- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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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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8.3: <i>Invited Paper:</i> Ultra High Resolution Display for Digital Holography
摘要： Ultra high resolution display panels are one of the technical trends for future display and essential for the realization of digital hologram. Two approaches for the development toward 1um pixel pitch are introduced. SLM panel with 3μm pixel pitch based on reflected TFT-LCD was fabricated. Reconstructed hologram images were successfully demonstrated. SLM based on phase change materials was under development. In this case the driving circuitry was consist of Si CMOS backplane. Due to the scalability of PCM materials, accomplishment of pixel pitch with 1μm is very promising.
关键词： TFT-LCD,Spatial Light Modulator,Ultra high resolution,Holography,Phase modulation,Active-matrix displays,TFTs,Phase Change Materials
更新于2025-09-12 10:27:22
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Review on feature extraction for 3D incoherent image processing using optical scanning holography
摘要： The advancement of digital holography in the past 2 decades has enabled precise capturing of three-dimensional (3-D) images of physical objects. This important technology has been widely applied in numerous industrial sectors such as, but not limited to remote sensing, metrology, bio-medical imaging, advertising, and entertainment. Most of the hologram acquisition techniques developed to date are employing digital cameras for recording the hologram, hence imposing rigid restrictions on the size and resolution of the captured 3-D image. This limitation, however, is not found in optical scanning holography (OSH). Based on a scanning mechanism and a single pixel sensor, OSH is capable of capturing digital holograms of both macroscopic and microscopic, as well as fluorescent objects with high precision. Since its invention in the late 70s, numerous research works have been conducted to enhance this technology, optimizing important factors such as acquisition speed, precision, data size, and security. The objective of this review paper is to provide a walkthrough of the state-of-the-art of the OSH technology, from its original principle, to different variants that have been developed over the years with emphasis on their feature extraction capabilities under the incoherent mode of operation. Whenever possible, we shall provide the key formulations of each approach, and experimental outcomes for demonstrating the pros and cons of the method.
关键词： generalized two-pupil image processing system,spiral-phase pupil,anisotropic edge detection,feature extraction,annular pupil,Optical Scanning Holography (OSH)
更新于2025-09-12 10:27:22
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Quantitative Amplitude and Phase Imaging with Interferometric Plasmonic Microscopy
摘要： Plasmonic microscopy is a powerful tool for nanoscopic bio- and chemical sample analysis due to its high sensitivity. Phase quantification in plasmonic microscopy would provide inherent information, i.e. refractive index, for identification of nanomaterials. However, it usually relies on complex optics to acquire quantitative phase images. Here, we demonstrated the quantitative amplitude and phase imaging capabilities through holographical reconstructions of the plasmonic patterns recorded in the interferometric plasmonic microscopy. Operating the plasmonic microscopy over the surface plasmon resonance angle separates the twin images, and allows for accurate mapping of the amplitude and phase distribution of surface plasmon near fields. Results show that the imaging capabilities enable direct visualization of complex surface plasmon fields arising from interactions with nanoparticles and nanowires, without the need for nanoscopic scanning probes. Theoretical and experimental analysis also suggests future applications in the identification of nanoparticles and super resolution imaging. The proposed technology is thus promising for nanoplasmonic study and various sensing purposes.
关键词： interferometric plasmonic microscopy,surface plasmon resonance,holography,nanoparticles,phase retrieval
更新于2025-09-12 10:27:22
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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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Nanosecond electron holography by interference gating
摘要： The interference gating is a novel method for robust time-resolved electron holographic measurements by directly switching the interference. Here, a new arrangement is presented in which a biprism in the condenser aperture as a fast electric phase shifter is used to control the interference pattern. High-frequency stimulation of the electric phase shifter in the gigahertz range are performed and observed via electron holography, proving the feasibility of interference gating in the upper picosecond range. Despite the bandwidth limitation of 180 MHz of the current signal generator, a time resolution of 100 ns is achieved through forward correction of the control signal. With this time resolution, it is already possible to measure the transient response of the biasing holder system. Our method paves the way towards a closer look on fast dynamic processes with high temporal and spatial resolution.
关键词： Interference gating,Time-resolved electron holography,Nanosecond time resolution,Condenser biprism,Electrical biasing
更新于2025-09-12 10:27:22
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Study on Compact Head-Mounted Display System Using Electro-Holography for Augmented Reality
摘要： Head-mounted displays (HMDs) and augmented reality (AR) are actively being studied. However, ordinary AR HMDs for visual assistance have a problem in which users have di?culty simultaneously focusing their eyes on both the real target object and the displayed image because the image can only be displayed at a ?xed distance from an user’s eyes in contrast to where the real object three-dimensionally exists. Therefore, we considered incorporating a holographic technology, an ideal three-dimensional (3D) display technology, into an AR HMD system. A few studies on holographic HMDs have had technical problems, and they have faults in size and weight. This paper proposes a compact holographic AR HMD system with the purpose of enabling an ideal 3D AR HMD system which can correctly reconstruct the image at any depth. In this paper, a Fourier transform optical system (FTOS) was implemented using only one lens in order to achieve a compact and lightweight structure, and a compact holographic AR HMD system was constructed. The experimental results showed that the proposed system can reconstruct sharp images at the cor- rect depth for a wide depth range. This study enabled an ideal 3D AR HMD system that enables simultaneous viewing of both the real target object and the reconstructed image without feeling visual fatigue.
关键词： augmented reality,electro-holography,head-mounted display,computer-generated hologram
更新于2025-09-12 10:27:22
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Trichromatic and Tri-polarization-channel Holography with Non-interleaved Dielectric Metasurface
摘要： Metasurfaces hold great potentials for advanced holographic display with extraordinary information capacity and pixel sizes in an ultrathin flat profile. Dual-polarization channel to encode two independent phase profiles or spatially multiplexed meta-holography by interleaved metasurfaces are captivated popular solutions to projecting multiplexed and vectorial images. However, the intrinsic limit of orthogonal polarization-channels, their crosstalk due to coupling between meta-atoms, and interleaving-induced degradation of efficiency and reconstructed image quality set great barriers for sophisticated meta-holography from being widely adopted. Here we report a non-interleaved TiO2 metasurface holography, and three distinct phase profiles are encoded into three orthogonal polarization bases with almost zero crosstalk. The corresponding three independently constructed intensity profiles are therefore assigned to trichromatic (RGB) beams, resulting in high-quality and high-efficiency vectorial meta-holography in the whole visible regime. Our strategy presents an unconventionally advanced holographic scheme by synergizing trichromatic colors and tri-polarization channels, simply realized with a minimalist non-interleaved metasurface. Our work unlocks the metasurface’s potentials on massive information storage, polarization optics, polarimetric imaging, holographic data encryption, etc.
关键词： polarization conversion,non-interleaved metasurface,tri-polarization-channel metasurface,trichromatic vectorial holography,dielectric nanostructures
更新于2025-09-12 10:27:22
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Determination of electronic band structure by electron holography of etched-and-regrown interfaces in GaN <i>p-i-n</i> diodes
摘要： The electrostatic potential variation across etched-and-regrown GaN p-i-n diodes for power electronics has been studied using electron holography in a transmission electron microscope. The potential profiles have been correlated with the composition profiles of Mg, Si, and O obtained by secondary ion mass spectroscopy. Electronic charges obtained from the potential profiles correlate well with the presence of Si and O impurities at regrown interfaces. The overlap of Mg and Si when Mg doped GaN is grown directly over an etched undoped GaN surface results in the formation of a highly doped p-n junction. The introduction of a thin undoped layer over the etched GaN surface prevents the formation of such a junction as the regrowth interface is moved away from the Mg-doped GaN, and results in diodes with improved reverse leakage currents, close to the best values of continuously grown p-i-n diodes. Potential profiles of continuously grown (not etched) p-i-n diodes are compared to those of etched-and-regrown diodes.
关键词： Mg,O impurities,regrown interfaces,Si,secondary ion mass spectroscopy,electrostatic potential,GaN p-i-n diodes,electron holography
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