- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 IEEE International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO) - Zhenjiang, China (2019.8.4-2019.8.8)] 2019 IEEE International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO) - Imaging Analysis of Micro-milling Tool in the Process of Tool Setting Based on Digital Holography
摘要： In the process of ultra-precision machining, the tool-setting accuracy of the micro-milling tool is limited by the tool diameter. The accuracy of tool setting decreases with the decrease of tool diameter, which becomes an important factor for restricting the accuracy of ultra-precision machining. Based on the imaging principle of digital in-line holography, an efficient and non-contacted method for tool setting was proposed for improving the accuracy of tool setting. Aiming at the imaging problem of micro-milling tool, the evaluation function based on wavelet transform was introduced in the process of progressive search, so the optimal reconstructed image was accurately obtained through the autofocusing algorithm. Then the zero-order term and the conjugate image were eliminated via the self-snake diffusion. The tool contour was extracted by Sobel operator, and tool diameter was measured using different methods. Measurement results proved that holographic imaging can meet the requirements of in-position dynamic measurement for micro-milling tools, and also provided an important basis for the accuracy of tool setting.
关键词： tool setting,auto-focusing,digital holography
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 2nd Ukraine Conference on Electrical and Computer Engineering (UKRCON) - Lviv, Ukraine (2019.7.2-2019.7.6)] 2019 IEEE 2nd Ukraine Conference on Electrical and Computer Engineering (UKRCON) - Retrievieng the Surface Relief of the Smooth Objects by the Digital Holography
摘要： A new method for the surface relief study using digital holography is presented. This method includes an approach for digital refocusing and elimination of optical aberrations. Experimental study of the standard roughness sample allowed estimation of the error of the proposed method. The practical application for solving real tasks of materials science is shown.
关键词： aberration elimination,Digital holography,surface relief,digital refocusing,nondestructive testing
更新于2025-09-12 10:27:22
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Size measurement of Daphnia pulex using low-coherence Gabor digital holography
摘要： We measured the size of Daphnia pulex (D. pulex), which is an indicator organism used for examining toxicity, under freely-swimming and stress-free conditions, made possible by the post-focusing ability of digital holography (DH). This environmental measurement is a new application of DH. This implementation, which is a key point of this research, should be applicable to real on-site use in non-sterile and unstable mechanical situations. Through trial and error, we arrived at the simplest interferometer configuration using a single beam line that can withstand vibrations, a low-coherence light source for reducing coherent noise, and single-shot image capturing. Automatic size measurement based on DH with image processing was performed. The originality of this research is the quantitative size measurement and performance estimation achieved by comparing the results with those from conventional manual eye measurement using ordinary optical microscope observation and image processing software. The estimation also allowed us to determine the proper parameters in the image processing for DH measurement.
关键词： Digital holography,Size measurement,Daphnia pulex,Image processing,Low-coherence light
更新于2025-09-12 10:27:22
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Recent Developments in Dual-Laser Digital Holography for Plasma-Facing Surface Characterization
摘要： A digital holography device is currently undergoing development at the Oak Ridge National Laboratory for the purpose of measuring surface topography, with the goal of deployment as a real-time plasma-facing component diagnostic for the study of materials that could be utilized in a nuclear fusion device. The holography system utilizes one or two lasers depending on the scale of surface features under measurement. Measurements of surface roughness were performed in a single-laser mode and compared with the data from profilometry, with a linear correlation of increased holographic measurement fidelity as surfaces became smoother. Characterization of the dual-laser operating mode has been performed via surface measurement of stainless steel targets with “stair-step” features in various sizes. Results demonstrated that surface features with known sizes as small as 25.4 μm could be resolved. Measurements were within ～55 μm or less deviation from the actual sizes, and measurement accuracy was improved as feature size was increased, corresponding to the effect of noise becoming less pronounced. A target exposed to plasma generated by an electrothermal (ET) arc source was analyzed with flat-field correction and averaging of sequential image frames to demonstrate the improved measurement quality in preparation for future use of holography on ET arc-exposed targets.
关键词： plasma-facing component interaction (PMI),Digital holography (DH),plasma (PFC),plasma-material diagnostic,nuclear fusion
更新于2025-09-12 10:27:22
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Single-shot Fresnel incoherent digital holography based on geometric phase lens
摘要： Single-shot and incoherent imaging are two important properties of digital holography that can extend its application range. In this study, a simple, compact, in-line Fresnel incoherent digital holographic recording system is proposed that is capable of single-shot and three-dimensional imaging. A geometric phase lens is used as the common-path beam splitter based on its special wave separation property. Parallel phase-shifting holography is used to achieve single-shot operation with the use of a polarization imaging camera together with space-division multiplexing. The capabilities of the proposed technique are experimentally confirmed by imaging two standard test charts based on a compact setup.
关键词： incoherent digital holography,Single-shot,three-dimensional imaging,Parallel phase-shifting method,space-division multiplexing,geometric phase lens
更新于2025-09-12 10:27:22
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Biological Lenses as a Photomask for Writing Laser Spots into Ferroelectric Crystals
摘要： Red Blood Cells on the surface of Lithium Niobate crystal can be used as optical lenses for direct writing of laser-induced refractive index changes. The writing process by such photomask made of biological lenses is due to photorefractive effect. Wavefront analysis by digital holographic microscope is performed for deep and accurate evaluation of local refractive index changes. Different focusing properties can be imprinted on the crystal depending on which type of RBC is employed, discocytes or spherical-like ones. The possibility to fix into a solid material the optical fingerprint of RBCs will have impact on both diagnostics and cell\material interfacing.
关键词： photo-lithography,bio-lenses,photorefractive effect,digital holography,RBC
更新于2025-09-12 10:27:22
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Detecting the Extremely Small Angle of an Axicon by Phase-Shifting Digital Holography
摘要： Axicon is an optical element that can be used to produce high-quality Bessel beams efficiently. In general, the smaller the base angle of the axicon is, the longer the diffraction-free distance of the generated Bessel beam will be. Therefore, axicon with an extremely small base angle is important for the generation of Bessel beam. However, the measurement of an extremely small base angle is a challenge. Here, we applied the phase-shifting digital holography in the measurement of axicon angle. The errors of the three measured axicons with base angles of 0.5°, 1°, and 1° were 1.94%, 4.43%, and 1.63%, respectively.
关键词： digital holography,axicon,phase measurement,phase shift
更新于2025-09-11 14:15:04
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2D resolution improvement via 1D scanning Space-Time Digital Holography (STDH) in Optofluidics
摘要： Space-Time Digital Holography (STDH) exploits the object motion to record the hologram in a hybrid space-time domain. This representation adds new capabilities to conventional DH, such as unlimited extension of the Field of View (FoV) and tunable phase shifting. Here we show that STDH is able to improve the spatial resolution as well. Differently from other super-resolution approaches, stitching between holograms or their spectra is no longer required. Moreover, we introduce a new STDH modality to record and process hybrid space-time representations. This allows improving resolution with one single object scan, paving the way to the use of STDH for superresolution imaging onboard Lab on a Chip devices.
关键词： Space-Time Digital Holography,STDH,Lab on a Chip,optofluidics,super-resolution
更新于2025-09-11 14:15:04
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[IEEE 2019 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Saint-Petersburg, Russia (2019.6.3-2019.6.7)] 2019 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Rgb Laser Source for Color Digital Holography
摘要： A three-wavelength light source for color digital holography is discussed. It is based on the Nd:YAG active element and three KTP crystals, in which the radiation at red (634 nm), green (532 nm) and blue (451 nm) wavelengths is generated. We propose to use this laser in digital holography schemes for simultaneous acquisition of three interference patterns and, therefore, for the analysis of the specimen’s spectral properties as well as its phase structure.
关键词： microscopy,laser,digital holography
更新于2025-09-11 14:15:04
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A methodology for the digital reconstruction of an interferogram, a schlieren image, or a shadowgram from a single digital holographic recording
摘要： This study presents an optical assembly and digital reconstruction method that is based on digital holography for characterizing transparent objects. The image-plane optical setup is based on a versatile Mach-Zehnder interferometer for the formation of controlled parallel fringe patterns, of tens micrometers of separations or less. The numerical reconstruction of the propagated wavefront by the hologram is performed by the Fresnel-Kirchhoff transform, and it is used of three ways: (a) interferometric phase reconstruction (as in interferometry) in the phase object position, (b) reconstruction of the wavefront amplitude at a determined distance from the object (shadowgraph technique), and (c) a composed digital reconstruction process of the wavefront amplitude, defined by a digital optical assembly for the selection of angular deflections produced by the phase object (schlieren technique). The resolving power of holographic reconstruction methodology proposed is determined by the sensitivity of hologram for detecting the interferometric phase. The fringe pattern of the hologram defines a minimum phase shift resolution of 0.15π rad. The scope of the technique is experimentally tested for a steady-state phase object.
关键词： interferometry,Fresnel-Kirchhoff transform,shadowgraph,schlieren,digital holography
更新于2025-09-09 09:28:46