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European Microscopy Congress 2016: Proceedings || A closer look at high-resolution electron holography
摘要： In the recent years high-resolution off-axis holography made huge advances in the field of electron microscopy. While the side-band reconstruction is well understood, the influence of aberrations on the reconstructed exit wave is not. Here, we show that the aberrations of the reconstructed exit wave are not dominated by the shot noise anymore. By means of simulations we demonstrate that the aberrations of the reconstructed exit wave can be reduced by a factor of two if the aberrations of the imaging system are known. This is a significant improvement compared to the state of the art.
关键词： aberrations,electron microscopy,exit wave reconstruction,off-axis holography
更新于2025-09-11 14:15:04
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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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Holography with Photochromic Diarylethenes
摘要： Photochromic materials are attractive for the development of holograms for different reasons: they show a modulation of the complex refractive index, meaning they are suitable for both amplitude and phase holograms; they are self-developing materials, which do not require any chemical process after the light exposure to obtain the final hologram; the holograms are rewritable, making the system a convenient reconfigurable platform for these types of diffractive elements. In this paper, we will show the features of photochromic materials, in particular diarylethenes in terms of the modulation of a transparency and refractive index, which are mandatory for their use in holography. Moreover, we report on the strategies used to write binary and grayscale holograms and their achieved results. The outcomes are general, and they can be further applied to other classes of photochromic materials in order to optimize the system for achieving high efficiency and high fidelity holograms.
关键词： holography,refractive index,diarylethenes,photochromism,CGH
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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Principles of Engineering Physics 1 () || Holography
摘要： Electromagnetic radiation scattered by an object contains all the information about the object. In photography, distribution of only the intensities of light scattered from the object are recorded on photographic plates. It is a 2-D representation of 2-D or 3-D object; it gives only a single view. The term “holography” is derived from Greek by combining Holos (whole) and graphy (writing) meaning complete recording of information on images in terms of scattered intensities and phases. In holography, distribution of intensities of light scattered from the object along with is phases are recorded on photographic plates. It is a 3-D representation of a 3-D object on a 2-D sheet; it gives a 3-D view. Here three-dimensional images using coherent laser light are produced on photographic plates. Therefore, though holography was invented by Dennis Gabor in 1948 (it earned him the Nobel prize in Physics in 1971), it gained momentum only after the invention of the laser in 1960, the powerful source of coherent light. In this chapter, the concept of holography is presented very briefly.
关键词： photographic plates,coherent light,3-D representation,laser,holography
更新于2025-09-11 14:15:04
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Robust holography of the temporal wave function via second-order interference
摘要： Containing the capacity to record both amplitude and phase information of the light ?eld, holography is of great importance in science and technology. Here, we present robust holography via second-order interference, considering both single-photon states and coherent states. Temporal amplitude and phase distribution carried by a weak coherent state are reconstructed experimentally. By comparison between holography using ?rst-order interference and second-order interference, the robustness against phase noise of our method is veri?ed. Besides, information about the state can be directly retrieved, with no complex algorithm required.
关键词： single-photon states,holography,coherent states,second-order interference,phase noise
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE 62nd International Midwest Symposium on Circuits and Systems (MWSCAS) - Dallas, TX, USA (2019.8.4-2019.8.7)] 2019 IEEE 62nd International Midwest Symposium on Circuits and Systems (MWSCAS) - Logic Obfuscation using Metasurface Holography
摘要： Over the years, system design companies have developed sophisticated and accurate Reverse Engineering (RE) tools to debug the functionality of their own designs, ensure the legitimacy of their Intellectual Properties (IPs), and to some extent- gather information on their competitors. Technologies such as optical imaging, Scanning Electron Microscopy (SEM), Tunneling Electron Microscopy (TEM), X-ray Tomography, etc. have made it possible to acquire images of individual layers of a delayered Integrated Circuit (IC) with super?ne resolution. State-of-the-art tools such as ICWorks from Chipworks can perform automatic extraction of netlists from images of each layer. An adversary can unlock valuable IPs through such attacks and pirate the design or sell the cloned IP to other competitors for unjust motives. Logic and interconnect obfuscation have been proposed to make the RE effort behind such approaches prohibitively high for the adversaries. Several solutions have been proven to be vulnerable to Satis?ability (SAT) based attacks where an adversary can deobfuscate the circuit reasonably quickly. In this paper, we have presented a novel obfuscation technique based on the concepts of cloaked nets and fake holographic gates using metasurface holography. The proposed approach can address optical and X-ray imaging based RE.
关键词： IC Camou?aging,Metasurface Holography,Cloaked Nets,Reverse Engineering,Fake Gates
更新于2025-09-11 14:15:04
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Building magnetic hysteresis in holography
摘要： We study the spontaneous magnetization and the magnetic hysteresis using the gauge/gravity duality. We (cid:12)rst propose a novel and general formula to compute the magnetization in a large class of holographic models. By using this formula, we compute the spontaneous magnetization in a model like a holographic superconductor. Furthermore, we turn on the external magnetic (cid:12)eld and build the hysteresis curve of magnetization and charge density. To our knowledge, this is the (cid:12)rst holographic model realizing the hysteresis accompanied with spontaneous symmetry breaking.
关键词： Holography and condensed matter physics (AdS/CMT),Gauge-gravity correspondence
更新于2025-09-11 14:15:04
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European Microscopy Congress 2016: Proceedings || Quantitative measurement of doping and surface charge in a ZnO nanowire using in-situ biasing and off-axis electron holography
摘要： The measurement of doping and surface charge in a Zn2N3 nanowire using in-situ biasing and off-axis electron holography
关键词： surface charge,in-situ biasing,off-axis electron holography,Zn2N3 nanowire,doping
更新于2025-09-11 14:15:04