overcome.

The invention relates to the technical field of display, in particular to a liquid crystal photo-alignment control method. The method specifically includes the steps that a liquid crystal alignment layer containing a photosensitive material is formed on a display substrate; after coherence of two ultraviolet light beams with the included angle being 2theta, the ultraviolet light beams vertically irradiate on the liquid crystal alignment layer, first alignment patterns and second alignment patterns are formed, the first alignment patterns have liquid crystal alignment in the same direction, the second alignment patterns have another liquid crystal alignment in the same direction, and the first alignment patterns and the second alignment patterns are perpendicular to each other. According to the liquid crystal molecule photo-alignment control method, liquid crystal molecules are aligned through the double-alignment pattern vertical structures close to 45 degrees, vertical dual-domain liquid crystal alignment is formed through one-time interference exposure by means of a two-beam interference method (without mask), product quality is improved to the largest extent, and the processing period is shortened.

The present invention provides a two-beam interference exposure system that can be simply adjusted by rotating only one mirror. By placing a half-wave plate in one of the interference arms and precisely scanning the relative fiber position, the present invention can expose true apodized fiber Bragg gratings in a single scan by simultaneously rotating the angle of the half-wave plate. By rotationally switching the fast and slow axes of the half-wave plate, the present invention can also expose n-phase-shifted fiber grating by the same system.

The invention discloses a real-time test device and method for sensitivity of double-detector time division multiplexing volume holographic materials. The device comprises a coherent light source, aninterference light path, a first photoelectric detector, a second photoelectric detector, an acquisition card and an upper computer. Through an electronic shutter in the interference light path, the whole test process is divided into periodic exposure processes and acquisition processes; during the exposure, both two beams in the two-beam interference light path are irradiated on the surface of avolume holographic material at the same time; and during the acquisition, only one beam in the two-beam interference light path is irradiated on the surface of the volume holographic material, and thephotoelectric detectors carry out data acquisition. According to the device and method, diffraction test is carried out by adoption of incident light completely consistent with the incident beams inthe exposure process, so that the high-precision matching of Bragg angles can be ensured all the time and is not influenced by the factors of inconsistent mounting, material shrinkage and the like. The wavelength used in the measurement is consistent with the recorded wavelength, so that the whole process only needs one laser, and the detection wavelength does not need to avoid the absorption spectrum areas.

The invention discloses a wave surface measuring system based on coaxial interference. The wave surface measuring system comprises a Mach-Zehnder two-beam interference light path, a coaxial interference recording unit, a two-dimensional moving platform, a laser interferometer unit and a data processing unit; an optical element to be measured is arranged in the Mach-Zehnder two-beam interference light path; the Mach-Zehnder two-beam interference light path is used for generating two beams of Mach-Zehnder interference light, one beam of the light serves as reference light, and the other beam ofthe light serves as measurement light, wherein the measuring light passes through the optical element to be measured; the coaxial interference recording unit is arranged on the two-dimensional movingplatform, and is used for combining the two beams of the Mach-Zehnder interference light into a coaxial interference signal, and recording light intensity information of the coaxial interference signal. The size and the precision of the measured wave surface are no longer limited by the size and the surface quality of a beam splitter, so that the system has a good application prospect in surface shape measurement of large-size wave surfaces and large-size optical elements.