- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Dual-wavelength Raman fusion spectroscopy
摘要： Spatially compressed dual-wavelength Raman spectroscopy allows recording the full Raman spectrum using a detection system with limited spectral range. The common approach is to record the spectra with the two excitation lasers consecutively and then concatenate the full spectrum. However, with this approach quantitative analysis for process monitoring is not possible as the investigated object may change between the two acquisitions. In this Note, spectral fusion is proposed as a concept to overcome this problem. The sample is illuminated by the two lasers simultaneously hence leading to an on-chip fusion of the different parts of the Raman spectrum. It is shown that the resulting data are suitable for quantitative evaluation using univariate and multivariate methods. Dual-wavelength Raman fusion spectroscopy offers new opportunities for building highly compact devices for analytical chemistry.
关键词： Raman spectroscopy,principal component analysis,data processing
更新于2025-09-23 15:22:29
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Virtual subpixel approach for single-mask phase-contrast imaging using Timepix3
摘要： X-ray phase contrast imaging provides a method to distinguish materials with similar density and effective atomic number, which otherwise would be difficult using conventional X-ray absorption contrast. In recent years, multiple methods have been developed to acquire X-ray phase contrast images using incoherent laboratory sources. The single mask edge illumination setup has been demonstrated as a possible candidate for large scale applications due to its relaxed restrictions on longitudinal coherence and mask alignment, and for its ability to do bi-directional phase contrast images in a single sample exposure. Unfortunately, the single mask edge illumination setup's refraction sensitivity, and thereby signal to noise, is limited by detector artifacts. Furthermore, it requires multiple exposures to perform dark-field imaging, a method that enables imaging of micro-structures smaller than the image resolution. We propose using an Advapix detector with Timepix3 pixel-readout chip in a single mask imaging setup to improve signal to noise ratio in phase contrast images. This is achieved using the Timepix3 chip's ability to simultaneously acquire fast time of arrival and time over threshold measurement of single photon events, which enables sub-pixel identification of individual photons. In this paper, we demonstrate that signal to noise ratio can be improved by at least 67 ± 5 % using subpixel identification of single photons compared to conventional acquisitions methods. Thereby the required sample dose can be reduced considerably. This shows that there is a great potential in using Timepix3 chip to improve x-ray phase contrast imaging. Further, the results indicate the possibility for dark field imaging in a single sample exposure using Timepix3 in a single mask edge illumination setup.
关键词： X-ray detectors,X-ray radiography and digital radiography (DR),Data processing methods,Inspection with x-rays
更新于2025-09-23 15:22:29
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[IEEE 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII) - Berlin, Germany (2019.6.23-2019.6.27)] 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII) - Infrared Photodetector with Copper Resonator in Silicon Nanohole Array
摘要： A highly linear broadband photonic-assisted analog-to-digital converter (ADC) based on high-frequency optical sampling utilizing a dual output Mach–Zehnder modulator operating with signal frequencies up to 50 GHz is presented. The pulses employed in the optical sampling were generated by a cavity-less pulse source operated at 10 GHz in preference to conventional mode-locked lasers. The optical sampling front-end greatly extends the operational frequency range of the Nyquist limited electronic digitization back-end. The performance of the sampling system is characterized with 7.1 effective number of bits (ENOBs) at 40 with 5 GHz fully accessible bandwidth, and greater than 99 dB·Hz2/3 spurious free dynamic range for the 30–40 GHz frequency range. Furthermore, more than 8 ENOB was achieved by reducing the effective bandwidth to 1 GHz with a digital ?lter, demonstrating the additional advantage of using a higher sampling rate compared to previous demonstrations. A new ?gure of merit of photonic-assisted sub-sampled ADCs is also presented accompanied with a comparison to previous implementations.
关键词： microwave photonics,optical data processing,sampling,Analog-digital conversion,detection,sub-sampling,optical ?ber communications
更新于2025-09-23 15:19:57
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Current trends in laser-induced breakdown spectroscopy: a tutorial review
摘要： The purpose of this tutorial article is to provide a brief update on the advances available for laser-induced breakdown spectroscopy (LIBS), focusing broad experimental and instrumental possibilities. Due to the inherent versatility of LIBS, this technique can be elegantly applied to various applications. However, during the method development one should have prior knowledge about its analytical limitations in order to obtain reliable results. In the present review, we summarize key analytical variables required for proper sample treatment, analytical signal enhancement, data processing, qualitative and quantitative approaches as well as recent research and developments using LIBS. Remarkable analytical advances have recently been proposed for LIBS and raised its analytical performance to a level never reached before. Most prominent perhaps, have been the development of many nontraditional calibration approaches based on transition atomic energies (emission wavelengths), the use of a single standard for calibration, increase of the ablated sample mass (accumulated laser pulses), and even overcoming severe LIBS problems such as the matrix effects.
关键词： LIBS,signal enhancement,calibration,qualitative analysis,data processing,sample preparation
更新于2025-09-23 15:19:57
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An open-source software ecosystem for the interactive exploration of ultrafast electron scattering data
摘要： This paper details a software ecosystem comprising three free and open-source Python packages for processing raw ultrafast electron scattering (UES) data and interactively exploring the processed data. The first package, iris, is graphical user-interface program and library for interactive exploration of UES data. Under the hood, iris makes use of npstreams, an extensions of numpy to streaming array-processing, for high-throughput parallel data reduction. Finally, we present scikit-ued, a library of reusable routines and data structures for analysis of UES data, including specialized image processing algorithms, simulation routines, and crystal structure manipulation operations. In this paper, some of the features or all three packages are highlighted, such as parallel data reduction, image registration, interactive exploration. The packages are fully tested and documented and are released under permissive licenses.
关键词： Ultrafast electron scattering,Visualization,Data processing,Open-source
更新于2025-09-19 17:15:36
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Advanced statistical analysis of LIBS spectra for the sourcing of obsidian samples
摘要： Numerous prehistoric populations around the world have made intensive use of the conchoidal properties of obsidian, a volcanic glass, to make tools and weapons. For archaeologists, knowing the geological origin of these artifacts is vital to reconstruct population movements and interactions. In this paper, we discuss the results obtained by Laser-Induced Breakdown Spectroscopy [LIBS] on a corpus of 228 geological obsidian samples from the West Mediterranean area. For the purposes of this study LIBS was undertaken in a laboratory setting. However, handheld LIBS should one day allow an extension of this work directly on site, on archaeological excavations or in a museum setting. The LIBS spectra are analyzed through the supervised multivariate approach called Quadratic Discriminant Analysis [QDA]. The methodology of this advanced data processing approach is detailed and the ability of the resulting model to sort the samples is assessed thanks to several figures of merit. The results obtained for the set of obsidian samples considered in the present study reveal that LIBS data treated by QDA is an efficient approach for answering the question of sourcing in this particular case-study. The same model can be applied to archeological samples from the same geographical area. More generally, the methodology presented here can be considered as a general guideline for any other LIBS-based sorting purpose.
关键词： archaeology,LIBS,lithic sourcing,obsidian,advanced data processing
更新于2025-09-19 17:15:36
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Design and Data Processing of China's First Spaceborne Laser Altimeter System for Earth Observation: GaoFen-7
摘要： The GaoFen-7 (GF-7) satellite, which was launched on November 3, 2019, is China’s first civilian submeter stereo mapping satellite. The satellite is equipped with the first laser altimeter officially in China for earth observation. Except for the laser altimeter, the GF-7 spaceborne laser altimeter system also includes two laser footprint cameras and a laser optical axis surveillance camera. The laser altimeter system is designed and used to assist improving the elevation accuracy without ground control points of the two line-array stereo mapping cameras. This article details the design of the GF-7 spaceborne laser altimeter system, its ranging performance in the laboratory, and its data processing method. The type of data products is also released. These data will play a vital role in the application of geography, glaciology, forestry, and other industries.
关键词： laser products,Data processing,footprint camera,optical axis surveillance camera,laser altimeter,GF-7 satellite
更新于2025-09-19 17:13:59
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Optimizing input data for training an artificial neural network used for evaluating defect depth in infrared thermographic nondestructive testing
摘要： Ten different sets of input data have been used for training and verification of the neural network intended for determining defect depth in infrared thermographic nondestructive testing. The input data sets included raw temperature data, polynomial fitting, principle component analysis, Fourier transform and others. A minimum error (up 0.02 mm for defects in CFRP at depths from 0.5 to 2.5 mm) has been achieved by using polynomial fitting in logarithmic coordinates with further computation of the first temperature derivatives (the TSR technique), and close results have been obtained by processing raw data with the PCA technique. Both techniques require no use of reference points.
关键词： Neural network,Data processing,Defect depth,Composite material,Infrared thermographic testing
更新于2025-09-16 10:30:52
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3-D Laser Scanning Landslide Deformation Monitoring and Data Processing Based on Computer Cluster
摘要： Landslide monitoring is an important technical means for monitoring and forecasting landslides. At present, three-dimensional laser scanning technology has been applied to deformation monitoring, such as landslide monitoring. The three-dimensional laser scanning technology can measure the three-dimensional coordinates of the object surface with high precision, high density and high speed, thus describing the details of the surface in detail. It has been successfully applied in static shape measurement. Computer cluster is widely used in various computationally intensive tasks because of its high cost performance and good scalability. Combined with the deformation information of deformation monitoring points, the deformation trend of landslide body is effectively monitored and predicted. In order to process the obtained data in a timely and rapid manner, the computer cluster performs the absolute orientation of the sequence point cloud collected in different periods to complete the coordinate system, and then acquires a set of points of different periods of point cloud data at the same position of the computer cluster. The data was compared and analyzed. In addition, the acquisition of ground-type 3D laser scanner data does not require the deployment of monitoring points, which can reflect the surface morphology of the landslide more quickly and accurately than the traditional monitoring means, and then obtain the surface deformation value.
关键词： 3-D Laser Scanning,Data Processing,Computer Cluster,Landslide Deformation Monitoring
更新于2025-09-12 10:27:22
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[IEEE 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - Sarajevo, Bosnia and Herzegovina (2019.9.2-2019.9.4)] 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - GPON Frame Data Processing
摘要： This article presents a method for data analysis of GPON frames transmitted over passive optical networks using the gigabit encapsulation method. First, the introduction is described. The following sections are focused on individual parts of our designed system, including capturing frames, storing frames, analysis and interpretation of results.
关键词： Python,data processing,GPON,database
更新于2025-09-12 10:27:22