Holographic Research Articles

Holographic Einstein ring of a charged Rastall AdS black hole with bulk electromagnetic field* *Supported by the National Natural Science Foundation of China (11675140, 11705005, 12375043), the Innovation and Development Joint Foundation of Chongqing Natural Science Foundation (CSTB2022NSCQ-LZX0021), and the Basic Research Project of Science and Technology Committee of Chongqing (CSTB2023NSCQ-MSX0324)

We study the Einstein images of a charged Rastall AdS black hole (BH) within the fabric of AdS/CFT correspondence. Considering the holographic setup, we analyze the amplitude of the total response function for various values of model parameters. With an increase in parameter λ and temperature T, the amplitude of the response function decreases, while it increases with an increase in electric charge e and chemical potential μ. The influence of frequency ω also plays an important role in the bulk field, as it is found that decreasing ω leads to an increase in the periods of the waves, which means that the amplitude of the response function also depends on the wave source. The relation between T and the inverse of the horizon for various values of parameter λ is interpreted under fixed values of other involved parameters. These, in turn, affect the behavior of the response function and the Einstein ring, which may be used to differentiate the present study from previous ones. We construct the holographic images of the BH in bulk via a special optical system. The results show that the Einstein ring always appears with concentric stripes at the position of the north pole, and this ring transforms into a luminosity-deformed ring or bright light spot when the distant observer lies away from the north pole. Finally, we discuss the influence of the associated parameters on the Einstein ring radius, which is consistent with wave optics.

Amplitude‐Phase Dual‐Channel Encrypted Acoustic Meta‐Holograms

AbstractEncrypted acoustic meta‐holograms have potential applications in confidential acoustic information communication, noise control, acoustic cloaking, acoustic illusion, etc. Conventional encrypted optical and acoustic meta‐holograms only focus on the encrypted hologram in a single channel, viz. modulating spatial amplitude to project a holographic image. Here, the concept of an amplitude‐phase dual‐channel encrypted acoustic meta‐hologram (DrEAM) is proposed, capable of generating, encrypting, and decrypting both amplitude and phase holographic images. This unique concept of “phase holographic image” introduces a new degree of freedom for meta‐holograms, leading to dual‐channel encrypted acoustic holography. Acoustic metasurface with simultaneous amplitude and phase modulations is employed to realize this dual‐channel encryption. The findings may offer the possibility to increase the capacity of the encrypted acoustic meta‐holograms, which can lead to practical applications in, for example, multi‐channel acoustic field communications, complex noise control, and acoustic illusions.

Single-shot dual-wavelength telecentric in-line-and-off-axis hybrid digital holography with non-prior reconstruction

Dual-wavelength in-line-and-off-axis hybrid digital holography (iohDH) can achieve high-resolution holographic dynamic imaging. However, it requires the prediction of the diffraction distance and the complex amplitude of the reference beam, which is time consuming and results in complications and accuracy limitations. While telecentric imaging technique can obtain nondiffractive images without predicting the diffraction distance, it also can even eliminate spherical aberration and astigmatic aberration. Therefore, a dual-wavelength telecentric iohDH is proposed to realize non-prior high-resolution reconstruction in a single shot. Employing the dual-wavelength telecentric iohDH, our approach acquires the focused in-line-and-off-axis hologram using a color camera in a single shot. In this case, we perform wavelength conversion on the phase and low-frequency information about the off-axis hologram as constraints for in-line iteration. Then, the in-line amplitude constraints are performed in the spatial and frequency domains until the algorithm converges. Compared to the state-of-the-art dual-wavelength iohDH, our approach can streamline the reconstructed processes without demanding a priori information of the diffraction distance and the complex amplitude of the reference beam. More importantly, our approach enables higher quality and efficient reconstruction under the telecentric system. We verified our approach using simulations and experiments, and the results indicate that our approach can allow the amplitude and phase reconstruction with high resolution in a single shot.

Optical router based on a phase-coding multiplexed collinear holographic storage system

This paper analyzes the distribution characteristics of crosstalk in a phase-coded multiplexed collinear holographic storage system and realizes an optical router by this characteristic. The system employs collinear holographic storage technology to cache the signals of the optical router in the holographic storage material. Different routing addresses are represented by the phase code. The system reads the signals in the holographic storage material and accomplishes the routing function. The benefit of this approach is that it minimizes the loss of optical signal and possesses robust anti-interference capability, offering an efficient solution in the development of optical routing.

Range selective digital holographic imaging of vibrating objects using FMCW lidar

The use of frequency modulated continuous wave (FMCW) chirped transmit and reference waveforms in digital holographic (DH) imaging has enabled range selectivity. By frequency shifting the reference beam to compensate for the typical FMCW lidar beat frequency associated with a particular range, a temporally stable holographic image is formed for objects at the selected range and coherently integrates on a short wave infrared (SWIR) sensor. For vibrating objects, longitudinal movements of the object greater than half of an optical wavelength during the exposure time of the sensor array induce phase shifts that can wash out the hologram. An analog feedback system was designed and constructed whereby a lidar subassembly provides real time phase compensation information to a DH subassembly in order to stabilize the range selective digital holographic recording of the object. The design and characterization of the feedback system, as well as the results demonstrating the performance for vibrating objects that move over 17 wavelengths during the sensor exposure, are discussed.

Chip-scale integrated holographic devices based on top-emitting vertical cavity surface emitting lasers.

Holography technology is considered the ultimate three-dimensional (3D) visualization technology in the future. However, conventional methods for achieving holography generally utilize discrete optical components and off-chip laser sources, resulting in a large size and high complexity, which are undesirable for practical applications. In this Letter, chip-scale integrated holographic devices are realized by integrating top-emitting vertical cavity surface emitting lasers (VCSELs) with micro holograms printed by 3D femtosecond laser nanoprinting technology. The VCSELs are designed to operate in a single fundamental mode with a Gaussian emission profile. Then the Gaussian beams are phase-modulated by the integrated micro holograms designed by the Gerchberg-Saxton (GS) algorithm and the target holographic images can be displayed behind the holograms. Such integrated holographic devices are of micron size and can be easily scaled into arrays with arbitrary channels on-demand, which are important for achieving miniaturized and portable holographic imaging systems.

Adaptive phase control of a phase-only spatial light modulator using the Shack-Hartmann wavefront sensor

We present a method to study both static and dynamic phase errors in a phase-only spatial light modulator (SLM) caused by surface irregularities and an imperfect response of each pixel to the applied field. This, in turn, degrades optical reconstruction, particularly in holographic projection applications. The approach uses the Shack-Hartmann wavefront sensor (SHWFS) to measure these errors. A plane wave illuminates the SLM, and the reflected wavefront is measured by the SHWFS and converted into a phase-only computer-generated hologram (CGH). This CGH is displayed on the SLM to compensate for phase errors, which are verified by subsequent wavefront measurements. Experimental results demonstrate the simplicity, robustness to vibration, and real-time capabilities of the SHWFS in contrast to interferometric methods.

Multi-Perspective Heterodyne Digital Holography For High-Speed Imaging Of Density Fluctuations In Supersonic Flow

Density fluctuation measurements with high spatio-temporal resolution provide meaningful insights into the dynamics of turbulent structures in shear layers, boundary layers, and disturbances that influence the transition to turbulence. The current contribution presents a new multiple perspective digital holographic imaging technique that aims to resolve high-frequency density fluctuations with spatial discrimination along the line of sight. A key element of the proposed method is the generation of a beamlet array of varying view angles that is spatially overlapped within the measurement zone. We present the first experimental realization of this approach using a 7-element hexagonally packed fly’s eye lens array and analyze results for a pair of mutually perpendicular and axially offset sonic jets. The experimental apparatus also incorporates heterodyne detection with a heterodyne frequency set to 1/4 of the imaging frame rate. The optical system performance is evaluated for a crossing jet flow and key design considerations for the multi-perspective optical system are discussed.

Optoelectronic system for measuring and analyzing the parameters of an electrical signal in a radio receiver path

The relevance of monitoring the level of signal distortion in radio reception equipment is substantiated. A block diagram of a holographic optoelectronic system for measuring and analyzing the level of an electrical signal in a radio receiver path is presented. The measurement algorithm is described. The sensitivity of the holographic sensitive unit of the developed system was researched. Mathematical modeling made it possible to evaluate the influence of the parameters of the optical circuit of the holographic sensitive element in the developed optoelectronic system on its sensitivity was carried out.

Minimalist design of multifunctional metasurfaces for helicity multiplexed holography and nanoprinting

Recently, polarization multiplexing has become a common strategy to enhance the information capacity of metasurfaces. Nevertheless, the intricate design of anisotropic nanostructures forming a polarization multiplexed metasurface poses a significant challenge, increasing the requirements for manufacturing processes and diminishing overall robustness. Herein, we present a minimalist metasurface comprised of only two kinds of nanostructures to achieve the integration of continuous-amplitude modulated nanoprinting and eight-step phase-only helicity-multiplexed holography. Specifically, the nanoprinting image governed by Malus’s law can be observed in the orthogonally polarized light path, while holographic images can be switched by changing the chirality of the incident circularly polarized light. More importantly, the geometric phase and the propagation phase of the metasurface are optimized simultaneously according to the target images. Thus, the metasurface does not require optimizing many kinds of nanostructures to achieve the phase but only needs two kinds of nanostructures, forming a minimalist metasurface that significantly relieves the design and fabrication burden. Moreover, the proposed methodology is universal and applicable not only in polarization multiplexing but also in other multi-channel multiplexing technologies. Consequently, the proposed scheme holds promising applications in image display, information encryption, data storage, anti-counterfeiting, and more.

Addressing variability in cell electrorotation through holographic imaging and correction factors

This study addresses the variations observed in electrorotation measurements due to cell positioning and movement. Electrorotation provides a non-disruptive method for inferring the electrical properties of individual cells. However, its widespread adoption is hindered by significant variation in the observed speed. By mitigating the impact of positional dependencies and other influencing factors, our methodology opens avenues for broader applications of electrorotation in single-cell analysis without the need for complex setups to trap and retain the cell in place. Our novel approach combines multi-plane imaging with mathematical treatment of rotation data. This method uses a conventional quadrupole chip and lens-free imaging to track cell movement, resulting in a simpler design and set-up. Through numerical simulations incorporating cell coordinates, chip design, and experimental parameters, we calculate the variation in torque for each position. These values serve as the basis for the correction factors. Validation experiments with T-lymphocytes and fibroblasts show that the correction factors reduce electrorotation speed variation due to cell movement, with an average reduction to 21% and 18%, respectively. These corrections also revealed previously concealed changes in cell properties, in response to external stimuli, thereby enhancing the reliability of measurements and enabling broader applications in single-cell analysis.

Contact lens holographic projection display based on curved volume‐holographic optical element

Contact lens holographic projection display based on curved volume‐holographic optical element

Design and Development of Metasurface Materials for Enhancing Photodetector Properties.

Recently, metasurface-based photodetectors (metaphotodetectors) have been developed and applied in various fields. Metasurfaces are artificial materials with unique properties that have emerged over the past decade, and photodetectors are powerful tools used to quantify incident electromagnetic wave information by measuring changes in the conductivity of irradiated materials. Through an efficient microstructural design, metasurfaces can effectively regulate numerous characteristics of electromagnetic waves and have demonstrated unique advantages in various fields, including holographic projection, stealth, biological image enhancement, biological sensing, and energy absorption applications. Photodetectors play a crucial role in military and civilian applications; therefore, efficient photodetectors are essential for optical communications, imaging technology, and spectral analysis. Metaphotodetectors have considerably improved sensitivity and noise-equivalent power and miniaturization over conventional photodetectors. This review summarizes the advantages of metaphotodetectors based on five aspects. Furthermore, the applications of metaphotodetectors in various fields including military and civil applications, are systematically discussed. It highlights the potential future applications and developmental trends of metasurfaces in metaphotodetectors, provides systematic guidance for their development, and establishes metasurfaces as a promising technology.

Deep learning in medicine: advancing healthcare with intelligent solutions and the future of holography imaging in early diagnosis

Deep learning in medicine: advancing healthcare with intelligent solutions and the future of holography imaging in early diagnosis

Simple and low-cost microscopy setup for 3D particle field measurement using incoherent illumination and open-source hardware.

The quantification of 3D particle field is of interest for a vast range of fields. While in-line particle holography (PH) can provide high-resolution measurements of particles, it suffers from speckle noise. Plenoptic imaging (PI) is less susceptible to speckle noises, but it involves a trade-off between spatial and angular resolution, rendering images with low resolution. Here, we report a simple microscopy setup with the goals of getting the strengths of both techniques. It is built with off-the-shelf and cost-effective components including a photographic lens, a diaphragm, and a CCD camera. The cost of the microscopy setup is affordable to small labs and individual researchers. The pupil plane of the proposed setup can be mechanically accessible, allowing us to implement pupil plane modulation and increase the depth of field (DOF) without requiring any additional relay lenses. It also allows us to understand the working principle of pupil plane modulation clearly, benefiting microscopy education. It illuminates the sample (particles) using diffuse white light, and thus avoids the problem of speckle noise. It captures multiple perspective images via pupil plane modulation, without requiring trading off angular and spatial resolution. We validate the setup with 2D and 3D particle samples. RESEARCH HIGHLIGHTS: We report a simple and cost-effective microscopy setup with the goals of getting the strengths of plenoptic imaging and in-line particle holography. It is built with off-the-shelf and cost-effective components. The cost of the microscopy setup is affordable to small labs and individual researchers. The pupil plane of the proposed setup can be mechanically accessible, allowing us to implement pupil plane modulation and increase the DOF without requiring any additional relay lenses. It also allows us to understand the working principle of pupil plane modulation clearly, benefiting microscopy education. It illuminates the sample (particles) using diffuse white light, and thus avoids the problem of speckle noise. It captures multiple perspective images via pupil plane modulation, without requiring trading off angular and spatial resolution. We validate the setup with 2D and 3D particle samples.

Broadband Complex Amplitude‐Modulated Metasurfaces for Nanoprinting and Vectorial Hologram with Continuously Varying Linear Polarization Distributions

AbstractThe multi‐dimensional light‐field manipulation capability of metasurfaces positions them as promising candidates for displaying nanoprinting and holographic images at ultra‐short distances with subwavelength resolution. In recent years, merging nanoprinting and holographic images into a single‐layer metasurface has emerged as a research focus to enhance information storage capacity. However, existing multi‐channel metasurface designs often limit the number of polarization states available for the holographic image. Here, a scheme is proposed and demonstrated to encode both a continuous grayscale image and a vectorial hologram with a continuously varying linear polarization distribution onto a complex amplitude‐modulated metasurface. The nanoprinting and holographic images generated from dielectric metasurface exhibit broadband response for the visible light. This method paves the way for compact optical devices tailored for applications in information encoding, high‐density optical storage, and information anti‐counterfeiting.

Design of boadband THz multi-beam splitting metasurface

Generating multiple local oscillator (LO) beams by beam splitters is a crucial aspect of large heterodyne array receivers operating at terahertz (THz) frequencies, with over 100 pixels. Metasurfaces have received considerable attention due to their unique and flexible wavefront modulation capabilities. Nevertheless, the design of beam-splitting metasurfaces faces significant challenges in increasing the number of diffraction beams, improving power efficiency, and achieving greater homogeneity. A SA-GS-based design model for beam-splitting metasurfaces is proposed to achieve multi-beam with high power efficiency and homogeneity. As a proof of concept, we have designed and optimized a 16-beam splitting metasurface from 0.82 THz to 1.6 THz. The objective is to develop large-pixel THz multi-beam heterodyne array receivers and optical systems. The number of beams is also extended to 100-, 144-, 225-, and 289-beam configurations, with power efficiencies of 93.55%, 93.92%, 96.01%, and 96.18% at 0.85 THz, respectively. Moreover, the main beams exhibit excellent homogeneity. This model can be employed in the design of multi-beam metasurfaces with variable deflection angles and intensity ratios. Finally, the multi-beam splitting metasurface is fabricated, and the experimental measurement agrees with the simulation. This work presents an effective approach for the inverse design of beam splitters or holographic imaging devices.

O-113 Non-invasive evaluation of embryo metabolic activity through hyperspectral microscopy

Abstract Current approaches for assessing embryo quality are subjective (morphology) or invasive (biopsy) and are not always predictive of live birth. Development of an accurate and non-invasive method to assess embryo quality would likely improve IVF success. We have taken a different approach towards developing a non-invasive diagnostic for embryo quality: optical imaging. We use low levels of light to illuminate the embryo and obtain spatial information on cell metabolism as well as biophysical properties of the embryo. Here I will present our work showing that hyperspectral imaging can be used to accurately discriminate between euploid and aneuploid mouse embryos, and in light sheet mode, able to generate 3D metabolic maps of developing embryos. Importantly, we show that this form of imaging is safe: compared to embryos that were not imaged, hyperspectral imaged embryos had similar, and not significantly different, pregnancy and implantation rates, with offspring weight at weaning also comparable. Another potential optical approach to assess embryo quality is digital holographic imaging. To date, little attention has been paid to the physical parameters of an embryo and whether these could be markers of embryo quality. One such physical parameter is refractive index. We have shown that digital holographic microscopy is able to measure very small changes in refractive index between good and poor-quality mouse embryos. Importantly, these optical approaches occur in the absence of stains or exogenous tags. Used alone, or in combination, such optical approaches may prove beneficial in developing an accurate, non-invasive diagnostic for embryo quality.

P-043 Preliminary clinical outcome using the Q300™ device in a reproductive laboratory environment

Abstract Study question How does the Q300™ Device impact clinical outcomes in a reproductive laboratory environment compared to established standards? Summary answer The device showed favorable clinical outcomes and was user-friendly. More research is needed to identify the patient subgroups that can benefit the most from system What is known already Embryologists struggle with accurately assessing sperm morphology without staining, prompting interest in emerging technologies like AI. These methods evaluate motility parameters, offering non-invasive sperm selection. A previous study comparing Q300 to manual staining methods showed high agreement and repeatability, indicating Q300’s accuracy in measuring live sperm cells. It aids in selecting cells per WHO2021 guidelines without staining, potentially revolutionizing sperm assessment. Study design, size, duration The study is an open-label, non-randomized study. Semen samples intended for ICSI were imaged by the Q300™ device before micro-injection to aid in selecting morphologically compliant sperm cells. The data collected was compared to the Key Performance Indicators (KPI) for ART laboratories according to the Vienna Consensus. Up to 5 sites will be enrolled in the study, with up to 100 couples in total from all sites. Study duration: 18 months Participants/materials, setting, methods The Q300™ device is an optical system using quantitative phase microscopy and holographic imaging to analyze human semen morphology. The device aids embryologists in selecting live and motile sperm cells for ICSI by providing automatic, objective analysis. Couples meeting inclusion criteria, including female age ≤40 and availability of motile sperm, were recruited for ICSI procedures. There were no restrictions on previous IVF/ICSI cycles. Endpoints: fertilization, day-3 embryo development, good blastocyst development rates, and implantation rates. Main results and the role of chance 14 couples were recruited from Barzilay Medical Center’s IVF unit in Ashkelon, Israel. The average fertilization rate is 79.1% (Vienna consensus competency is ≥ 65%), the day 3 embryo development rate is 55% (Vienna consensus competency is ≥ 45%), and the good blastocyst development rate is 42.5% (Vienna consensus competency is ≥ 30%). The implantation rate (day 3+day5) is 36.8% (Vienna consensus competency is ≥ 25% for day 3 embryo transfers and ≥ 35% for blastocyst transfers). The intended users performed the procedures with no reported malfunctions. 270 sperm imaging procedures were performed using the Q300 device to select 109 morphologically suitable cells for ICSI. The utilization of the product resulted in approximately a 40% yield of correct selections by the embryologist. Consequently, out of every 10 cells deemed compliant by the embryologist, only 4 were confirmed by the device, with roughly 3 falling within a margin of 10% around the WHO measurement range. Moreover, only about 1 of these selections fell within the boundaries defined by the WHO standards. This observation offers insights into the characteristics of cells routinely chosen for injection into oocytes. Limitations, reasons for caution The study recruited 14 couples from a single site; it is important to validate and statistically power the outcome measures and compare them with clinical control groups in the future. In the next generation of the product, incorporating an objective selection based on sperm motility can further improve its functionality. Wider implications of the findings The findings offer insights into optimizing sperm selection processes, potentially improving fertilization, embryo development, and implantation rates in couples undergoing ICSI. Moreover, the study highlights the importance of continued research and refinement of technological innovations in ART to better serve patient needs and improve treatment outcomes. Trial registration number NCT06232720

Algebraic ER=EPR and complexity transfer

We propose an algebraic definition of ER=EPR in the GN → 0 limit, which associates bulk spacetime connectivity/disconnectivity to the operator algebraic structure of a quantum gravity system. The new formulation not only includes information on the amount of entanglement, but also more importantly the structure of entanglement. We give an independent definition of a quantum wormhole as part of the proposal. This algebraic version of ER=EPR sheds light on a recent puzzle regarding spacetime disconnectivity in holographic systems with O\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{O} $$\\end{document}(1/GN) entanglement. We discuss the emergence of quantum connectivity in the context of black hole evaporation and further argue that at the Page time, the black hole-radiation system undergoes a transition involving the transfer of an emergent type III1 subalgebra of high complexity operators from the black hole to radiation. We argue this is a general phenomenon that occurs whenever there is an exchange of dominance between two competing quantum extremal surfaces.