- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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3D focusing through highly scattering media using PSF modulation
摘要： In this letter, we present an approach to achieve three-dimensional (3D) focusing through highly scattering media. The method combines 3D computer-generated holography (CGH) with point-spread-function (PSF) based wavefront shaping. With a single transmission matrix measurement, CGH-aided PSF engineering enables us to control light volumetrically under multiple scattering. As a proof of concept, generating user-speci?ed 2D intensity patterns and 3D focusing through scattering media were demonstrated. Further, axial scanning of the focus was realized digitally by using a digital micromirror device. Experimentally, our method achieves an axial scanning range (cid:2)20 times larger than that obtained by the memory effect method. Our work is expected to bene?t long-range optical trapping and volumetric imaging through highly scattering media.
关键词： computer-generated holography,PSF modulation,highly scattering media,3D focusing,wavefront shaping
更新于2025-09-10 09:29:36
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6.2: <i>Invited Paper:</i> The Development of a Head Mounted Holographic Retina Display
摘要： Based on MGSA, the holography display system is proposed in this study, and the eyepiece is designed according to suitable wearing parameters. Besides, images computed with MGSA could be proceeded optical reconstruction without lenses to reduce the use of optical elements. This head mounted display system is optimized by referring to the human eyes to realize the simple display system with high-quality image contents.
关键词： the head mounted display,modified Gerchberg-Saxton algorithm,computer generated holography
更新于2025-09-10 09:29:36
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Synthesis Algorithm for Near-Field Power Pattern Control and Its Experimental Verification via Metasurfaces
摘要： Antennas and metasurfaces have enabled a number of far-field manipulation functions. According to the addition theorem of multipoles, near fields have richer spatial spectra than far fields, hence in the near-field region it is easier to achieve complex manipulations on field distributions. In this work, an algorithm is presented to synthesize the near fields of source arrays. Given target distributions of near-field intensities and also predefined source magnitudes, the algorithm will find the needed source phases, which can then be applied on active antenna arrays and passive metasurfaces to induce the target distribution of fields. The algorithm adopts the dyadic Green’s function as the propagator, hence it naturally takes account of the near-field and vector properties of electromagnetic fields. As typical application of the algorithm, an example is given to obtain the excitation phases of a dipole array, which is then physically imitated by a coding metasurface. Experimental measurement is performed and the result proves the validity of the algorithm. From the perspective of information metasurface, the algorithm finds the phase-coding pattern of matesurface to achieve specific functions.
关键词： near-field control,Antenna pattern synthesis,computer-generated holography,phase coding,metasurface
更新于2025-09-10 09:29:36
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Multichannel vectorial holographic display and encryption
摘要： Since its invention, holography has emerged as a powerful tool to fully reconstruct the wavefronts of light including all the fundamental properties (amplitude, phase, polarization, wave vector, and frequency). For exploring the full capability for information storage/display and enhancing the encryption security of metasurface holograms, smart multiplexing techniques together with suitable metasurface designs are highly demanded. Here, we integrate multiple polarization manipulation channels for various spatial phase profiles into a single birefringent vectorial hologram by completely avoiding unwanted cross-talk. Multiple independent target phase profiles with quantified phase relations that can process significantly different information in different polarization states are realized within a single metasurface. For our metasurface holograms, we demonstrate high fidelity, large efficiency, broadband operation, and a total of twelve polarization channels. Such multichannel polarization multiplexing can be used for dynamic vectorial holographic display and can provide triple protection for optical security. The concept is appealing for applications of arbitrary spin to angular momentum conversion and various phase modulation/beam shaping elements.
关键词： metasurfaces,polarization multiplexing,holography,optical encryption,vectorial holography
更新于2025-09-09 09:28:46
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Aberrated dark-field imaging systems
摘要： We study generalized dark-field imaging systems. These are a subset of linear shift-invariant optical imaging systems that exhibit arbitrary aberrations and for which normally incident plane-wave input yields zero output. We write down the theory for the forward problem of imaging coherent scalar optical fields using such arbitrarily aberrated dark-field systems and give numerical examples. The associated images may be viewed as a form of dark-field Gabor holography, utilizing arbitrary outgoing Green’s functions as generalized Huygens-type wavelets, with the Young-type boundary wave forming the holographic reference.
关键词： dark-field imaging,aberrations,linear shift-invariant optical imaging systems,Gabor holography,Huygens-type wavelets
更新于2025-09-09 09:28:46
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High-speed quantitative 3D imaging by dual-illumination holographic microscopy
摘要： A new blood flow imaging (BFI) technique using digital holography with double illumination of the sample is proposed. We imaged the moving red blood cells (RBCs) using a two microscope objective lenses setup. The setup consists in a larger angle of separation (90 (cid:1)) between the two illumination beams, allowing a wider angular rotation at good z resolution. Moreover, the setup geometry allows an easier displacement of the sample in all directions. Results show that this technique is able to perform phase-shifting reconstruction for the two beams at the same time which is more suitable for the future implementation of live 3D holography. Experimental results are carried out for the verification of the effectiveness of the proposed technique on a zebrafish larvae sample.
关键词： preclinical models,red blood cells,fish embryo,holography,microcirculation
更新于2025-09-09 09:28:46
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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
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La física en la extensión universitaria a través de la holografía como medio de educación social
摘要： With the emergence and development of the white-light holograms, new possibilities were created for its utilization as a social education medium due to the characteristic of producing a three-dimensional image which constitutes an optical duplicate of the object. The paper describes the merits and characteristics of the hologram as a means of social education and experience in the construction and use of permanent holographic exhibitions in museums and traveling in the community as a result of university extension from physics.
关键词： holography,university extension,social education means,physics
更新于2025-09-04 15:30:14
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Incoherent holographic camera based on Michelson Interferometer
摘要： Incoherent holography is a hybrid imaging technology with coherent and incoherent processes. Compared with coherent holography, incoherent holography can alleviate coherent noise and speckle noise, and thus achieve higher signal-to-noise ratio. In this article, the incoherent holographic camera based on Michelson interferometer is built, which consists of a telescope, a beam-splitting cube, two plane mirrors, two lenses and a monochromatic charge coupled device. The Point Spread Function (PSF) of the system is determined for the first time according to the Fresnel diffraction theory. Both the simulated and experimental 2D PSFs are coincident with each other. The three-step generalized phase shift interferometry instead of the piezo-actuator is used to eliminate zero-order and twin images. The two one-jiao coins with 15mm apart and a toy house are recorded under xenon lamp illuminated. The reconstructed image clearly demonstrates the system has the ability to obtain spatial 3D information of an object.
关键词： Incoherent holography,Michelson interferometer,Generalized phase-shift interferometry
更新于2025-09-04 15:30:14
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Surface scanning for 3D dose calculation in intraoperative electron radiation therapy
摘要： Dose calculations in intraoperative electron radiation therapy (IOERT) rely on the conventional assumption of water-equivalent tissues at the applicator end, which defines a flat irradiation surface. However, the shape of the irradiation surface modifies the dose distribution. Our study explores, for the first time, the use of surface scanning methods for three-dimensional dose calculation of IOERT. Two different three-dimensional scanning technologies were evaluated in a simulated IOERT scenario: a tracked conoscopic holography sensor (ConoProbe) and a structured-light three-dimensional scanner (Artec). Dose distributions obtained from computed tomography studies of the surgical field (gold standard) were compared with those calculated under the conventional assumption or from pseudo-computed tomography studies based on surfaces. In the simulated IOERT scenario, the conventional assumption led to an average gamma pass rate of 39.9% for dose values greater than 10% (two configurations, with and without blood in the surgical field). Results improved when considering surfaces in the dose calculation (88.5% for ConoProbe and 92.9% for Artec). More accurate three-dimensional dose distributions were obtained when considering surfaces in the dose calculation of the simulated surgical field. The structured-light three-dimensional scanner provided the best results in terms of dose distributions. The findings obtained in this specific experimental setup warrant further research on surface scanning in the IOERT context owing to the clinical interest of improving the documentation of the actual IOERT scenario.
关键词： Intraoperative radiotherapy,Structured-light 3D scanner,IOERT,Dose distribution,Surface scanning,Conoscopic holography
更新于2025-09-04 15:30:14