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26 results about "Diffuse scattering" patented technology

Diffuse scattering is the scattering that arises from any departure of the material structure from that of a perfectly regular lattice. One can think of it as the signal that arises from disordered structures, and it appears in experimental data as scattering spread over a wide q-range (diffuse).

Wave-absorbing and diffuse-scattering mixed ultra-wideband RCS (radar cross section) reduction metasurface with wave-transparent window

The invention discloses an ultra-wideband RCS (radar cross section) reduction metasurface with mixed wave absorption and diffuse scattering and a wave-transparent window, and belongs to the technical field of electromagnetic metamaterials. The metasurface adopts a four-layer cascade structure and comprises a first layer of polarization conversion structure, a second layer of 2.5 D lossy structure, a third layer of Jerusalem cross-shaped lossy structure and a fourth layer of frequency selective surface structure. By loading a lumped resistor at a specific position and adopting a metal through hole interconnection technology, dual functions of radar cross section reduction in a 1-20GHz ultra-wideband and low insertion loss wave transmission in a 8-12GHz frequency band are realized. The structure of each layer adopts a highly symmetrical design and has the characteristic of polarization insensitivity, and meanwhile, by optimizing interlayer air gaps and dielectric material selection, the structure compactness is realized on the premise of ensuring the performance. The method has important application value in the aspect of integration of stealth equipment and a communication system.
Owner:JIAXING CMAG COMPOSITE MATERIAL CO LTD +1

Optical spectroscopy with controlled path length for non-invasive measurement through skin

Aspects relate to mechanisms to control the effective optical path length through skin tissue for non-invasive optical spectroscopy measurements. An apparatus can include a path length control part configured to control the effective optical path length of diffusely scattered light transmitted through skin tissue to produce a target effective optical path length. The apparatus may further include a spectral sensor, a detector, and a light source configured to produce input light directed towards the path length control part or the spectral sensor. The detector is configured to obtain a spectrum of an analyte under test based on the diffusely scattered light. The spectral sensor is configured to either receive the input light, produce modulated light based on the input light, and direct the modulated light to the skin tissue, or to receive the diffusely scattered light from the skin tissue and obtain the spectrum using the detector.
Owner:SI WARE SYSTEMS INC(EG)

Highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator for X-ray detection imaging and preparation method of highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator

The invention discloses a highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator for X-ray detection imaging and a preparation method of the highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator, and relates to the technical field of radiation detection and scintillation materials, the highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator comprises phenethyl ammonium bromide, cesium lead tribromide and ammonium thiocyanate, the molar ratio of the phenethyl ammonium bromide to the cesium lead tribromide to the ammonium thiocyanate is 2: 4: 2, the scintillator contains a methylamine thiocyanate additive which accounts for 0-1 equivalent weight of the dosage of the ammonium thiocyanate, and the scintillator is of a flaky polycrystal structure; the perovskite crystal of the polycrystalline wafer has a quasi-two-dimensional layered crystal structure, and each crystal grain is arranged in a height orientation manner, so that the layered crystal face is parallel to the main plane of the scintillator sheet. According to the highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator for X-ray detection imaging and the preparation method of the highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator, a highly-oriented layered structure is formed in the crystal, diffuse scattering of emergent light is greatly reduced, brightness uniformity and spatial resolution of X-ray imaging are improved, and a finer imaging effect is achieved.
Owner:SUZHOU LIUYANG OPTOELECTRONICS TECH

A general channel modeling method for underground space autonomous vehicle communication

This application belongs to the field of wireless communication technology and provides a general channel modeling method for communication of autonomous vehicles in underground spaces. The method includes: first, initializing model parameters and calculating path loss based on the scene; then, updating the orientation of the transceiver antennas using an attitude matrix and calculating their three-dimensional real-time positions; subsequently, selecting appropriate mechanisms to generate scattering clusters according to different underground scenarios such as pillar-type, tunnel-type, and cave-type, and updating their survival status based on the vehicle's motion state; next, generating and evolving specular multipath components and dense multipath components formed by specular reflection and diffuse scattering within each surviving scattering cluster; finally, combining line-of-sight and the two types of multipath components to calculate the time-varying channel impulse response and generate the channel matrix. This application can provide a more accurate and reliable general channel model foundation for the design, deployment, and performance evaluation of 6G underground communication systems, effectively supporting high-reliability communication assurance for underground autonomous vehicles.
Owner:SOUTHEAST UNIV +1

System and method for enhancing inspection of surface with specular reflection

An inspection system for enhancing diffuse scattering from a sample during inspection includes a stage and an optical subsystem, wherein the optical subsystem includes an illumination source, one or more optical elements, and a camera. The inspection system also includes one or more fluid delivery nozzles positioned proximate to the stage. The one or more fluid delivery nozzles are configured to deliver fluid via a fluid flow to one or more reflective components of the sample to temporarily cause adsorption of material on a surface of the one or more reflective components of the sample to cause temporary enhancement of diffuse scattering from the one or more reflective components of the sample. The camera is configured to image the one or more reflective components of the sample during the temporary enhancement of diffuse scattering from the one or more reflective components of the sample.
Owner:ORBOTECH LTD

Glass defect data set acquisition device and method for AI training multi-mode imaging

The invention relates to an AI training multi-modal imaging-oriented glass defect data set acquisition device and method, and aims to solve the problems of inconsistent imaging quality, complex device structure and incapability of automatically constructing a high-quality multi-modal data set in the existing glass defect acquisition technology. The device comprises a darkroom structure, and a light source regulation and control module, a polarization regulation and control module, a spectrum regulation and control module, a diffuse scattering regulation and control module, a rotary loading platform and an imaging module which are integrated in the darkroom structure, and each module is controlled by a control unit in a coordinated manner; according to the method, a multi-dimensional parameter combination matrix is established, parameters are called in sequence to collect images and bind metadata, and a structured data set is output after image registration and fusion. According to the method, ambient light interference is inhibited through modular electric control design, the consistency and definition of defect images are improved, differentiated display of multiple types of glass defects is realized, a high-quality multi-modal data set with optical parameter labels is automatically constructed, and reliable data support is provided for AI defect detection model training.
Owner:HANGZHOU DIANZI UNIV

A direct snow depth inversion method based on a spaceborne photon counting lidar

PendingCN122362326ASnowpackPoint cloud
This invention discloses a direct snow depth inversion method based on a spaceborne photon-counting lidar, comprising: extracting the target snow-covered area, removing areas with thick cloud cover and non-target surface point clouds, aligning the surface, and performing noise correction; performing deconvolution to obtain a corrected snow attenuation backscattering profile; setting an initial snow absorption coefficient, inverting the backscattering path length distribution of non-absorbing snow, and calculating the first and second moments of this distribution; based on the first and second moments, simultaneously inverting snow depth, snow albedo, and diffuse scattering coefficient; combining the snow albedo and diffuse scattering coefficient to calculate an updated snow absorption coefficient; if the updated snow absorption coefficient does not meet the set convergence threshold, using the updated snow absorption coefficient as the new initial snow absorption coefficient, and repeating the iteration; if it meets the threshold, outputting the final snow depth. Using this invention, along-track snow depth inversion can be achieved directly without relying on any other data.
Owner:ZHEJIANG UNIV

High-precision detection device for dipulse laser energy of laser radar

The dual-pulse laser energy high-precision detection device is suitable for an integral path differential absorption (IPDA) laser radar dual-pulse laser energy high-precision detection device, can realize high-precision real-time monitoring of laser energy, and meets the strict precision requirement of the IPDA laser radar in the aspect of energy monitoring. The device comprises a laser emission module, a dual-wavelength pulse laser and a spectroscope; the speckle suppression module comprises an attenuator, a rough diffuse scatterer and a rotating motor capable of adjusting the rotating speed; the receiving module comprises an integrating sphere, a delay optical fiber, a collimating mirror, a receiving telescope and a photoelectric detector; and a data acquisition and processing module. According to the invention, speckle errors are suppressed through the rotating rough diffuse scatterer, the influence of laser pointing change is eliminated in combination with the integrating sphere, and the same detector is used for receiving energy signals of the detection light beam and the monitoring light beam, so that the precision of energy monitoring is improved, and the measurement error of the IPDA laser radar is reduced.
Owner:SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI

A DLP car lamp adaptive lighting mode switching method and system

PendingCN122640909AIlluminanceLight spot
The present application relates to the technical field of adaptive lighting, in particular to a DLP vehicle lamp adaptive lighting mode switching method and system, the method comprising the following steps: collecting front image and attitude data, calculating light shape boundary gradient, dark area stray light leakage and bright area illumination decay, determining lens contamination and inverting the maximum diffuse scattering angle, calculating boundary retreat width, micromirror gradual change duty cycle and compensation driving current, checking anti-dazzle parameters according to light spot feedback, establishing feedforward mapping in association with mileage, temperature and wiper state and executing mode switching.In the present application, the scattering and absorption deviation caused by lens contamination is converted into a degradation index to uniformly constrain dark area leakage suppression and bright area illumination recovery by means of the diffuse angle, the boundary retreat, gradual change bandwidth and lateral spread angle are corrected in combination with light spot feedback, the anti-dazzle parameters are converged with the projection state, the feedforward reference is formed by means of vehicle working condition association, the opposite glare is reduced and effective illumination is maintained, and the mode switching adaptability and stability are improved.
Owner:DANYANG YUBO PHOTOELECTRIC TECH CO LTD

Apparatuses and methods for examining the movement of constituents within tissue cells

Apparatuses and methods for investigating the inside of a tissue cell are disclosed. Embodiments include diffusely scattering light off a target sample, producing two crossing beams from the scattered light, and using a camera to create an image from the light. Some embodiments utilize a Fourier lens and a Fresnel biprism, and optionally include a long-coherence light source, a delay plate (which can be a polarization rotator or an optical flat), and / or a beam expander. Still further embodiments utilize a diffraction grating, a spatial filter (which may include two differently sized apertures), and a Fourier lens, and optionally include differently sized apertures in the spatial filter. Some embodiments include a transparent support and illuminating the target at an oblique angle through the transparent support. Still further embodiments utilize a low-coherence light source and / or immobilizing the sample tissue using surface bonding chemistry.
Owner:PURDUE RES FOUND

Differential ray tracing target characteristic intelligent learning method

The invention relates to the field of radar image processing and target characteristic information extraction, in particular to a differential ray tracing target characteristic intelligent learning method. The method comprises the following steps: firstly, inputting an actual measurement image and observation parameters, and initializing target geometry and scattering parameters; then ray tracing forward microwave rendering is carried out, and a micro-surface microwave rendering model containing mirror surface and diffuse scattering tradeoff is adopted to generate a simulation SAR image; and by taking the simulation and actual measurement difference as a target function, calculating an internal item and boundary item differentiable form of a geometric parameter based on SAR imaging integration, spatial transformation and a Jacobian matrix, realizing gradient flow backward propagation and iteratively updating the geometric parameter until convergence and outputting a three-dimensional result. The method is high in physical consistency, low in dependence on the number of visual angles, stable in boundary details and capable of evaluating the consistency of the voxel intersection-to-union ratio, the point cloud distance, the Hausdorff distance and the normal.
Owner:FUDAN UNIVERSITY

Laser scanner with stereo camera vision for improved selective feature scanning

A selective laser scanner, comprising a target component which can be rotated about two rotation axes and is configured to transmit a distance measuring beam defining a target axis. The selective laser scanner further comprises a distance measuring unit configured to carry out distance measurements by means of the distance measuring beam on cooperative targets or on diffusely scattering targets. The selective laser scanner is equipped with a plurality of overview cameras arranged on the target component offset from the target axis in a fixed positional arrangement with respect to each other having field of views which at least partly overlap each other. The selective laser scanner further comprises a display for displaying an environment image provided by imaging data of at least one of the cameras as well as automatic feature and area detections.
Owner:LEICA GEOSYSTEMS AG

Proximity effect risk analysis method and system for noise sensitive area

The invention provides an adjacent avoidance effect risk analysis method and system for a noise sensitive area, and the method comprises the steps: obtaining a noise source sound power frequency spectrum and a three-dimensional scene model containing a sensitive area and an obstacle, and generating an initial sound ray set carrying energy, phase and frequency; a sound ray path is tracked in the 3D model, and phase disturbance and amplitude fluctuation caused by atmospheric turbulence are calculated; reflection, diffuse scattering, transmission and vibration re-radiation generated by the action of sound rays and the surface of an obstacle; the method comprises the following steps of: arranging a virtual receiver array in a noise sensitive area according to a diffraction effect when a sound ray arrives at the edge, and reconstructing a time domain sound pressure signal of each receiving point by performing coherent superposition on complex sound pressure reaching the sound ray; psychoacoustic indexes such as loudness are calculated on the basis of the signals and fused into a comprehensive risk index representing the neighbor effect through a preset weighting model.
Owner:SOUTH CHINA INST OF ENVIRONMENTAL SCI MEP

Socket surface defect detection method and system based on image processing

The application discloses a socket surface defect detection method and system based on image processing, and particularly relates to the technical field of industrial surface defect detection, and is used for solving the problem of low detection precision caused by mirror reflection noise interference and complex curved surface defect feature coupling of high light reflection material socket surface; by means of dynamically adjusting the incident angle and light intensity control parameters of an adjustable polarized light source, combining with frequency domain decomposition processing to separate surface geometric profile and defect high frequency features, mirror reflection interference is inhibited and defect contrast is enhanced; based on diffuse scattering spot form analysis under the direction of orthogonal incident light, a two-dimensional feature space of radial curvature and light intensity modulation depth is constructed to quantize the difference of defect physical scattering characteristics; by means of adaptive density clustering, metal oxidation and mechanical damage defect types are distinguished, and affine transformation mapping is used to realize accurate output of defect positions, so that the detection robustness and accuracy of small defects on complex curved surface high light reflection surface are significantly improved.
Owner:广东贝尔金智能科技有限公司

Intelligent silicon wafer screening method and system

The invention discloses an intelligent screening method and system for silicon wafers, and relates to the technical field of intelligent screening, corresponding surface defects are determined according to detection of diffuse scattering phenomena, corresponding multi-modal images are determined according to the surface defects, corresponding procedures and processing contents of the silicon wafers, deep learning is performed on the multi-modal images, and the processing contents of the silicon wafers are obtained. And the depth characteristics and gray gradient changes of each surface defect are deeply quantified to output the defect event of the silicon wafer, so that the accuracy of the defect event of the silicon wafer is improved. Determining the quality grade of the silicon wafer according to the potential risk and defect event of the silicon wafer; and mapping the quality grade and the defect distribution diagram of the silicon wafer to an upstream optimization process, outputting an intelligent screening route of the silicon wafer, determining a plurality of intelligent maintenance nodes of the silicon wafer based on the intelligent screening route of the silicon wafer and an upstream maintenance mechanism, marking corresponding maintenance content in each intelligent maintenance node, and carrying out maintenance on the silicon wafer. And the maintenance accuracy of the silicon wafer is improved.
Owner:NORDKETTE (SUZHOU) INTELLIGENT EQUIPMENT CO LTD

Intelligent method and system for wafer sorting

The application discloses a kind of intelligent screening methods and systems of silicon wafer, and the application relates to the technical field of intelligent screening, according to the detection of diffuse scattering phenomenon to determine the corresponding surface defect, according to the surface defect, corresponding process and the processing content of silicon wafer determines the corresponding multimodal image, carries out deep learning to multimodal image, and in-depth quantification each surface defect depth feature and gray scale gradient change, to output the defect event of silicon wafer, improve the accuracy of the defect event of silicon wafer.According to the potential risk and defect event of silicon wafer, the quality grade of silicon wafer is determined;The quality grade and defect distribution map of the silicon wafer are mapped to the optimized process upstream, and the intelligent screening route of the silicon wafer is output, based on the intelligent screening route of the silicon wafer and the upstream maintenance mechanism, a plurality of intelligent maintenance nodes of the silicon wafer are determined, and the corresponding maintenance content is marked in each intelligent maintenance node, which improves the maintenance accuracy of the silicon wafer.
Owner:NORDKETTE (SUZHOU) INTELLIGENT EQUIPMENT CO LTD

Self-adaptive underwater buried object detection method and device

The invention provides a self-adaptive underwater buried object detection method and device, and relates to the technical field of underwater detection. The method comprises the following steps: establishing a wave number integral model of a non-uniform medium, and correcting a traditional Helmholtz equation to represent sound wave propagation characteristics between a sedimentary layer and a buried target; constructing a coupling perturbation scattering model, expanding the coupling perturbation scattering model to a second order through Taylor expansion, and realizing joint modeling of coherent scattering and diffuse scattering in combination with a correction integral equation; carrying out global modeling on the multi-interface layered medium by adopting a transfer matrix method, and deducing a total reflection coefficient; establishing a constitutive relation model of the viscoelastic material based on the fractional derivative, and realizing acoustic response prediction of multi-physics coupling in combination with a random equivalent medium theory; and training detection signal data by using a long short-term memory auto-encoder network, and judging the existence of a target by calculating a reconstruction error. Through the method and the device provided by the invention, accurate detection in a complex underwater environment is realized, the problems of poor environmental adaptability, insufficient data and the like of a traditional method are avoided, and the detection accuracy and reliability are improved.
Owner:BEIHANG UNIV

Ultrafast-UV Laser Integrating Cavity Mediated Inactivation of a Pathogen

PendingUS20260041808A1RadiationBiotechnologyUv laser
Methodology for increasing efficiency of a pathogen inactivation via enhancing UVC light absorption at such pathogen by multiple diffuse scattering of the light at a wall defining a substantially closed volume, thereby increasing a number of angles at which the pathogen is being irradiate as compared with a direct irradiation of the pathogen with a beam of such light.
Owner:UNIV OF SOUTH FLORIDA

Preparation method of ultra-wideband radar stealth material coating

The present application relates to a kind of preparation methods of ultra-wideband radar stealth material coating, based on the principle that three-dimensional ordered nanostructured material produces diffuse reflection to radar wave, adopt the thorn ball nano nickel powder formed by needle-like nano nickel, strengthen its microstructure with SiO2 Sol, as primary particle structure;Due to the easy agglomeration of nano particles, combined as thorn ball nano nickel powder agglomerate to form secondary ordered structure;Mixed evenly with silicone adhesive to make stealth material coating, so that thorn ball nano nickel powder is evenly distributed in the stealth material coating with a thickness of about 2mm, forming three-dimensional ordered structure;Equivalent to a statistically all-around reflection macroscopic planar structure composed of countless small, different direction reflection particles, diffuse scattering to radar microwave to attenuate radar echo signal intensity, realize ultra-wideband radar microwave stealth.
Owner:NINGHAI EAST HONY ADVANCED MATERIAL CO LTD

Method for determining the interplanar spacing of hard carbon material 002

This invention belongs to the field of X-ray material detection technology, specifically a method for determining the interplanar spacing of hard carbon material 002. Addressing the technical problems in existing technologies where the standards for determining the interplanar spacing of hard carbon material 002 are inconsistent, the measurements are inaccurate, and the repeatability of the test data is poor, hindering the research and preparation of hard carbon materials in the power battery field, this application provides a method for determining the interplanar spacing of hard carbon material 002. The method uses silicon powder to calibrate the 2θ peak angle of the X-ray diffractometer. The peak angle of the 111 crystal plane of silicon powder is 28.442°. A mixture of hard carbon material and silicon powder is used for detection, with a mass ratio of hard carbon material to silicon powder of 95:5 to 99:1. The obtained diffraction peaks have complete shapes, which is more conducive to the analysis software reading the peak angle of the diffuse scattering peak of hard carbon. Furthermore, through angle calibration with standard samples, the obtained data on the interplanar spacing of hard carbon material 002 has high accuracy and good repeatability, providing a favorable guarantee for guiding the development and application of power battery materials.
Owner:HEFEI GUOXUAN HIGH TECH POWER ENERGY

Optical spectroscopy with controlled path length for non-invasive measurement through skin

Aspects relate to mechanisms to control the effective optical path length through skin tissue for non-invasive optical spectroscopy measurements. An apparatus can include a path length control part configured to control the effective optical path length of diffusely scattered light transmitted through skin tissue to produce a target effective optical path length. The apparatus may further include a spectral sensor, a detector, and a light source configured to produce input light directed towards the path length control part or the spectral sensor. The detector is configured to obtain a spectrum of an analyte under test based on the diffusely scattered light. The spectral sensor is configured to either receive the input light, produce modulated light based on the input light, and direct the modulated light to the skin tissue, or to receive the diffusely scattered light from the skin tissue and obtain the spectrum using the detector.
Owner:SI WARE SYSTEMS INC(US)

Ultrafast-UV laser integrating cavity mediated inactivation of a pathogen

ActiveUS12447225B2RadiationUv laserLight beam
Method for increasing efficiency of a pathogen inactivation via enhancing UVC light absorption at such pathogen by multiple diffuse scattering of the light at a wall defining a substantially closed volume, thereby increasing a number of angles at which the pathogen is being irradiate as compared with a direct irradiation of the pathogen with a beam of such light.
Owner:UNIV OF SOUTH FLORIDA

Methods and devices for analyzing therapeutic payloads carried by nanoparticle delivery carriers

There is described a method of determining at least one characteristic of a therapeutic payload and / or a nanoparticle delivery vehicle, the therapeutic payload and the nanoparticle delivery vehicle forming a diffuse scattering liquid suspension sample, the method comprising: positioning the sample within an integration chamber; the probe light is guided to a first port of the integral cavity; receiving a portion of the probe light from the second port of the integration cavity after scattering from the sample; measuring one or more spectral characteristics of the probe light received at the second port; and determining at least one quantitative characteristic of the therapeutic payload and / or the nanoparticle delivery vehicle in the liquid suspension based on the measured one or more spectral characteristics of the probe light received at the second port. An apparatus is also described.
Owner:MARAMA LAB LTD

Mechanochromic film with low angle dependence and fatigue resistance and preparation method and application thereof

ActiveCN119391399BTenebresent compositionsAngle dependenceDouble bond
The application provides a force-induced color change film with low angle dependence and fatigue resistance and a preparation method and application thereof, and the force-induced color change film is prepared by the following steps: preparing a silica amorphous photonic crystal film through a sol-gel method, KH570 modification and a pulling method; and uniformly coating PDMS solution on both sides of the film to obtain the force-induced color change film with low angle dependence and fatigue resistance. The nano-silica photonic crystal has uniform particle size and good dispersibility in ethanol, so that the periodic and regular arranged amorphous photonic crystal film can be prepared through the pulling method, and the film has low angle dependence when observed at different angles under indoor diffuse light; through modification, carbon-carbon double bonds are grafted on the surface of the silica nanoparticles, the carbon-carbon double bonds react with hydroxyl groups and mercapto groups on the surface of PDMS, chemical bonds are introduced, the interface interaction between the inorganic silica nanoparticles and the PDMS is enhanced, and therefore the mechanical properties and fatigue resistance of the material are improved.
Owner:WUHAN TEXTILE UNIV

Illuminating device for bacterial colony counting instrument

ActiveCN224263513UStrong feedback signalLighting elementsCoatingsPetri dishLight reflection
The utility model discloses a colony counter's illumination device, it includes heaven light uniformizing reflector and LED lamp bank, the lower surface of heaven light uniformizing reflector's main body is indent arc reflecting surface, the reflecting surface covers the sample petri dish area, the middle part of reflecting surface has the lens opening corresponding to the camera, and the LED lamp bank has the lens opening corresponding to the camera. The sky light equalizing reflector is further provided with a side wall facing downwards along the edge of the reflecting face, the LED lamp set is arranged on the inner side wall, an irradiation light source of the LED lamp set only irradiates upwards to the area of the reflecting face, and the irradiation light source is reflected by the reflecting face to form nearly-vertical light rays which are incident to the area of the sample culture dish and then reflected to the camera again. Therefore, an optimal irradiation light path is formed. According to the invention, nearly vertical light rays can be generated through light homogenizing reflection of the vault, the refraction angle of the nearly vertical light rays is close to zero after the nearly vertical light rays enter bacterial colonies, light quantity consumption caused by diffuse scattering can be reduced, and light feedback approximate to surface reflection intensity is formed.
Owner:SHANGHAI PANMAI TECH CO LTD

Fourier notch filter method and system

PendingUS20260185879A1Fast Fourier transformWavelength
A technique for determining the temperature of a semiconductor film during multiple quantum well (MQW) film growth via Metal-Organic Chemical Vapor Deposition (MOCVD). The temperature is determined in real-time as the film grows and increases in thickness. A spectrum based on the diffusely scattered light from the film is produced at each incremental thickness. A reference division is performed on each spectrum to correct for equipment artifacts. The thickness of the film and an optical absorption edge wavelength value are determined from the spectrum. The temperature of the film is determined as a function of the optical absorption edge wavelength and the thickness of the film using the spectrum, a thickness calibration table, and a temperature calibration table. The film temperature is accurately determined to + / −0.25° C. using a Fast Fourier Transform (FFT) and a notch filter.
Owner:K SPACE ASSOCS