Millimeter Wave Holographical Inspection of Honeycomb Composites
Case, J. T.; Kharkovsky, S.; Zoughi, R.; Stefes, G.; Hepburn, Frank L.; Hepburn, Frank L.
2007-01-01
Multi-layered composite structures manufactured with honeycomb, foam or balsa wood cores are finding increasing utility in a variety of aerospace, transportation, and infrastructure applications. Due to the low conductivity and inhomogeneity associated with these composites standard nondestructive testing (NDT) methods are not always capable of inspecting their interior for various defects caused during the manufacturing process or as a result of in-service loading. On the contrary, microwave and millimeter wave NDT methods are well-suited for inspecting these structures since signals at these frequencies readily penetrate through these structures and reflect from different interior boundaries revealing the presence of a wide range of defects such as disbond, delamination, moisture and oil intrusion, impact damage, etc. Millimeter wave frequency spectrum spans 30 GHz - 300 GHz with corresponding wavelengths of 10 - 1 mm. Due to the inherent short wavelengths at these frequencies, one can produce high spatial resolution images of these composites either using real-antenna focused or synthetic-aperture focused methods. In addition, incorporation of swept-frequency in the latter method (i.e., holography) results in high-resolution three-dimensional images. This paper presents the basic steps behind producing such images at millimeter wave frequencies and the results of two honeycomb composite panels are demonstrated at Q-band (33-50 GHz). In addition, these results are compared to previous results using X-ray computed tomography.
Millimeter Wave Holographical Inspection of Honeycomb Composites
Case, J. T.; Kharkovsky, S.; Zoughi, R.; Steffes, G.; Hepburn, F. L.
2008-02-01
Multi-layered composite structures manufactured with honeycomb, foam, or balsa wood cores are finding increasing utility in a variety of aerospace, transportation, and infrastructure applications. Due to the low conductivity and inhomogeneity associated with these composites, standard nondestructive testing (NDT) methods are not always capable of inspecting their interior for various defects caused during the manufacturing process or as a result of in-service loading. On the contrary, microwave and millimeter wave NDT methods are well-suited for inspecting these structures since signals at these frequencies readily penetrate through these structures and reflect from different interior boundaries revealing the presence of a wide range of defects such as isband, delamination, moisture and oil intrusion, impact damage, etc. Millimeter wave frequency spectrum spans 30 GHz-300 GHz with corresponding wavelengths of 10-1 mm. Due to the inherent short wavelengths at these frequencies, one can produce high spatial resolution images of these composites either using real-antenna focused or synthetic-aperture focused methods. In addition, incorporation of swept-frequency in the latter method (i.e., holography) results in high-resolution three-dimensional images. This paper presents the basic steps behind producing such images at millimeter wave frequencies and the results of two honeycomb composite panels are demonstrated at Q-band (33-50 GHz). In addition, these results are compared to previous results using X-ray computed tomography.
Holographic magnetisation density waves
Energy Technology Data Exchange (ETDEWEB)
Donos, Aristomenis [Centre for Particle Theory and Department of Mathematical Sciences, Durham University,Stockton Road, Durham, DH1 3LE (United Kingdom); Pantelidou, Christiana [Departament de Fisica Quantica i Astrofisica & Institut de Ciencies del Cosmos (ICC),Universitat de Barcelona,Marti i Franques 1, 08028 Barcelona (Spain)
2016-10-10
We numerically construct asymptotically AdS black brane solutions of D=4 Einstein theory coupled to a scalar and two U(1) gauge fields. The solutions are holographically dual to d=3 CFTs in a constant external magnetic field along one of the U(1)’s. Below a critical temperature the system’s magnetisation density becomes inhomogeneous, leading to spontaneous formation of current density waves. We find that the transition can be of second order and that the solutions which minimise the free energy locally in the parameter space of solutions have averaged stressed tensor of a perfect fluid.
Composite materials inspection. [ultrasonic vibration holographic NDT
Erf, R. K.
1974-01-01
Investigation of the application requirements, advantages, and limitations of nondestructive testing by a technique of ultrasonic-vibration holographic-interferometry readout used in a production control facility for the inspection of a single product such as composite compressor blades. It is shown that, for the detection and characterization of disbonds in composite material structures, this technique may represent the most inclusive test method.
S -duality for holographic p -wave superconductors
Gorsky, Alexander; Gubankova, Elena; Meyer, René; Zayakin, Andrey
2017-11-01
We consider the generalization of the S -duality transformation previously investigated in the context of the fractional quantum Hall effect (FQHE) and s -wave superconductivity to p -wave superconductivity in 2 +1 dimensions in the framework of the AdS /CFT correspondence. The vector Cooper condensate transforms under the S -duality action to the pseudovector condensate at the dual side. The 3 +1 -dimensional Einstein-Yang-Mills theory, the holographic dual to p -wave superconductivity, is used to investigate the S -duality action via the AdS /CFT correspondence. It is shown that, in order to implement the duality transformation, chemical potentials on both the electric and magnetic sides of the duality have to be introduced. A relation for the product of the non-Abelian conductivities in the dual models is derived. We also conjecture a flavor S -duality transformation in the holographic dual to 3 +1 -dimensional QCD low-energy QCD with non-Abelian flavor gauge groups. The conjectured S -duality interchanges isospin and baryonic chemical potentials.
Holographic p-wave superconductor models with Weyl corrections
Directory of Open Access Journals (Sweden)
Lu Zhang
2015-04-01
Full Text Available We study the effect of the Weyl corrections on the holographic p-wave dual models in the backgrounds of AdS soliton and AdS black hole via a Maxwell complex vector field model by using the numerical and analytical methods. We find that, in the soliton background, the Weyl corrections do not influence the properties of the holographic p-wave insulator/superconductor phase transition, which is different from that of the Yang–Mills theory. However, in the black hole background, we observe that similarly to the Weyl correction effects in the Yang–Mills theory, the higher Weyl corrections make it easier for the p-wave metal/superconductor phase transition to be triggered, which shows that these two p-wave models with Weyl corrections share some similar features for the condensation of the vector operator.
Three-Dimensional Microwave Holographic Imaging Employing Forward-Scattered Waves Only
Directory of Open Access Journals (Sweden)
Reza K. Amineh
2013-01-01
Full Text Available We propose a three-dimensional microwave holographic imaging method based on the forward-scattered waves only. In the proposed method, one transmitter and multiple receivers perform together a two-dimensional scan on two planar apertures on opposite sides of the inspected domain. The ability to achieve three-dimensional imaging without back-scattered waves enables the imaging of high-loss objects, for example, tissues, where the back-scattered waves may not be available due to low signal-to-noise ratio or nonreciprocal measurement setup. The simulation and experimental results demonstrate the satisfactory performance of the proposed method in providing three-dimensional images. Resolution limits are derived and confirmed with simulation examples.
Holographic P -wave superconductors in 1 +1 dimensions
Alkac, Gokhan; Chakrabortty, Shankhadeep; Chaturvedi, Pankaj
2017-10-01
We study (1 +1 )-dimensional P -wave holographic superconductors described by three- dimensional Einstein-Maxwell gravity coupled to a massive complex vector field in the context of AdS3/CFT2 correspondence. In the probe limit, where the backreaction of matter fields is neglected, we show that there is a formation of a vector hair around the black hole below a certain critical temperature. In the dual strongly coupled (1 +1 )-dimensional boundary theory, this holographically corresponds to the formation of a charged vector condensate which breaks spontaneously both the U (1 ) and S O (1 ,1 ) symmetries. We numerically compute both the free energy and the ac conductivity for the superconducting phase of the boundary field theory. Our numerical computations clearly establish that the superconducting phase of the boundary theory is favorable to the normal phase, and the presence of a magnetic moment term in the dual bulk theory effects the conductivity in the boundary field theory.
Holographic p-wave superfluid in Gauss–Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Liu, Shancheng [Department of Physics, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, Hunan 410081 (China); Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, Hunan 410081 (China); Pan, Qiyuan, E-mail: panqiyuan@126.com [Department of Physics, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, Hunan 410081 (China); Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, Hunan 410081 (China); Jing, Jiliang, E-mail: jljing@hunnu.edu.cn [Department of Physics, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, Hunan 410081 (China); Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, Hunan 410081 (China)
2017-02-10
We construct the holographic p-wave superfluid in Gauss–Bonnet gravity via a Maxwell complex vector field model and investigate the effect of the curvature correction on the superfluid phase transition in the probe limit. We obtain the rich phase structure and find that the higher curvature correction hinders the condensate of the vector field but makes it easier for the appearance of translating point from the second-order transition to the first-order one or for the emergence of the Cave of Winds. Moreover, for the supercurrents versus the superfluid velocity, we observe that our results near the critical temperature are independent of the Gauss–Bonnet parameter and agree well with the Ginzburg–Landau prediction.
Entanglement entropy in a holographic p-wave superconductor model
Directory of Open Access Journals (Sweden)
Li-Fang Li
2015-05-01
Full Text Available In a recent paper, arXiv:1309.4877, a holographic p-wave model has been proposed in an Einstein–Maxwell-complex vector field theory with a negative cosmological constant. The model exhibits rich phase structure depending on the mass and the charge of the vector field. We investigate the behavior of the entanglement entropy of dual field theory in this model. When the above two model parameters change, we observe the second order, first order and zeroth order phase transitions from the behavior of the entanglement entropy at some intermediate temperatures. These imply that the entanglement entropy can indicate not only the occurrence of the phase transition, but also the order of the phase transition. The entanglement entropy is indeed a good probe to phase transition. Furthermore, the “retrograde condensation” which is a sub-dominated phase is also reflected on the entanglement entropy.
Lifshitz effects on holographic p-wave superfluid
Directory of Open Access Journals (Sweden)
Ya-Bo Wu
2015-02-01
Full Text Available In the probe limit, we numerically build a holographic p-wave superfluid model in the four-dimensional Lifshitz black hole coupled to a Maxwell-complex vector field. We observe the rich phase structure and find that the Lifshitz dynamical exponent z contributes evidently to the effective mass of the matter field and dimension of the gravitational background. Concretely, we obtain that the Cave of Winds appeared only in the five-dimensional anti-de Sitter (AdS spacetime, and the increasing z hinders not only the condensate but also the appearance of the first-order phase transition. Furthermore, our results agree with the Ginzburg–Landau results near the critical temperature. In addition, the previous AdS superfluid model is generalized to the Lifshitz spacetime.
Digital holographic inspection system for the inner surface of a straight pipe
Yokota, Masayuki; Koyama, Teppei; Takeda, Kazufumi
2017-10-01
A multicolor digital holographic inspection system achieving both automatic scanning sensing head and automatic correction of a distortion in the profile due to positional error of a sensing head has been applied to the inner surface of a straight brass pipe having artificial defects on its wall. To investigate the inner surface of the pipe, the sensing head consisting of a cone-shaped mirror (CSM) glued to an aluminum base in the pipe is illuminated by the collimated RGB laser beams from the outside of the pipe. In the system, by changing the wavelength of the illumination light and scanning the CSM in the pipe, data acquisitions and analysis are performed using a personal computer. It is shown that the pipe inspection, including a classification of defects, can be successfully conducted by comparing the multicolor intensity images and the height profile of inner surface of pipe.
Fuh, Andy Ying-Guey; Li, Ming Shian; Wu, Shing Trong
2011-07-04
This study investigates the transversely propagating waves in a body-centered tetragonal photonic crystal based on a holographic polymer-dispersed liquid crystal film. Rotating the film reveals three different transverse propagating waves. Degeneracy of optical Bloch waves from reciprocal lattice vectors explains their symmetrical distribution.
A Practical Millimeter-Wave Holographic Imaging System with Tunable IF Attenuator
Zhu, Yu-Kun; Yang, Ming-Hui; Wu, Liang; Sun, Yun; Sun, Xiao-Wei
2017-10-01
A practical millimeter-wave (mmw) holographic imaging system with tunable intermediate frequency (IF) attenuator has been developed. It can be used for the detection of concealed weapons at security checkpoints, especially the airport. The system is utilized to scan the passenger and detect the weapons hidden in the clothes. To reconstruct the three dimensions (3-D) image, a holographic mmw imaging algorithm based on aperture synthesis and back scattering is presented. The system is active and works at 28-33 GHz. Tunable IF attenuator is applied to compensate the intensity and phase differences between multi-channels and multi-frequencies.
P-wave holographic superconductor/insulator phase transitions affected by dark matter sector
Energy Technology Data Exchange (ETDEWEB)
Rogatko, Marek; Wysokinski, Karol I. [Institute of Physics, Maria Curie-Skłodowska University,20-031 Lublin, pl. Marii Curie-Skłodowskiej 1 (Poland)
2016-03-31
The holographic approach to building the p-wave superconductors results in three different models: the Maxwell-vector, the SU(2) Yang-Mills and the helical. In the probe limit approximation, we analytically examine the properties of the first two models in the theory with dark matter sector. It turns out that the effect of dark matter on the Maxwell-vector p-wave model is the same as on the s-wave superconductor studied earlier. For the non-Abelian model we study the phase transitions between p-wave holographic insulator/superconductor and metal/superconductor. Studies of marginally stable modes in the theory under consideration allow us to determine features of p-wave holographic droplet in a constant magnetic field. The dependence of the superconducting transition temperature on the coupling constant α to the dark matter sector is affected by the dark matter density ρ{sub D}. For ρ{sub D}>ρ the transition temperature is a decreasing function of α. The critical chemical potential μ{sub c} for the quantum phase transition between insulator and metal depends on the chemical potential of dark matter μ{sub D} and for μ{sub D}=0 is a decreasing function of α.
Digital holographic inspection for drying processes of paint films and ink dots
Yokota, M.; Aoyama, F.
2017-06-01
Digital holographic techniques to investigate drying processes of both paint films and ink dot is presented. The proposed technique based on digital holographic interferometry can achieve both visualization of variations and analysis of dryness of paint films in the drying process by using phase changes between two subsequent reconstructed complex amplitudes of the reflected light from the film. To follow the drying processes, holograms are recorded at a constant time interval. Phase-shifting digital holography has been applied to analyze the dryness of commercial paints applied on the metal plate. For analysis of an ink dot having diameter of a few hundred micrometers, digital holographic microscopy is applied to evaluating the time history of dryness of ink dot in the drying process. This paper describes these holographic techniques applied to the commercially available paint and ink and presents some experimental results.
Optical image encoding based on digital holographic recording on polarization state of vector wave.
Lin, Chao; Shen, Xueju; Xu, Qinzu
2013-10-01
We propose and analyze a compact optical image encoder based on the principle of digital holographic recording on the polarization state of a vector wave. The optical architecture is a Mach-Zehnder interferometer with in-line digital holographic recording mechanism. The original image is represented by distinct polarization states of elliptically polarized light. This state of polarization distribution is scrambled and then recorded by a two-step digital polarization holography method with random phase distributed reference wave. Introduction of a rotation key in the object arm and phase keys in the reference arm can achieve the randomization of plaintext. Statistical property of cyphertext is analyzed from confusion and diffusion point of view. Fault tolerance and key sensitivity of the proposed approach are also investigated. A chosen plaintext attack on the proposed algorithm exhibits its high security level. Simulation results that support the theoretical analysis are presented.
Form Factors and Wave Functions of Vector Mesons in Holographic QCD
Energy Technology Data Exchange (ETDEWEB)
Hovhannes R. Grigoryan; Anatoly V. Radyushkin
2007-07-01
Within the framework of a holographic dual model of QCD, we develop a formalism for calculating form factors of vector mesons. We show that the holographic bound states can be described not only in terms of eigenfunctions of the equation of motion, but also in terms of conjugate wave functions that are close analogues of quantum-mechanical bound state wave functions. We derive a generalized VMD representation for form factors, and find a very specific VMD pattern, in which form factors are essentially given by contributions due to the first two bound states in the Q^2-channel. We calculate electric radius of the \\rho-meson, finding the value < r_\\rho^2>_C = 0.53 fm^2.
Thermal wave imaging techniques for inspection of plywood materials
Mulaveesala, Ravibabu; Venkata Nagarjuna, P.; Ravi, Dadda; Amarnath, Muniyappa
2012-06-01
Infrared non-destructive testing and evaluation (IRNDT&E) is an emerging approach for materials characterization due to its capability to test wide variety of solid materials such as metals, composites and semiconductors of industrial interest. Further it supports thorough inspection and evaluation by its unique remote and fast and whole field testing capabilities. Wood is one of the most commonly used house hold building material it has both structural and decorative applications. It is used both in natural and processed form like ply wood, veneer, ply-board etc. Defects like knots, worm track, delaminations, glue smear etc. influences its in-service capabilities. Even though various non-destructive methods such as optical, ultrasonic and radiography are commonly used to inspect wooden materials, infrared imaging has its own advantage due to its safe, whole field inspection capabilities. This paper describes the applicability of the transient thermal wave imaging (TWI) method for inspection of ply wood. This paper highlights applicability of transient pulsed thermal imaging approach for finding out the hidden defects. Capability of the proposed method and its defect detection capabilities have been highlighted through experimental results.
Wang, Jun; Zhao, Jianlin; Di, Jianglei; Jiang, Biqiang
2015-04-01
A scheme for recording fast process at nanosecond scale by using digital holographic interferometry with continuous wave (CW) laser is described and demonstrated experimentally, which employs delayed-time fibers and angular multiplexing technique and can realize the variable temporal resolution at nanosecond scale and different measured depths of object field at certain temporal resolution. The actual delay-time is controlled by two delayed-time fibers with different lengths. The object field information in two different states can be simultaneously recorded in a composite hologram. This scheme is also suitable for recording fast process at picosecond scale, by using an electro-optic modulator.
Guided wave inspection and monitoring of railway track
CSIR Research Space (South Africa)
Loveday, PW
2012-04-01
Full Text Available . This presentation will provide an overview of some of the approaches proposed for developing non-destructive inspection and monitoring systems and the modelling techniques used to support these....
Energy Technology Data Exchange (ETDEWEB)
Kang, Young Jun; Moon, Sang Jun; Choi, Jang Sub; Bae, Kang Sik; Park, Jung Hwan [Junpook National University, Kwangju (Korea, Republic of); Na, Uey Kyun [Kunsan University, Kunsan (Korea, Republic of)
1995-08-01
Conventional inspection methods using ultrasonic wave or x-ray, eddy current for non-destructive testing in nuclear power plants have been performed as the method of contact with objects to be inspected. With this reason these methods have been taken relatively much time, money and manpower. And the area to be inspected is limited by the location of probe or film. These difficulties make the inspection a time-consuming work. We propose a noncontact optical defect detection method using the real time holographic interferometry. This method has an advantage that the inspection can be performed at a time for relatively wide area which illuminated by the laser beam, a coherent light source and can help an inspector to recognize not only defects but also the high stressed areas. The goal of this project is the investigation of the method which can inspect pressure vessels in which defects existed with the holographic interferometry. summarized. (author). 20 refs.
Laser ultrasonic surface wave inspection of alumina ceramics of varying density
Kehoe; Coyle; Murray; Flannery; Crean
2000-03-01
In this paper, the surface acoustic wave velocity results acquired from the inspection of specially manufactured and characterised alumina ceramic materials are presented. Ultrasonic velocity data of alumina-based ceramics in the range 60-100% theoretical density was generated utilising non-contacting laser-ultrasonic measurements based on laser generation and detection of surface acoustic waves with the objective of creating a routine technique for industrial advanced alumina inspection. With linear fitting the surface acoustic wave velocity data serves as a calibration graph for using laser ultrasonics for routine monitoring of alumina. A second laser ultrasonic technique based on the laser generation and foil transducer detection of surface acoustic waves was used to validate the surface acoustic wave velocities measured by the laser generation/detection technique.
Application of LCR Waves to Inspect Aircraft Structures
2013-01-01
Acoustoelasticity to Measure the Stress Generated by Milling in ASTM A36 Steel Plates. Accepted to be published: Journal of the Brazilian Society of Mechanical...of Design of Experiments to Evaluation the Propagation Speed of Lcr Waves. 5 th Pan American Conference for NDT , 2011. Cancum, Mexico. Proceedings of...Ourak M (1999) Ultrasonic evaluation of stresses in orthotropic materials using Rayleigh waves. NDT &E Int 32:189-199. doi:10.1016/S0963-8695(98
Vertical Wave Impacts on Offshore Wind Turbine Inspection Platforms
DEFF Research Database (Denmark)
Bredmose, Henrik; Jacobsen, Niels Gjøl
2011-01-01
. The dependence of the vertical platform load to the platform level is discussed. Attention is given to the significant downward force that occur after the upward force associated with the vertical impact. The effect of the numerical resolution on the results is assessed. The position of wave overturning is found...
Khitun, Alexander; Kozhevnikov, Alexander; Gertz, Frederick; Filimonov, Yuri
2015-03-01
Collective oscillation of spins in magnetic lattice known as spin waves (magnons) possess relatively long coherence length at room temperature, which makes it possible to build sub-micrometer scale holographic devices similar to the devices developed in optics. In this work, we present a prototype 2-bit magnonic holographic memory. The memory consists of the double-cross waveguide structure made of Y3Fe2(FeO4)3 with magnets placed on the top of waveguide junctions. Information is encoded in the orientation of the magnets, while the read-out is accomplished by the spin waves generated by the micro-antennas placed on the edges of the waveguides. The interference pattern produced by multiple spin waves makes it possible to build a unique holographic image of the magnetic structure and recognize the state of the each magnet. The development of magnonic holographic devices opens a new horizon for building scalable holographic devices compatible with conventional electronic devices. This work was supported in part by the FAME Center, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA and by the National Science Foundation under the NEB2020 Grant ECCS-1124714.
Directory of Open Access Journals (Sweden)
Sungho Choi
2016-12-01
Full Text Available Harsh environments and confined spaces require that nondestructive inspections be conducted with robotic systems. Ultrasonic guided waves are well suited for robotic systems because they can provide efficient volumetric coverage when inspecting for various types of damage, including cracks and corrosion. Shear horizontal guided waves are especially well suited for robotic inspection because they are sensitive to cracks oriented perpendicular or parallel to the wave propagation direction and can be generated with electromagnetic acoustic transducers (EMATs and magnetostrictive transducers (MSTs. Both types of transducers are investigated for crack detection in a stainless steel plate. The MSTs require the robot to apply a compressive normal force that creates frictional force coupling. However, the coupling is observed to be very dependent upon surface roughness and surface debris. The EMATs are coupled through the Lorentz force and are thus noncontact, although they depend on the lift off between transducer and substrate. After comparing advantages and disadvantages of each transducer for robotic inspection the EMATs are selected for application to canisters that store used nuclear fuel.
Non-contact ultrasonic guided wave inspection of rails
Mariani, Stefano; Nguyen, Thompson V.; Phillips, Robert Ronald; Kijanka, Piotr; Lanza di Scalea, Francesco; Staszewski, Wieslaw Jerzy
2013-04-01
The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is developing a system for high-speed and non-contact rail integrity evaluation. A prototype using an ultrasonic air-coupled guided wave signal generation and air-coupled signal detection in pair with a real-time statistical analysis algorithm has been realized. This solution presents an improvement over the previously considered laser/air-coupled hybrid system because it replaces the costly and hard-to-maintain laser with a much cheaper, faster, and easier-to-maintain air-coupled transmitter. This system requires a specialized filtering approach due to the inherently poor signal-to-noise ratio of the air-coupled ultrasonic measurements in rail steel. Various aspects of the prototype have been designed with the aid of numerical analyses. In particular, simulations of ultrasonic guided wave propagation in rails have been performed using a LISA algorithm. Many of the system operating parameters were selected based on Receiver Operating Characteristic (ROC) curves, which provide a quantitative manner to evaluate different detection performances based on the trade-off between detection rate and false positive rate. Experimental tests have been carried out at the UCSD Rail Defect Farm. The laboratory results indicate that the prototype is able to detect internal rail defects with a high reliability. A field test will be planned later in the year to further validate these results. Extensions of the system are planned to add rail surface characterization to the internal rail defect detection.
Holographic video display based on guided-wave acousto-optic devices
Smalley, Daniel E.; Smithwick, Quinn Y. J.; Bove, V. Michael, Jr.
2007-02-01
We introduce a new holo-video display architecture ("Mark III") developed at the MIT Media Laboratory. The goal of the Mark III project is to reduce the cost and size of a holo-video display, making it into an inexpensive peripheral to a standard desktop PC or game machine which can be driven by standard graphics chips. Our new system is based on lithium niobate guided-wave acousto-optic devices, which give twenty or more times the bandwidth of the tellurium dioxide bulk-wave acousto-optic modulators of our previous displays. The novel display architecture is particularly designed to eliminate the high-speed horizontal scanning mechanism that has traditionally limited the scalability of Scophony- style video displays. We describe the system architecture and the guided-wave device, explain how it is driven by a graphics chip, and present some early results.
Aldrin, John C.; Hopkins, Deborah; Datuin, Marvin; Warchol, Mark; Warchol, Lyudmila; Forsyth, David S.; Buynak, Charlie; Lindgren, Eric A.
2017-02-01
For model benchmark studies, the accuracy of the model is typically evaluated based on the change in response relative to a selected reference signal. The use of a side drilled hole (SDH) in a plate was investigated as a reference signal for angled beam shear wave inspection for aircraft structure inspections of fastener sites. Systematic studies were performed with varying SDH depth and size, and varying the ultrasonic probe frequency, focal depth, and probe height. Increased error was observed with the simulation of angled shear wave beams in the near-field. Even more significant, asymmetry in real probes and the inherent sensitivity of signals in the near-field to subtle test conditions were found to provide a greater challenge with achieving model agreement. To achieve quality model benchmark results for this problem, it is critical to carefully align the probe with the part geometry, to verify symmetry in probe response, and ideally avoid using reference signals from the near-field response. Suggested reference signals for angled beam shear wave inspections include using the `through hole' corner specular reflection signal and the full skip' signal off of the far wall from the side drilled hole.
Microwave and Millimeter Wave Imaging Using Synthetic Aperture Focusing and Holographical Techniques
Case, Joseph Tobias
2005-01-01
Microwave and millimeter wave nondestructive testing and evaluation (NDT&E) methods have shown great potential for determining material composition in composite structures, determining material thickness or debond thickness between two layers, and determining the location and size of flaws, defects, and anomalies. The same testing methods have also shown great potential to produce relatively high-resolution images of voids inside Spray On Foam Insulation (SOFI) test panels using real focused methods employing lens antennas. An alternative to real focusing methods are synthetic focusing methods. The essence of synthetic focusing is to match the phase of the scattered signal to measured points spaced regularly on a plane. Many variations of synthetic focusing methods have already been developed for radars, ultrasonic testing applications, and microwave concealed weapon detection. Two synthetic focusing methods were investigated; namely, a) frequency-domain synthetic aperture focusing technique (FDSAFT), and b) wide-band microwave holography. These methods were applied towards materials whose defects were of low dielectric contrast like air void in SOFI. It is important to note that this investigation used relatively low frequencies from 8.2 GHz to 26.5 GHz that are not conducive for direct imaging of the SOFI. The ultimate goal of this work has been to demonstrate the capability of these methods before they are applied to much higher frequencies such as the millimeter wave frequency spectrum (e.g., 30-300 GHz).
Holographic analysis of photopolymers
Sullivan, Amy C.; Alim, Marvin D.; Glugla, David J.; McLeod, Robert R.
2017-05-01
Two-beam holographic exposure and subsequent monitoring of the time-dependent first-order Bragg diffraction is a common method for investigating the refractive index response of holographic photopolymers for a range of input writing conditions. The experimental set up is straightforward, and Kogelnik's well-known coupled wave theory (CWT)[1] can be used to separate measurements of the change in index of refraction (Δn) and the thickness of transmission and reflection holograms. However, CWT assumes that the hologram is written and read out with a plane wave and that the hologram is uniform in both the transverse and depth dimensions, assumptions that are rarely valid in practical holographic testing. The effect of deviations from these assumptions on the measured thickness and Δn become more pronounced for over-modulated exposures. As commercial and research polymers reach refractive index modulations on the order of 10-2, even relatively thin (material analysis must be carefully evaluated in this regime. We present a study of the effects of the finite Gaussian write and read beams on the CWT analysis of photopolymer materials and discuss what intuition this can give us about the effect other non-uniformities, such as mechanical stresses and significant absorption of the write beam, will have on the analysis of the maximum attainable refractive index in a material system. We use this analysis to study a model high Δn two-stage photopolymer holographic material using both transmission and reflection holograms.
Combined Holographic Infrared Inspection Instrumentation
1989-12-01
Shearography imaging system . As mentioned, the combination of Shearography and Infrared images could prove to be a successful method of defect characterization... system and more recent experience with newly available electronic shearography is that the shearography -infrared combination (Shearo-IR) offers... systems . Nevertheless, operation of the phase-locked Ho!o system requires exteiided control of environmental conditions. The shearography system , on
A novel method for surface defect inspection of optic cable with short-wave infrared illuminance
Chen, Xiaohong; Liu, Ning; You, Bo; Xiao, Bin
2016-07-01
Intelligent on-line detection of cable quality is a crucial issue in optic cable factory, and defects on the surface of optic cable can dramatically depress cable grade. Manual inspection in optic cable quality cannot catch up with the development of optic cable industry due to its low detection efficiency and huge human cost. Therefore, real-time is highly demanded by industry in order to replace the subjective and repetitive process of manual inspection. For this reason, automatic cable defect inspection has been a trend. In this paper, a novel method for surface defect inspection of optic cable with short-wave infrared illuminance is presented. The special condition of short-wave infrared cannot only provide illumination compensation for the weak illumination environment, but also can avoid the problem of exposure when using visible light illuminance, which affects the accuracy of inspection algorithm. A series of image processing algorithms are set up to analyze cable image for the verification of real-time and veracity of the detection method. Unlike some existing detection algorithms which concentrate on the characteristics of defects with an active search way, the proposed method removes the non-defective areas of the image passively at the same time of image processing, which reduces a large amount of computation. OTSU algorithm is used to convert the gray image to the binary image. Furthermore, a threshold window is designed to eliminate the fake defects, and the threshold represents the considered minimum size of defects ε . Besides, a new regional suppression method is proposed to deal with the edge burrs of the cable, which shows the superior performance compared with that of Open-Close operation of mathematical morphological in the boundary processing. Experimental results of 10,000 samples show that the rates of miss detection and false detection are 2.35% and 0.78% respectively when ε equals to 0.5 mm, and the average processing period of one frame
Picosecond Holographic-Grating Spectroscopy
Duppen, K.
1987-01-01
Interfering light waves produce an optical interference pattern in any medium that interacts with light. This modulation of some physical parameter of the system acts as a classical holographic grating for optical radiation. When such a grating is produced through interaction of pulsed light waves
DEFF Research Database (Denmark)
Ramanujam, P.S.; Holme, NCR; Berg, RH
1999-01-01
A Two-dimensional holographic memory for archival storage is described. Assuming a coherent transfer function, an A4 page can be stored at high resolution in an area of 1 mm(2). Recently developed side-chain liquid crystalline azobenzene polyesters are found to be suitable media for holographic...... storage. They exhibit high resolution, high diffraction efficiency, have long storage life, are fully erasable and are mechanically stable....
Application of Macrofiber Composite for Smart Transducer of Lamb Wave Inspection
Directory of Open Access Journals (Sweden)
Gang Ren
2013-01-01
Full Text Available Macrofiber composite (MFC has been developed recently as a new type of smart material for piezoelectric transducers. It shows advantages over traditional piezoelectric ceramic materials (PZT including the method of application, sensitivity, and cost. It can be embedded on the structure, which provides the possibility to monitor the structural health in real time. In this paper, the feasibility of this transducer for the Lamb wave inspection has been experimentally explored. A pair of MFC patches is bonded on a 2 mm thick aluminum plate, and it has been demonstrated that the dispersive characteristics of S0 and A0 modes, generated and detected by MFC patches, agreed well with the theory. The influence of the bonding condition of the transducer was also tested to show that rigid bonding is required to assure a high amplitude signal. In order to illustrate the performance of defect detection, an artificial defect fabricated on the surface of a specimen was inspected in the pitch-catch mode. The results showed that the MFC transducer is a promising Lamb wave transducer for nondestructive testing (NDT and structural health monitoring (SHM.
De Marchi, Luca; Marzani, Alessandro; Moll, Jochen; Kudela, Paweł; Radzieński, Maciej; Ostachowicz, Wiesław
2017-07-01
The performance of Lamb wave based monitoring systems, both in terms of diagnosis time and data complexity, can be enhanced by increasing the number of transducers used to actuate simultaneously the guided waves in the inspected medium. However, in case of multiple simultaneously-operated actuators the interference among the excited wave modes within the acquired signals has to be considered for the further processing. To this aim, in this work a code division strategy based on the Warped Frequency Transform is presented. At first, the proposed procedure encodes actuation pulses using Gold sequences. Next, for each considered actuator the acquired signals are compensated from dispersion by cross correlating the warped version of the actuated and received signals. Compensated signals form the base for a final wavenumber imaging meant at emphasizing defects and or anomalies by removing incident wavefield and edge reflections. The proposed strategy is tested numerically, and validated through an experiment in which guided waves are actuated in a plate by four piezoelectric transducers operating simultaneously.
Odhner, Jefferson E.
2016-07-01
Holographic optical elements (HOEs) work on the principal of diffraction and can in some cases replace conventional optical elements that work on the principal of refraction. An HOE can be thinner, lighter, can have more functionality, and can be lower cost than conventional optics. An HOE can serve as a beam splitter, spectral filter, mirror, and lens all at the same time. For a single wavelength system, an HOE can be an ideal solution but they have not been widely accepted for multispectral systems because they suffer from severe chromatic aberration. A refractive optical system also suffers from chromatic aberration but it is generally not as severe. To color correct a conventional refractive optical system, a flint glass and a crown glass are placed together such that the color dispersion of the flint and the crown cancel each other out making an achromatic lens (achromat) and the wavelengths all focus to the same point. The color dispersion of refractive lenses and holographic lenses are opposite from each other. In a diffractive optical system, long wavelengths focus closer (remember for HOEs: RBM "red bends more") than nominal focus while shorter wavelengths focus further out. In a refractive optical system, it is just the opposite. For this reason, diffractives can be incorporated into a refractive system to do the color correction and often cut down on the number of optical elements used [1.]. Color correction can also be achieved with an all-diffractive system by combining a holographic optical element with its conjugate. In this way the color dispersion of the first holographic optical element can be cancelled by the color dispersion of the second holographic optic. It is this technique that will be exploited in this paper to design a telescope made entirely of holographic optical elements. This telescope could be more portable (for field operations) the same technique could be used to make optics light enough for incorporation into a UAV.
Sugimoto, Tsuneyoshi; Sugimoto, Kazuko; Kosuge, Nobuaki; Utagawa, Noriyuki; Katakura, Kageyoshi
2017-07-01
The noncontact acoustic inspection method focuses on the resonance phenomenon, and the target surface is measured by being vibrated with an airborne sound. It is possible to detect internal defects near the surface layer of a concrete structure from a long distance. However, it requires a fairly long measurement time to achieve the signal-to-noise (S/N) ratio just to find some resonance frequencies. In our method using the conventional waveform “single-tone burst wave”, only one frequency was used for one-sound-wave emission to achieve a high S/N ratio using a laser Doppler vibrometer (LDV) at a safe low power (e.g., He-Ne 1 mW). On the other hand, in terms of the difference in propagation velocity between laser light and sound waves, the waveform that can be used for high-speed measurement was devised using plural frequencies for one-sound-wave emission (“multitone burst wave”). The measurement time at 35 measurement points has been dramatically decreased from 210 to 28 s when using this waveform. Accordingly, 7.5-fold high-speed measurement became possible. By some demonstration experiments, we confirmed the effectiveness of our measurement technique.
Holographic Optical Data Storage
Timucin, Dogan A.; Downie, John D.; Norvig, Peter (Technical Monitor)
2000-01-01
Although the basic idea may be traced back to the earlier X-ray diffraction studies of Sir W. L. Bragg, the holographic method as we know it was invented by D. Gabor in 1948 as a two-step lensless imaging technique to enhance the resolution of electron microscopy, for which he received the 1971 Nobel Prize in physics. The distinctive feature of holography is the recording of the object phase variations that carry the depth information, which is lost in conventional photography where only the intensity (= squared amplitude) distribution of an object is captured. Since all photosensitive media necessarily respond to the intensity incident upon them, an ingenious way had to be found to convert object phase into intensity variations, and Gabor achieved this by introducing a coherent reference wave along with the object wave during exposure. Gabor's in-line recording scheme, however, required the object in question to be largely transmissive, and could provide only marginal image quality due to unwanted terms simultaneously reconstructed along with the desired wavefront. Further handicapped by the lack of a strong coherent light source, optical holography thus seemed fated to remain just another scientific curiosity, until the field was revolutionized in the early 1960s by some major breakthroughs: the proposition and demonstration of the laser principle, the introduction of off-axis holography, and the invention of volume holography. Consequently, the remainder of that decade saw an exponential growth in research on theory, practice, and applications of holography. Today, holography not only boasts a wide variety of scientific and technical applications (e.g., holographic interferometry for strain, vibration, and flow analysis, microscopy and high-resolution imagery, imaging through distorting media, optical interconnects, holographic optical elements, optical neural networks, three-dimensional displays, data storage, etc.), but has become a prominent am advertising
Banks, T.; Fischler, W.
2004-01-01
We describe a cosmology of the very early universe, based on the holographic principle of 't Hooft and Susskind. We have described the initial state as a dense black hole fluid. Here we present a mathematical model of this heuristic picture, as well as a non-rigorous discussion of how a more normal universe could evolve out of such a state. The gross features of the cosmology depend on a few parameters, which cannot yet be calculated from first principles. For some range of these parameters, ...
Tremblay, Simon-Pierre; Karray, Mourad; Chekired, Mohamed; Bessette, Carole; Jinga, Livius
2018-01-01
The possibility of performing the inspection of an underground structure directly from the surface of the soil would be advantageous for the inspection of various type of underground utility structures present in modern cities. In part I, the behavior of elastic waves propagating in a soil profile containing a shallowly buried underground concrete utility structure was studied and it was found that it is possible to evaluate the condition of the surface of the lid of such structures based on the propagation velocity of elastic waves. The part II follows from the work that was previously performed to develop a nondestructive technique for the inspection of shallowly buried utility structures based on the propagation of elastic waves. First, the three-dimensional finite difference method implemented in the software Fast Lagrangian Analysis of Continuum was used to model an underground concrete structure to show how the presence of a manhole and of a pavement at the surface of the soil affect the propagation of elastic waves. Second, a receiver configuration typically used in three-dimensional seismic surveys is presented and its effectiveness is tested on three different existing underground structures. The signals collected during the field tests are analyzed independently in the velocity-frequency plane using an adaptive signal processing technique. The velocity-frequency representation of each signal is then used to identify the different elastic waves and to calculate their group velocities. Third, the variation of the group velocity at the surface of the three concrete structures is presented in the form of two-dimensional contour maps that enabled the detection of anomalies on the surface of two of these structures. Finally, it is shown how the collected data can be used to obtain a three-dimensional tomography representative of the condition of the surface of an underground structure.
Haba, Kazumoto; Matsuzaki, Shinya; Yamawaki, Koichi
2010-09-01
Technidilaton, a pseudo-Nambu-Goldstone boson of scale symmetry, was predicted long ago in the scale-invariant/walking/conformal technicolor (SWC-TC) as a remnant of the (approximate) scale symmetry associated with the conformal fixed point, based on the conformal gauge dynamics of ladder Schwinger-Dyson (SD) equation with nonrunning coupling. We study the technidilaton as a flavor-singlet bound state of technifermions by including the technigluon condensate (tGC) effect into the previous (bottom-up) holographic approach to the SWC-TC, a deformation of the holographic QCD with γm≃0 by large anomalous dimension γm≃1. With including a bulk scalar field corresponding to the gluon condensate, we first improve the operator product expansion of the current correlators so as to reproduce gluonic 1/Q4 term both in QCD and SWC-TC. We find in QCD about 10% (negative) contribution of gluon condensate to the ρ meson mass. We also calculate the oblique electroweak S-parameter in the presence of the effect of the tGC and find that for the fixed value of S the tGC effects dramatically reduce the flavor-singlet scalar (technidilaton) mass MTD (in the unit of Fπ), while the vector and axial-vector masses Mρ and Ma1 are rather insensitive to the tGC, where Fπ is the decay constant of the technipion. If we use the range of values of tGC implied by the ladder SD analysis of the nonperturbative scale anomaly in the large Nf QCD near the conformal window, the phenomenological constraint S≃0.1 predicts the technidilaton mass MTD˜600GeV which is within reach of LHC discovery.
Holographic interferometry in construction analysis
Energy Technology Data Exchange (ETDEWEB)
Hartikainen, T.
1995-12-31
In this work techniques for visualizing phase and opaque objects by ruby laser interferometry are introduced. A leakage flow as a phase object is studied by holographic interferometry and the intensity distribution of the interferograms presenting the leakage flow are computer-simulated. A qualitative and quantitative analysis of the leakage flow is made. The analysis is based on the experimental and theoretical results presented in this work. The holographic setup and the double pass method for visualizing leakage flow are explained. A vibrating iron plate is the opaque object. Transient impact waves are generated by a pistol bullet on the iron plate and visualized by holographic interferometry. An apparatus with the capability of detecting and calculating the delays necessary for laser triggering is introduced. A time series of interferograms presenting elastic wave formation in an iron plate is shown. A computer-simulation of the intensity distributions of these interferograms is made. An analysis based on the computer-simulation and the experimental data of the transient elastic wave is carried out and the results are presented. (author)
Multi-Path Guided Wave Imaging for Inspection and Monitoring of Large, Complex Structures Project
National Aeronautics and Space Administration — There is a well-recognized need within NASA and the aerospace community at large for rapid and reliable methods for inspection of large, complex structures. This...
Li, Dan; Yu, Hao; Xu, Feng; Liu, Da Peng; Qiu Zhang, Jian; Ta, De an
2017-10-01
In this paper, an lp-norm approach to robust probabilistic inspection of plate-like structure defects with guided waves is proposed. Analytical results show that the more the outliers in the measurements, the smaller p is preferred. Moreover, the relationship between our and the conventional signal difference coefficient (SDC) is also provided. While the experimental results verify the analytical ones, it is also shown that our approach has a good tolerance for impulsive noise interference, namely the unexpected artifacts in the reconstructed tomographic image caused by the impulsive interference are eliminated.
Hepburn, F. L.; Case, J. T.; Zoughi, R.
2006-01-01
The Space Shuttle Columbia's catastrophic failure is thought to have been caused by a dislodged piece of external tank spray on foam insulation (SOFI) striking the left wing of the orbiter causing significant damage to some of the reinforced carbon/carbon leading edge wing panels [1]. Microwave and millimeter wave nondestructive evaluation methods have shown great potential for inspecting SOFI for the purpose of detecting anomalies such as small air voids that may cause separation of the SOFI from the external tank during a launch [2,3]. These methods are capable of producing relatively high-resolution images of the interior of SOFI. Although effective, there are some advantages in using synthetic focusing methods as opposed to real focusing methods such as reduced probe size, the ability to determine depth from multiple views, and the ability to slice images due to sufficient range resolution. To this end, synthetic aperture focusing techniques (SAFT) were first pursued for this purpose and later wide-band microwave holography was implemented [4-7]. This paper presents the results of this investigation using frequency domain synthetic aperture focusing technique (FD-SAFT) and wide-band microwave holography methods illustrating their potential capabilities for inspecting the space shuttle's SOFI at millimeter wave frequencies.
Revisiting holographic superconductors with hyperscaling violation
Energy Technology Data Exchange (ETDEWEB)
Pan, Qiyuan [Universidade de Sao Paulo, Instituto de Fisica, C.P. 66318, Sao Paulo (Brazil); Hunan Normal University, Department of Physics, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Changsha, Hunan (China); Institute of Theoretical Physics, Chinese Academy of Sciences, State Key Laboratory of Theoretical Physics, Beijing (China); Zhang, Shao-Jun [Universidade de Sao Paulo, Instituto de Fisica, C.P. 66318, Sao Paulo (Brazil)
2016-03-15
We investigate the effect of the hyperscaling violation on the holographic superconductors. In the s-wave model, we find that the critical temperature decreases first and then increases as the hyperscaling violation increases, and the mass of the scalar field will not modify the value of the hyperscaling violation which gives the minimum critical temperature. We analytically confirm the numerical results by using the Sturm-Liouville method with the higher order trial function and improve the previous findings in Fan (J High Energy Phys 09:048, 2013). However, different from the s-wave case, we note that the critical temperature decreases with the increase of the hyperscaling violation in the p-wave model. In addition, we observe that the hyperscaling violation affects the conductivity of the holographic superconductors and changes the expected relation in the gap frequency in both s-wave and p-wave models. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Cho, Youn Ho [Inje University, Kimhae (Korea)
2002-04-01
The Potential of Ultrasonic Guided Waves which can propagate along the geometry of structures was explored for the inspection of such various components of nuclear power plants as tubings, pipings and plate-like structures etc. In this project, the fundamental research on the various aspects of guided wave modal characteristics was carried out to provide physically based guidelines which are essential to implement the guided waves as a promising inspection tool in the near future. The efforts for guided wave research include both theoretical and experimental works to make it possible to transfer the technology to power industry beyond the scope of pure academic subject. In the theoretical works, the softwares for the dispersion curves and wave structures of both layered structures and cylindrical ones were developed in the aims of mode identification and determination of probe design parameters. 40 refs., 92 figs., 14 tabs. (Author)
An ultrasonic guided wave approach for the inspection of overhead transmission line cables
DEFF Research Database (Denmark)
Yücel, Mehmet K.; Legg, Mathew; Kappatos, Vasileios
2017-01-01
technique for untensioned aluminium conductor steel reinforced cable specimens. The identification and analysis of wave propagation for a broad range of frequencies is performed using a laser scanning vibrometer, and the effect of defect size on wave propagation is studied. Signal processing algorithms...
Ultrasonic Guided Wave Simulation Toolbox for Virtual Inspection of Composites Project
National Aeronautics and Space Administration — Ultrasonic guided wave nondestructive evaluation (NDE) techniques are being used to detect flaws and damage in fracture critical structures such as composites. In...
Terahertz in-line digital holographic multiplane imaging method
Huang, Haochong; Wang, Dayong; Rong, Lu; Li, Weihua; Wang, Yunxin
2017-05-01
Terahertz waves of which frequency spans from 0.1 to 10 THz bridge the gap between the infrared spectrum and microwaves. Owing to the special features of terahertz wave, such as penetrability and non-ionizing, terahertz imaging technique is a very significant and important method for inspections and detections. Digital holography can reconstruct the amplitude and phase distributions of a sample without scanning and it already has many successful applications in the area of visible and infrared light. The terahertz in-line digital holographic multi-plane imaging system which is presented in this paper is the combination of a continuous-wave terahertz source and the in-line scheme of digital holography. In order to observe a three dimensional (3D) shape sample only a portion of which appears in good focus, the autofocusing algorithm is brought to the data process. The synthetic aperture method is also applied to provide the high resolution imaging effect in the terahertz waveband. Both intrinsic twin images and defocused objective images confuse the quality of the image in an individual reconstructed plane. In order to solve this issue, phase retrieval iteration algorithm is used for the reconstruction. In addition, the reconstructed amplitude image in each plane multiplies the mask of which the threshold depends on the values of the autofocusing curve. A sample with simple artificial structure is observed which verifies that the present method is an authentic tool to acquire the multi-plane information of a target in terahertz waves. It can expect a wide application in terahertz defect detecting, terahertz medical inspection and other important areas in the future.
An EMAT-based shear horizontal (SH) wave technique for adhesive bond inspection
Arun, K.; Dhayalan, R.; Balasubramaniam, Krishnan; Maxfield, Bruce; Peres, Patrick; Barnoncel, David
2012-05-01
The evaluation of adhesively bonded structures has been a challenge over the several decades that these structures have been used. Applications within the aerospace industry often call for particularly high performance adhesive bonds. Several techniques have been proposed for the detection of disbonds and cohesive weakness but a reliable NDE method for detecting interfacial weakness (also sometimes called a kissing bond) has been elusive. Different techniques, including ultrasonic, thermal imaging and shearographic methods, have been proposed; all have had some degree of success. In particular, ultrasonic methods, including those based upon shear and guided waves, have been explored for the assessment of interfacial bond quality. Since 3-D guided shear horizontal (SH) waves in plates have predominantly shear displacement at the plate surfaces, we conjectured that SH guided waves should be influenced by interfacial conditions when they propagate between adhesively bonded plates of comparable thickness. This paper describes a new technique based on SH guided waves that propagate within and through a lap joint. Through mechanisms we have yet to fully understand, the propagation of an SH wave through a lap joint gives rise to a reverberation signal that is due to one or more reflections of an SH guided wave mode within that lap joint. Based upon a combination of numerical simulations and measurements, this method shows promise for detecting and classifying interfacial bonds. It is also apparent from our measurements that the SH wave modes can discriminate between adhesive and cohesive bond weakness in both Aluminum-Epoxy-Aluminum and Composite-Epoxy-Composite lap joints. All measurements reported here used periodic permanent magnet (PPM) Electro-Magnetic Acoustic Transducers (EMATs) to generate either or both of the two lowest order SH modes in the plates that comprise the lap joint. This exact configuration has been simulated using finite element (FE) models to
Directory of Open Access Journals (Sweden)
Margherita Capriotti
2017-06-01
Full Text Available This paper discusses a non-destructive evaluation (NDE technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI from ground service equipment (GSE, such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers.
Capriotti, Margherita; Kim, Hyungsuk E; Scalea, Francesco Lanza di; Kim, Hyonny
2017-06-04
This paper discusses a non-destructive evaluation (NDE) technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI) from ground service equipment (GSE), such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers.
Case, J. T.; Hepburn, F. L.; Zoughi, R.
2006-01-01
The Space Shuttle Columbia s catastrophic failure is thought to have been caused by a dislodged piece of external tank spray on foam insulation (SOFI) striking and significantly damaging the left wing of the orbiter, which may have been due to a flawed section of SOFI. Microwave and millimeter wave nondestructive evaluation (NDE) methods have shown great potential detecting anomalies in SOFI such as small air voids using a horn and lens in a (real) focused configuration. Synthetic focusing methods may also be used to detect air voids in SOFI and may additionally offer the ability to locate the defect in three dimensions. To this end, two different methods were investigated; namely, frequency domain synthetic aperture focusing technique (FD-SAFT) and wide-band microwave holography. To illustrate the performance of these methods they were applied to two different SOFI samples. The results of these investigations demonstrate the capabilities of these methods for SOFI inspection.
Inspection of lamb waves in carbon fiber composites using shearographic interferometry
Focke, O.; Hildebrand, A.; von Kopylow, C.; Calomfirescu, M.
2008-03-01
The implementation of structural health monitoring systems in modern aircraft structures requires a deeper understanding of impact and piezoelectric generated lamb wave propagation on carbon fibre reinforced plastics. In this paper a digital shearing interferometry method is presented that visualizes lamb waves excited by impact events or piezoelectric actuators. The contactless full field measurement of these waves is realized by a Mach-Zehnder interferometer which combines spatial phase shifting and Shearography. The latter is a laser based technique whereby the first order derivates of the displacement is indicated. Since a dynamical process is observed the spatial phase shifting technique is required. The optical implementation of both techniques within the interferometically setup and experimental results with the possibility to measure the out of plane displacement are presented. Therefore the underlying wavefield is reconstructed from the measured first order derivatives. Subsequently these results are compared with a one point measuring method and FEM simulation.
McFadden, P.L.; Skenderis, K.
2010-01-01
We present a holographic description of four-dimensional single-scalar inflationary universes in terms of a three-dimensional quantum field theory (QFT). The holographic description correctly reproduces standard inflationary predictions in their regime of applicability. In the opposite case, wherein
Handbook of Holographic Interferometry: Optical and Digital Methods
Kreis, Thomas
2005-01-01
The book presents the principles and methods of holographic interferometry - a coherent-optical measurement technique for deformation and stress analysis, for the determination of refractive-index distributions, or applied to non-destructive testing. Emphasis of the book is on the quantitative computer-aided evaluation of the holographic interferograms. Based upon wave-optics the evaluation methods, their implementation in computer-algorithms, and their applications in engineering are described.
Magnonic holographic imaging of magnetic microstructures
Energy Technology Data Exchange (ETDEWEB)
Gutierrez, D.; Chiang, H.; Bhowmick, T.; Volodchenkov, A.D.; Ranjbar, M.; Liu, G.; Jiang, C.; Warren, C. [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States); Khivintsev, Y.; Filimonov, Y. [Kotelnikov Institute of Radioengineering and Electronics of Russian Academy of Sciences, Saratov Branch, Saratov 410019 (Russian Federation); Saratov State University, Saratov 410012 (Russian Federation); Garay, J.; Lake, R.; Balandin, A.A. [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States); Khitun, A., E-mail: akhitun@engr.ucr.edu [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States)
2017-04-15
We propose and demonstrate a technique for magnetic microstructure imaging via their interaction with propagating spin waves. In this approach, the object of interest is placed on top of a magnetic testbed made of material with low spin wave damping. There are micro-antennas incorporated in the testbed. Two of these antennas are used for spin wave excitation while another one is used for the detecting of inductive voltage produced by the interfering spin waves. The measurements are repeated for different phase differences between the spin wave generating antennas which is equivalent to changing the angle of illumination. The collected data appear as a 3D plot – the holographic image of the object. We present experimental data showing magnonic holographic images of a low-coercivity Si/Co sample, a high-coercivity sample made of SrFe{sub 12}O{sub 19} and a diamagnetic copper sample. We also present images of the three samples consisting of a different amount of SrFe{sub 12}O{sub 19} powder. The imaging was accomplished on a Y{sub 3}Fe{sub 2}(FeO{sub 4}){sub 3} testbed at room temperature. The obtained data reveal the unique magnonic signatures of the objects. Experimental data is complemented by the results of numerical modeling, which qualitatively explain the characteristic features of the images. Potentially, magnonic holographic imaging may complement existing techniques and be utilized for non-destructive in-situ magnetic object characterization. The fundamental physical limits of this approach are also discussed. - Highlights: • A technique for magnetic microstructure imaging via their interaction with propagating spin waves is proposed. • In this technique, magnetic structures appear as 3D objects. • Several holographic images of magnetic microstructures are presented.
Non-contact ultrasonic guided wave inspection of rails: field test results and updates
Mariani, Stefano; Nguyen, Thompson V.; Zhu, Xuan; Lanza di Scalea, Francesco; Fateh, Mahmood
2015-04-01
The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is developing a system for high-speed and non-contact rail defect detection. A prototype using an ultrasonic air-coupled guided wave signal generation and air-coupled signal detection, paired with a real-time statistical analysis algorithm, has been realized. This system requires a specialized filtering approach based on electrical impedance matching due to the inherently poor signal-to-noise ratio of air-coupled ultrasonic measurements in rail steel. Various aspects of the prototype have been designed with the aid of numerical analyses. In particular, simulations of ultrasonic guided wave propagation in rails have been performed using a Local Interaction Simulation Approach (LISA) algorithm. The system's operating parameters were selected based on Receiver Operating Characteristic (ROC) curves, which provide a quantitative manner to evaluate different detection performances based on the trade-off between detection rate and false positive rate. Results from the first field test of the non-contact air-coupled defect detection prototype conducted at the Transportation Technology Center (TTC) in Pueblo, Colorado, in October 2014 are presented and discussed in this paper. The results indicate that the prototype is able to detect internal cracks with high reliability.
Simulation of non-destructive inspections and acoustic emission measurements involving guided waves
Baronian, V.; Lhémery, A.; Bonnet-Ben Dhia, A.-S.
2009-11-01
In a structure that guides elastic waves, a discontinuity (defect, shape variation) causes scattering (reflection, partial extinction or mode conversion). Two modal formulations have been developed to link separate models dealing with the calculation of the modal decomposition, with the generation and reception of guided waves (GW), with their scattering. The first concerns pulse-echo configurations (involving a single transducer), the other concerns pitch-catch configurations (two transducers involved). A new finite element (FE) method has been developed to compute the scattering by an arbitrary discontinuity, based on the modal decomposition of the field. Perfectly transparent boundary conditions (Dirichlet-to-Neuman boundaries) are developed, allowing the FE computation zone to be reduced to a minimum. A specific variational problem including these boundary conditions was obtained and solved using FE tools. By combining the modal formulations, the new FE scheme and tools for GW radiation, propagation and reception based on the Semi-Analytical Finite Element (SAFE) method, a new simulation tool has been developed. It can address almost arbitrary configurations of GW nondestructive testing. Moreover, a source inside the FE computation zone can be defined so that configurations of testing by acoustic emission can also be simulated. Examples of use of this tool are shown, some dealing with junctions of complex geometry between two guides, other with surface or bulk sources of acoustic emission.
Holographic Dark Information Energy
Directory of Open Access Journals (Sweden)
Michael Paul Gough
2011-04-01
Full Text Available Landauer’s principle and the Holographic principle are used to derive the holographic information energy contribution to the Universe. Information energy density has increased with star formation until sufficient to start accelerating the expansion of the universe. The resulting reduction in the rate of star formation due to the accelerated expansion may provide a feedback that limits the information energy density to a constant level. The characteristics of the universe’s holographic information energy then closely match those required to explain dark energy and also answer the cosmic coincidence problem. Furthermore the era of acceleration will be clearly limited in time.
Dynamical holographic QCD model
Directory of Open Access Journals (Sweden)
Li Danning
2014-01-01
Full Text Available We develop a dynamical holographic QCD model, which resembles the renormalization group from ultraviolet (UV to infrared (IR. The dynamical holographic model is constructed in the graviton-dilaton-scalar framework with the dilaton background field Φ and scalar field X responsible for the gluodynamics and chiral dynamics, respectively. We summarize the results on hadron spectra, QCD phase transition and transport properties including the jet quenching parameter and the shear/bulk viscosity in the framework of the dynamical holographic QCD model.
Analysis of the optical parameters of phase holographic gratings
Directory of Open Access Journals (Sweden)
Є.О. Тихонов
2008-03-01
Full Text Available Suitability of 2- wave approximation of the coupled waves theory tor description of holographic phase gratings recorded on photopolymer compound ФПК-488 is proved. Using the basic formulas of the theory, main grating optical parameters - a depth of modulation and finished thickness are not measured immediately are determined.
Periodically driven holographic superconductor
National Research Council Canada - National Science Library
Li, Wei-Jia; Tian, Yu; Zhang, Hongbao
2013-01-01
.... As a result, our holographic superconductor is driven to the final oscillating state, where the condensate is suppressed and the oscillation frequency is controlled by twice of the driving frequency...
Volume polarization holographic recording in thick photopolymer for optical memory.
Lin, Shiuan Huei; Cho, Sheng-Lung; Chou, Shin-Fu; Lin, June Hua; Lin, Chih Min; Chi, Sien; Hsu, Ken Yuh
2014-06-16
Based on a vector wave theory of volume holograms, dependence of holographic reconstruction on the polarization states of the writing and reading beams is discussed. It is found that under paraxial approximation the circular polarization holograms provide a better distinction of the reading beams. Characteristics of recording polarization holograms in thick phenanthrenequinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymer are experimentally investigated. It is found that the circular polarization holographic recording possesses better dynamic range and material sensitivity, and a uniform spatial frequency response over a wide range. The performance is comparable to that of the intensity holographic recording in PQ/PMMA. Based on theoretical analyses and the material properties, a polarization multiplexing holographic memory using circularly polarization recording configuration for increasing storage capacity has been designed and experimentally demonstrated.
Visor-display design based on planar holographic optics.
Amitai, Y; Reinhorn, S; Friesem, A A
1995-03-10
A method for designing and recording visor displays based on planar holographic optics is presented. This method can deal with the problem of recording-readout wavelength shift. The display system is composed of two holographic optical elements that are recorded on the same substrate. One element collimates the waves from each data point in the display into a plane wave that is trapped inside the substrate by total internal reflection. The other diffracts the plane waves into the eye of an observer. Because the chromatic dispersion of the first element can be corrected by the dispersion of the second, this configuration is relatively insensitive to source wavelength shifts. The method is illustrated by the design, recording, and testing of a compact holographic doublet visor display. The recording was at a wavelength of 458 nm, and readout was at 633 nm. The results indicate that diffraction-limited performance and relatively low chromatic dispersion over a wide field of view can be obtained.
Method to Enhance the Operation of an Optical Inspection Instrument Using Spatial Light Modulators
Trolinger, James; Lal, Amit; Jo, Joshua; Kupiec, Stephen
2012-01-01
For many aspheric and freeform optical components, existing interferometric solutions require a custom computer-generated hologram (CGH) to characterize the part. The overall objective of this research is to develop hardware and a procedure to produce a combined, dynamic, Hartmann/ Digital Holographic interferometry inspection system for a wide range of advanced optical components, including aspheric and freeform optics. This new instrument would have greater versatility and dynamic range than currently available measurement systems. The method uses a spatial light modulator to pre-condition wavefronts for imaging, interferometry, and data processing to improve the resolution and versatility of an optical inspection instrument. Existing interferometers and Hartmann inspection systems have either too small a dynamic range or insufficient resolution to characterize conveniently unusual optical surfaces like aspherical and freeform optics. For interferometers, a specially produced, computer-generated holographic optical element is needed to transform the wavefront to within the range of the interferometer. A new hybrid wavefront sensor employs newly available spatial light modulators (SLMs) as programmable holographic optical elements (HOEs). The HOE is programmed to enable the same instrument to inspect an optical element in stages, first by a Hartmann measurement, which has a very large dynamic range but less resolution. The first measurement provides the information required to precondition a reference wave that avails the measurement process to the more precise phase shifting interferometry. The SLM preconditions a wavefront before it is used to inspect an optical component. This adds important features to an optical inspection system, enabling not just wavefront conditioning for null testing and dynamic range extension, but also the creation of hybrid measurement procedures. This, for example, allows the combination of dynamic digital holography and Hartmann
Holographic Spherically Symmetric Metrics
Petri, Michael
The holographic principle (HP) conjectures, that the maximum number of degrees of freedom of any realistic physical system is proportional to the system's boundary area. The HP has its roots in the study of black holes. It has recently been applied to cosmological solutions. In this article we apply the HP to spherically symmetric static space-times. We find that any regular spherically symmetric object saturating the HP is subject to tight constraints on the (interior) metric, energy-density, temperature and entropy-density. Whenever gravity can be described by a metric theory, gravity is macroscopically scale invariant and the laws of thermodynamics hold locally and globally, the (interior) metric of a regular holographic object is uniquely determined up to a constant factor and the interior matter-state must follow well defined scaling relations. When the metric theory of gravity is general relativity, the interior matter has an overall string equation of state (EOS) and a unique total energy-density. Thus the holographic metric derived in this article can serve as simple interior 4D realization of Mathur's string fuzzball proposal. Some properties of the holographic metric and its possible experimental verification are discussed. The geodesics of the holographic metric describe an isotropically expanding (or contracting) universe with a nearly homogeneous matter-distribution within the local Hubble volume. Due to the overall string EOS the active gravitational mass-density is zero, resulting in a coasting expansion with Ht = 1, which is compatible with the recent GRB-data.
Talbot, Michael
1991-01-01
'There is evidence to suggest that our world and everything in it - from snowflakes to maple trees to falling stars and spinning electrons - are only ghostly images, projections from a level of reality literally beyond both space and time.' This is the astonishing idea behind the holographic theory of the universe, pioneered by two eminent thinkers: physicist David Bohm, a former protege of Albert Einstein, and quantum physicist Karl Pribram. The holographic theory of the universe encompasses consciousness and reality as we know them, but can also explain such hitherto unexplained phenomena as telepathy, out-of-body experiences and even miraculous healing. In this remarkable book, Michael Talbot reveals the extraordinary depth and power of the holographic theory of the universe, illustrating how it makes sense of the entire range of experiences within our universe - and in other universes beyond our own.
Phenomenology of Holographic Quenches
da Silva, Emilia; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre
2015-10-01
We study holographic models related to global quantum quenches in finite size systems. The holographic set up describes naturally a CFT, which we consider on a circle and a sphere. The enhanced symmetry of the conformal group on the circle motivates us to compare the evolution in both cases. Depending on the initial conditions, the dual geometry exhibits oscillations that we holographically interpret as revivals of the initial field theory state. On the sphere, this only happens when the energy density created by the quench is small compared to the system size. However on the circle considerably larger energy densities are compatible with revivals. Two different timescales emerge in this latter case. A collapse time, when the system appears to have dephased, and the revival time, when after rephasing the initial state is partially recovered. The ratio of these two times depends upon the initial conditions in a similar way to what is observed in some experimental setups exhibiting collapse and revivals.
High quality digital holographic reconstruction on analog film
Nelsen, B.; Hartmann, P.
2017-05-01
High quality real-time digital holographic reconstruction, i.e. at 30 Hz frame rates, has been at the forefront of research and has been hailed as the holy grail of display systems. While these efforts have produced a fascinating array of computer algorithms and technology, many applications of reconstructing high quality digital holograms do not require such high frame rates. In fact, applications such as 3D holographic lithography even require a stationary mask. Typical devices used for digital hologram reconstruction are based on spatial-light-modulator technology and this technology is great for reconstructing arbitrary holograms on the fly; however, it lacks the high spatial resolution achievable by its analog counterpart, holographic film. Analog holographic film is therefore the method of choice for reconstructing highquality static holograms. The challenge lies in taking a static, high-quality digitally calculated hologram and effectively writing it to holographic film. We have developed a theoretical system based on a tunable phase plate, an intensity adjustable high-coherence laser and a slip-stick based piezo rotation stage to effectively produce a digitally calculated hologram on analog film. The configuration reproduces the individual components, both the amplitude and phase, of the hologram in the Fourier domain. These Fourier components are then individually written on the holographic film after interfering with a reference beam. The system is analogous to writing angularly multiplexed plane waves with individual component phase control.
Didactical Holographic Exhibit Including Holo TV (holographic Television)
Lunazzi, José J.; Magalhães, Daniel S. F.; Rivera, Noemí I. R.
2008-04-01
Our Institute of Physics exposes since 1980 didactical exhibitions of holography in Brazil where nice holograms are shown altogether with basic experiments of geometric and wave optics. This experiments lead to the understanding of the phenomenon of images of an ample way. Thousands of people have been present at them, in their majority of the Universidade Estadual de Campinas, where since 2002 they have taken the format of a course without formal evaluation. This way the exhibition has been divided in four modules, in each one of them are shown different holograms, experiments of optics and applications of diffractive images with white light developed in the Institute of Physics. The sequence of the learning through the modules begins with the geometric optics, later we explain the wave optics and finally holography. The phenomenon of the diffraction in daily elements is shown experimentally from the beginning. As well as the application of the holographic screens in white light: the television images that appear in front of the screen and the spectator can try to experience the reality illusion. Put something so exclusive (that only exists in the laboratory) to the public is a way to approximate the persons to an investigation in course. The vision of images that seem to be of holograms, but in movement, and size of until a square meter completes this exhibition of an exclusive way in the world.
Intelligent holographic databases
Barbastathis, George
Memory is a key component of intelligence. In the human brain, physical structure and functionality jointly provide diverse memory modalities at multiple time scales. How could we engineer artificial memories with similar faculties? In this thesis, we attack both hardware and algorithmic aspects of this problem. A good part is devoted to holographic memory architectures, because they meet high capacity and parallelism requirements. We develop and fully characterize shift multiplexing, a novel storage method that simplifies disk head design for holographic disks. We develop and optimize the design of compact refreshable holographic random access memories, showing several ways that 1 Tbit can be stored holographically in volume less than 1 m3, with surface density more than 20 times higher than conventional silicon DRAM integrated circuits. To address the issue of photorefractive volatility, we further develop the two-lambda (dual wavelength) method for shift multiplexing, and combine electrical fixing with angle multiplexing to demonstrate 1,000 multiplexed fixed holograms. Finally, we propose a noise model and an information theoretic metric to optimize the imaging system of a holographic memory, in terms of storage density and error rate. Motivated by the problem of interfacing sensors and memories to a complex system with limited computational resources, we construct a computer game of Desert Survival, built as a high-dimensional non-stationary virtual environment in a competitive setting. The efficacy of episodic learning, implemented as a reinforced Nearest Neighbor scheme, and the probability of winning against a control opponent improve significantly by concentrating the algorithmic effort to the virtual desert neighborhood that emerges as most significant at any time. The generalized computational model combines the autonomous neural network and von Neumann paradigms through a compact, dynamic central representation, which contains the most salient features
Photoacoustic holographic imaging of absorbers embedded in silicone.
Olsson, Erik; Gren, Per; Sjödahl, Mikael
2011-06-10
Light absorbing objects embedded in silicone have been imaged using photoacoustic digital holography. The photoacoustic waves were generated using a pulsed Nd:YAG laser, λ=1064 nm, and pulse length=12 ns. When the waves reached the silicone surface, they were measured optically along a line using a scanning laser vibrometer. The acoustic waves were then digitally reconstructed using a holographic algorithm. The laser vibrometer is proven to be sensitive enough to measure the surface velocity due to photoacoustic waves generated from laser pulses with a fluence allowed for human tissue. It is also shown that combining digital holographic reconstructions for different acoustic wavelengths provides images with suppressed noise and improved depth resolution. The objects are imaged at a depth of 16.5 mm with a depth resolution of 0.5 mm.
Deriving covariant holographic entanglement
Energy Technology Data Exchange (ETDEWEB)
Dong, Xi [School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540 (United States); Lewkowycz, Aitor [Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Rangamani, Mukund [Center for Quantum Mathematics and Physics (QMAP), Department of Physics, University of California, Davis, CA 95616 (United States)
2016-11-07
We provide a gravitational argument in favour of the covariant holographic entanglement entropy proposal. In general time-dependent states, the proposal asserts that the entanglement entropy of a region in the boundary field theory is given by a quarter of the area of a bulk extremal surface in Planck units. The main element of our discussion is an implementation of an appropriate Schwinger-Keldysh contour to obtain the reduced density matrix (and its powers) of a given region, as is relevant for the replica construction. We map this contour into the bulk gravitational theory, and argue that the saddle point solutions of these replica geometries lead to a consistent prescription for computing the field theory Rényi entropies. In the limiting case where the replica index is taken to unity, a local analysis suffices to show that these saddles lead to the extremal surfaces of interest. We also comment on various properties of holographic entanglement that follow from this construction.
Holographic collisions in non-conformal theories
Attems, Maximilian; Casalderrey-Solana, Jorge; Mateos, David; Santos-Oliván, Daniel; Sopuerta, Carlos F.; Triana, Miquel; Zilhão, Miguel
2017-01-01
We numerically simulate gravitational shock wave collisions in a holographic model dual to a non-conformal four-dimensional gauge theory. We find two novel effects associated to the non-zero bulk viscosity of the resulting plasma. First, the hydrodynamization time increases. Second, if the bulk viscosity is large enough then the plasma becomes well described by hydrodynamics before the energy density and the average pressure begin to obey the equilibrium equation of state. We discuss implications for the quark-gluon plasma created in heavy ion collision experiments.
Holographic entanglement entropy
Rangamani, Mukund
2017-01-01
This book provides a comprehensive overview of developments in the field of holographic entanglement entropy. Within the context of the AdS/CFT correspondence, it is shown how quantum entanglement is computed by the area of certain extremal surfaces. The general lessons one can learn from this connection are drawn out for quantum field theories, many-body physics, and quantum gravity. An overview of the necessary background material is provided together with a flavor of the exciting open questions that are currently being discussed. The book is divided into four main parts. In the first part, the concept of entanglement, and methods for computing it, in quantum field theories is reviewed. In the second part, an overview of the AdS/CFT correspondence is given and the holographic entanglement entropy prescription is explained. In the third part, the time-dependence of entanglement entropy in out-of-equilibrium systems, and applications to many body physics are explored using holographic methods. The last part f...
The Holographic Principle in a Cosmological Setting
Savonije, Ivo Lothar
2003-01-01
We study the holographic principle in a cosmological context. First, entropy bounds are derived from the holographic principle and applied within a Anti-de Sitter spacetime. Next, the compatibility of the holographic principle and de Sitter spacetime is considered. The holographic principle is a
Directory of Open Access Journals (Sweden)
Javad Rostami
2017-06-01
Full Text Available Ultrasonic guided wave is an effective tool for structural health monitoring of structures for detecting defects. In practice, guided wave signals are dispersive and contain multiple modes and noise. In the presence of overlapped wave-packets/modes and noise together with dispersion, extracting meaningful information from these signals is a challenging task. Handling such challenge requires an advanced signal processing tool. The aim of this study is to develop an effective and robust signal processing tool to deal with the complexity of guided wave signals for non-destructive testing (NDT purpose. To achieve this goal, Sparse Representation with Dispersion Based Matching Pursuit (SDMP is proposed. Addressing the three abovementioned facts that complicate signal interpretation, SDMP separates overlapped modes and demonstrates good performance against noise with maximum sparsity. With the dispersion taken into account, an overc-omplete and redundant dictionary of basic atoms based on a narrowband excitation signal is designed. As Finite Element Method (FEM was used to predict the form of wave packets propagating along structures, these atoms have the maximum resemblance with real guided wave signals. SDMP operates in two stages. In the first stage, similar to Matching Pursuit (MP, the approximation improves by adding, a single atom to the solution set at each iteration. However, atom selection criterion of SDMP utilizes the time localization of guided wave reflections that makes a portion of overlapped wave-packets to be composed mainly of a single echo. In the second stage of the algorithm, the selected atoms that have frequency inconsistency with the excitation signal are discarded. This increases the sparsity of the final representation. Meanwhile, leading to accurate approximation, as discarded atoms are not representing guided wave reflections, it simplifies extracting physical meanings for defect detection purpose. To verify the
Holographic Baryons and Instanton Crystal
Kaplunovsky, Vadim; Melnikov, Dmitry; Sonnenschein, Jacob
In a wide class of holographic models, like the one proposed by Sakai and Sugimoto, baryons can be approximated by instantons of non-abelian gauge fields that live on the world-volume of flavor D-branes. In the leading order, those are just the Yang-Mills instantons, whose solutions can be constructed from the celebrated ADHM construction. This fact can be used to study various properties of baryons in the holographic limit. In particular, one can attempt to construct a holographic description of the cold dense nuclear matter phase of baryons. It can be argued that holographic baryons in such a regime are necessarily in a solid crystalline phase. In this review we summarize the known results on the construction and phases of crystals of the holographic baryons.
Holographic baryons and instanton crystals
Kaplunovsky, Vadim; Melnikov, Dmitry; Sonnenschein, Jacob
2015-06-01
In a wide class of holographic models, like the one proposed by Sakai and Sugimoto, baryons can be approximated by instantons of non-Abelian gauge fields that live on the world-volume of flavor D-branes. In the leading order, those are just the Yang-Mills instantons, whose solutions can be constructed from the celebrated Atiyah-Drinfeld-Hitchin-Manin (ADHM) construction. This fact can be used to study various properties of baryons in the holographic limit. In particular, one can attempt to construct a holographic description of the cold dense nuclear matter phase of baryons. It can be argued that holographic baryons in such a regime are necessarily in a solid crystalline phase. In this review, we summarize the known results on the construction and phases of crystals of the holographic baryons.
A holographic bound for D3-brane
Energy Technology Data Exchange (ETDEWEB)
Momeni, Davood; Myrzakul, Aizhan; Myrzakulov, Ratbay [Eurasian National University, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan); Eurasian National University, Department of General Theoretical Physics, Astana (Kazakhstan); Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Bahamonde, Sebastian [University College London, Department of Mathematics, London (United Kingdom)
2017-06-15
In this paper, we will regularize the holographic entanglement entropy, holographic complexity and fidelity susceptibility for a configuration of D3-branes. We will also study the regularization of the holographic complexity from the action for a configuration of D3-branes. It will be demonstrated that for a spherical shell of D3-branes the regularized holographic complexity is always greater than or equal to the regularized fidelity susceptibility. Furthermore, we will also demonstrate that the regularized holographic complexity is related to the regularized holographic entanglement entropy for this system. Thus, we will obtain a holographic bound involving regularized holographic complexity, regularized holographic entanglement entropy and regularized fidelity susceptibility of a configuration of D3-brane. We will also discuss a bound for regularized holographic complexity from action, for a D3-brane configuration. (orig.)
An automatic holographic adaptive phoropter
Amirsolaimani, Babak; Peyghambarian, N.; Schwiegerling, Jim; Bablumyan, Arkady; Savidis, Nickolaos; Peyman, Gholam
2017-08-01
Phoropters are the most common instrument used to detect refractive errors. During a refractive exam, lenses are flipped in front of the patient who looks at the eye chart and tries to read the symbols. The procedure is fully dependent on the cooperation of the patient to read the eye chart, provides only a subjective measurement of visual acuity, and can at best provide a rough estimate of the patient's vision. Phoropters are difficult to use for mass screenings requiring a skilled examiner, and it is hard to screen young children and the elderly etc. We have developed a simplified, lightweight automatic phoropter that can measure the optical error of the eye objectively without requiring the patient's input. The automatic holographic adaptive phoropter is based on a Shack-Hartmann wave front sensor and three computercontrolled fluidic lenses. The fluidic lens system is designed to be able to provide power and astigmatic corrections over a large range of corrections without the need for verbal feedback from the patient in less than 20 seconds.
Digital Double-Pulse Holographic Interferometry for Vibration Analysis
Directory of Open Access Journals (Sweden)
H.J. Tiziani
1996-01-01
Full Text Available Different arrangements for double-pulsed holographic and speckle interferometry for vibration analysis will be described. Experimental results obtained with films (classical holographic interferometry and CCD cameras (digital holographic interferometry as storage materials are presented. In digital holography, two separate holograms of an object under test are recorded within a few microseconds using a CCD camera and are stored in a frame grabber. The phases of the two reconstructed wave fields are calculated from the complex amplitudes. The deformation is obtained from the phase difference. In the case of electronic speckle pattern interferometry (or image plane hologram, the phase can be calculated by using the sinusoid-fitting method. In the case of digital holographic interferometry, the phase is obtained by digital reconstruction of the complex amplitudes of the wave fronts. Using three directions of illumination and one direction of observation, all the information necessary for the reconstruction of the 3-dimensional deformation vector can be recorded at the same time. Applications of the method for measuring rotating objects are discussed where a derotator needs to be used.
Noncontact holographic detection for photoacoustic tomography
Buj, Christian; Münter, Michael; Schmarbeck, Benedikt; Horstmann, Jens; Hüttmann, Gereon; Brinkmann, Ralf
2017-10-01
A holographic method for high-speed, noncontact photoacoustic tomography is introduced and evaluated. Relative changes of the object's topography, induced by the impact of thermoelastic pressure waves, were determined at nanometer sensitivity without physical contact. The object's surface was illuminated with nanosecond laser pulses and imaged with a high-speed CMOS camera. From two interferograms measured before and after excitation of the acoustic wave, surface displacement was calculated and then used as the basis for a tomographic reconstruction of the initial pressure caused by optical absorption. The holographic detection scheme enables variable sampling rates of the photoacoustic signal of up to 50 MHz. The total acquisition times for complete volumes with 230 MVoxel is far below 1 s. Measurements of silicone and porcine skin tissue phantoms with embedded artificial absorbers, which served as a model for human subcutaneous vascular networks, were possible. Three-dimensional reconstructions of the absorbing structures show details with a diameter of 310 μm up to a depth of 2.5 mm. Theoretical limitations and the experimental sensitivity, as well as the potential for in vivo imaging depending on the detection repetition rate, are analyzed and discussed.
Holographic effective field theories
Energy Technology Data Exchange (ETDEWEB)
Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei' , Università di Padova,and INFN - Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Zaffaroni, Alberto [Dipartimento di Fisica, Università di Milano-Bicocca,and INFN - Sezione di Milano-Bicocca, I-20126 Milano (Italy)
2016-06-28
We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.
Directory of Open Access Journals (Sweden)
Cornelia Denz
2000-05-01
Full Text Available Volume holography represents a promising alternative to existing storage technologies. Its parallel data storage leads to high capacities combined with short access times and high transfer rates. The design and realization of a compact volume holographic storage demonstrator is presented. The technique of phase-coded multiplexing implemented to superimpose many data pages in a single location enables to store up to 480 holograms per storage location without any moving parts. Results of analog and digital data storage are shown and real time optical image processing is demonstrated.
Laser adaptive holographic hydrophone
Energy Technology Data Exchange (ETDEWEB)
Romashko, R V; Kulchin, Yu N; Bezruk, M N; Ermolaev, S A [Institute of Automation and Control Processes, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok (Russian Federation)
2016-03-31
A new type of a laser hydrophone based on dynamic holograms, formed in a photorefractive crystal, is proposed and studied. It is shown that the use of dynamic holograms makes it unnecessary to use complex optical schemes and systems for electronic stabilisation of the interferometer operating point. This essentially simplifies the scheme of the laser hydrophone preserving its high sensitivity, which offers the possibility to use it under a strong variation of the environment parameters. The laser adaptive holographic hydrophone implemented at present possesses the sensitivity at a level of 3.3 mV Pa{sup -1} in the frequency range from 1 to 30 kHz. (laser hydrophones)
Geller, Michael; Telem, Ofri
2015-05-15
We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider.
Generalized holographic cosmology
Banerjee, Souvik; Bhowmick, Samrat; Sahay, Anurag; Siopsis, George
2013-04-01
We consider general black hole solutions in five-dimensional spacetime in the presence of a negative cosmological constant. We obtain a cosmological evolution via the gravity/gauge theory duality (holography) by defining appropriate boundary conditions on a four-dimensional boundary hypersurface. The standard counterterms are shown to renormalize the bare parameters of the system (the four-dimensional Newton's constant and cosmological constant). We discuss the thermodynamics of cosmological evolution and present various examples. The standard brane-world scenarios are shown to be special cases of our holographic construction.
Kemper, Björn; Bauwens, Andreas; Vollmer, Angelika; Ketelhut, Steffi; Langehanenberg, Patrik; Müthing, Johannes; Karch, Helge; von Bally, Gert
2010-05-01
Digital holographic microscopy (DHM) enables quantitative multifocus phase contrast imaging for nondestructive technical inspection and live cell analysis. Time-lapse investigations on human brain microvascular endothelial cells demonstrate the use of DHM for label-free dynamic quantitative monitoring of cell division of mother cells into daughter cells. Cytokinetic DHM analysis provides future applications in toxicology and cancer research.
Fischler Susskind holographic cosmology revisited
Diaz, Pablo; Per, M. A.; Segui, Antonio
2007-11-01
When Fischler and Susskind proposed a holographic prescription based on the particle horizon, they found that spatially closed cosmological models do not verify it due to the apparently unavoidable recontraction of the particle horizon area. In this paper, after a short review of their original work, we expose graphically and analytically that spatially closed cosmological models can avoid this problem if they expand fast enough. It has also been shown that the holographic principle is saturated for a codimension one-brane dominated universe. The Fischler Susskind prescription is used to obtain the maximum number of degrees of freedom per Planck volume at the Planck era compatible with the holographic principle.
The traveltime holographic principle
Huang, Y.
2014-11-06
Fermat\\'s interferometric principle is used to compute interior transmission traveltimes τpq from exterior transmission traveltimes τsp and τsq. Here, the exterior traveltimes are computed for sources s on a boundary B that encloses a volume V of interior points p and q. Once the exterior traveltimes are computed, no further ray tracing is needed to calculate the interior times τpq. Therefore this interferometric approach can be more efficient than explicitly computing interior traveltimes τpq by ray tracing. Moreover, the memory requirement of the traveltimes is reduced by one dimension, because the boundary B is of one fewer dimension than the volume V. An application of this approach is demonstrated with interbed multiple (IM) elimination. Here, the IMs in the observed data are predicted from the migration image and are subsequently removed by adaptive subtraction. This prediction is enabled by the knowledge of interior transmission traveltimes τpq computed according to Fermat\\'s interferometric principle. We denote this principle as the ‘traveltime holographic principle’, by analogy with the holographic principle in cosmology where information in a volume is encoded on the region\\'s boundary.
Digital holographic microscopy
Barkley, Solomon; Dimiduk, Thomas; Manoharan, Vinothan
Digital holographic microscopy is a 3D optical imaging technique with high temporal ( ms) and spatial ( 10 nm) precision. However, its adoption as a characterization technique has been limited due to the inherent difficulty of recovering 3D data from the holograms. Successful analysis has traditionally required substantial knowledge about the sample being imaged (for example, the approximate positions of particles in the field of view), as well as expertise in scattering theory. To overcome the obstacles to widespread adoption of holographic microscopy, we developed HoloPy - an open source python package for analysis of holograms and scattering data. HoloPy uses Bayesian statistical methods to determine the geometry and properties of discrete scatterers from raw holograms. We demonstrate the use of HoloPy to measure the dynamics of colloidal particles at interfaces, to ascertain the structures of self-assembled colloidal particles, and to track freely swimming bacteria. The HoloPy codebase is thoroughly tested and well-documented to facilitate use by the broader experimental community. This research is supported by NSF Grant DMR-1306410 and NSERC.
Linearity of holographic entanglement entropy
National Research Council Canada - National Science Library
Almheiri, Ahmed; Dong, Xi; Swingle, Brian
2017-01-01
We consider the question of whether the leading contribution to the entanglement entropy in holographic CFTs is truly given by the expectation value of a linear operator as is suggested by the Ryu-Takayanagi formula...
Adventures in Holographic Dimer Models
Energy Technology Data Exchange (ETDEWEB)
Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC; Karch, Andreas; /Washington U., Seattle; Yaida, Sho; /Stanford U., Phys. Dept.
2011-08-12
We abstract the essential features of holographic dimer models, and develop several new applications of these models. Firstly, semi-holographically coupling free band fermions to holographic dimers, we uncover novel phase transitions between conventional Fermi liquids and non-Fermi liquids, accompanied by a change in the structure of the Fermi surface. Secondly, we make dimer vibrations propagate through the whole crystal by way of double trace deformations, obtaining nontrivial band structure. In a simple toy model, the topology of the band structure experiences an interesting reorganization as we vary the strength of the double trace deformations. Finally, we develop tools that would allow one to build, in a bottom-up fashion, a holographic avatar of the Hubbard model.
Adventures in holographic dimer models
Kachru, Shamit; Karch, Andreas; Yaida, Sho
2011-03-01
We abstract the essential features of holographic dimer models, and develop several new applications of these models. Firstly, semi-holographically coupling free band fermions to holographic dimers, we uncover novel phase transitions between conventional Fermi liquids and non-Fermi liquids, accompanied by a change in the structure of the Fermi surface. Secondly, we make dimer vibrations propagate through the whole crystal by way of double trace deformations, obtaining nontrivial band structure. In a simple toy model, the topology of the band structure experiences an interesting reorganization as we vary the strength of the double trace deformations. Finally, we develop tools that would allow one to build, in a bottom-up fashion, a holographic avatar of the Hubbard model.
Sadri, A; Gebski, P.; Gordon, Y.
2014-01-01
Generally speaking, a blast furnace is the main equipment in Ironmaking and the campaign life of a blast furnace depends on its remaining hearth refractory lining [1]. The Acousto Ultrasonic- Echo (AU-E) is a stress wave propagation technique that uses time and frequency data analysis to determine coarse-grained material thicknesses, such as refractory and stave materials in operating blast furnaces. A mechanical impact on the surface of the structure (via a hammer or a mechanical impactor) g...
Energy Technology Data Exchange (ETDEWEB)
Estes, John [Blackett Laboratory, Imperial College,London SW7 2AZ (United Kingdom); Jensen, Kristan [Department of Physics and Astronomy, University of Victoria,Victoria, BC V8W 3P6 (Canada); C.N. Yang Institute for Theoretical Physics, SUNY Stony Brook,Stony Brook, NY 11794-3840 (United States); O’Bannon, Andy [Rudolf Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, Oxford OX1 3NP (United Kingdom); Tsatis, Efstratios [8 Kotylaiou Street, Athens 11364 (Greece); Wrase, Timm [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94305 (United States)
2014-05-19
We study a number of (3+1)- and (2+1)-dimensional defect and boundary conformal field theories holographically dual to supergravity theories. In all cases the defects or boundaries are planar, and the defects are codimension-one. Using holography, we compute the entanglement entropy of a (hemi-)spherical region centered on the defect (boundary). We define defect and boundary entropies from the entanglement entropy by an appropriate background subtraction. For some (3+1)-dimensional theories we find evidence that the defect/boundary entropy changes monotonically under certain renormalization group flows triggered by operators localized at the defect or boundary. This provides evidence that the g-theorem of (1+1)-dimensional field theories generalizes to higher dimensions.
Estes, John; Jensen, Kristan; O'Bannon, Andy; Tsatis, Efstratios; Wrase, Timm
2014-05-01
We study a number of (3 + 1)- and (2 + 1)-dimensional defect and boundary conformal field theories holographically dual to supergravity theories. In all cases the defects or boundaries are planar, and the defects are codimension-one. Using holography, we compute the entanglement entropy of a (hemi-)spherical region centered on the defect (boundary). We define defect and boundary entropies from the entanglement entropy by an appropriate background subtraction. For some (3 + 1)-dimensional theories we find evidence that the defect/boundary entropy changes monotonically under certain renormalization group flows triggered by operators localized at the defect or boundary. This provides evidence that the g-theorem of (1 + 1)-dimensional field theories generalizes to higher dimensions.
Causality & holographic entanglement entropy
Energy Technology Data Exchange (ETDEWEB)
Headrick, Matthew [Martin Fisher School of Physics, Brandeis University, MS 057, 415 South Street, Waltham, MA 02454 (United States); Hubeny, Veronika E. [Centre for Particle Theory & Department of Mathematical Sciences,Science Laboratories, South Road, Durham DH1 3LE (United Kingdom); Lawrence, Albion [Martin Fisher School of Physics, Brandeis University, MS 057, 415 South Street, Waltham, MA 02454 (United States); Rangamani, Mukund [Centre for Particle Theory & Department of Mathematical Sciences,Science Laboratories, South Road, Durham DH1 3LE (United Kingdom)
2014-12-29
We identify conditions for the entanglement entropy as a function of spatial region to be compatible with causality in an arbitrary relativistic quantum field theory. We then prove that the covariant holographic entanglement entropy prescription (which relates entanglement entropy of a given spatial region on the boundary to the area of a certain extremal surface in the bulk) obeys these conditions, as long as the bulk obeys the null energy condition. While necessary for the validity of the prescription, this consistency requirement is quite nontrivial from the bulk standpoint, and therefore provides important additional evidence for the prescription. In the process, we introduce a codimension-zero bulk region, named the entanglement wedge, naturally associated with the given boundary spatial region. We propose that the entanglement wedge is the most natural bulk region corresponding to the boundary reduced density matrix.
Holographic Vortex Coronagraph
Palacios, David
2010-01-01
A holographic vortex coronagraph (HVC) has been proposed as an improvement over conventional coronagraphs for use in high-contrast astronomical imaging for detecting planets, dust disks, and other broadband light scatterers in the vicinities of stars other than the Sun. Because such light scatterers are so faint relative to their parent stars, in order to be able to detect them, it is necessary to effect ultra-high-contrast (typically by a factor of the order of 1010) suppression of broadband light from the stars. Unfortunately, the performances of conventional coronagraphs are limited by low throughput, dispersion, and difficulty of satisfying challenging manufacturing requirements. The HVC concept offers the potential to overcome these limitations.
Holographic versatile disc system
Horimai, Hideyoshi; Tan, Xiaodi
2005-09-01
A Holographic Versatile Disc (HVD) system, using Collinear Technologies for a high capacity and high data transfer rates storage system, is proposed. With its unique configuration the optical pickup can be designed as small as a DVD's, and can be placed on one side of the disc. With the HVD's special structure, the system can servo the focus/track and locate reading/writing address. A unique selectable capacity recording format of HVD and its standardization activity are also introduced. Experimental and theoretical studies suggest that the tilt, wavelength, defocus and de-track margins are wide enough to miniaturize the HVD system at a low cost. HVD systems using Collinear Technologies will be compatible with existing disc storage systems, like CD and DVD, and will enable us to expand its applications into other optical information storage systems.
Effects of backreaction on power-Maxwell holographic superconductors in Gauss-Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Salahi, Hamid Reza; Montakhab, Afshin [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Sheykhi, Ahmad [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of)
2016-10-15
We analytically and numerically investigate the properties of s-wave holographic superconductors by considering the effects of scalar and gauge fields on the background geometry in five-dimensional Einstein-Gauss-Bonnet gravity. We assume the gauge field to be in the form of the power-Maxwell nonlinear electrodynamics. We employ the Sturm-Liouville eigenvalue problem for analytical calculation of the critical temperature and the shooting method for the numerical investigation. Our numerical and analytical results indicate that higher curvature corrections affect condensation of the holographic superconductors with backreaction. We observe that the backreaction can decrease the critical temperature of the holographic superconductors, while the power-Maxwell electrodynamics and Gauss-Bonnet coefficient term may increase the critical temperature of the holographic superconductors. We find that the critical exponent has the mean-field value β = 1/2, regardless of the values of Gauss-Bonnet coefficient, backreaction and power-Maxwell parameters. (orig.)
Holographic View of the Brain Memory Mechanism Based on Evanescent Superluminal Photons
Directory of Open Access Journals (Sweden)
Takaaki Musha
2012-08-01
Full Text Available D. Pollen and M. Trachtenberg proposed the holographic brain theory to help explain the existence of photographic memories in some people. They suggested that such individuals had more vivid memories because they somehow could access a very large region of their memory holograms. Hameroff suggested in his paper that cylindrical neuronal microtubule cavities, or centrioles, function as waveguides for the evanescent photons for quantum signal processing. The supposition is that microtubular structures of the brain function as a coherent fiber bundle set used to store holographic images, as would a fiber-optic holographic system. In this paper, the author proposes that superluminal photons propagating inside the microtubules via evanescent waves could provide the access needed to record or retrieve a quantum coherent entangled holographic memory.
Mariani, Stefano; Nguyen, Thompson V.; Sternini, Simone; Lanza di Scalea, Francesco; Fateh, Mahmood; Wilson, Robert
2016-04-01
The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is developing a system for high-speed and non-contact rail defect detection. A prototype using an ultrasonic air-coupled guided wave signal generation and air-coupled signal detection, paired with a real-time statistical analysis algorithm, has been realized. This system requires a specialized filtering approach based on electrical impedance matching due to the inherently poor signal-to-noise ratio of air-coupled ultrasonic measurements in rail steel. Various aspects of the prototype have been designed with the aid of numerical analyses. In particular, simulations of ultrasonic guided wave propagation in rails have been performed using a Local Interaction Simulation Approach (LISA) algorithm. The system's operating parameters were selected based on Receiver Operating Characteristic (ROC) curves, which provide a quantitative manner to evaluate different detection performances based on the trade-off between detection rate and false positive rate. The prototype based on this technology was tested in October 2014 at the Transportation Technology Center (TTC) in Pueblo, Colorado, and again in November 2015 after incorporating changes based on lessons learned. Results from the 2015 field test are discussed in this paper.
Holographic Waveguided See-Through Display Project
National Aeronautics and Space Administration — To address the NASA need for lightweight, space suit-mounted displays, Luminit proposes a novel Holographic Waveguided See-Through Display. Our proposed Holographic...
3D holographic printer: fast printing approach.
Morozov, Alexander V; Putilin, Andrey N; Kopenkin, Sergey S; Borodin, Yuriy P; Druzhin, Vladislav V; Dubynin, Sergey E; Dubinin, German B
2014-02-10
This article describes the general operation principles of devices for synthesized holographic images such as holographic printers. Special emphasis is placed on the printing speed. In addition, various methods to increase the printing process are described and compared.
U.S. Department of Health & Human Services — FDA is disclosing the final inspection classification for inspections related to currently marketed FDA-regulated products. The disclosure of this information is not...
Holographic Gratings for Slow-Neutron Optics
Klepp, Juergen; Pruner, Christian; Tomita, Yasuo; Geltenbort, Peter; Drevenšek-Olenik, Irena; Gyergyek, Saso; Kohlbrecher, Joachim; Fally, Martin
2012-01-01
Recent progress in the development of holographic gratings for neutron-optics applications is reviewed. We summarize the properties of gratings recorded in deuterated (poly)methylmethacrylate, holographic polymer-dispersed liquid crystals and nanoparticle-polymer composites revealed by diffraction experiments with slow neutrons. Existing and anticipated neutron-optical instrumentations based on holographic gratings are discussed.
Directory of Open Access Journals (Sweden)
Kay-Michael Voit
2013-01-01
Full Text Available Holographic spectroscopy is highlighted as a powerful tool for the analysis of photosensitive materials with pronounced alterations of the complex permittivity over a broad range in the visible spectrum, due to the advances made both in the fields of advanced holographic media and highly tunable lasers systems. To analytically discuss consequences for in- and off-Bragg reconstruction, we revised Kogelnik’s coupled wave theory strictly on the basis of complex permittivities. We extended it to comply with modern experimental parameters such as out-of-phase mixed holograms and highly modulated gratings. A spatially modulated, wavelength-dependent permittivity that superimposes a spatially homogeneous wavelength-dependent ground state spectrum is taken into account for signal wave reconstruction with bulky elementary mixed gratings as an example. The dispersion characteristics of the respective diffraction efficiency is modelled for color-center-absorption and absorption of strongly localized carriers. As an example for the theoretical possibilities of our newly derived set of equations, we present a quantitative analysis of the Borrmann effect connected to out-of-phase gratings, providing easier and more intuitive methods for the derivation of their grating parameters.
Holographic framework for eternal inflation
Freivogel, Ben; Sekino, Yasuhiro; Susskind, Leonard; Yeh, Chen-Pin
2006-10-01
In this paper we provide some circumstantial evidence for a holographic duality between bubble nucleation in an eternally inflating universe and a Euclidean conformal field theory (CFT). The holographic correspondence (which is different than Strominger’s de Sitter (dS)/CFT duality) relates the decay of (3+1)-dimensional de Sitter space to a two-dimensional CFT. It is not associated with pure de Sitter space, but rather with Coleman-De Luccia bubble nucleation. Alternatively, it can be thought of as a holographic description of the open, infinite, Friedmann-Robertson-Walker (FRW) cosmology that results from such a bubble. The conjectured holographic representation is of a new type that combines holography with the Wheeler-DeWitt formalism to produce a Wheeler-DeWitt theory that lives on the spatial boundary of a k=-1 FRW cosmology. We also argue for a more ambitious interpretation of the Wheeler-DeWitt CFT as a holographic dual of the entire Landscape.
Cellular Dynamics Revealed by Digital Holographic Microscopy☆
Marquet, P.
2016-11-22
Digital holographic microscopy (DHM) is a new optical method that provides, without the use of any contrast agent, real-time, three-dimensional images of transparent living cells, with an axial sensitivity of a few tens of nanometers. They result from the hologram numerical reconstruction process, which permits a sub wavelength calculation of the phase shift, produced on the transmitted wave front, by the optically probed cells, namely the quantitative phase signal (QPS). Specifically, in addition to measurements of cellular surface morphometry and intracellular refractive index (RI), various biophysical cellular parameters including dry mass, absolute volume, membrane fluctuations at the nanoscale and biomechanical properties, transmembrane water permeability as swell as current, can be derived from the QPS. This article presents how quantitative phase DHM (QP-DHM) can explored cell dynamics at the nanoscale with a special attention to both the study of neuronal dynamics and the optical resolution of local neuronal network.
Holographic photolysis for multiple cell stimulation in mouse hippocampal slices.
Directory of Open Access Journals (Sweden)
Morad Zahid
Full Text Available BACKGROUND: Advanced light microscopy offers sensitive and non-invasive means to image neural activity and to control signaling with photolysable molecules and, recently, light-gated channels. These approaches require precise and yet flexible light excitation patterns. For synchronous stimulation of subsets of cells, they also require large excitation areas with millisecond and micrometric resolution. We have recently developed a new method for such optical control using a phase holographic modulation of optical wave-fronts, which minimizes power loss, enables rapid switching between excitation patterns, and allows a true 3D sculpting of the excitation volumes. In previous studies we have used holographic photololysis to control glutamate uncaging on single neuronal cells. Here, we extend the use of holographic photolysis for the excitation of multiple neurons and of glial cells. METHODS/PRINCIPAL FINDINGS: The system combines a liquid crystal device for holographic patterned photostimulation, high-resolution optical imaging, the HiLo microscopy, to define the stimulated regions and a conventional Ca(2+ imaging system to detect neural activity. By means of electrophysiological recordings and calcium imaging in acute hippocampal slices, we show that the use of excitation patterns precisely tailored to the shape of multiple neuronal somata represents a very efficient way for the simultaneous excitation of a group of neurons. In addition, we demonstrate that fast shaped illumination patterns also induce reliable responses in single glial cells. CONCLUSIONS/SIGNIFICANCE: We show that the main advantage of holographic illumination is that it allows for an efficient excitation of multiple cells with a spatiotemporal resolution unachievable with other existing approaches. Although this paper focuses on the photoactivation of caged molecules, our approach will surely prove very efficient for other probes, such as light-gated channels, genetically
Cui, Tie Jun; Wu, Rui Yuan; Wu, Wei; Shi, Chuan Bo; Li, Yun Bo
2017-10-01
We propose fast and accurate designs to large-scale and low-profile transmission-type anisotropic coding metasurfaces with multiple functions in the millimeter-wave frequencies based on the antenna-array method. The numerical simulation of an anisotropic coding metasurface with the size of 30λ × 30λ by the proposed method takes only 20 min, which however cannot be realized by commercial software due to huge memory usage in personal computers. To inspect the performance of coding metasurfaces in the millimeter-wave band, the working frequency is chosen as 60 GHz. Based on the convolution operations and holographic theory, the proposed multifunctional anisotropic coding metasurface exhibits different effects excited by y-polarized and x-polarized incidences. This study extends the frequency range of coding metasurfaces, filling the gap between microwave and terahertz bands, and implying promising applications in millimeter-wave communication and imaging.
Electronic recording of holograms with applications to holographic displays
Claspy, P. C.; Merat, F. L.
1979-01-01
The paper describes an electronic heterodyne recording which uses electrooptic modulation to introduce a sinusoidal phase shift between the object and reference wave. The resulting temporally modulated holographic interference pattern is scanned by a commercial image dissector camera, and the rejection of the self-interference terms is accomplished by heterodyne detection at the camera output. The electrical signal representing this processed hologram can then be used to modify the properties of a liquid crystal light valve or a similar device. Such display devices transform the displayed interference pattern into a phase modulated wave front rendering a three-dimensional image.
On holographic entanglement density
Gushterov, Nikola I.; O'Bannon, Andy; Rodgers, Ronnie
2017-10-01
We use holographic duality to study the entanglement entropy (EE) of Conformal Field Theories (CFTs) in various spacetime dimensions d, in the presence of various deformations: a relevant Lorentz scalar operator with constant source, a temperature T , a chemical potential μ, a marginal Lorentz scalar operator with source linear in a spatial coordinate, and a circle-compactified spatial direction. We consider EE between a strip or sphere sub-region and the rest of the system, and define the "entanglement density" (ED) as the change in EE due to the deformation, divided by the sub-region's volume. Using the deformed CFTs above, we show how the ED's dependence on the strip width or sphere radius, L, is useful for characterizing states of matter. For example, the ED's small- L behavior is determined either by the dimension of the perturbing operator or by the first law of EE. For Lorentz-invariant renormalization group (RG) flows between CFTs, the "area theorem" states that the coefficient of the EE's area law term must be larger in the UV than in the IR. In these cases the ED must therefore approach zero from below as L→∞. However, when Lorentz symmetry is broken and the IR fixed point has different scaling from the UV, we find that the ED often approaches the thermal entropy density from above, indicating area theorem violation.
Magnonic holographic devices for special type data processing
Khitun, Alexander
2013-04-01
In this work, we consider the possibility of building magnetic analog logic devices utilizing spin wave interference for special task data processing. As an example, we consider a multi-terminal magnonic matrix switch comprising multiferroic elements and a two-dimensional grid of magnetic waveguides connected via four-terminal cross-junctions. The multiferroic elements are placed on the periphery of the switch and used as input/output ports for signal conversion among the electric and magnetic domains. Data processing is accomplished via the use of spin wave interference within the magnonic matrix. We present the results of numerical modeling illustrating device operation for pattern matching, finding the period of the data string, and image processing. We also present the results of numerical modeling showing the device capabilities as a magnetic holographic memory. Magnonic holographic devices are of great potential to complement the conventional general-type processors in special task data processing and may provide a new direction for functional throughput enhancement. According to estimates, magnonic holographic devices can provide up to 1 Tb/cm2 data storage density and data processing rate exceeding 1018 bits/s/cm2. The physical limitations and practical challenges of the proposed approach are discussed.
Advances with holographic DESA emulsions
Dünkel, Lothar; Eichler, Jürgen; Schneeweiss, Claudia; Ackermann, Gerhard
2006-02-01
DESA emulsions represent layer systems based on ultra-fine grained silver halide (AgX) technology. The new layers have an excellent performance for holographic application. The technology has been presented repeatedly in recent years, including the emulsion characterization and topics of chemical and spectral sensitization. The paper gives a survey of actual results referring to panchromatic sensitization and other improvements like the application of silver halide sensitized gelatine (SHSG) procedure. These results are embedded into intensive collaborations with small and medium enterprises (SME's) to commercialize DESA layers. Predominant goals are innovative products with holographic components and layers providing as well as cost effectiveness and high quality.
Pinning of holographic sliding stripes
Jokela, Niko; Järvinen, Matti; Lippert, Matthew
2017-11-01
In a holographic probe-brane model exhibiting a spontaneously spatially modulated ground state, we introduce explicit sources of symmetry breaking in the form of ionic and antiferromagnetic lattices. For the first time in a holographic model, we demonstrate pinning, in which the translational Goldstone mode is lifted by the introduction of explicit sources of translational symmetry breaking. The numerically computed optical conductivity fits very well to a Drude-Lorentz model with a small residual metallicity, precisely matching analytic formulas for the DC conductivity. We also find an instability of the striped phase in the presence of a large-amplitude ionic lattice.
Mandula, G.; Ellabban, M. A.; Rupp, R. A.; Fally, M.; Hartmann, E.; Kovacs, L.; Polgar, K.
2003-01-01
The activation energy of thermal fixing of photorefractive gratings is determined in congruent and nearly stoichiometric lithium niobate crystals, both doped with iron or manganese. The novel technique called holographic scattering method is compared with the standard two-wave mixing method. A measurement of the angular distribution of the self scattered intensity and its possible-analytical function is presented. The mathematical problems of the holographic scattering method are discussed applying the angular distribution functions.
Holographic superconductors in the presence of dark matter
Rogatko, Marek; Wysokiński, Karol I.
2017-10-01
The application of the gauge-gravity duality, also known as anti-de Sitter/conformal field theory (AdS/CFT) correspondence to study condensed matter systems has resulted in a number of important findings. Using the analogy, we have studied the phase transitions between a holographic insulator and a metal at zero temperature as well as finite temperature transition between a metal and a holographic superconductor of s- and p-wave symmetry. The main aim of this note is to look in which way the dark matter might affect the properties of superconductors. The hope is that some of the observed modifications could be used to detect this ubiquitous but still elusive component of matter in the Universe.
Fingerprint sensor using a polymer dispersed liquid crystal holographic lens.
Jie, Ying; Jihong, Zheng
2010-09-01
We used a polymer dispersed liquid crystal material holographic lens in a fingerprint sensor, which reduced the total size of the sensor and improved image quality. The beam carrying fingerprint information was diffracted by the holographic lens and converged onto the complementary metal-oxide semiconductor image sensor directly, which omitted the traditional lens or fiber taper. The phenomenon that the image quality is poor when the finger is too dry or wet was explained based on the evanescent wave theory. The total size of the device was 50 mm x 25 mm x 30 mm. The fingerprint image had a contrast of 250:1 and a resolution of 800 dots/in.
Coexistence of two vector order parameters: a holographic model for ferromagnetic superconductivity
Energy Technology Data Exchange (ETDEWEB)
Amoretti, Andrea [Dipartimento di Fisica, Università di Genova, and I.N.F.N. - Sezione di Genova, via Dodecaneso 33, 16146, Genova (Italy); Braggio, Alessandro [CNR-SPIN, via Dodecaneso 33, 16146, Genova (Italy); Maggiore, Nicola; Magnoli, Nicodemo [Dipartimento di Fisica, Università di Genova, and I.N.F.N. - Sezione di Genova, via Dodecaneso 33, 16146, Genova (Italy); Musso, Daniele [Physique Théorique et Mathématique, Université Libre de Bruxelles, C.P. 231, 1050 Bruxelles (Belgium)
2014-01-13
We study a generalization of the standard holographic p-wave superconductor featuring two interacting vector order parameters. Basing our argument on the symmetry and linear response properties of the model, we propose it as a holographic effective theory describing a strongly coupled ferromagnetic superconductor. We show that the two order parameters undergo concomitant condensations as a manifestation of an intrinsically interlaced charge/spin dynamics. Such intertwined dynamics is confirmed by the study of the transport properties. We characterize thoroughly the equilibrium and the linear response (i.e. optical conductivity and spin susceptibility) of the model at hand by means of a probe approximation analysis. Some insight about the effects of backreaction in the normal phase can be gained by analogy with the s-wave unbalanced holographic superconductor.
High-resolution holographic imaging technology by microscopic image plane holography
Wang, Xuhui; Gong, Wendi; Liu, Feifei; Wang, Huaying
2010-11-01
The imaging technology of digital microscopic image plane holography (DMIPH) is studied in this paper. The point spread function expression and the recording conditions of DMIPH system are derived. The quadratic phase factor which introduced by the microscope objective lens can be eliminated through choosing the proper position of the reference point source when the hologram is recorded by spherical reference waves. By using plane waves and spherical waves as reference waves respectively two image plane holographic recording systems are built. Using a USAF test target as microscopic object, the recorded digital holograms are reconstructed by angular spectrum algorithm. The experimental results show that in the case of spherical reference waves if the distance from the equivalent of lighting point source to CCD plane is equal to the distance between the reference point source and CCD plane the quadratic phase distortion introduced by the microscope objective lens can be removed and that DMIPH is superior to common digital holographic microscopy.
Conformal symmetry and holographic cosmology
Bzowski, A.W.
2013-01-01
This thesis presents a novel approach to cosmology using gauge/gravity duality. Analysis of the implications of conformal invariance in field theories leads to quantitative cosmological predictions which are in agreement with current data. Furthermore, holographic cosmology extends the theory of
Holographic Grating Study. Volume 1
1979-03-01
EFFICIENCY GRATING ANALYSIS AND MEASUREMENT 167 4. 1 High-Efficiency Holographic Grating Desl ^ri Isaues .... 167 4.2 Computer Modeling of High...one or more higher orders is maximized . This distinguishes them from low-efficiency gratings which utilize the zero order at hi^h efficiency
Code Properties from Holographic Geometries
Directory of Open Access Journals (Sweden)
Fernando Pastawski
2017-05-01
Full Text Available Almheiri, Dong, and Harlow [J. High Energy Phys. 04 (2015 163.JHEPFG1029-847910.1007/JHEP04(2015163] proposed a highly illuminating connection between the AdS/CFT holographic correspondence and operator algebra quantum error correction (OAQEC. Here, we explore this connection further. We derive some general results about OAQEC, as well as results that apply specifically to quantum codes that admit a holographic interpretation. We introduce a new quantity called price, which characterizes the support of a protected logical system, and find constraints on the price and the distance for logical subalgebras of quantum codes. We show that holographic codes defined on bulk manifolds with asymptotically negative curvature exhibit uberholography, meaning that a bulk logical algebra can be supported on a boundary region with a fractal structure. We argue that, for holographic codes defined on bulk manifolds with asymptotically flat or positive curvature, the boundary physics must be highly nonlocal, an observation with potential implications for black holes and for quantum gravity in AdS space at distance scales that are small compared to the AdS curvature radius.
Thermalization after holographic bilocal quench
Aref'eva, Irina Ya.; Khramtsov, Mikhail A.; Tikhanovskaya, Maria D.
2017-09-01
We study thermalization in the holographic (1 + 1)-dimensional CFT after simultaneous generation of two high-energy excitations in the antipodal points on the circle. The holographic picture of such quantum quench is the creation of BTZ black hole from a collision of two massless particles. We perform holographic computation of entanglement entropy and mutual information in the boundary theory and analyze their evolution with time. We show that equilibration of the entanglement in the regions which contained one of the initial excitations is generally similar to that in other holographic quench models, but with some important distinctions. We observe that entanglement propagates along a sharp effective light cone from the points of initial excitations on the boundary. The characteristics of entanglement propagation in the global quench models such as entanglement velocity and the light cone velocity also have a meaning in the bilocal quench scenario. We also observe the loss of memory about the initial state during the equilibration process. We find that the memory loss reflects on the time behavior of the entanglement similarly to the global quench case, and it is related to the universal linear growth of entanglement, which comes from the interior of the forming black hole. We also analyze general two-point correlation functions in the framework of the geodesic approximation, focusing on the study of the late time behavior.
Code Properties from Holographic Geometries
Pastawski, Fernando; Preskill, John
2017-04-01
Almheiri, Dong, and Harlow [J. High Energy Phys. 04 (2015) 163., 10.1007/JHEP04(2015)163] proposed a highly illuminating connection between the AdS /CFT holographic correspondence and operator algebra quantum error correction (OAQEC). Here, we explore this connection further. We derive some general results about OAQEC, as well as results that apply specifically to quantum codes that admit a holographic interpretation. We introduce a new quantity called price, which characterizes the support of a protected logical system, and find constraints on the price and the distance for logical subalgebras of quantum codes. We show that holographic codes defined on bulk manifolds with asymptotically negative curvature exhibit uberholography, meaning that a bulk logical algebra can be supported on a boundary region with a fractal structure. We argue that, for holographic codes defined on bulk manifolds with asymptotically flat or positive curvature, the boundary physics must be highly nonlocal, an observation with potential implications for black holes and for quantum gravity in AdS space at distance scales that are small compared to the AdS curvature radius.
Holographic complexity and spacetime singularities
Energy Technology Data Exchange (ETDEWEB)
Barbón, José L.F. [Instituto de Física Teórica IFT UAM/CSIC,C/ Nicolás Cabrera 13, Campus Universidad Autónoma de Madrid,Madrid 28049 (Spain); Rabinovici, Eliezer [Racah Institute of Physics, The Hebrew University,Jerusalem 91904 (Israel); Laboratoire de Physique Théorique et Hautes Energies, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France)
2016-01-15
We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.
Holographic memory for high-density data storage and high-speed pattern recognition
Gu, Claire
2002-09-01
As computers and the internet become faster and faster, more and more information is transmitted, received, and stored everyday. The demand for high density and fast access time data storage is pushing scientists and engineers to explore all possible approaches including magnetic, mechanical, optical, etc. Optical data storage has already demonstrated its potential in the competition against other storage technologies. CD and DVD are showing their advantages in the computer and entertainment market. What motivated the use of optical waves to store and access information is the same as the motivation for optical communication. Light or an optical wave has an enormous capacity (or bandwidth) to carry information because of its short wavelength and parallel nature. In optical storage, there are two types of mechanism, namely localized and holographic memories. What gives the holographic data storage an advantage over localized bit storage is the natural ability to read the stored information in parallel, therefore, meeting the demand for fast access. Another unique feature that makes the holographic data storage attractive is that it is capable of performing associative recall at an incomparable speed. Therefore, volume holographic memory is particularly suitable for high-density data storage and high-speed pattern recognition. In this paper, we review previous works on volume holographic memories and discuss the challenges for this technology to become a reality.
Analysis of localized fringes in the holographic optical Schlieren system
Kurtz, R. L.
1980-01-01
The relation between localization of interference fringes in classical and holographic interferometry is reviewed and an application of holographic interferometry is considered for which the object is a transparent medium with nonhomogeneous refractive index. The technique is based on the analysis of the optical path length change of the object wave as it propagates through a transparent medium. Phase shifts due to variations of the speed of light within the medium give rise to an interference pattern. The resulting interferogram can be used to determine the physical properties of the medium or transparent object. Such properties include the mass density of fluids, electron densities of plasmas, the temperature of fluids, the chemical species concentration of fluids, and the state of stress in solids. The optical wave used can be either a simple plane or spherical wave, or it may be a complicated spatial wave scattered by a diffusing screen. The mathematical theory on the formation and analysis of localized fringes, the general theoretical concepts used, and a computer code for analysis are included along with the inversion of fringe order data.
Self-interference digital holographic microscopy for live cell imaging
Kemper, Björn; Dartmann, Sebastian; Schlichthaber, Frank; Vollmer, Angelika; Ketelhut, Steffi; von Bally, Gert
2012-06-01
Quantitative digital holographic multi-focus phase imaging enables label-free minimally invasive live cell analysis by high resolution detection of sample induced optical path length changes. However, a drawback of many experimental arrangements for the analysis of living cells with digital holography is the requirement for a separate reference wave which results in a phase stability decrease and the demand for a precise adjustment of the intensity ratio between object and reference wave. Thus, a self interference digital holographic microscopy (DHM) approach was explored which only requires a single object illumination wave. Due to the Michelson interferometer design of the proposed experimental setup two wave fronts with an almost identical curvature are superimposed. This results in a simplified evaluation of the digital holograms. The applicability of the proposed self interference principle is illustrated by results from a technical specimen and living single cells. Furthermore, adherent cancer cells have been analyzed for morphology changes in perfusion chambers due to flow and the refractive index of suspended cells was determined. In summary, the method prospects to be a versatile tool for quantitative phase imaging as simplification is important for the establishment of these methods in live cell analysis.
Holographic kinetic k-essence model
Energy Technology Data Exchange (ETDEWEB)
Cruz, Norman [Departamento de Fisica, Facultad de Ciencia, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: ncruz@lauca.usach.cl; Gonzalez-Diaz, Pedro F.; Rozas-Fernandez, Alberto [Colina de los Chopos, Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain)], E-mail: a.rozas@cfmac.csic.es; Sanchez, Guillermo [Departamento de Matematica y Ciencia de la Computacion, Facultad de Ciencia, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: gsanchez@usach.cl
2009-08-31
We consider a connection between the holographic dark energy density and the kinetic k-essence energy density in a flat FRW universe. With the choice c{>=}1, the holographic dark energy can be described by a kinetic k-essence scalar field in a certain way. In this Letter we show this kinetic k-essential description of the holographic dark energy with c{>=}1 and reconstruct the kinetic k-essence function F(X)
Holographic complexity in gauge/string superconductors
Directory of Open Access Journals (Sweden)
Davood Momeni
2016-05-01
Full Text Available Following a methodology similar to [1], we derive a holographic complexity for two dimensional holographic superconductors (gauge/string superconductors with backreactions. Applying a perturbation method proposed by Kanno in Ref. [2], we study behaviors of the complexity for a dual quantum system near critical points. We show that when a system moves from the normal phase (T>Tc to the superconductor phase (T
Color waveguide transparent screen using lens array holographic optical element
Liu, Siqi; Sun, Peng; Wang, Chang; Zheng, Zhenrong
2017-11-01
A color transparent screen was designed in this paper, a planar glass was used as a waveguide structure and the lens array holographic optical element (HOE) was used as a display unit. The lens array HOE was exposed by two coherent beams. One was the reference wave which directly illuminated on the holographic material and the other was modulated by the micro lens array. The lens array HOE can display the images with see-through abilities. Unlike the conventional lens array HOE, a planar glass was adopted as the waveguide in the experiment. The projecting light was totally internal-reflected in the planar glass to eliminate the undesired zero-order diffracted light. By using waveguide, it also brings advantage of compact structure. Colorful display can be realized in our system as the holographic materials were capable for multi-wavelength display. In this paper, a color transparent screen utilizing the lens array HOE and waveguide were designed. Experiment results showed a circular display area on the transparent screen. The diameter of the area is 20 mm and it achieved the pixel resolution of 100 μm. This simple and effective method could be an alternative in the augment reality (AR) applications, such as transparent phone and television.
Holographic Two-Photon Induced Photopolymerization
Federal Laboratory Consortium — Holographic two-photon-induced photopolymerization (HTPIP) offers distinct advantages over conventional one-photon-induced photopolymerization and current techniques...
3D color reconstructions in single DMD holographic display with LED source and complex coding scheme
Chlipała, Maksymilian; Kozacki, Tomasz
2017-06-01
In the paper we investigate the possibility of color reconstructions of holograms with a single DMD and incoherent LED source illumination. Holographic display is built with 4F imaging system centering reconstruction volume around the DMD surface. The display design employs complex coding scheme, which allows reconstructing complex wave from a binary hologram. In order to improve the quality of reconstructed holograms time multiplexing method is used. During the optical reconstructions we analyze quality of reconstructed holograms with incoherent RGB light sources as a function of reconstruction distance, present the possibility of 3D hologram reconstruction, and investigate temporal coherence effects in holographic display with the DMD.
U.S. Department of Health & Human Services — Welcome to hospitalinspections.org, a website run by the Association of Health Care Journalists (AHCJ) that aims to make federal hospital inspection reports easier...
Holographic reflector for reflective LCDs
Sato, Atsushi; Murillo-Mora, Luis M.; Iwata, Fujio
1997-05-01
We describe a new holographic optical element to improve the image's quality of a reflective liquid crystal displays (LCDs). This new holographic reflector consists basically of 2 layers: a volume type transmission hologram layer and a metallic reflection layer. Compared with conventional reflectors for reflective LCDs, a high optical efficiency can be obtained because the hologram is able to concentrate the reflected light to the observer's eyes. Also, it avoids the problems of glare in the LCDs by deviating the reflected incident light (used for display) away from the direction of the direct reflection light. The transmission hologram's low wavelength selectivity permits us to obtain a near white color reflector for reflective LCDs which for multiple applications is the preferable color for the background.
Holographic Chern-Simons defects
Energy Technology Data Exchange (ETDEWEB)
Fujita, Mitsutoshi [Department of Physics and Astronomy, University of Kentucky,Lexington, KY 40506 (United States); Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan); Melby-Thompson, Charles M. [Department of Physics, Fudan University,220 Handan Road, 200433 Shanghai (China); Kavli Institute for the Physics and Mathematics of the Universe (WPI),The University of Tokyo Institutes for Advanced Study (UTIAS),The University of Tokyo, Kashiwanoha, Kashiwa, 277-8583 (Japan); Meyer, René [Department of Physics and Astronomy, Stony Brook University,Stony Brook, New York 11794-3800 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI),The University of Tokyo Institutes for Advanced Study (UTIAS),The University of Tokyo, Kashiwanoha, Kashiwa, 277-8583 (Japan); Sugimoto, Shigeki [Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI),The University of Tokyo Institutes for Advanced Study (UTIAS),The University of Tokyo, Kashiwanoha, Kashiwa, 277-8583 (Japan)
2016-06-28
We study SU(N) Yang-Mills-Chern-Simons theory in the presence of defects that shift the Chern-Simons level from a holographic point of view by embedding the system in string theory. The model is a D3-D7 system in Type IIB string theory, whose gravity dual is given by the AdS soliton background with probe D7 branes attaching to the AdS boundary along the defects. We holographically renormalize the free energy of the defect system with sources, from which we obtain the correlation functions for certain operators naturally associated to these defects. We find interesting phase transitions when the separation of the defects as well as the temperature are varied. We also discuss some implications for the Fractional Quantum Hall Effect and for 2-dimensional QCD.
Holographic renormalization in teleparallel gravity
Energy Technology Data Exchange (ETDEWEB)
Krssak, Martin [Universidade Estadual Paulista, Instituto de Fisica Teorica, Sao Paulo, SP (Brazil)
2017-01-15
We consider the problem of IR divergences of the action in the covariant formulation of teleparallel gravity in asymptotically Minkowski spacetimes. We show that divergences are caused by inertial effects and can be removed by adding an appropriate surface term, leading to the renormalized action. This process can be viewed as a teleparallel analog of holographic renormalization. Moreover, we explore the variational problem in teleparallel gravity and explain how the variation with respect to the spin connection should be performed. (orig.)
Photopolymerizable Nanocomposites for Holographic Applications
Leite, Elsa
2010-01-01
Photopolymerizable nanocomposites with good optical properties consisting of an acrylamide based photopolymer and zeolite nanoparticles (Beta, zeolite A, AlPO-18, silicalite-1 and zeolite L) were fabricated and characterized for holographic applications. The colloidal zeolite solutions used in this project were characterized by several techniques including X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and Raman spectroscopy to ensure their success...
Constructive use of holographic projections
Energy Technology Data Exchange (ETDEWEB)
Schroer, Bert [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Institut fuer Theoretische Physik der FU, Berlin (Germany)
2008-07-01
Revisiting the old problem of existence of interacting models of QFT with new conceptual ideas and mathematical tools, one arrives at a novel view about the nature of QFT. The recent success of algebraic methods in establishing the existence of factorizing models suggests new directions for a more intrinsic constructive approach beyond Lagrangian quantization. Holographic projection simplifies certain properties of the bulk theory and hence is a promising new tool for these new attempts. (author)
Engineering Holographic Superconductor Phase Diagrams
Chen, Jiunn-Wei; Dai, Shou-Huang; Maity, Debaprasad; Zhang, Yun-Long
2016-01-01
We study how to engineer holographic models with features of a high temperature superconductor phase diagram. We introduce a field in the bulk which provides a tunable "doping" parameter in the boundary theory. By designing how this field changes the effective masses of other order parameter fields, desired phase diagrams can be engineered. We give examples of generating phase diagrams with phase boundaries similar to a superconducting dome and an anti-ferromagnetic phase by including two ord...
Holographic analysis of dispersive pupils in space--time optics
Energy Technology Data Exchange (ETDEWEB)
Calatroni, J.; Vienot, J.C.
1981-06-01
Extension of space--time optics to objects whose transparency is a function of the temporal frequency v = c/lambda is examined. Considering the effects of such stationary pupils on white light waves, they are called temporal pupils. It is shown that simultaneous encoding both in the space and time frequency domains is required to record pupil parameters. The space-time impulse response and transfer functions are calculated for a dispersive nonabsorbent material. An experimental method providing holographic recording of the dispersion curve of any transparent material is presented.
Holographic cosmology from BIonic solutions
Sepehri, Alireza; Faizal, Mir; Setare, Mohammad Reza; Ali, Ahmed Farag
2017-02-01
In this paper, we will use a BIonic solution for analyzing the holographic cosmology. A BIonic solution is a configuration of a D3-brane and an anti-D3-brane connected by a wormhole, and holographic cosmology is a recent proposal to explain cosmic expansion by using the holographic principle. In our model, a BIonic configuration will be produced by the transition of fundamental black strings. The formation of a BIonic configuration will cause inflation. As the D3-brane moves away from the anti-D3-brane, the wormhole will get annihilated, and the inflation will end with the annihilation of this wormhole. However, it is possible for a D3-brane to collide with an anti-D3-brane. Such a collision will occur if the distance between the D3-brane and the anti-D3-brane reduces, and this will create tachyonic states. We will demonstrate that these tachyonic states will lead to the formation of a new wormhole, and this will cause acceleration of the universe before such a collision.
Medical applications of holographic stereograms
Tsujiuchi, Jumpei
1991-02-01
A method for displaying 3D images of medical objects by using holographic stereogram is described together with basic properties of reconstructed images of cylindrical holographic stereograms. INTRODUCTI ON A holographic stereogram (HS) is a synthesized hologram from an original film which consists of a series of ordinary photographs taken from different directions of an object and is possible to apply to an object whose hologram is very difficult or impossible to take with conventional techniques [U. Such a feature of HS can be used for 3D display of medical images such as X-ray images computer assisted tomogrphy (CT) images nuclear magnetic reasonance images (MRI) or ultrasonic images of a patient. CYLINDRICAL HOLOGRAPHI C STEREOGRAMS The original film of the medical HS is taken by rotating around the body axis of a patient a U-shaped arm equipment one end of which has a pulse X-ray source and the other end a movie camera with an image intensifier [2]. Synthesis of HS is carried out by using a special optical system the hologram is shaped into a cylinder and is reconstructed by illuminating the hologram with a small white light source located on the axis of the cylinder. Such a HS is called multiplex hologram (MH) the most popular HS and the reconstructed image can be observed in the cylinder. The formation of reconstructed image is made in unusual way and fundamental properties
DEFF Research Database (Denmark)
Ibsen, Lars Bo
2008-01-01
Estimates for the amount of potential wave energy in the world range from 1-10 TW. The World Energy Council estimates that a potential 2TW of energy is available from the world’s oceans, which is the equivalent of twice the world’s electricity production. Whilst the recoverable resource is many...... times smaller it remains very high. For example, whilst there is enough potential wave power off the UK to supply the electricity demands several times over, the economically recoverable resource for the UK is estimated at 25% of current demand; a lot less, but a very substantial amount nonetheless....
All-dielectric meta-holograms with holographic images transforming longitudinally
Wang, Qiu
2017-11-22
Metasurfaces are unique subwavelength geometries capable of engineering electromagnetic waves at will, delivering new opportunities for holography. Most previous meta-holograms, so-called phase-only meta-holograms, modulate only the amplitude distribution of a virtual object, and require optimizing techniques to improve the image quality. However, the phase distribution of the reconstructed image is usually overlooked in previous studies, leading to inevitable information loss. Here, we demonstrate all-dielectric meta-holograms that allow tailoring of both the phase and amplitude distributions of virtual objects. Several longitudinal manipulations of the holographic images are theoretically and experimentally demonstrated, including shifting, stretching, and rotating, enabling a large depth of focus. Furthermore, a new meta-hologram with a three-dimensional holographic design method is demonstrated with an even enhanced depth of focus. The proposed meta-holograms offer more freedom in holographic design and open new avenues for designing complex three-dimensional holography.
Holographic Plasmonic Nanotweezers for Dynamic Trapping and Manipulation.
Huft, Preston R; Kolbow, Joshua D; Thweatt, Jonathan T; Lindquist, Nathan C
2017-12-13
We demonstrate dynamic trapping and manipulation of nanoparticles with plasmonic holograms. By tailoring the illumination pattern of an incident light beam with a computer-controlled spatial light modulator, constructive and destructive interference of plasmon waves create a focused hotspot that can be moved across a surface. Specifically, a computer-generated hologram illuminating the perimeter of a silver Bull's Eye nanostructure generates surface plasmons that propagate toward the center. Shifting the phase of the plasmon waves as a function of space gives complete control over the location of the focus. We show that 200 nm diameter nanoparticles trapped in this focus can be moved in arbitrary patterns. This allows, for example, circular motion with linearly polarized light. These results show the versatility of holographically generated surface plasmon waves for advanced trapping and manipulation of nanoparticles.
Tetraquarks in holographic QCD
Gutsche, Thomas; Lyubovitskij, Valery E.; Schmidt, Ivan
2017-08-01
Using a soft-wall AdS/QCD approach we derive the Schrödinger-type equation of motion for the tetraquark wave function, which is dual to the dimension-4 AdS bulk profile. The latter coincides with the number of constituents in the leading Fock state of the tetraquark. The obtained equation of motion is solved analytically, providing predictions for both the tetraquark wave function and its mass. A low mass limit for possible tetraquark states is given by M ≥2 κ =1 GeV , where κ =0.5 GeV is the typical value of the scale parameter in soft-wall AdS/QCD. We confirm results of the COMPASS Collaboration recently reported on the discovery of the a1(1414 ) state, interpreted as a tetraquark state composed of light quarks and having JP C=1++. Our prediction for the mass of this state, Ma1=√{2 } GeV ≃1.414 GeV , is in good agreement with the COMPASS result Ma1=1.41 4-0.013+0.015 GeV . Next we included finite quark mass effects, which are essential for the tetraquark states involving heavy quarks.
Pattern-Recognition Processor Using Holographic Photopolymer
Chao, Tien-Hsin; Cammack, Kevin
2006-01-01
proposed joint-transform optical correlator (JTOC) would be capable of operating as a real-time pattern-recognition processor. The key correlation-filter reading/writing medium of this JTOC would be an updateable holographic photopolymer. The high-resolution, high-speed characteristics of this photopolymer would enable pattern-recognition processing to occur at a speed three orders of magnitude greater than that of state-of-the-art digital pattern-recognition processors. There are many potential applications in biometric personal identification (e.g., using images of fingerprints and faces) and nondestructive industrial inspection. In order to appreciate the advantages of the proposed JTOC, it is necessary to understand the principle of operation of a conventional JTOC. In a conventional JTOC (shown in the upper part of the figure), a collimated laser beam passes through two side-by-side spatial light modulators (SLMs). One SLM displays a real-time input image to be recognized. The other SLM displays a reference image from a digital memory. A Fourier-transform lens is placed at its focal distance from the SLM plane, and a charge-coupled device (CCD) image detector is placed at the back focal plane of the lens for use as a square-law recorder. Processing takes place in two stages. In the first stage, the CCD records the interference pattern between the Fourier transforms of the input and reference images, and the pattern is then digitized and saved in a buffer memory. In the second stage, the reference SLM is turned off and the interference pattern is fed back to the input SLM. The interference pattern thus becomes Fourier-transformed, yielding at the CCD an image representing the joint-transform correlation between the input and reference images. This image contains a sharp correlation peak when the input and reference images are matched. The drawbacks of a conventional JTOC are the following: The CCD has low spatial resolution and is not an ideal square
Digital Holographic Interferometry for Airborne Particle Characterization
2015-03-19
and its extinction cross section, and a computational demonstration that holographic interferometry can resolve aerosol particle size evolution ...hologram and its extinction cross section, and a computational demonstration that holographic interferometry can resolve aerosol particle size... evolution . 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6. AUTHORS 7. PERFORMING
Holographic complexity for time-dependent backgrounds
Energy Technology Data Exchange (ETDEWEB)
Momeni, Davood, E-mail: davoodmomeni78@gmail.com [Eurasian International Center for Theoretical Physics and Department of General Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Faizal, Mir, E-mail: mirfaizalmir@googlemail.com [Irving K. Barber School of Arts and Sciences, University of British Columbia, Okanagan, 3333 University Way, Kelowna, British Columbia V1V 1V7 (Canada); Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta, T1K 3M4 (Canada); Bahamonde, Sebastian, E-mail: sebastian.beltran.14@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Myrzakulov, Ratbay [Eurasian International Center for Theoretical Physics and Department of General Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan)
2016-11-10
In this paper, we will analyze the holographic complexity for time-dependent asymptotically AdS geometries. We will first use a covariant zero mean curvature slicing of the time-dependent bulk geometries, and then use this co-dimension one spacelike slice of the bulk spacetime to define a co-dimension two minimal surface. The time-dependent holographic complexity will be defined using the volume enclosed by this minimal surface. This time-dependent holographic complexity will reduce to the usual holographic complexity for static geometries. We will analyze the time-dependence as a perturbation of the asymptotically AdS geometries. Thus, we will obtain time-dependent asymptotically AdS geometries, and we will calculate the holographic complexity for such time-dependent geometries.
Directory of Open Access Journals (Sweden)
Fabian Friederich
2018-01-01
Full Text Available Radomes protecting sensitive radar, navigational, and communications equipment of, e.g., aircraft, are strongly exposed to the environment and have to withstand harsh weather conditions and potential impacts. Besides their significance to the structural integrity of the radomes, it is often crucial to optimize the composite structures for best possible radio performance. Hence, there exists a significant interest in non-destructive testing techniques, which can be used for defect inspection of radomes in field use as well as for quality inspection during the manufacturing process. Contactless millimeter-wave and terahertz imaging techniques provide millimeter resolution and have the potential to address both application scenarios. We report on our development of a three-dimensional (3D terahertz imaging system for radome inspection during industrial manufacturing processes. The system was designed for operation within a machining center for radome manufacturing. It simultaneously gathers terahertz depth information in adjacent frequency ranges, from 70 to 110 GHz and from 110 to 170 GHz by combining two frequency modulated continuous-wave terahertz sensing units into a single measurement device. Results from spiraliform image acquisition of a radome test sample demonstrate the successful integration of the measurement system.
COMPARISON OF HOLOGRAPHIC AND ITERATIVE METHODS FOR AMPLITUDE OBJECT RECONSTRUCTION
Directory of Open Access Journals (Sweden)
I. A. Shevkunov
2015-01-01
Full Text Available Experimental comparison of four methods for the wavefront reconstruction is presented. We considered two iterative and two holographic methods with different mathematical models and algorithms for recovery. The first two of these methods do not use a reference wave recording scheme that reduces requirements for stability of the installation. A major role in phase information reconstruction by such methods is played by a set of spatial intensity distributions, which are recorded as the recording matrix is being moved along the optical axis. The obtained data are used consistently for wavefront reconstruction using an iterative procedure. In the course of this procedure numerical distribution of the wavefront between the planes is performed. Thus, phase information of the wavefront is stored in every plane and calculated amplitude distributions are replaced for the measured ones in these planes. In the first of the compared methods, a two-dimensional Fresnel transform and iterative calculation in the object plane are used as a mathematical model. In the second approach, an angular spectrum method is used for numerical wavefront propagation, and the iterative calculation is carried out only between closely located planes of data registration. Two digital holography methods, based on the usage of the reference wave in the recording scheme and differing from each other by numerical reconstruction algorithm of digital holograms, are compared with the first two methods. The comparison proved that the iterative method based on 2D Fresnel transform gives results comparable with the result of common holographic method with the Fourier-filtering. It is shown that holographic method for reconstructing of the object complex amplitude in the process of the object amplitude reduction is the best among considered ones.
Glueball-baryon interactions in holographic QCD
Li, Si-Wen
2017-10-01
Studying the Witten-Sakai-Sugimoto model with type IIA string theory, we find the glueball-baryon interaction is predicted in this model. The glueball is identified as the 11D gravitational waves or graviton described by the M5-brane supergravity solution. Employing the relation of M-theory and type IIA string theory, glueball is also 10D gravitational perturbations which are the excited modes by close strings in the bulk of this model. On the other hand, baryon is identified as a D4-brane wrapped on S4 which is named as baryon vertex, so the glueball-baryon interaction is nothing but the close string/baryon vertex interaction in this model. Since the baryon vertex could be equivalently treated as the instanton configurations on the flavor brane, we identify the glueball-baryon interaction as ;graviton-instanton; interaction in order to describe it quantitatively by the quantum mechanical system for the collective modes of baryons. So the effective Hamiltonian can be obtained by considering the gravitational perturbations in the flavor brane action. With this Hamiltonian, the amplitudes and the selection rules of the glueball-baryon interaction can be analytically calculated in the strong coupling limit. We show our calculations explicitly in two characteristic situations which are ;scalar and tensor glueball interacting with baryons;. Although there is a long way to go, our work provides a holographic way to understand the interactions of baryons in hadronic physics and nuclear physics by the underlying string theory.
1977-05-01
toilet known or suspected not to be entitled to duty-free articles), entry is found in a member’s accompanied *R. No more than 50 cigars or 200 ciga...responsibility of the oper. junction with or following, required mortuary ator of the air or ocean terminal having juris- inspections. Examination, to include
Holographic memory module with ultra-high capacity and throughput
Energy Technology Data Exchange (ETDEWEB)
Vladimir A. Markov, Ph.D.
2000-06-04
High capacity, high transfer rate, random access memory systems are needed to archive and distribute the tremendous volume of digital information being generated, for example, the human genome mapping and online libraries. The development of multi-gigabit per second networks underscores the need for next-generation archival memory systems. During Phase I we conducted the theoretical analysis and accomplished experimental tests that validated the key aspects of the ultra-high density holographic data storage module with high transfer rate. We also inspected the secure nature of the encoding method and estimated the performance of full-scale system. Two basic architectures were considered, allowing for reversible compact solid-state configuration with limited capacity, and very large capacity write once read many memory system.
Holographic Protection of Chronology in Universes of the Godel Type
Energy Technology Data Exchange (ETDEWEB)
Boyda, Edward; Ganguli, Surya; Horava, Petr; Varadarajan, Uday
2002-12-07
We analyze the structure of supersymmetric Godel-like cosmological solutions of string theory. Just as the original four-dimensional Godel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on"phenomenological" aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Godel universes. We find that holography can serve as a chronology protection agency: The closed timelike curves are either hidden behind the holographic screen, or broken by it into causal pieces. In fact, holography in Godel universes has many features in common with de Sitter space, suggesting that Godel universes could represent a supersymmetric laboratory for addressing the conceptual puzzles of de Sitter holography. Then we initiate the investigation of"microscopic" aspects of holography of Godel universes in string theory. We show that Godel universes are T-dual to pp-waves, and use this fact to generate new Godel-like solutions of string and M-theory by T-dualizing known supersymmetric pp-wave solutions.
Mok, F.; Zhou, G.; Psaltis, D.
The most successful use of optical memories so far has been as read-only memories (ROM). A main reason for this success has been the availability of inexpensive methods to mass-produce copies of recorded disks. This has made it possible to publish data (audio, video, databases, computer games) and distribute it widely through normal retail channels. In this chapter, we show results of a holographic read-only memory (HROM) of which digital data on a master disk can be copied onto replicate disks efficiently.
A Holographic Twin Higgs Model
Geller, Michael; Telem, Ofri
2014-01-01
We present a UV completion of the twin Higgs idea in the framework of holographic composite Higgs. The SM contribution to the Higgs potential is effectively cut off by the SM-singlet mirror partners at the sigma-model scale f, naturally allowing for m_{KK} beyond the LHC reach. The bulk symmetry is SU(7) X SO(8), broken on the IR brane into SU(7) X SO(7) and on the UV brane into (SU(3) X SU(2) X U(1))^{SM} X (SU(3) X SU(2) X U(1))^{mirror} X Z2. The field content on the UV brane is the SM, ex...
Moving through a multiplex holographic scene
Mrongovius, Martina
2013-02-01
This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.
Fidelity susceptibility as holographic PV-criticality
Energy Technology Data Exchange (ETDEWEB)
Momeni, Davood, E-mail: davoodmomeni78@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Faizal, Mir, E-mail: mirfaizalmir@googlemail.com [Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada); Irving K. Barber School of Arts and Sciences, University of British Columbia – Okanagan, 3333 University Way, Kelowna, British Columbia V1V 1V7 (Canada); Myrzakulov, Kairat, E-mail: kairatmyrzakul@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Myrzakulov, Ratbay, E-mail: rmyrzakulov@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan)
2017-02-10
It is well known that entropy can be used to holographically establish a connection among geometry, thermodynamics and information theory. In this paper, we will use complexity to holographically establish a connection among geometry, thermodynamics and information theory. Thus, we will analyze the relation among holographic complexity, fidelity susceptibility, and thermodynamics in extended phase space. We will demonstrate that fidelity susceptibility (which is the informational complexity dual to a maximum volume in AdS) can be related to the thermodynamical volume (which is conjugate to the cosmological constant in the extended thermodynamic phase space). Thus, this letter establishes a relation among geometry, thermodynamics, and information theory, using complexity.
Analogue holographic correspondence in optical metamaterials
Khveshchenko, D. V.
2015-03-01
We assess the prospects of using metamaterials for simulating various aspects of analogue gravity and holographic correspondence. Albeit requiring a careful engineering of the dielectric media, some hallmark features reminiscent of the hypothetical “generalized holographic conjecture” can be detected by measuring non-local optical field correlations. The possibility of such simulated behavior might also shed light on the true origin of those ostensibly holographic phenomena in the condensed-matter systems with emergent effective metrics which may not, in fact, require any reference to the string-theoretical holography.
Holographic entanglement entropy on generic time slices
Kusuki, Yuya; Takayanagi, Tadashi; Umemoto, Koji
2017-06-01
We study the holographic entanglement entropy and mutual information for Lorentz boosted subsystems. In holographic CFTs at zero and finite temperature, we find that the mutual information gets divergent in a universal way when the end points of two subsystems are light-like separated. In Lifshitz and hyperscaling violating geometries dual to non-relativistic theories, we show that the holographic entanglement entropy is not well-defined for Lorentz boosted subsystems in general. This strongly suggests that in non-relativistic theories, we cannot make a real space factorization of the Hilbert space on a generic time slice except the constant time slice, as opposed to relativistic field theories.
Corrections to holographic entanglement plateau
Chen, Bin; Li, Zhibin; Zhang, Jia-ju
2017-09-01
We investigate the robustness of the Araki-Lieb inequality in a two-dimensional (2D) conformal field theory (CFT) on torus. The inequality requires that Δ S = S( L) - | S( L - ℓ) - S( ℓ)| is nonnegative, where S( L) is the thermal entropy and S( L - ℓ), S( ℓ) are the entanglement entropies. Holographically there is an entanglement plateau in the BTZ black hole background, which means that there exists a critical length such that when ℓ ≤ ℓ c the inequality saturates Δ S =0. In thermal AdS background, the holographic entanglement entropy leads to Δ S = 0 for arbitrary ℓ. We compute the next-to-leading order contributions to Δ S in the large central charge CFT at both high and low temperatures. In both cases we show that Δ S is strictly positive except for ℓ = 0 or ℓ = L. This turns out to be true for any 2D CFT. In calculating the single interval entanglement entropy in a thermal state, we develop new techniques to simplify the computation. At a high temperature, we ignore the finite size correction such that the problem is related to the entanglement entropy of double intervals on a complex plane. As a result, we show that the leading contribution from a primary module takes a universal form. At a low temperature, we show that the leading thermal correction to the entanglement entropy from a primary module does not take a universal form, depending on the details of the theory.
Bit Threads and Holographic Entanglement
Freedman, Michael; Headrick, Matthew
2017-05-01
The Ryu-Takayanagi (RT) formula relates the entanglement entropy of a region in a holographic theory to the area of a corresponding bulk minimal surface. Using the max flow-min cut principle, a theorem from network theory, we rewrite the RT formula in a way that does not make reference to the minimal surface. Instead, we invoke the notion of a "flow", defined as a divergenceless norm-bounded vector field, or equivalently a set of Planck-thickness "bit threads". The entanglement entropy of a boundary region is given by the maximum flux out of it of any flow, or equivalently the maximum number of bit threads that can emanate from it. The threads thus represent entanglement between points on the boundary, and naturally implement the holographic principle. As we explain, this new picture clarifies several conceptual puzzles surrounding the RT formula. We give flow-based proofs of strong subadditivity and related properties; unlike the ones based on minimal surfaces, these proofs correspond in a transparent manner to the properties' information-theoretic meanings. We also briefly discuss certain technical advantages that the flows offer over minimal surfaces. In a mathematical appendix, we review the max flow-min cut theorem on networks and on Riemannian manifolds, and prove in the network case that the set of max flows varies Lipshitz continuously in the network parameters.
Entanglement entropy and complexity for one-dimensional holographic superconductors
Directory of Open Access Journals (Sweden)
Mahdi Kord Zangeneh
2017-08-01
Full Text Available Holographic superconductor is an important arena for holography, as it allows concrete calculations to further understand the dictionary between bulk physics and boundary physics. An important quantity of recent interest is the holographic complexity. Conflicting claims had been made in the literature concerning the behavior of holographic complexity during phase transition. We clarify this issue by performing a numerical study on one-dimensional holographic superconductor. Our investigation shows that holographic complexity does not behave in the same way as holographic entanglement entropy. Nevertheless, the universal terms of both quantities are finite and reflect the phase transition at the same critical temperature.
Holographic injection-locking of a broad-area laser diode via a photorefractive thin film device
van Voorst, P.D.; de Wit, M.R.; Offerhaus, Herman L.; Tay, S.; Thomas, J.; Peyghambarian, N.; Boller, Klaus J.
2007-01-01
We demonstrate locking of a high power broad area laser diode to a single frequency using holographic feedback from a photorefractive polymer thin-film device for the first time. A four-wave mixing setup is used to generate feedback for the broad area diode at the wavelength of the single frequency
G-corrected holographic dark energy model
Malekjani, M
2013-01-01
Here we investigate the holographic dark energy model in the framework of FRW cosmology where the Newtonian gravitational constant,$G$, is varying with cosmic time. Using the complementary astronomical data which support the time dependency of $G$, the evolutionary treatment of EoS parameter and energy density of dark energy model are calculated in the presence of time variation of $G$. It has been shown that in this case, the phantom regime can be achieved at the present time. We also calculate the evolution of $G$- corrected deceleration parameter for holographic dark energy model and show that the dependency of $G$ on the comic time can influence on the transition epoch from decelerated expansion to the accelerated phase. Finally we perform the statefinder analysis for $G$- corrected holographic model and show that this model has a shorter distance from the observational point in $s-r$ plane compare with original holographic dark energy model.
Surface counterterms and regularized holographic complexity
Yang, Run-Qiu; Niu, Chao; Kim, Keun-Young
2017-09-01
The holographic complexity is UV divergent. As a finite complexity, we propose a "regularized complexity" by employing a similar method to the holographic renor-malization. We add codimension-two boundary counterterms which do not contain any boundary stress tensor information. It means that we subtract only non-dynamic back-ground and all the dynamic information of holographic complexity is contained in the regularized part. After showing the general counterterms for both CA and CV conjectures in holographic spacetime dimension 5 and less, we give concrete examples: the BTZ black holes and the four and five dimensional Schwarzschild AdS black holes. We propose how to obtain the counterterms in higher spacetime dimensions and show explicit formulas only for some special cases with enough symmetries. We also compute the complexity of formation by using the regularized complexity.
Holographic equipartition and the maximization of entropy
Krishna, P. B.; Mathew, Titus K.
2017-09-01
The accelerated expansion of the Universe can be interpreted as a tendency to satisfy holographic equipartition. It can be expressed by a simple law, Δ V =Δ t (Nsurf-ɛ Nbulk) , where V is the Hubble volume in Planck units, t is the cosmic time in Planck units, and Nsurf /bulk is the number of degrees of freedom on the horizon/bulk of the Universe. We show that this holographic equipartition law effectively implies the maximization of entropy. In the cosmological context, a system that obeys the holographic equipartition law behaves as an ordinary macroscopic system that proceeds to an equilibrium state of maximum entropy. We consider the standard Λ CDM model of the Universe and show that it is consistent with the holographic equipartition law. Analyzing the entropy evolution, we find that it also proceeds to an equilibrium state of maximum entropy.
Some applications of holographic interferometry in biomechanics
Ebbeni, Jean P. L.
1992-03-01
Holographic interferometry is well adapted for the determination of 2D strain fields in osseous structures. The knowledge of those strain fields is important for the understanding of structure behavior such as arthrosis.
Entropy Bounds, Holographic Principle and Uncertainty Relation
Directory of Open Access Journals (Sweden)
I. V. Volovich
2001-06-01
Full Text Available Abstract: A simple derivation of the bound on entropy is given and the holographic principle is discussed. We estimate the number of quantum states inside space region on the base of uncertainty relation. The result is compared with the Bekenstein formula for entropy bound, which was initially derived from the generalized second law of thermodynamics for black holes. The holographic principle states that the entropy inside a region is bounded by the area of the boundary of that region. This principle can be called the kinematical holographic principle. We argue that it can be derived from the dynamical holographic principle which states that the dynamics of a system in a region should be described by a system which lives on the boundary of the region. This last principle can be valid in general relativity because the ADM hamiltonian reduces to the surface term.
Fischler-Susskind holographic cosmology revisited
Diaz, Pablo; Per, M. A.; Segui, Antonio
2007-01-01
When Fischler and Susskind proposed a holographic prescription based on the Particle Horizon, they found that spatially closed cosmological models do not verify it due to the apparently unavoidable recontraction of the Particle Horizon area. In this article, after a short review of their original work, we expose graphically and analytically that spatially closed cosmological models can avoid this problem if they expand fast enough. It has been also shown that the Holographic Principle is satu...
Strongly interacting matter from holographic QCD model
Directory of Open Access Journals (Sweden)
Chen Yidian
2016-01-01
Full Text Available We introduce the 5-dimension dynamical holographic QCD model, which is constructed in the graviton-dilaton-scalar framework with the dilaton background field Φ and the scalar field X responsible for the gluodynamics and chiral dynamics, respectively. We review our results on the hadron spectra including the glueball and light meson spectra, QCD phase transitions and transport properties in the framework of the dynamical holographic QCD model.
High-speed inline holographic Stokesmeter imaging.
Liu, Xue; Heifetz, Alexander; Tseng, Shih C; Shahriar, M S
2009-07-01
We demonstrate a high-speed inline holographic Stokesmeter that consists of two liquid crystal retarders and a spectrally selective holographic grating. Explicit choices of angles of orientation for the components in the inline architecture are identified to yield higher measurement accuracy than the classical architecture. We show polarimetric images of an artificial scene produced by such a Stokesmeter, demonstrating the ability to identify an object not recognized by intensity-only imaging systems.
Soft wall model for a holographic superconductor
Energy Technology Data Exchange (ETDEWEB)
Afonin, S.S.; Pusenkov, I.V. [Saint Petersburg State University, St.Petersburg (Russian Federation)
2016-06-15
We consider the soft wall holographic approach for description of the high-T{sub c} superconductivity. In comparison with the existing bottom-up holographic superconductors, the proposed approach is more phenomenological and does not describe the superconducting phase transition. On the other hand, technically it is simpler and has more freedom for fitting the conductivity properties of the real high-T{sub c} materials in the superconducting phase. Some examples of emerging models are analyzed. (orig.)
Feasibility of Magnetostrictive Sensor Inspection of Containments
Energy Technology Data Exchange (ETDEWEB)
Kwun, H.
1999-03-01
This report describes the results of a study on the feasibility of using guided waves for long-range global inspection of containment metallic pressure boundaries (i.e., steel containments and liners of reinforced concrete containments) in nuclear power plants. Of particular concern in this study was the potential of the guided-wave approach for remotely inspecting the regions that are inaccessible; for example, regions where the metallic pressure boundary is backed by concrete on one or both sides. The study includes a literature review on long-range guided-wave inspection techniques, a modeling study of the behavior of guided waves in plates with different boundary conditions (e.g., freestanding and backed by concrete on one or both sides), and an experimental investigation of the feasibility of a guided-wave technique called ''magnetostrictive sensor (MsS)'' for (1) generating and detecting guided waves in plates and (2) detecting a defect over a long range. Results of the study showed (1) that it is feasible to achieve long-range global inspection of plates, including regions that are inaccessible, using low-frequency guided waves and (2) that the MsS technique is well suited for this application. Recommendations are made to further test and develop the MsS technique for practical implementation for containment inspection in nuclear power plants.
History Of Holographic Display In Japan
Iwata, Fujio
1987-06-01
The first exhibition of holographic display was held at Seibu Museum of Art in Tokyo in 1975 and played a role of opening of the holographic era in Japan. This exhibition and the next big exhibition of holography held at Isetan department store 3 years later in 1978 were really epoch-making facts on holographic display in Japan. Since these two exhibitions, holographic display in Japan has come to attract attention of a lot of people to the new display media, holography. At that time, mass production technology of holograms had not been fully developed yet, and the hologram was so expensive that they were found only at the big event. Some companies and universities still continued research and development to have holograms get into practical applications of display media. Few years later, people became interested in 3-D displays and sometimes many peoples took an interest in holographic display, mainly mass produced embossed type holograms applied to the field of publications, book and magazine, etc. 3-D display booms occurred in the year of Tsukuba Science Expo'85 in 1985 and embossed type hologram became much popular. History of holographic display of Japan in terms of technical development and practical use on laser reconstruction hologram, rainbow hologram, multiplex hologram and lippmann hologram will be introduced.
Holographic reconstruction by compressive sensing
Leportier, T.; Park, M.-C.
2017-06-01
Techniques based on compressive sensing (CS) have been proposed recently for the optical capture of compressed holographic data. However, even though several remarkable articles have presented mathematical theories and numerical simulations, only a few experimental demonstrations have been reported. In this paper, we investigate the use of different metrics for the estimation of sparsity and show that the Gini index is the most consistent. In addition, we compare the sparsifying bases based on discrete cosine transform, Fourier transform and Fresnelets. We demonstrate that the Fresnelets basis is the best choice for the reconstruction of digital holograms by CS. Finally, we present an experimental set-up for optical acquisition of phase-shifted holograms with an imaging system based on a single-pixel sensor.
Soft Pomeron in Holographic QCD
Ballon-Bayona, Alfonso; Costa, Miguel S; Djurić, Marko
2016-01-01
We study the graviton Regge trajectory in Holographic QCD as a model for high energy scattering processes dominated by soft pomeron exchange. This is done by considering spin J fields from the closed string sector that are dual to glueball states of even spin and parity. In particular, we construct a model that governs the analytic continuation of the spin J field equation to the region of real J < 2, which includes the scattering domain of negative Maldelstam variable t. The model leads to approximately linear Regge trajectories and is compatible with the measured values of 1.08 for the intercept and 0.25 GeV$^{-2}$ for the slope of the soft pomeron. The intercept of the secondary pomeron trajectory is in the same region of the subleading trajectories, made of mesons, proposed by Donnachie and Landshoff, and should therefore be taken into account.
Note on subregion holographic complexity
Roy, Pratim; Sarkar, Tapobrata
2017-07-01
The volume inside a Ryu-Takayanagi surface has been conjectured to be related to the complexity of subregions of the boundary field theory. Here, we study the behavior of this volume analytically, when the entangling surface has a strip geometry. We perform systematic expansions in the low- and high-temperature regimes for AdS-Schwarzschild and RN-AdS black holes. In the latter regime, we point out spurious divergences that might occur due to the limitations of a near horizon expansion. A similar analysis is performed for extremal black holes and, at large charge, we find that there might be some new features of the volume as compared to the area. Finally, we numerically study a four-dimensional RN-AdS black hole in global AdS, the entangling surface being a sphere. We find that the holographic complexity captures essentially the same information as the entanglement entropy, as far as phase transitions are concerned.
Emergent Spacetime and Holographic CFTs
El-Showk, Sheer
2012-01-01
We discuss universal properties of conformal field theories with holographic duals. A central feature of these theories is the existence of a low-lying sector of operators whose correlators factorize. We demonstrate that factorization can only hold in the large central charge limit. Using conformal invariance and factorization we argue that these operators are naturally represented as fields in AdS as this makes the underlying linearity of the system manifest. In this class of CFTs the solution of the conformal bootstrap conditions can be naturally organized in structures which coincide with Witten diagrams in the bulk. The large value of the central charge suggests that the theory must include a large number of new operators not captured by the factorized sector. Consequently we may think of the AdS hologram as an effective representation of a small sector of the CFT, which is embedded inside a much larger Hilbert space corresponding to the black hole microstates.
DEFF Research Database (Denmark)
Nikolova, Ludmila; Todorov, T.; Ivanov, Mario Tonev
1996-01-01
We investigate thin phase polarization holographic gratings recorded with two waves with orthogonal linear polarizations in materials in which illumination with linearly/circularly polarized light gives rise to linear/circular birefringence. The theoretical analysis shows that the presence......-crystalline azobenzene polyester that is a photoanisotropic material of the considered type confirm the unusual polarization properties. It is shown that polarization holography may be used for real-time simultaneous measurement of photoinduced linear and circular birefringence....
Funamizu, Hideki; Sonoda, Kotaro; Goto, Ryoji; Aizu, Yoshihisa
2017-04-01
Digital holography is a useful technique for recording and reconstruction of the complex amplitude of an optical field. In this technique, an interference pattern of two waves is detected by an image sensor, and digital holograms are acquired in computer. The wavefront is reconstructed by a numerical calculation. In this study, we present the real-time threedimensional counting and shape measurement of RBCs using flow cytometry with digital holographic microscopy.
Georges, Marc P; Vandenrijt, Jean-François; Thizy, Cédric; Stockman, Yvan; Queeckers, Patrick; Dubois, Frank; Doyle, Dominic
2013-01-01
Digital holographic interferometry in the long-wave infrared domain has been developed by combining a CO(2) laser and a microbolometer array. The long wavelength allows large deformation measurements, which are of interest in the case of large space reflectors undergoing thermal changes when in orbit. We review holography at such wavelengths and present some specific aspects related to this spectral range on our measurements. For the design of our digital holographic interferometer, we studied the possibility of illuminating specular objects by a reflective diffuser. We discuss the development of the interferometer and the results obtained on a representative space reflector, first in the laboratory and then during vacuum cryogenic test.
Interactions in higher-spin gravity: a holographic perspective
Sleight, Charlotte
2017-09-01
This review is an elaboration of recent results on the holographic re-construction of metric-like interactions in higher-spin gauge theories on anti-de Sitter space (AdS), employing their conjectured duality with free conformal field theories (CFTs). After reviewing the general approach and establishing the necessary intermediate results, we extract explicit expressions for the complete cubic action on AdSd+1 and the quartic self-interaction of the scalar on AdS4 for the type A minimal bosonic higher-spin theory from the three- and four- point correlation functions of single-trace operators in the free scalar O(N) vector model. For this purpose tools were developed to evaluate tree-level three-point Witten diagrams involving totally symmetric fields of arbitrary integer spin and mass, and the conformal partial wave expansions of their tree-level four-point Witten diagrams. We also discuss the implications of the holographic duality on the locality properties of interactions in higher-spin gauge theories.
Dynamical stability of the holographic system with two competing orders
Energy Technology Data Exchange (ETDEWEB)
Du, Yiqiang [School of Physics, University of Chinese Academy of Sciences,Beijing 100049 (China); Lan, Shan-Quan [Department of Physics, Beijing Normal University,Beijing 100875 (China); Tian, Yu [School of Physics, University of Chinese Academy of Sciences,Beijing 100049 (China); State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics, Chinese Academy of Science,Beijing 100190 (China); Zhang, Hongbao [Department of Physics, Beijing Normal University,Beijing 100875 (China); Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium)
2016-01-04
We investigate the dynamical stability of the holographic system with two order parameters, which exhibits competition and coexistence of condensations. In the linear regime, we have developed the gauge dependent formalism to calculate the quasi-normal modes by gauge fixing, which turns out be considerably convenient. Furthermore, by giving different Gaussian wave packets as perturbations at the initial time, we numerically evolve the full nonlinear system until it arrives at the final equilibrium state. Our results show that the dynamical stability is consistent with the thermodynamical stability. Interestingly, the dynamical evolution, as well as the quasi-normal modes, shows that the relaxation time of this model is generically much longer than the simplest holographic system. We also find that the late time behavior can be well captured by the lowest lying quasi-normal modes except for the non-vanishing order towards the single ordered phase. To our knowledge, this exception is the first counter example to the general belief that the late time behavior towards a final stable state can be captured by the lowest lying quasi-normal modes. In particular, a double relation is found for this exception in certain cases.
Glueball–baryon interactions in holographic QCD
Directory of Open Access Journals (Sweden)
Si-Wen Li
2017-10-01
Full Text Available Studying the Witten–Sakai–Sugimoto model with type IIA string theory, we find the glueball–baryon interaction is predicted in this model. The glueball is identified as the 11D gravitational waves or graviton described by the M5-brane supergravity solution. Employing the relation of M-theory and type IIA string theory, glueball is also 10D gravitational perturbations which are the excited modes by close strings in the bulk of this model. On the other hand, baryon is identified as a D4-brane wrapped on S4 which is named as baryon vertex, so the glueball–baryon interaction is nothing but the close string/baryon vertex interaction in this model. Since the baryon vertex could be equivalently treated as the instanton configurations on the flavor brane, we identify the glueball–baryon interaction as “graviton–instanton” interaction in order to describe it quantitatively by the quantum mechanical system for the collective modes of baryons. So the effective Hamiltonian can be obtained by considering the gravitational perturbations in the flavor brane action. With this Hamiltonian, the amplitudes and the selection rules of the glueball–baryon interaction can be analytically calculated in the strong coupling limit. We show our calculations explicitly in two characteristic situations which are “scalar and tensor glueball interacting with baryons”. Although there is a long way to go, our work provides a holographic way to understand the interactions of baryons in hadronic physics and nuclear physics by the underlying string theory.
Rewritable azobenzene polyester for polarization holographic data storage
DEFF Research Database (Denmark)
Kerekes, A; Sajti, Sz.; Loerincz, Emoeke
2000-01-01
Optical storage properties of thin azobenzene side-chain polyester films were examined by polarization holographic measurements. The new amorphous polyester film is the candidate material for the purpose of rewritable holographic memory system. Temporal formation of anisotropic and topographic...
Frozen waves: experimental generation
Vieira, TA; Gesualdi, MRR; Zamboni-Rached, M
2012-01-01
Frozen waves (FWs) are very interesting particular cases of nondiffracting beams whose envelopes are static and whose longitudinal intensity patterns can be chosen a priori. We present here for the first time (that we know of) the experimental generation of FWs. The experimental realization of these FWs was obtained using a holographic setup for the optical reconstruction of computer generated holograms (CGH), based on a 4-f Fourier filtering system and a nematic liquid crystal spatial light ...
Ando, Toshio; Masaki, Kazuyoshi; Shimizu, Takehiro
2010-08-01
The deposition of reflector after writing (DRAW) process has been proposed for the fabrication of reflective-type holographic read-only memories. In the DRAW process, a reflector is deposited on a recording medium after signal writing, resulting in the reduction of noise holograms written by reflected beams from a reflector in the write process. Significant improvements are experimentally confirmed in read and write (R/W) performances in DRAW-processed holographic media. The combination of the DRAW process and an aromatic photopolymer recording material realizes low noise, high signal-to-noise ratio, and low symbol error rate characteristics at large multiplexing numbers up to 1020. In conventional reflective-type holographic media, ghost noise is superimposed on the readout signal, causing deterioration in R/W characteristics. The wave vector analyses clarify the mechanism by which the noise holograms are written and ghost noise is superimposed on the signal beam in the conventional media.
Holographic fluorescence microscopy with incoherent digital holographic adaptive optics.
Jang, Changwon; Kim, Jonghyun; Clark, David C; Lee, Seungjae; Lee, Byoungho; Kim, Myung K
2015-01-01
Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: a wavefront sensor, wavefront corrector, and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, for example, lenslet arrays for sensing or multiactuator deformable mirrors for correcting. We have previously introduced an alternate approach based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile are possible not only with conventional coherent digital holography, but also with a new type of digital holography using incoherent light: selfinterference incoherent digital holography (SIDH). The SIDH generates a complex—i.e., amplitude plus phase—hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. Adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.
Shift-Peristrophic Multiplexing for High Density Holographic Data Storage
Directory of Open Access Journals (Sweden)
Zenta Ushiyama
2014-03-01
Full Text Available Holographic data storage is a promising technology that provides very large data storage capacity, and the multiplexing method plays a significant role in increasing this capacity. Various multiplexing methods have been previously researched. In the present study, we propose a shift-peristrophic multiplexing technique that uses spherical reference waves, and experimentally verify that this method efficiently increases the data capacity. In the proposed method, a series of holograms is recorded with shift multiplexing, in which the recording material is rotated with its axis perpendicular to the material’s surface. By iterating this procedure, multiplicity is shown to improve. This method achieves more than 1 Tbits/inch2 data density recording. Furthermore, a capacity increase of several TB per disk is expected by maximizing the recording medium performance.
Directory of Open Access Journals (Sweden)
N.S. Mazhari
2017-03-01
Full Text Available The holographic complexity and fidelity susceptibility have been defined as new quantities dual to different volumes in AdS. In this paper, we will use these new proposals to calculate both of these quantities for a variety of interesting deformations of AdS. We obtain the holographic complexity and fidelity susceptibility for an AdS black hole, Janus solution, a solution with cylindrical symmetry, an inhomogeneous background and a hyperscaling violating background. It is observed that the holographic complexity depends on the size of the subsystem for all these solutions and the fidelity susceptibility does not have any such dependence.
Energy Technology Data Exchange (ETDEWEB)
Mazhari, N.S., E-mail: najmemazhari86@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Momeni, Davood, E-mail: davoodmomeni78@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Bahamonde, Sebastian, E-mail: sebastian.beltran.14@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Faizal, Mir, E-mail: mirfaizalmir@googlemail.com [Irving K. Barber School of Arts and Sciences, University of British Columbia - Okanagan, 3333 University Way, Kelowna, British Columbia, V1V 1V7 (Canada); Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta, T1K 3M4 (Canada); Myrzakulov, Ratbay, E-mail: rmyrzakulov@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan)
2017-03-10
The holographic complexity and fidelity susceptibility have been defined as new quantities dual to different volumes in AdS. In this paper, we will use these new proposals to calculate both of these quantities for a variety of interesting deformations of AdS. We obtain the holographic complexity and fidelity susceptibility for an AdS black hole, Janus solution, a solution with cylindrical symmetry, an inhomogeneous background and a hyperscaling violating background. It is observed that the holographic complexity depends on the size of the subsystem for all these solutions and the fidelity susceptibility does not have any such dependence.
AdS/QCD duality and the quarkonia holographic information entropy
Braga, Nelson R. F.; da Rocha, Roldão
2018-01-01
Bottomonium and charmonium, representing quarkonia states, are scrutinized under the point of view of the information theory, in the AdS/QCD holographic setup. A logarithmic measure of information, comprised by the configurational entropy, is here employed to quantitatively study quarkonia radially excited S-wave states. The configurational entropy provides data regarding the relative dominance and the abundance of the bottomonium and charmonium states, whose underlying information is more compressed, in the Shannon's theory meaning. The derived configurational entropy, therefore, identifies the lower phenomenological prevalence of higher S-wave resonances and higher masses quarkonia in Nature.
Theta dependence in holographic QCD
Energy Technology Data Exchange (ETDEWEB)
Bartolini, Lorenzo [Dipartimento di Fisica “E. Fermi' , Università di Pisa and INFN, Sezione di Pisa,Largo B. Pontecorvo 3, I-56127 Pisa (Italy); Bigazzi, Francesco [INFN, Sezione di Firenze,Via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Bolognesi, Stefano [Dipartimento di Fisica “E. Fermi' , Università di Pisa and INFN, Sezione di Pisa,Largo B. Pontecorvo 3, I-56127 Pisa (Italy); Cotrone, Aldo L. [INFN, Sezione di Firenze,Via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze,Via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Manenti, Andrea [Institute of Physics, EPFL,Rte de la Sorge, BSP 728, CH-1015 Lausanne (Switzerland)
2017-02-07
We study the effects of the CP-breaking topological θ-term in the large N{sub c} QCD model by Witten, Sakai and Sugimoto with N{sub f} degenerate light flavors. We first compute the ground state energy density, the topological susceptibility and the masses of the lowest lying mesons, finding agreement with expectations from the QCD chiral effective action. Then, focusing on the N{sub f}=2 case, we consider the baryonic sector and determine, to leading order in the small θ regime, the related holographic instantonic soliton solutions. We find that while the baryon spectrum does not receive O(θ) corrections, this is not the case for observables like the electromagnetic form factor of the nucleons. In particular, it exhibits a dipole term, which turns out to be vector-meson dominated. The resulting neutron electric dipole moment, which is exactly the opposite as that of the proton, is of the same order of magnitude of previous estimates in the literature. Finally, we compute the CP-violating pion-nucleon coupling constant ḡ{sub πNN}, finding that it is zero to leading order in the large N{sub c} limit.
Holographic Optics For Vision Systems
Freeman, Michael H.
1989-05-01
The human visual system is often equated to a photographic camera. This is a poor analogy because the differences are far greater than the similarities. The processing of the human visual system is complex and non-linear so that even optical transfer function concepts must be applied with caution. Holographic optics offers some extra degrees of freedom with respect to refractive optics. Unlike refractive optics, diffractive effects are not, in the first order, dependent on material and geometric shape and require no significant volume. On the other hand they may suffer from fractional efficiencies and strong wavelength dependencies. The Pilkington 'Diffrax' lens invented by the author is an example of a product which steers between the disadvantages and maximises the advantages to provide the world's first diffractive bifocal contact lens. Indications for other visual applications are not very propitious although time and development may show this to be incorrect. This paper will review the interaction between the preferences and antipathies of the human visual system and the optical effects of diffractive systems.
Holographic model for charmonium dissociation
Braga, Nelson R. F.; Ferreira, Luiz F.; Vega, Alfredo
2017-11-01
We present a holographic bottom up model for the thermal behavior of c c bar vector mesons in a finite temperature and density plasma. There is a clear physical interpretation for the three input energy parameters of the model. Two of them are related to the mass spectrum of the heavy meson. Namely the quark mass and the string tension of the quark-anti-quark interaction. The third parameter is a large energy scale associated with the non-hadronic meson decay. In such a process the heavy meson is transformed into a much lighter state by electroweak processes. The corresponding transition amplitude is assumed to depend on the energy scale associated with this large mass variation. With this three parameter model one can fit the masses and decay constants of J / Ψ and three radial excitations with an rms error of 20.7%. Using the geometry of a charged black hole, one finds the spectral function for charmonium states inside a plasma at finite temperature and density. The charmonium dissociation in the medium is represented by the decrease in the height of the spectral function peaks.
Holographic correlation functions in Critical Gravity
Anastasiou, Giorgos; Olea, Rodrigo
2017-11-01
We compute the holographic stress tensor and the logarithmic energy-momentum tensor of Einstein-Weyl gravity at the critical point. This computation is carried out performing a holographic expansion in a bulk action supplemented by the Gauss-Bonnet term with a fixed coupling. The renormalization scheme defined by the addition of this topological term has the remarkable feature that all Einstein modes are identically cancelled both from the action and its variation. Thus, what remains comes from a nonvanishing Bach tensor, which accounts for non-Einstein modes associated to logarithmic terms which appear in the expansion of the metric. In particular, we compute the holographic 1-point functions for a generic boundary geometric source.
Holographic butterfly effect at quantum critical points
Ling, Yi; Liu, Peng; Wu, Jian-Pin
2017-10-01
When the Lyapunov exponent λL in a quantum chaotic system saturates the bound λL ≤ 2π k B T , it is proposed that this system has a holographic dual described by a gravity theory. In particular, the butterfly effect as a prominent phenomenon of chaos can ubiquitously exist in a black hole system characterized by a shockwave solution near the horizon. In this paper we propose that the butterfly velocity can be used to diagnose quantum phase transition (QPT) in holographic theories. We provide evidences for this proposal with an anisotropic holographic model exhibiting metal-insulator transitions (MIT), in which the derivatives of the butterfly velocity with respect to system parameters characterizes quantum critical points (QCP) with local extremes in zero temperature limit. We also point out that this proposal can be tested by experiments in the light of recent progress on the measurement of out-of-time-order correlation function (OTOC).
Holographic dark energy in the DGP model
Energy Technology Data Exchange (ETDEWEB)
Cruz, Norman [Universidad de Santiago, Departamento de Fisica, Facultad de Ciencia, Santiago (Chile); Lepe, Samuel [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Facultad de Ciencias, Valparaiso (Chile); Pena, Francisco [Universidad de La Frontera, Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Avda. Francisco Salazar 01145, Casilla 54-D, Temuco (Chile); Avelino, Arturo [Universidad de Guanajuato, Departamento de Fisica, DCI, Codigo Postal 37150, Leon, Guanajuato (Mexico)
2012-09-15
The braneworld model proposed by Dvali, Gabadadze, and Porrati leads to an accelerated universe without cosmological constant or any other form of dark energy. Nevertheless, we have investigated the consequences of this model when an holographic dark energy is included, taking the Hubble scale as IR cutoff. We have found that the holographic dark energy leads to an accelerated flat universe (de Sitter-like expansion) for the two branches: {epsilon}={+-}1, of the DGP model. Nevertheless, in universes with no null curvature the dark energy presents an EoS corresponding to a phantom fluid during the present era and evolving to a de Sitter-like phase for future cosmic time. In the special case in which the holographic parameter c is equal to one we have found a sudden singularity in closed universes. In this case the expansion is decelerating. (orig.)
Holographic bulk viscosity: GPR vs EO
Buchel, Alex; Kiritsis, Elias
2011-01-01
Recently Eling and Oz (EO) proposed a formula for the holographic bulk viscosity, in arXiv:1103.1657, derived from the null horizon focusing equation. This formula seems different from that obtained earlier by Gubser, Pufu and Rocha (GPR) in arXiv:0806.0407 calculated from the IR limit of the two-point function of the trace of the stress tensor. The two were shown to agree only for some simple scaling cases. We point out that the two formulae agree in two non-trivial holographic theories describing RG flows. The first is the strongly coupled N=2* gauge theory plasma. The second is the semi-phenomenological model of Improved Holographic QCD.
Anomalous transport and holographic momentum relaxation
Copetti, Christian; Fernández-Pendás, Jorge; Landsteiner, Karl; Megías, Eugenio
2017-09-01
The chiral magnetic and vortical effects denote the generation of dissipationless currents due to magnetic fields or rotation. They can be studied in holographic models with Chern-Simons couplings dual to anomalies in field theory. We study a holographic model with translation symmetry breaking based on linear massless scalar field backgrounds. We compute the electric DC conductivity and find that it can vanish for certain values of the translation symmetry breaking couplings. Then we compute the chiral magnetic and chiral vortical conductivities. They are completely independent of the holographic disorder couplings and take the usual values in terms of chemical potential and temperature. To arrive at this result we suggest a new definition of energy-momentum tensor in presence of the gravitational Chern-Simons coupling.
Holographic duality in condensed matter physics
Zaanen, Jan; Sun, Ya-Wen; Schalm, Koenraad
2015-01-01
A pioneering treatise presenting how the new mathematical techniques of holographic duality unify seemingly unrelated fields of physics. This innovative development morphs quantum field theory, general relativity and the renormalisation group into a single computational framework and this book is the first to bring together a wide range of research in this rapidly developing field. Set within the context of condensed matter physics and using boxes highlighting the specific techniques required, it examines the holographic description of thermal properties of matter, Fermi liquids and superconductors, and hitherto unknown forms of macroscopically entangled quantum matter in terms of general relativity, stars and black holes. Showing that holographic duality can succeed where classic mathematical approaches fail, this text provides a thorough overview of this major breakthrough at the heart of modern physics. The inclusion of extensive introductory material using non-technical language and online Mathematica not...
Collapse and revival in holographic quenches
da Silva, Emilia; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre
2015-04-01
We study holographic models related to global quantum quenches in finite size systems. The holographic set up describes naturally a CFT, which we consider on a circle and a sphere. The enhanced symmetry of the conformal group on the circle motivates us to compare the evolution in both cases. Depending on the initial conditions, the dual geometry exhibits oscillations that we holographically interpret as revivals of the initial field theory state. On the sphere, this only happens when the energy density created by the quench is small compared to the system size. However on the circle considerably larger energy densities are compatible with revivals. Two different timescales emerge in this latter case. A collapse time, when the system appears to have dephased, and the revival time, when after rephasing the initial state is partially recovered. The ratio of these two times depends upon the initial conditions in a similar way to what is observed in some experimental setups exhibiting collapse and revivals.
Analysis of a collinear holographic storage system: introduction of pixel spread function
Shimura, Tsutomu; Ichimura, Shotaro; Fujimura, Ryushi; Kuroda, Kazuo; Tan, Xiaodi; Horimai, Hideyoshi
2006-05-01
Image formation in a collinear holographic storage system was analyzed. The wavefront from each pixel of a spatial light modulator was regarded as a plane wave in the recording medium, and its wave vector was determined by the position of the pixel. The hologram in the recording medium was treated as the summation of all gratings written by all combinations of two plane waves. The image of a data page was formed by diffraction of the reference waves by all gratings. The results of the simulation showed good agreement with experiment. We introduced the pixel spread function to describe the image formation characteristics. Analysis of the pixel spread function reveals that a radial-line pixel pattern for reference waves gave a sharper image than other reference pixel patterns. It is also shown that a random phase modulation applied to each reference pixel improved the image formation.
Wavelength techniques for digital holographic memories
Lande, David
Holographic storage is a technique to store and retrieve information spread out in a volume, in contrast to current optical devices which store information locally on a surface. It provides for parallel page-by-page recording and readout of data instead of the usual serial, bit-by-bit, technique, and offers much higher diffraction-limited capacity. Success in the development of a competitive holographic storage device then depends on its cost, compactness and reliability. Since the first digital demonstrations, considerable effort by various groups has been spent in the development of high performance, practical holographic systems. This thesis presents several contributions toward this goal, suitable for holographic storage in lithium niobate and other applicable media. An intuitive explanation of volume holography is given, and Fourier analysis is used to derive the diffraction- limited capacity of digital storage in the form of elementary refractive index gratings. The physics of photorefractive materials, which are commonly used in holographic recording, is then presented, along with an established phenomenological model for grating formation. Following an analysis of imaging and multiplexing, a completely automated storage system implementing wavelength-multiplexed holography is described and evaluated, highlighting the feasibility of systems with fewer optical and mechanical components. The volatility of information in photorefractive media is then addressed by a demonstration of optical fixing, a technique based on two-photon recording mechanisms. Such an all-optical technique removes the need for heating elements, high voltages, or other post-processing elements currently used in non-volatile systems. Two-photon recording is also used to modulate, or apodize, the amplitude of volume gratings within the crystal bulk, providing a flexible technique to reduce cross-talk noise between stored pages and optimize the system capacity. Finally, simulations of
Energy Technology Data Exchange (ETDEWEB)
Munikoti, V.K.
2001-03-01
In this work the propagation behaviour of ultrasound in austenitic weld metal has been analyzed by the time-harmonic plane wave approach. Bounded beam and pulse propagation as occurring in ultrasonic testing can be sufficiently dealt with by this approach. More sophisticated approaches principally do not offer any improvements in the results of plane wave modeling except for diffraction and aperture effects and, therefore, the subject matter of this work has been limited to plane wave propagation in the bulk of the medium and at different types of interfaces. Inspite of the fact, that the individual columnar grains of the weld metal have cubic symmetry, the austenitic weld metal as a whole exhibits cylinder-symmetrical texture, as substantiated by metallurgical examination, and therefore has been treated as an anisotropic poly-crystalline medium with transverse isotropic symmetry. (orig.) [German] In der vorliegenden Arbeit wird die Ultraschallausbreitung in akustisch anisotropen, homogenen Werkstoffen mit stengelkristalliner Textur wie austenitischen Plattierungen und Schweissverbindungen, austenitischem Guss oder geschweissten Komponenten aus austenitischem Guss modelliert. Wie die in dieser Arbeit referierten metallurgischen Untersuchungen gezeigt haben, koennen austenitisches Schweissgut und stengelkristallin erstarrter austenitischer Guss makroskopisch als polykristallines Medium mit zylindersymmetrischer Textur behandelt werden, also als Medium mit transversal isotroper Symmetrie, obwohl mikroskopisch die einzelnen Stengelkristallite kubische Symmetrie aufweisen. Die Schallausbreitung wird mit Hilfe des Ansatzes ebener Wellen modelliert. Obwohl bei der Ultraschallpruefung gepulste und begrenzte Schallbuendel verwendet werden, liefert dieser Ansatz die bei der Ultraschallpruefung beobachteten Wellenarten mit Geschwindigkeiten und Polarisationen, Schallbuendelablenkung und Reflexion und Brechnung nach Richtung und Amplitude, so dass ueber das Modell der ebenen
Wang, Kangni; Zheng, Jihong; Liu, Yourong; Gao, Hui; Zhuang, Songlin
2017-06-01
An electrically tunable two-dimensional (2D) holographic polymer-dispersed liquid crystal (H-PDLC) grating with variable period was fabricated by inserting a cylindrical lens in a conventional holographic interference beam. The interference between the plane wave and cylindrical wave resulting in varying intersection angles on the sample, combined with dual exposure along directions perpendicular to each other, generates a 2D H-PDLC grating with varied period. We have identified periods varying from 3.109 to 5.158 μm across a 16 mm width, with supporting theoretical equations for the period. The period exhibits a symmetrical square lattice in a diagonal direction, with an asymmetrical rectangular lattice in off-diagonal locations. With the first exposure at 2 s and the second exposure at 60 s, the phase separation between the prepolymer and liquid crystal was most evident. The diffraction properties and optic-electric characteristics were also studied. The diffraction efficiency of first-order light was observed to be 13.5% without external voltage, and the transmission efficiency of non-diffracted light was 78% with an applied voltage of 100 V. The proposed method provides the capability of generating period variation to the conventional holographic interference path, with potential application in diffractive optics such as tunable multi-wavelength organic lasing from a dye-doped 2D H-PDLC grating.
Holographic mutual information for singular surfaces
Energy Technology Data Exchange (ETDEWEB)
Mozaffar, M. Reza Mohammadi; Mollabashi, Ali [School of Physics, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Omidi, Farzad [School of Astronomy, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)
2015-12-14
We study corner contributions to holographic mutual information for entangling regions composed of a set of disjoint sectors of a single infinite circle in 3-dimensional conformal field theories. In spite of the UV divergence of holographic mutual information, it exhibits a first order phase transition. We show that tripartite information is also divergent for disjoint sectors, which is in contrast with the well-known feature of tripartite information being finite even when entangling regions share boundaries. We also verify the locality of corner effects by studying mutual information between regions separated by a sharp annular region. Possible extensions to higher dimensions and hyperscaling violating geometries is also considered for disjoint sectors.
Holographic corrections to meson scattering amplitudes
Energy Technology Data Exchange (ETDEWEB)
Armoni, Adi; Ireson, Edwin, E-mail: 746616@swansea.ac.uk
2017-06-15
We compute meson scattering amplitudes using the holographic duality between confining gauge theories and string theory, in order to consider holographic corrections to the Veneziano amplitude and associated higher-point functions. The generic nature of such computations is explained, thanks to the well-understood nature of confining string backgrounds, and two different examples of the calculation in given backgrounds are used to illustrate the details. The effect we discover, whilst only qualitative, is re-obtainable in many such examples, in four-point but also higher point amplitudes.
Holographic Photon Production and Anisotropic Flow
Iatrakis, Ioannis; Kiritsis, Elias; Shen, Chun; Yang, Di-Lun
2017-08-01
The thermal-photon emission from strongly coupled gauge theories at finite temperature via the bottom-up models in holographic QCD in the deconfined phase is studied. The models are constructed to approximately reproduce the electric conductivity obtained from lattice simulations for the quark gluon plasma (QGP). The emission rates are then embedded in hydrodynamic simulations combined with prompt photons and hadronic contributions to analyze the spectra and anisotropic flow of direct photons in RHIC and LHC. In general, the holographic models enhance the yield and improve the agreement in spectra, while they reduce the flow in low pT and increase it in high pT.
Liquid crystals for holographic optical data storage
DEFF Research Database (Denmark)
Matharu, Avtar; Jeeva, S.; Ramanujam, P.S.
2007-01-01
A tutorial review is presented to inform and inspire the reader to develop and integrate strong scientific links between liquid crystals and holographic data storage, from a materials scientist's viewpoint. The principle of holographic data storage as a means of providing a solution...... to the information storage demands of the 21st century is detailed. Holography is a small subset of the much larger field of optical data storage and similarly, the diversity of materials used for optical data storage is enormous. The theory of polarisation holography which produces holograms of constant intensity...
A computer test of holographic flavour dynamics
Energy Technology Data Exchange (ETDEWEB)
Filev, Veselin G.; O’Connor, Denjoe [School of Theoretical Physics, Dublin Institute for Advanced Studies,10 Burlington Road, Dublin 4 (Ireland)
2016-05-20
We perform computer simulations of the Berkooz-Douglas (BD) matrix model, holographically dual to the D0/D4-brane intersection. We generate the fundamental condensate versus bare mass curve of the theory both holographically and from simulations of the BD model. Our studies show excellent agreement of the two approaches in the deconfined phase of the theory and significant deviations in the confined phase. We argue the discrepancy in the confined phase is explained by the embedding of the D4-brane which yields stronger α{sup ′} corrections to the condensate in this phase.
Peptide oligomers for holographic data storage
DEFF Research Database (Denmark)
Berg, Rolf Henrik; Hvilsted, Søren; Ramanujam, P.S.
1996-01-01
chromophores-which appear particularly promising for erasable holographic data storage applications. The rationale for our approach is to use the structural properties of peptide-like molecules to impose orientational order on the chromophores, and thereby optimize the optical properties of the resulting...... materials. Here we show that holographic gratings with large first-order diffraction efficiencies (up to 80%) can be written and erased optically in oligomer films only a few micrometres thick. The holograms also exhibit good thermal stability, and are not erased after heating to 180 degrees C for one month...
Holographic Aspects of a Relativistic Nonconformal Theory
Directory of Open Access Journals (Sweden)
Chanyong Park
2013-01-01
Full Text Available We study a general D-dimensional Schwarzschild-type black brane solution of the Einstein-dilaton theory and derive, by using the holographic renormalization, its thermodynamics consistent with the geometric results. Using the membrane paradigm, we calculate the several hydrodynamic transport coefficients and compare them with the results obtained by the Kubo formula, which shows the self-consistency of the gauge/gravity duality in the relativistic nonconformal theory. In order to understand more about the relativistic non-conformal theory, we further investigate the binding energy, drag force, and holographic entanglement entropy of the relativistic non-conformal theory.
Electronic shearography for bridge inspection
Satpathi, Debashis; Maji, Arup K.
1995-04-01
Electronic shearography (ES) is a laser based non-destructive testing method that has the potential to be developed into a commercial bridge monitoring technique. The primary advantage of ES over other similar techniques like electronic speckle pattern interferometry (ESPI) is its decreased sensitivity to in-plane rigid body movement and vibrations. Bridge inspection with ES has proven to be a daunting task so far. The main problem has been the inability of the method to handle the large deflections and vibrations that might be expected in a typical bridge subjected to normal service loads. Earlier research has shown that the extent of in-plane movement that can be tolerated by the system is dependent on the speckle size. The speckle size also affects the fringe quality by imposing resolution requirements on the imaging device. This article shall undertake the study of speckle size as a function of the focal length of the imaging lens, object distance and illumination wavelength using high resolution holographic film and a high magnification optical microscope.
Angular Spacing Control for Segmented Data Pages in Angle-Multiplexed Holographic Memory
Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Kikuchi, Hiroshi; Shimidzu, Naoki; Ando, Toshio; Masaki, Kazuyoshi; Shimizu, Takehiro
2011-09-01
To improve the recording density of angle-multiplexed holographic memory, it is effective to increase the numerical aperture of the lens and to shorten the wavelength of the laser source as well as to increase the multiplexing number. The angular selectivity of a hologram, which determines the multiplexing number, is dependent on the incident angle of not only the reference beam but also the signal beam to the holographic recording medium. The actual signal beam, which is a convergent or divergent beam, is regarded as the sum of plane waves that have different propagation directions, angular selectivities, and optimal angular spacings. In this paper, focusing on the differences in the optimal angular spacing, we proposed a method to control the angular spacing for each segmented data page. We investigated the angular selectivity of a hologram and crosstalk for segmented data pages using numerical simulation. The experimental results showed a practical bit-error rate on the order of 10-3.
Directory of Open Access Journals (Sweden)
Mayu Miki
2014-05-01
Full Text Available We report on theoretical and experimental investigations of optical wave propagations in two-dimensional photonic lattice structures formed in a holographic polymer-dispersed liquid crystal (HPDLC film. In the theoretical analysis we employed the 2×2 matrix formulation and the statistical thermodynamics model to analyze the formation of anisotropic photonic lattice structures by holographic polymerization. The influence of multiple reflections inside an HPDLC film on the formed refractive index distribution was taken into account in the analysis. In the experiment we fabricated two-dimensional photonic lattice structures in an HPDLC film under three-beam interference holographic polymerization and performed optical measurements of spectral transmittances and wavelength dispersion. We also demonstrated the electrical control capability of the fabricated photonic lattice structure and its dependence on incident wave polarization. These measured results were compared with the calculated ones by means of photonic band and beam propagation calculations.
Miki, Mayu; Ohira, Ryuichiro; Tomita, Yasuo
2014-01-01
We report on theoretical and experimental investigations of optical wave propagations in two-dimensional photonic lattice structures formed in a holographic polymer-dispersed liquid crystal (HPDLC) film. In the theoretical analysis we employed the 2 × 2 matrix formulation and the statistical thermodynamics model to analyze the formation of anisotropic photonic lattice structures by holographic polymerization. The influence of multiple reflections inside an HPDLC film on the formed refractive index distribution was taken into account in the analysis. In the experiment we fabricated two-dimensional photonic lattice structures in an HPDLC film under three-beam interference holographic polymerization and performed optical measurements of spectral transmittances and wavelength dispersion. We also demonstrated the electrical control capability of the fabricated photonic lattice structure and its dependence on incident wave polarization. These measured results were compared with the calculated ones by means of photonic band and beam propagation calculations. PMID:28788643
Miki, Mayu; Ohira, Ryuichiro; Tomita, Yasuo
2014-05-07
We report on theoretical and experimental investigations of optical wave propagations in two-dimensional photonic lattice structures formed in a holographic polymer-dispersed liquid crystal (HPDLC) film. In the theoretical analysis we employed the 2×2 matrix formulation and the statistical thermodynamics model to analyze the formation of anisotropic photonic lattice structures by holographic polymerization. The influence of multiple reflections inside an HPDLC film on the formed refractive index distribution was taken into account in the analysis. In the experiment we fabricated two-dimensional photonic lattice structures in an HPDLC film under three-beam interference holographic polymerization and performed optical measurements of spectral transmittances and wavelength dispersion. We also demonstrated the electrical control capability of the fabricated photonic lattice structure and its dependence on incident wave polarization. These measured results were compared with the calculated ones by means of photonic band and beam propagation calculations.
Structure of Vector Mesons in Holographic Model with Linear Confinement
Energy Technology Data Exchange (ETDEWEB)
Anatoly Radyushkin; Hovhannes Grigoryan
2007-11-01
We investigate wave functions and form factors of vector mesons in the holographic dual model of QCD with oscillator-like infrared cutoff. We introduce wave functions conjugate to solutions of the 5D equation of motion and develop a formalism based on these wave functions, which are very similar to those of a quantum-mechanical oscillator. For the lowest bound state (rho-meson), we show that all its elastic form factors can be built from the basic form factor which, in this model, exhibits a perfect vector meson dominance, i.e., is given by the rho-pole contribution alone. We calculate the electric radius of the rho-meson and find the value _C = 0.655 fm, which is larger than in the case of the hard-wall cutoff. We calculate the coupling constant f_rho and find that the experimental value is in the middle between the values given by the oscillator and hard-wall models.
Holographic display for see-through augmented reality using mirror-lens holographic optical element.
Li, Gang; Lee, Dukho; Jeong, Youngmo; Cho, Jaebum; Lee, Byoungho
2016-06-01
A holographic display system for realizing a three-dimensional optical see-through augmented reality (AR) is proposed. A multi-functional holographic optical element (HOE), which simultaneously performs the optical functions of a mirror and a lens, is adopted in the system. In the proposed method, a mirror that is used to guide the light source into a reflection type spatial light modulator (SLM) and a lens that functions as Fourier transforming optics are recorded on a single holographic recording material by utilizing an angular multiplexing technique of volume hologram. The HOE is transparent and performs the optical functions just for Bragg matched condition. Therefore, the real-world scenes that are usually distorted by a Fourier lens or an SLM in the conventional holographic display can be observed without visual disturbance by using the proposed mirror-lens HOE (MLHOE). Furthermore, to achieve an optimized optical recording condition of the MLHOE, the optical characteristics of the holographic material are measured. The proposed holographic AR display system is verified experimentally.
Experimental holographic movie to estimate picture quality for holographic television (III)
Higuchi, Kazuhito; Ishikawa, Jun; Hiyama, Shigeo
1994-05-01
Holographic movies can be seen as a tool to estimate the picture quality of moving holographic images as a step towards holographic television. The authors have previously developed two versions of an experimental holographic movie system, and this paper is a report on an improved version 3 of the system. The new version features a newly-developed recording system which utilizes a pulsed Nd:YAG laser with an injection seeder, and an automatic film driver unit which moves perforated 35 mm holographic film intermittently. The system is mounted on a dolly to which a hydraulic lifter is attached. A twin diamond-shaped hologram format, developed for an earlier version of the system, is adopted for the films. After the films are developed, they are driven intermittently with a shutter, illuminated by the LD pumped CW Nd:YAG laser, and viewed through twin diamond-shaped windows. This version 3 system makes it possible to record live scenes, including those of the human body, flowing liquids, smoke, etc., which was impossible in the version 1 and version 3 systems. As a consequence, the characteristics of holographic 3D images with motion can be studied over an area covered by both eyes, and the labor required of animators in taking holograms is greatly reduced.
A holographic model for black hole complementarity
Energy Technology Data Exchange (ETDEWEB)
Lowe, David A. [Physics Department, Brown University,Providence, RI 02912 (United States); Thorlacius, Larus [University of Iceland, Science Institute,Dunhaga 3, IS-107, Reykjavik (Iceland); The Oskar Klein Centre for Cosmoparticle Physics,Department of Physics, Stockholm University,AlbaNova University Centre, 10691 Stockholm (Sweden)
2016-12-07
We explore a version of black hole complementarity, where an approximate semiclassical effective field theory for interior infalling degrees of freedom emerges holographically from an exact evolution of exterior degrees of freedom. The infalling degrees of freedom have a complementary description in terms of outgoing Hawking radiation and must eventually decohere with respect to the exterior Hamiltonian, leading to a breakdown of the semiclassical description for an infaller. Trace distance is used to quantify the difference between the complementary time evolutions, and to define a decoherence time. We propose a dictionary where the evolution with respect to the bulk effective Hamiltonian corresponds to mean field evolution in the holographic theory. In a particular model for the holographic theory, which exhibits fast scrambling, the decoherence time coincides with the scrambling time. The results support the hypothesis that decoherence of the infalling holographic state and disruptive bulk effects near the curvature singularity are complementary descriptions of the same physics, which is an important step toward resolving the black hole information paradox.
Display applications for holographic optical elements
Gambogi, William J., Jr.; Armstrong, Mark L.; Hamzavy, Babak; Levin, Michael L.; Mackara, Steven R.; Molteni, William J., Jr.; Steijn, Kirk W.; Stevenson, Sylvia H.; Felder, Thomas C.; Heidt, Gerald L.; Miller, Douglas R.
2001-06-01
In the last several years, holographic elements have been introduced into a wide array of display applications. Holographic Reflectors are incorporated with liquid crystal displays to shift optimum viewing angle away form specular glare and raise brightness by concentrating light at a convenient viewing angle. Reflectors can be produced in blue, green, gold, red, or white colors. Denso GlassVision projection screens incorporate transmission holograms to efficiently direct projected light to the viewer in a screen that reverts to clear glass When the projection image is turned off. JVC has introduce da large-screen HDTV that uses a holographic color filter to separate blue, green, and red light from the illumination beam, and direct the sorted colors to the appropriate color pixel, raising brightness with a passive component. Most recently, HOE prototypes have been produced to improve the efficiency of portable liquid crystal color display. Front diffuser are affixed to the face of reflective color LCDs and direct output light from the LCD to the viewer at a convenient viewing angle in a concentrated view cone. Reflective Colors Filters are pixelated diffuse reflectors internal to the LCD structure and aligned to the LCD matrix. These reflective filters provide higher brightness, larger color gamut, and better color saturation including a holographic grating are under development to provide wider view angle in direct-view LCDs.
Holographic applications of logarithmic conformal field theories
Grumiller, D.; Riedler, W.; Rosseel, J.; Zojer, T.
2013-01-01
We review the relations between Jordan cells in various branches of physics, ranging from quantum mechanics to massive gravity theories. Our main focus is on holographic correspondences between critically tuned gravity theories in anti-de Sitter space and logarithmic conformal field theories in
Holographic recording in two-stage networks
McLeod, Robert R.; Peng, Haiyan; Nair, Devatha P.; Kowalski, Benjamin A.; Bowman, Christopher N.
2017-05-01
We demonstrate holography in a traditional two-component holographic photopolymer in which the solid polymer host matrix has three distinct sets of material properties: 1) an initially liquid state appropriate for formulation and casting into the desired final shape, 2) a rubbery state with low glass transition temperature appropriate for holographic recording, and 3) a final higher modulus state with improved mechanical robustness. The general chemical scheme is to form the second stage rubbery polymer network via a thiol-acrylate Michael addition with an excess of one functional group. Holographic recording then takes place via radically initiated photopolymerization of a mobile high refractive index monomer, per the common two-chemistry process. During final flood illumination of the material, the remaining monomer and excess functional groups are polymerized to increase crosslink density and improve the mechanical properties of the matrix. We described three such material schemes and report general trends. We demonstrate high (96%) efficiency holographic recording, low (1.1%) shrinkage, no oxygen sensitivity and stage 2 glass transition temperatures at or above room temperature, sufficient to enable self-supporting films.
Holographic space: presence and absence in time
Chang, Yin-Ren; Richardson, Martin
2017-03-01
In terms of contemporary art, time-based media generally refers to artworks that have duration as a dimension and unfold to the viewer over time, that could be a video, slide, film, computer-based technologies or audio. As part of this category, holography pushes this visual-oriented narrative a step further, which brings a real 3D image to invite and allow audiences revisiting the scene of the past, at the moment of recording in space and time. Audiences could also experience the kinetic holographic aesthetics through constantly moving the viewing point or illumination source, which creates dynamic visual effects. In other words, when the audience and hologram remain still, the holographic image can only be perceived statically. This unique form of expression is not created by virtual simulation; the principal of wavefront reconstruction process made holographic art exceptional from other time-based media. This project integrates 3D printing technology to explore the nature of material aesthetics, transiting between material world and holographic space. In addition, this series of creation also reveals the unique temporal quality of a hologram's presence and absence, an ambiguous relationship existing in this media.
Phases of kinky holographic nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Elliot-Ripley, Matthew; Sutcliffe, Paul; Zamaklar, Marija [Department of Mathematical Sciences, Durham University,South Road, Durham (United Kingdom)
2016-10-17
Holographic QCD at finite baryon number density and zero temperature is studied within the five-dimensional Sakai-Sugimoto model. We introduce a new approximation that models a smeared crystal of solitonic baryons by assuming spatial homogeneity to obtain an effective kink theory in the holographic direction. The kink theory correctly reproduces a first order phase transition to lightly bound nuclear matter. As the density is further increased the kink splits into a pair of half-kink constituents, providing a concrete realization of the previously suggested dyonic salt phase, where the bulk soliton splits into constituents at high density. The kink model also captures the phenomenon of baryonic popcorn, in which a first order phase transition generates an additional soliton layer in the holographic direction. We find that this popcorn transition takes place at a density below the dyonic salt phase, making the latter energetically unfavourable. However, the kink model predicts only one pop, rather than the sequence of pops suggested by previous approximations. In the kink model the two layers produced by the single pop form the surface of a soliton bag that increases in size as the baryon chemical potential is increased. The interior of the bag is filled with abelian electric potential and the instanton charge density is localized on the surface of the bag. The soliton bag may provide a holographic description of a quarkyonic phase.
Holographic Josephson junction from massive gravity
Hu, Ya-Peng; Li, Huai-Fan; Zeng, Hua-Bi; Zhang, H.
2016-01-01
We study the holographic superconductor-normal metal-superconductor (SNS) Josephson junction in de Rham-Gabadadze-Tolley massive gravity. If the boundary theory is independent of spatial directions, i.e., if the chemical potential is homogeneous in spatial directions, we find that the graviton mass
Additive Manufacturing Infrared Inspection
Gaddy, Darrell; Nettles, Mindy
2015-01-01
The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.
Kemper, Björn; Przibilla, Sabine; Rommel, Christina E.; Vollmer, Angelika; Ketelhut, Steffi; Schnekenburger, Jürgen; von Bally, Gert
2011-03-01
Many interferometry-based quantitative phase contrast imaging techniques require the generation of a coherent reference wave, which results in a phase stability decrease and the demand for a precise adjustment of the intensity ratio between object and reference wave. Thus, investigations on a simplified digital holographic microscopy approach that avoids a separate reference wave were performed. Results from live cell investigations demonstrate the capability of the method for quantitative phase contrast imaging. In further experiments the modification of the intracellular refractive index distribution by osmotic stimulation was analyzed. Data from human pancreas tumor cells show that by choice of suitable buffer solutions live cell imaging with enhanced quantitative phase contrast is achieved.
Norland Optical Adhesive 72® as phase holographic material
Directory of Open Access Journals (Sweden)
Mauricio Ortiz-Gutiérrez
2015-12-01
Full Text Available Characterization of the holographic material composed by adhesive polymer Norland Optical Adhesive 72® (NOA 72® was studied. With a wavelength of 457 nm from an Ar laser, real time phase holographic gratings under different parameters such as energy, frequency and thickness were recorded. The diffraction efficiency of the recorded holographic gratings was measured and some experimental results are shown. Furthermore, the material was used to record Fourier holograms.
Applications of holographic interferometry for spacecraft structural components
Rao, M. V.; Samuel, R.; Nair, P. S.
1994-06-01
An overview of the applications of holographic interferometry for spacecraft structural components at ISRO Satellite Center, Bangalore, India, is presented. The details of the development of a dual vacuum stressing technique and its application for holographic nondestructive testing (HNDT) of honeycomb panels are presented. Results of some calibration studies conducted for HNDT of propellant tanks are also presented. It is found that holographic interferometry is quite useful, particularly for HNDT of honeycomb panels and propellant tanks used for spacecraft structural components.
Kinematical and dynamical aspects of higher-spin bound-state equations in holographic QCD
Energy Technology Data Exchange (ETDEWEB)
de Téramond, Guy F.; Dosch, Hans Günter; Brodsky, Stanley J.
2013-04-01
In this paper we derive holographic wave equations for hadrons with arbitrary spin starting from an effective action in a higher-dimensional space asymptotic to anti–de Sitter (AdS) space. Our procedure takes advantage of the local tangent frame, and it applies to all spins, including half-integer spins. An essential element is the mapping of the higher-dimensional equations of motion to the light-front Hamiltonian, thus allowing a clear distinction between the kinematical and dynamical aspects of the holographic approach to hadron physics. Accordingly, the nontrivial geometry of pure AdS space encodes the kinematics, and the additional deformations of AdS space encode the dynamics, including confinement. It thus becomes possible to identify the features of holographic QCD, which are independent of the specific mechanisms of conformal symmetry breaking. In particular, we account for some aspects of the striking similarities and differences observed in the systematics of the meson and baryon spectra.
Polarization holographic high-density optical data storage in bacteriorhodopsin film.
Yao, Baoli; Ren, Zhiwei; Menke, Neimule; Wang, Yingli; Zheng, Yuan; Lei, Ming; Chen, Guofu; Hampp, Norbert
2005-12-01
Optical films containing the genetic variant bacteriorhodopsin BR-D96N were experimentally studied in view of their properties as media for holographic storage. Different polarization recording schemes were tested and compared. The influence of the polarization states of the recording and readout waves on the retrieved diffractive image's intensity and its signal-to-noise ratio were analyzed. The experimental results showed that, compared with the other tested polarization relations during holographic recording, the discrimination between the polarization states of diffracted and scattered light is optimized with orthogonal circular polarization of the recording beams, and thus a high signal-to-noise ratio and a high diffraction efficiency are obtained. Using a He-Ne laser (633 nm, 3 mW) for recording and readout, a spatial light modulator as a data input element, and a 2D-CCD sensor for data capture in a Fourier transform holographic setup, a storage density of 2 x 10(8) bits/cm2 was obtained on a 60 x 42 microm2 area in the BR-D96N film. The readout of encoded binary data was possible with a zero-error rate at the tested storage density.
Holographic vector superconductor in Gauss–Bonnet gravity
Directory of Open Access Journals (Sweden)
Jun-Wang Lu
2016-02-01
Full Text Available In the probe limit, we numerically study the holographic p-wave superconductor phase transitions in the higher curvature theory. Concretely, we study the influences of Gauss–Bonnet parameter α on the Maxwell complex vector model (MCV in the five-dimensional Gauss–Bonnet–AdS black hole and soliton backgrounds, respectively. In the two backgrounds, the improving Gauss–Bonnet parameter α and dimension of the vector operator Δ inhibit the vector condensate. In the black hole, the condensate quickly saturates a stable value at lower temperature. Moreover, both the stable value of condensate and the ratio ωg/Tc increase with α. In the soliton, the location of the second pole of the imaginary part increases with α, which implies that the energy of the quasiparticle excitation increases with the improving higher curvature correction. In addition, the influences of the Gauss–Bonnet correction on the MCV model are similar to the ones on the SU(2 p-wave model, which confirms that the MCV model is a generalization of the SU(2 Yang–Mills model even without the applied magnetic field to some extent.
Digital holographic microscopy for the characterization of microelectromechanical systems
Pagliarulo, V.; Miccio, L.; Ferraro, P.
2016-04-01
Digital holography (DH) in microscopy became an important interferometric tool in optical metrology since when camera sensors reached a higher pixel number with smaller size allowing to acquire more defined images and high-speed computers became able to process such data. Consequently, it was possible the investigation of engineered surfaces on micro-scale, such as micro-electromechanical systems (MEMS) that are micro-devices composed by mechanical elements, electronics, sensors and actuators built in a small volume, realized using different material layers superimposed in various process steps, usually starting from a silicon substrate. In DH is necessary to perform the reconstruction of the wave field by means of numerical tools. This entails a computational burden but offers the possibility of retrieving not only the intensity of the acquired wave field, but also the phase distribution. This work describes the principles of DH and shows some interesting numerical tools suitable to process the holographic images in the field of MEMS. The use of different numerical tools is discussed and illustrated with examples taken from the literature.
Saturation of the Holographic Principle for Spatially Closed Cosmological Models
Diaz, P.; Per, M. A.; Segui, A.
Under the assumption on the fundamental character of the Holographic Principle as a primary principle guiding the behavior of our universe the saturation of the holographic limit is reasonable. On the other hand the Fischler-Susskind holographic prescription seems to be incompatible with closed cosmological models due to the apparently unavoidable recontraction of the particle horizon area. However we will show that the saturation of the Fischler-Susskind holographic prescription over a closed (although almost flat) cosmological model enforces a cosmological evolution very similar to the observed universe.
Holographic display with LED sources illumination and enlarged viewing angle
Chlipała, Maksymilian; Kozacki, Tomasz
2016-09-01
In this work we present holographic display that uses LED sources illumination and have enlarged viewing angle. In this holographic display design we employ phase only SLM because it allows to obtain reconstructions of high quality. Our setup realizes complex coding scheme and allows to reconstruct complex holographic images. Thus reconstruction of inplane holograms is possible. Holograms displayed on SLM are computer generated. For enlargement of angular field of view we use three spatially separated illumination sources and time multiplexing technique. In experimental part, where we display computer generated holograms, we show that it is possible to obtain holographic reconstructions of 3D object with extended viewing angle.
Higher order corrections to holographic black hole chemistry
Sinamuli, Musema; Mann, Robert B.
2017-10-01
We investigate the holographic Smarr relation beyond the large N limit. By making use of the holographic dictionary, we find that the bulk correlates of subleading 1 /N corrections to this relation are related to the couplings in Lovelock gravity theories. We likewise obtain a holographic equation of state and check its validity for a variety of interesting and nontrivial black holes, including rotating planar black holes in Gauss-Bonnet-Born-Infeld gravity, and nonextremal rotating black holes in minimal five-dimensional gauged supergravity. We provide an explanation of the N -dependence of the holographic Smarr relation in terms of contributions due to planar and nonplanar diagrams in the dual theory.
HOMES - Holographic Optical Method for Exoplanet Spectroscopy Project
National Aeronautics and Space Administration — HOMES (Holographic Optical Method for Exoplanet Spectroscopy) is a space telescope designed for exoplanet discovery. Its double dispersion architecture employs a...
Biophotopol: A Sustainable Photopolymer for Holographic Data Storage Applications
Ortuño, Manuel; Gallego, Sergi; Márquez, Andrés; Neipp, Cristian; Pascual, Inmaculada; Beléndez, Augusto
2012-01-01
Photopolymers have proved to be useful for different holographic applications such as holographic data storage or holographic optical elements. However, most photopolymers have certain undesirable features, such as the toxicity of some of their components or their low environmental compatibility. For this reason, the Holography and Optical Processing Group at the University of Alicante developed a new dry photopolymer with low toxicity and high thickness called biophotopol, which is very adequate for holographic data storage applications. In this paper we describe our recent studies on biophotopol and the main characteristics of this material. PMID:28817008
Evaluation of Advanced Non-Destructive Inspection Methods for Aircraft Tires.
1980-02-01
technique which they call " Shearography " which uses a different optics system on the basic holographic tire inspection equipment. The tires are stressed...Prepared for U.S. DEPARTMENT Ole TRANSPORTATION FEDERAL AVIATION ADMINISTRATION Systems Research & Development Service CAWashington, D.C. 20590 -()b NO...and Address Final eo , U.S.Department of Transportation Febg JgW78-Augv@ 79 Federial Aviation Administration __ Systems Research and Development
Vorndran, Shelby D; Chrysler, Benjamin; Wheelwright, Brian; Angel, Roger; Holman, Zachary; Kostuk, Raymond
2016-09-20
This paper describes a high-efficiency, spectrum-splitting photovoltaic module that uses an off-axis volume holographic lens to focus and disperse incident solar illumination to a rectangular shaped high-bandgap indium gallium phosphide cell surrounded by strips of silicon cells. The holographic lens design allows efficient collection of both direct and diffuse illumination to maximize energy yield. We modeled the volume diffraction characteristics using rigorous coupled-wave analysis, and simulated system performance using nonsequential ray tracing and PV cell data from the literature. Under AM 1.5 illumination conditions the simulated module obtained a 30.6% conversion efficiency. This efficiency is a 19.7% relative improvement compared to the more efficient cell in the system (silicon). The module was also simulated under a typical meteorological year of direct and diffuse irradiance in Tucson, Arizona, and Seattle, Washington. Compared to a flat panel silicon module, the holographic spectrum splitting module obtained a relative improvement in energy yield of 17.1% in Tucson and 14.0% in Seattle. An experimental proof-of-concept volume holographic lens was also fabricated in dichromated gelatin to verify the main characteristics of the system. The lens obtained an average first-order diffraction efficiency of 85.4% across the aperture at 532 nm.
Aspects of Inspection Planning
DEFF Research Database (Denmark)
Faber, M. H.; Sørensen, John Dalsgaard
2000-01-01
Inspection planning for systems is considered with special emphasis to the effect of the quality of inspections on the system reliability and the probability of repair. Inspection quality is described and discussed in terms of inspection reliability and inspection coverage where the latter is set...... in relation to the correlation between the failure modes of the considered system. The inspection planning problem is described in general terms taking basis in the Bayesian decision theory. Practical applicable approaches are derived from the more general but also more involving formulations. The theoretical...... framework for updating of the reliability of components and systems on the basis of inspection results is outlined. Systems representative for inspection planning of different engineering systems subjected to typical deterioration processes are presented. Numerical simulation studies are performed...
Holographic interpolation between a and F
Energy Technology Data Exchange (ETDEWEB)
Kawano, Teruhiko [Department of Physics, Faculty of Science, The University of Tokyo,Bunkyo-ku, Tokyo 113-0033 (Japan); Nakaguchi, Yuki [Department of Physics, Faculty of Science, The University of Tokyo,Bunkyo-ku, Tokyo 113-0033 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo,5-1-5 Kashiwa-no-Ha, Kashiwa City, Chiba 277-8568 (Japan); Nishioka, Tatsuma [Department of Physics, Faculty of Science, The University of Tokyo,Bunkyo-ku, Tokyo 113-0033 (Japan)
2014-12-29
An interpolating function F-tilde between the a-anomaly coefficient in even dimensions and the free energy on an odd-dimensional sphere has been proposed recently and is conjectured to monotonically decrease along any renormalization group flow in continuous dimension d. We examine F-tilde in the large-N CFT’s in d dimensions holographically described by the Einstein-Hilbert gravity in the AdS{sub d+1} space. We show that F-tilde is a smooth function of d and correctly interpolates the a coefficients and the free energies. The monotonicity of F-tilde along an RG flow follows from the analytic continuation of the holographic c-theorem to continuous d, which completes the proof of the conjecture.
Holographic Associative Memory Employing Phase Conjugation
Soffer, B. H.; Marom, E.; Owechko, Y.; Dunning, G.
1986-12-01
The principle of information retrieval by association has been suggested as a basis for parallel computing and as the process by which human memory functions.1 Various associative processors have been proposed that use electronic or optical means. Optical schemes,2-7 in particular, those based on holographic principles,8'8' are well suited to associative processing because of their high parallelism and information throughput. Previous workers8 demonstrated that holographically stored images can be recalled by using relatively complicated reference images but did not utilize nonlinear feedback to reduce the large cross talk that results when multiple objects are stored and a partial or distorted input is used for retrieval. These earlier approaches were limited in their ability to reconstruct the output object faithfully from a partial input.
Multiplexed fluorescence spectroscopy with holographic optical tweezers
Cibula, M. A.; Kendrick, M. J.; Gruss, D. S.; Bychkova, V.; Pylypiuk, N.; Koesdjojo, M.; Remcho, V. T.; Ostroverkhova, O.; McIntyre, D. H.
2011-10-01
We present a multiplexed spectroscopy technique using holographic optical tweezers to trap and excite multiple sensor particles. Our goal is to develop a lab-on-a-chip measurement platform for monitoring pH and other ion concentrations with high spatial resolution in a microfluidic device or within biological cells. We have developed a variety of polymeric pH/ion sensitive nanoparticles with fluorescence spectra that change with the pH/ion concentration of the surrounding environment. We optically trap and manipulate multiple nanosensors using holographic optical tweezers. The trapped particles are irradiated with a separate excitation laser and the fluorescence from all the particles is detected simultaneously with an imaging spectrometer. Electronic separation of the parallel, discrete spectra allows for concurrent determination of multiple spectra.
Reheating of the Universe as holographic thermalization
Energy Technology Data Exchange (ETDEWEB)
Kawai, Shinsuke, E-mail: shinsuke.kawai@gmail.com [Department of Physics, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Nakayama, Yu [California Institute of Technology, 452-48, Pasadena, CA 91125 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, Kashiwa, Chiba 277-8583 (Japan)
2016-08-10
Assuming gauge/gravity correspondence we study reheating of the Universe using its holographic dual. Inflaton decay and thermalisation of the decay products correspond to collapse of a spherical shell and formation of a blackhole in the dual anti-de Sitter (AdS) spacetime. The reheating temperature is computed as the Hawking temperature of the developed blackhole probed by a dynamical boundary, and is determined by the inflaton energy density and the AdS radius, with corrections from the dynamics of the shell collapse. For given initial energy density of the inflaton field the holographic model typically gives lower reheating temperature than the instant reheating scenario, while it is shown to be safely within phenomenological bounds.
Spiral holographic imaging through quantum interference
Tang, Jie; Ming, Yang; Hu, Wei; Lu, Yan-qing
2017-07-01
Spiral holographic imaging in the Hong-Ou-Mandel interference scheme is introduced. Using spontaneous parametric down-conversion as a source of photon pairs, we analyze the joint orbital angular momentum spectrum of a reference photon and the photon encoding information of the object. The first-order interference of light beams in standard holographic imaging is replaced by the quantum interference of two-photon probability amplitudes. The difficulty in retrieving the amplitude and phase structure of an unknown photon is thereby avoided as classical interferometric techniques such as optical holography do not apply. Our results show that the full information of the object's transmission function can be recorded in the spiral hologram, which originates directly from the joint orbital angular momentum spectrum. This presents a lateral demonstration of compressive imaging and can potentially be used for remote sensing.
Holographic trace anomaly at finite temperature
Lee, Bum-Hoon; Nam, Siyoung; Park, Chanyong
2017-01-01
Using the holographic renormalization, we investigate the finite temperature and size effect to the energy-momentum tensor of the dual field theory and its renormalization group (RG) flow. Following the anti-de Sitter/conformal field theory correspondence, the dual field theory of the AdS space is well known to be a conformal field theory that has no nontrivial RG flow. Holographically, that theory can be lifted to a finite temperature version by considering a AdS black hole solution. Because the black hole horizon associated with temperature is dimensionful, it breaks the boundary conformal symmetry and leads to a nontrivial RG flow. In this work, we investigate the finite temperature and size correction to a strongly interacting conformal field theory along the Wisonian renormalization group flow.
Transonic flow visualization using holographic interferometry
Bryanston-Cross, Peter J.
1987-05-01
An account is made of some of the applications of holographic interferometry to the visualization of transonic flows. In the case of the compressor shock visualization, the method is used regularly and has moved from being a research department invention to a design test tool. With the implementation of automatic processing and simple digitization systems, holographic vibrational analysis has also moved into routine nondestructive testing. The code verification interferograms were instructive, but the main turbomachinery interest is now in 3 dimensional flows. A major data interpretation effort will be required to compute tomographically the 3 dimensional flow around the leading or the trailing edges of a rotating blade row. The bolt on approach shows the potential application to current unsteady flows of interest. In particular that of the rotor passing and vortex interaction effects is experienced by the new generation of unducted fans. The turbocharger tests presents a new area for the application of holography.
Reheating of the Universe as holographic thermalization
Directory of Open Access Journals (Sweden)
Shinsuke Kawai
2016-08-01
Full Text Available Assuming gauge/gravity correspondence we study reheating of the Universe using its holographic dual. Inflaton decay and thermalisation of the decay products correspond to collapse of a spherical shell and formation of a blackhole in the dual anti-de Sitter (AdS spacetime. The reheating temperature is computed as the Hawking temperature of the developed blackhole probed by a dynamical boundary, and is determined by the inflaton energy density and the AdS radius, with corrections from the dynamics of the shell collapse. For given initial energy density of the inflaton field the holographic model typically gives lower reheating temperature than the instant reheating scenario, while it is shown to be safely within phenomenological bounds.
Ogiwara, Akifumi; Watanabe, Minoru; Moriwaki, Retsu
2013-04-01
Grating devices using photosensitive organic materials play an important role in the development of optical and optoelectronic systems. High diffraction efficiency and polarization dependence achieved in a holographic polymer-dispersed liquid crystal (HPDLC) grating are expected to provide polarization controllable optical devices, such as the holographic memory for optically reconfigurable gate arrays (ORGAs). However, the optical property is affected by the thermal modulation around the transition temperature (T(ni)) that the liquid crystal (LC) changes from nematic to isotropic phases. The temperature dependence of the diffraction efficiency in HPDLC grating is discussed with two types of LC composites comprised of isotropic and LC diacrylate monomers. The holographic memory formed by the LC and LC diacrylate monomer performs precise reconstruction of the context information for ORGAs at high temperatures more than 150°C.
Holographic window for solar power generation
Kasezawa, Toshihiro; Horimai, Hideyoshi; Tabuchi, Hiroshi; Shimura, Tsutomu
2016-12-01
A new photovoltaic generation unit based on the application of holographic technologies called a Holo-Window is proposed in this work. The basic principle and the optical configuration used for the basic experimental unit are described. Suitable fabrication technology for a hologram with the broadband spectrum required to provide the appropriate sunlight capture capability is then discussed. Finally, a laboratory-prototype Holo-Window unit was developed and its performance was evaluated.
Non-relativistic geometry of holographic screens
Moosa, Mudassir
2017-06-01
We propose that the intrinsic geometry of holographic screens should be described by the Newton-Cartan geometry. As a test of this proposal, we show that the evolution equations of the screen can be written in a covariant form in terms of a stress tensor, an energy current, and a momentum one-form. We derive the expressions for the stress tensor, energy density, and momentum one-form using Brown-York action formalism.
Holographic cosmological models on the braneworld
Energy Technology Data Exchange (ETDEWEB)
Lepe, Samuel [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4950, Valparaiso (Chile); Saavedra, Joel [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4950, Valparaiso (Chile)], E-mail: joel.saavedra@ucv.cl; Pena, Francisco [Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Universidad de la Frontera, Avda. Francisco Salazar 01145, Casilla 54-D, Temuco (Chile)
2009-01-26
In this Letter we have studied a closed universe which a holographic energy on the brane whose energy density is described by {rho}(H)=3c{sup 2}H{sup 2} and we obtain an equation for the Hubble parameter. This equation gave us different physical behavior depending if c{sup 2}>1 or c{sup 2}<1 against of the sign of the brane tension.
Shrinkage measurement for holographic recording materials
Fernández, R.; Gallego, S.; Márquez, A.; Francés, J.; Navarro Fuster, V.; Neipp, C.; Ortuño, M.; Beléndez, A.; Pascual, I.
2017-05-01
There is an increasing demand for new holographic recording materials. One of them are photopolymers, which are becoming a classic media in this field. Their versatility is well known and new possibilities are being created by including new components, such as nanoparticles or dispersed liquid crystal molecules in classical formulations, making them interesting for additional applications in which the thin film preparation and the structural modification have a fundamental importance. Prior to obtaining a wide commercialization of displays based on photopolymers, one of the key aspects is to achieve a complete characterization of them. In this sense, one of the main parameters to estimate and control is the shrinkage of these materials. The volume variations change the angular response of the hologram in two aspects, the angular selectivity and the maximum diffraction efficiency. One criteria for the recording material to be used in a holographic data storage application is the shrinkage, maximum of 0.5%. Along this work, we compare two different methods to measure the holographic recording material shrinkage. The first one is measuring the angle of propagation for both diffracted orders +/-1 when slanted gratings are recorded, so that an accurate value of the grating vector can be calculated. The second one is based on interference measurements at zero spatial frequency limit. We calculate the shrinkage for three different photopolymers: a polyvinyl alcohol acrylamide (PVA/AA) based photopolymer, one of the greenest photopolymers whose patent belongs to the Alicante University called Biophotopol and on the last place a holographic-dispersed liquid crystal photopolymer (H-PDLC).
Holographic Investigation of Solid Propellant Particulates.
1981-12-01
used at the Naval Postgraduate School in an attempt to obtain this type of data. They are: 1. High speed cinematography of burning propellant strands in...techniques vice conventional photography. Utilization of the holographic procedure results in a film plate which has recorded on it both the phase and...AGFA-GEVAERT 8E75 HD film plate is mounted on a kinematic plate holder near the focal plane of a pair of plano convex lenses. This device serves to
Geometric Analogue of Holographic Reduced Representation
Aerts, Diederik; Czachor, Marek; De Moor, Bart
2007-01-01
Holographic reduced representations (HRR) are based on superpositions of convolution-bound $n$-tuples, but the $n$-tuples cannot be regarded as vectors since the formalism is basis dependent. This is why HRR cannot be associated with geometric structures. Replacing convolutions by geometric products one arrives at reduced representations analogous to HRR but interpretable in terms of geometry. Variable bindings occurring in both HRR and its geometric analogue mathematically correspond to two ...
Prehistory of holographic art: a personal view
Benyon, Margaret
1998-02-01
The history of art contains works by artists that may be seen as `holographic' in their aesthetic, philosophic and formal implications. This paper briefly explores some of these parallels, chosen for their interest as preholographic images. Examples are taken from works of Eastern and Western visionary art, works by individual artists such as Rembrandt and Marcel Duchamp, and from early 20th century art movements.
Fourier RGB synthetic aperture color holographic capture for wide angle holographic display
Gołoś, Anna; Zaperty, Weronika; Finke, Grzegorz; Makowski, Piotr; Kozacki, Tomasz
2016-09-01
In this work we present a high pixel count color holographic registration system that is designed to provide 3D holographic content of real-world large objects. Captured data is dedicated for holographic displays with a wide-viewing angle. The registration in color is realized by means of sequential recording with the use of three RGB laser light sources. The applied Fourier configuration of capture system gives large viewing angle and an optimal coverage of the detector resolution. Moreover, it enables to filter out zero order and twin image. In this work the captured Fourier holograms are transformed to general Fresnel type that is more suitable for 3D holographic displays. High resolution and large pixel count of holographic data and its spatial continuity is achieved through synthetic aperture concept with camera scanning and subpixel correlation based stitching. This grants an access to many tools of numerical hologram processing e.g. continuous viewing angle adjustment, and control of 3D image position and size. In this paper the properties of 1D synthetic aperture (60000 x 2500 pixels) are investigated. Each of the RGB 1D SA holograms is composed of 71 frames, which after stitching result in approx. 150 Megapixel hologram pixel count and 12° angular field of view. In experimental part high quality numerical reconstructions for each type of the hologram are shown. Moreover, the captured holograms are used for generation of hybrid hologram that is assembled from a set of RGB holograms of different color statues of height below 20 cm. In the final experiment this hybrid hologram as well as RGB hologram of a single object are reconstructed in the color holographic display.
Speckle-based off-axis holographic detection for non-contact photoacoustic tomography
Directory of Open Access Journals (Sweden)
Buj C.
2015-09-01
Full Text Available A very fast innovative holographic off-axis non-contact detection method for Photoacoustic Tomography (PAT is introduced. It overcomes the main problems of most state-of-the-art photoacoustic imaging approaches that are long acquisition times and the requirement of acoustic contact. In order to increase the acquisition speed significantly, the surface displacements of the object, caused by the photoacoustic pressure waves, are measured interferometrically in two dimensions. Phase alterations in the observed speckle field are used to identify changes in the object’s topography. A sampling rate of up to 80 MHz is feasible, which reduces the occurrence of motion artefacts.
Ellabban, M. A.; Mandula, G.; Fally, M.; Rupp, R. A.; Kovács, L.
2001-02-01
We introduce holographic scattering as a technique to determine the activation energy for thermal fixing of refractive index patterns in photorefractive crystals. After recording a parasitic hologram at ambient temperature, we measured the time dependence of the transmitted intensity at the fixing temperature, to determine the time constant. The temperature dependence of the latter allowed us to evaluate the thermal activation energy. For comparison, we performed an equivalent experiment employing the standard two-wave mixing method. The values obtained using the two techniques agree very well.
Rendl, J.; Rohler, R.; Sieger, C.
1983-12-01
To get quantitative information about principal aspects of the near-field propagation of sound in bone conduction, model experiments were performed with transparent silicon rubber as a vibrating material. Using the transparent silicon rubber instead of the bone itself made it possible to measure amplitudes and phases on interior planes of a solid medium of finite extent. To this end several holographic techniques were employed, among them speckle interferometry for analysing in-plane vibrations. A theory was developed which describes the basic features of wave propagation and shows the influence of the viscosity of the material on propagation behaviour. The application of the results on pracitcal audiometry will be discussed.
Holographically formed, acoustically switchable gratings based on polymer-dispersed liquid crystals.
Liu, Yan Jun; Lu, Mengqian; Ding, Xiaoyun; Leong, Eunice S P; Lin, Sz-Chin Steven; Shi, Jinjie; Teng, Jing Hua; Wang, Lin; Bunning, Timothy J; Huang, Tony Jun
2013-08-01
We report holographic polymer-dispersed liquid crystal (H-PDLC) gratings driven by surface acoustic waves (SAWs). Our experiments show that upon applying SAWs, the H-PDLC grating exhibited switchable properties: The diffraction of the H-PDLC grating decreased, whereas the transmission increased. This acoustically switchable behavior is due to the acoustic streaming-induced realignment of liquid crystals as well as absorption-resulted thermal diffusion. Such SAW-driven H-PDLC gratings are potentially useful in many photonic applications, such as optical switches, spatial light modulators, and switchable add/drop filters.
Huang, Wenbin; Liu, Yonggang; Diao, Zhihui; Yang, Chengliang; Yao, Lishuang; Ma, Ji; Xuan, Li
2012-06-20
We have performed a detailed characterization of the optical properties of a holographic polymer dispersed liquid crystal (LC) transmission grating with polymer scaffolding morphology, which was fabricated with conventional high-functionality acrylate monomer under low curing intensity. Temporal evolution of the grating formation was investigated, and the amount of phase-separated LC was determined by birefringence investigation. A grating model combined with anisotropic coupled-wave theory yielded good agreement with experimental data without any fitting parameter. The results in this study demonstrate the non droplet scaffolding morphology grating is characterized by a high degree of phase separation (70%), high anisotropy, low scattering loss (<6%), and high diffraction efficiency (95%).
Zeroth order phase transition in a holographic superconductor with single impurity
Directory of Open Access Journals (Sweden)
Hua Bi Zeng
2015-08-01
Full Text Available We investigate the single normal impurity effect in a superconductor by the holographic method. When the size of impurity is much smaller than the host superconductor, we can reproduce the Anderson theorem, which states that a conventional s-wave superconductor is robust to a normal (non-magnetic impurity with small impurity strength. However, by increasing the size of the impurity in a fixed-size host superconductor, we find a decreasing critical temperature Tc of the host superconductor, which agrees with the results in condensed matter literatures. More importantly, the phase transition at the critical impurity strength (or the critical temperature is of zeroth order.
M theory as a holographic field theory
Hořava, Petr
1999-02-01
We suggest that M theory could be nonperturbatively equivalent to a local quantum field theory. More precisely, we present a ``renormalizable'' gauge theory in eleven dimensions, and show that it exhibits various properties expected of quantum M theory, most notably the holographic principle of 't Hooft and Susskind. The theory also satisfies Mach's principle: A macroscopically large space-time (and the inertia of low-energy excitations) is generated by a large number of ``partons'' in the microscopic theory. We argue that at low energies in large eleven dimensions, the theory should be effectively described by eleven-dimensional supergravity. This effective description breaks down at much lower energies than naively expected, precisely when the system saturates the Bekenstein bound on energy density. We show that the number of partons scales like the area of the surface surrounding the system, and discuss how this holographic reduction of degrees of freedom affects the cosmological constant problem. We propose the holographic field theory as a candidate for a covariant, nonperturbative formulation of quantum M theory.
Drawing Lines with Light in Holographic Space
Chang, Yin-Ren; Richardson, Martin
2013-02-01
This paper explores the dynamic and expressive possibilities of holographic art through a comparison of art history and technical media such as photography, film and holographic technologies. Examples of modern art and creative expression of time and motions are examined using the early 20th century art movement, Cubism, where subjects are portrayed to be seen simultaneously from different angles. Folding space is represented as subject matter as it can depict space from multiple points of time. The paper also investigates the way holographic art has explored time and space. The lenticular lens-based media reveal a more subjective poetic art in the form of the lyrical images and messages as spectators pass through time, or walk along with the piece of work through an interactive process. It is argued that photographic practice is another example of artistic representation in the form of aesthetic medium of time movement and as such shares a common ground with other dynamic expression that require time based interaction.
Holographic Hall conductivities from dyonic backgrounds
Energy Technology Data Exchange (ETDEWEB)
Lindgren, Jonathan [Theoretische Natuurkunde, Vrije Universiteit Brussel and International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium); Physique Théorique et Mathématique, Université Libre de Bruxelles,Campus Plaine C.P. 231, B-1050 Bruxelles (Belgium); Papadimitriou, Ioannis [SISSA and INFN - Sezione di Trieste,Via Bonomea 265, I 34136 Trieste (Italy); Taliotis, Anastasios; Vanhoof, Joris [Theoretische Natuurkunde, Vrije Universiteit Brussel and International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium)
2015-07-20
We develop a general framework for computing the holographic 2-point functions and the corresponding conductivities in asymptotically locally AdS backgrounds with an electric charge density, a constant magentic field, and possibly non-trivial scalar profiles, for a broad class of Einstein-Maxwell-Axion-Dilaton theories, including certain Chern-Simons terms. Holographic renormalization is carried out for any theory in this class and the computation of the renormalized AC conductivities at zero spatial momentum is reduced to solving a single decoupled first order Riccati equation. Moreover, we develop a first order fake supergravity formulalism for dyonic renormalization group flows in four dimensions, allowing us to construct analytically infinite families of such backgrounds by specifying a superpotential at will. These RG flows interpolate between AdS{sub 4} in the UV and a hyperscaling violating Lifshitz geometry in the IR with exponents 1
Holographic Video Disc And Laser Scanning Optics.
Weingartner, I.; Rosenbruch, K. J.
1983-10-01
Holographic optical elements or systems of holographic elements may replace glass optical imaging systems or may be used for the correction of glass optics. The main advantages of such systems are their low weight, small and compact construction, and their simple and inexpensive manufacture. The disadvantages to be overcome are mainly the low light through-put and chromatic aberrations. In the special case of optics for video discs we present an optical imaging system which is capable of giving the required high resolution for illumination with polychromatic radiation of limited bandwidth in the case of semiconductor laser diodes. Optimization programs based on ray tracing yield highly corrected imaging systems by comparably simple holographic means. The use of only two surfaces gives very compact and lightweight systems, the image quality of which is described for monochromatic and polychro-matic irradiance by means of optical transfer functions. The holograms are recorded on photo-resist material with short wavelength laser radiation. Such holograms have almost no scatter light and do not alter their properties with time or under radiation. These holograms generate wavefronts for the correction of aberrations which, in the case of glass optics, could only be achieved by aspherical surfaces.
Holographic coherent states from random tensor networks
Qi, Xiao-Liang; Yang, Zhao; You, Yi-Zhuang
2017-08-01
Random tensor networks provide useful models that incorporate various important features of holographic duality. A tensor network is usually defined for a fixed graph geometry specified by the connection of tensors. In this paper, we generalize the random tensor network approach to allow quantum superposition of different spatial geometries. We setup a framework in which all possible bulk spatial geometries, characterized by weighted adjacient matrices of all possible graphs, are mapped to the boundary Hilbert space and form an overcomplete basis of the boundary. We name such an overcomplete basis as holographic coherent states. A generic boundary state can be expanded in this basis, which describes the state as a superposition of different spatial geometries in the bulk. We discuss how to define distinct classical geometries and small fluctuations around them. We show that small fluctuations around classical geometries define "code subspaces" which are mapped to the boundary Hilbert space isometrically with quantum error correction properties. In addition, we also show that the overlap between different geometries is suppressed exponentially as a function of the geometrical difference between the two geometries. The geometrical difference is measured in an area law fashion, which is a manifestation of the holographic nature of the states considered.
Holographic renormalization as a canonical transformation
Papadimitriou, Ioannis
2010-01-01
The gauge/string dualities have drawn attention to a class of variational problems on a boundary at infinity, which are not well defined unless a certain boundary term is added to the classical action. In the context of supergravity in asymptotically AdS spaces these problems are systematically addressed by the method of holographic renormalization. We argue that this class of a priori ill defined variational problems extends far beyond the realm of holographic dualities. As we show, exactly the same issues arise in gravity in non asymptotically AdS spaces, in point particles with certain unbounded from below potentials, and even fundamental strings in flat or AdS backgrounds. We show that the variational problem in all such cases can be made well defined by the following procedure, which is intrinsic to the system in question and does not rely on the existence of a holographically dual theory: (i) The first step is the construction of the space of the most general asymptotic solutions of the classical equati...
Focus-tunable multi-view holographic 3D display using a 4k LCD panel
Lin, Qiaojuan; Sang, Xinzhu; Chen, Zhidong; Yan, Binbin; Yu, Chongxiu; Wang, Peng; Dou, Wenhua; Xiao, Liquan
2016-10-01
A focus-tunable multi-view holographic three-dimensional (3D) display system with a 10.1 inch 4K liquid crystal device (LCD) panel is presented. In the proposed synthesizing method, computer-generated hologram (CGH) does not require calculations of light diffraction. When multiple rays pass through one point of a 3D image and enter the pupil simultaneously, the eyes can focus on the point according to the depth cue. Benefiting from the holograms, the dense multiple perspective viewpoints of the 3D object are recorded and combined into the CGH in a dense-super-view way, which make two or more rays emitted from the same point in reconstructed light field into the pupil simultaneously. In general, a wavefront is converged to a viewpoint with the amplitude distribution of multi-view images on the hologram plane, and the phase distribution of a spherical wave is converged to the viewpoint. Here, the wavefronts are calculated according to all the multi-view images and then they are summed up to obtain the object wave on the hologram plane. Moreover, the reference light (converging light) is adopted to converge the central diffraction wave from the liquid crystal display (LCD) into a common area in a short view distance. Experimental results shows that the proposed holographic display can regenerate the 3D objects with focus cues: accommodation and retinal blur.
Burner, A. W.; Goad, W. K.
1981-01-01
A technique of phase control during reconstruction of holographic interferograms is demonstrated in which the recorded scene beam with disturbance present is made to interfere with the real-time scene beam after the disturbance is removed. The reference phase is adjusted during reconstruction by manipulating either the scene or reference beams. Comparisons are made between the present technique and the two-reference-beam and two-plate techniques, more commonly used for phase control during reconstruction of holographic interferograms for flow visualization.
Holographically Encoded Volume Phase Masks
2015-07-13
optics ,” Nat. Photonics 4, 188–193 (2010). 26. H. Kogelnik, “Coupled wave theory for thick volume holograms ,” Bell System Tech. J. 45(9), 2909–2944...phase masks Marc SeGall, Ivan Divliansky,* Clémence Jollivet, Axel Schülzgen, and Leonid B. Glebov University of Central Florida, College of Optics and...satisfying the Bragg condition of the hologram . Moreover, this approach enables the capability to encode and multiplex several phase masks into a single
Holographic bounds on the UV cutoff scale in inflationary cosmology
DEFF Research Database (Denmark)
Keski-Vakkuri, Esko; Sloth, Martin Snoager
2003-01-01
We discuss how holographic bounds can be applied to the quantum fluctuations of the inflaton. In general the holographic principle will lead to a bound on the UV cutoff scale of the effective theory of inflation, but it will depend on the coarse-graining prescription involved in calculating the e...
Holographic renormalization of 3D minimal massive gravity
Energy Technology Data Exchange (ETDEWEB)
Alishahiha, Mohsen [School of Physics, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Qaemmaqami, Mohammad M.; Naseh, Ali [School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Shirzad, Ahmad [Department of Physics, Isfahan University of Technology,P.O.Box 84156-83111, Isfahan (Iran, Islamic Republic of); School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)
2016-01-19
We study holographic renormalization of 3D minimal massive gravity using the Chern-Simons-like formulation of the model. We explicitly present Gibbons- Hawking term as well as all counterterms needed to make the action finite in terms of dreibein and spin-connection. This can be used to find correlation functions of stress tensor of holographic dual field theory.
Reusable holographic velocimetry system based on polarization multiplexing in Bacteriorhodopsin
Koek, W.D.; Chan, V.S.S.; Ooms, T.A.; Bhattacharya, N.; Westerweel, J.; Braat, J.J.M.
2005-01-01
We present a novel holographic particle image velocimetry (HPIV) system using a reversible holographic material as the recording medium. In HPIV the three-dimensional flow field throughout a volume is detected by adding small tracer particles to a normally transparent medium. By recording the
A pocket device for high-throughput optofluidic holographic microscopy
Mandracchia, B.; Bianco, V.; Wang, Z.; Paturzo, M.; Bramanti, A.; Pioggia, G.; Ferraro, P.
2017-06-01
Here we introduce a compact holographic microscope embedded onboard a Lab-on-a-Chip (LoC) platform. A wavefront division interferometer is realized by writing a polymer grating onto the channel to extract a reference wave from the object wave impinging the LoC. A portion of the beam reaches the samples flowing along the channel path, carrying their information content to the recording device, while one of the diffraction orders from the grating acts as an off-axis reference wave. Polymeric micro-lenses are delivered forward the chip by Pyro-ElectroHydroDynamic (Pyro-EHD) inkjet printing techniques. Thus, all the required optical components are embedded onboard a pocket device, and fast, non-iterative, reconstruction algorithms can be used. We use our device in combination with a novel high-throughput technique, named Space-Time Digital Holography (STDH). STDH exploits the samples motion inside microfluidic channels to obtain a synthetic hologram, mapped in a hybrid space-time domain, and with intrinsic useful features. Indeed, a single Linear Sensor Array (LSA) is sufficient to build up a synthetic representation of the entire experiment (i.e. the STDH) with unlimited Field of View (FoV) along the scanning direction, independently from the magnification factor. The throughput of the imaging system is dramatically increased as STDH provides unlimited FoV, refocusable imaging of samples inside the liquid volume with no need for hologram stitching. To test our embedded STDH microscopy module, we counted, imaged and tracked in 3D with high-throughput red blood cells moving inside the channel volume under non ideal flow conditions.
Holographic characterization of colloidal particles in turbid media
Cheong, Fook Chiong; Kasimbeg, Priya; Ruffner, David B.; Hlaing, Ei Hnin; Blusewicz, Jaroslaw M.; Philips, Laura A.; Grier, David G.
2017-10-01
Holographic particle characterization uses in-line holographic microscopy and the Lorenz-Mie theory of light scattering to measure the diameter and the refractive index of individual colloidal particles in their native dispersions. This wealth of information has proved invaluable in fields as diverse as soft-matter physics, biopharmaceuticals, wastewater management, and food science but so far has been available only for dispersions in transparent media. Here, we demonstrate that holographic characterization can yield precise and accurate results even when the particles of interest are dispersed in turbid media. By elucidating how multiple light scattering contributes to image formation in holographic microscopy, we establish the range conditions under which holographic characterization can reliably probe turbid samples. We validate the technique with measurements on model colloidal spheres dispersed in commercial nanoparticle slurries.
Inspecting Rotating Structures by Lamb Waves
Veira Canle, Daniel
2016-01-01
Vain tiivistelmä. Opinnäytteiden arkistokappaleet ovat luettavissa Helsingin yliopiston kirjastossa. Hae HELKA-tietokannasta (http://www.helsinki.fi/helka/index.htm). Abstract only. The paper copy of the whole thesis is available for reading room use at the Helsinki University Library. Search HELKA online catalog (http://www.helsinki.fi/helka/index.htm). Endast avhandlingens sammandrag. Pappersexemplaret av hela avhandlingen finns för läsesalsbruk i Helsingfors universitets bibliotek. S...
Package inspection using inverse diffraction
McAulay, Alastair D.
2008-08-01
More efficient cost-effective hand-held methods of inspecting packages without opening them are in demand for security. Recent new work in TeraHertz sources,1 millimeter waves, presents new possibilities. Millimeter waves pass through cardboard and styrofoam, common packing materials, and also pass through most materials except those with high conductivity like metals which block light and are easily spotted. Estimating refractive index along the path of the beam through the package from observations of the beam passing out of the package provides the necessary information to inspect the package and is a nonlinear problem. So we use a generalized linear inverse technique that we first developed for finding oil by reflection in geophysics.2 The computation assumes parallel slices in the packet of homogeneous material for which the refractive index is estimated. A beam is propagated through this model in a forward computation. The output is compared with the actual observations for the package and an update computed for the refractive indices. The loop is repeated until convergence. The approach can be modified for a reflection system or to include estimation of absorption.
Model-based magnetization retrieval from holographic phase images
Energy Technology Data Exchange (ETDEWEB)
Röder, Falk, E-mail: f.roeder@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, Bautzner Landstr. 400, D-01328 Dresden (Germany); Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Vogel, Karin [Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Wolf, Daniel [Helmholtz-Zentrum Dresden-Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, Bautzner Landstr. 400, D-01328 Dresden (Germany); Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Hellwig, Olav [Helmholtz-Zentrum Dresden-Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, Bautzner Landstr. 400, D-01328 Dresden (Germany); AG Magnetische Funktionsmaterialien, Institut für Physik, Technische Universität Chemnitz, D-09126 Chemnitz (Germany); HGST, A Western Digital Company, 3403 Yerba Buena Rd., San Jose, CA 95135 (United States); Wee, Sung Hun [HGST, A Western Digital Company, 3403 Yerba Buena Rd., San Jose, CA 95135 (United States); Wicht, Sebastian; Rellinghaus, Bernd [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany)
2017-05-15
The phase shift of the electron wave is a useful measure for the projected magnetic flux density of magnetic objects at the nanometer scale. More important for materials science, however, is the knowledge about the magnetization in a magnetic nano-structure. As demonstrated here, a dominating presence of stray fields prohibits a direct interpretation of the phase in terms of magnetization modulus and direction. We therefore present a model-based approach for retrieving the magnetization by considering the projected shape of the nano-structure and assuming a homogeneous magnetization therein. We apply this method to FePt nano-islands epitaxially grown on a SrTiO{sub 3} substrate, which indicates an inclination of their magnetization direction relative to the structural easy magnetic [001] axis. By means of this real-world example, we discuss prospects and limits of this approach. - Highlights: • Retrieval of the magnetization from holographic phase images. • Magnetostatic model constructed for a magnetic nano-structure. • Decomposition into homogeneously magnetized components. • Discretization of a each component by elementary cuboids. • Analytic solution for the phase of a magnetized cuboid considered. • Fitting a set of magnetization vectors to experimental phase images.
Wideband Fractal Antennas for Holographic Imaging and Rectenna Applications
Energy Technology Data Exchange (ETDEWEB)
Bunch, Kyle J.; McMakin, Douglas L.; Sheen, David M.
2008-04-18
At Pacific Northwest National Laboratory, wideband antenna arrays have been successfully used to reconstruct three-dimensional images at microwave and millimeter-wave frequencies. Applications of this technology have included portal monitoring, through-wall imaging, and weapons detection. Fractal antennas have been shown to have wideband characteristics due to their self-similar nature (that is, their geometry is replicated at different scales). They further have advantages in providing good characteristics in a compact configuration. We discuss the application of fractal antennas for holographic imaging. Simulation results will be presented. Rectennas are a specific class of antennas in which a received signal drives a nonlinear junction and is retransmitted at either a harmonic frequency or a demodulated frequency. Applications include tagging and tracking objects with a uniquely-responding antenna. It is of interest to consider fractal rectenna because the self-similarity of fractal antennas tends to make them have similar resonance behavior at multiples of the primary resonance. Thus, fractal antennas can be suited for applications in which a signal is reradiated at a harmonic frequency. Simulations will be discussed with this application in mind.
Rewritable three-dimensional holographic data storage via optical forces
Energy Technology Data Exchange (ETDEWEB)
Yetisen, Ali K., E-mail: ayetisen@mgh.harvard.edu [Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, Massachusetts 02139 (United States); Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Montelongo, Yunuen [Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Butt, Haider [Nanotechnology Laboratory, School of Engineering Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom)
2016-08-08
The development of nanostructures that can be reversibly arranged and assembled into 3D patterns may enable optical tunability. However, current dynamic recording materials such as photorefractive polymers cannot be used to store information permanently while also retaining configurability. Here, we describe the synthesis and optimization of a silver nanoparticle doped poly(2-hydroxyethyl methacrylate-co-methacrylic acid) recording medium for reversibly recording 3D holograms. We theoretically and experimentally demonstrate organizing nanoparticles into 3D assemblies in the recording medium using optical forces produced by the gradients of standing waves. The nanoparticles in the recording medium are organized by multiple nanosecond laser pulses to produce reconfigurable slanted multilayer structures. We demonstrate the capability of producing rewritable optical elements such as multilayer Bragg diffraction gratings, 1D photonic crystals, and 3D multiplexed optical gratings. We also show that 3D virtual holograms can be reversibly recorded. This recording strategy may have applications in reconfigurable optical elements, data storage devices, and dynamic holographic displays.
Field lens multiplexing in holographic 3D displays by using Bragg diffraction based volume gratings
Fütterer, G.
2016-11-01
Applications, which can profit from holographic 3D displays, are the visualization of 3D data, computer-integrated manufacturing, 3D teleconferencing and mobile infotainment. However, one problem of holographic 3D displays, which are e.g. based on space bandwidth limited reconstruction of wave segments, is to realize a small form factor. Another problem is to provide a reasonable large volume for the user placement, which means to provide an acceptable freedom of movement. Both problems should be solved without decreasing the image quality of virtual and real object points, which are generated within the 3D display volume. A diffractive optical design using thick hologram gratings, which can be referred to as Bragg diffraction based volume gratings, can provide a small form factor and high definition natural viewing experience of 3D objects. A large collimated wave can be provided by an anamorphic backlight unit. The complex valued spatial light modulator add local curvatures to the wave field he is illuminated with. The modulated wave field is focused onto to the user plane by using a volume grating based field lens. Active type liquid crystal gratings provide 1D fine tracking of approximately +/- 8° deg. Diffractive multiplex has to be implemented for each color and for a set of focus functions providing coarse tracking. Boundary conditions of the diffractive multiplexing are explained. This is done in regards to the display layout and by using the coupled wave theory (CWT). Aspects of diffractive cross talk and its suppression will be discussed including longitudinal apodized volume gratings.
Pohl, L.; Kaiser, M.; Ketelhut, S.; Pereira, S.; Goycoolea, F.; Kemper, Björn
2016-03-01
Digital holographic microscopy (DHM) enables high resolution non-destructive inspection of technical surfaces and minimally-invasive label-free live cell imaging. However, the analysis of confluent cell layers represents a challenge as quantitative DHM phase images in this case do not provide sufficient information for image segmentation, determination of the cellular dry mass or calculation of the cell thickness. We present novel strategies for the analysis of confluent cell layers with quantitative DHM phase contrast utilizing a histogram based-evaluation procedure. The applicability of our approach is illustrated by quantification of drug induced cell morphology changes and it is shown that the method is capable to quantify reliable global morphology changes of confluent cell layers.
Kumar, Varun; Shakher, Chandra
2015-02-20
This paper presents the results of experimental investigations about the heat dissipation process of plate fin heat sink using digital holographic interferometry. Visual inspection of reconstructed phase difference maps of the air field around the heat sink with and without electric power in the load resistor provides qualitative information about the variation of temperature and the heat dissipation process. Quantitative information about the temperature distribution is obtained from the relationship between the digitally reconstructed phase difference map of ambient air and heated air. Experimental results are presented for different current and voltage in the load resistor to investigate the heat dissipation process. The effect of fin spacing on the heat dissipation performance of the heat sink is also investigated in the case of natural heat convection. From experimental data, heat transfer parameters, such as local heat flux and convective heat transfer coefficients, are also calculated.
A simple holographic scenario for gapped quenches
Energy Technology Data Exchange (ETDEWEB)
Lopez, Esperanza; Bosch, Guillermo Milans del [Instituto de Física Teórica IFT UAM/CSIC, Universidad Autónoma de Madrid,28049 Cantoblanco, Madrid (Spain)
2017-02-24
We construct gravitational backgrounds dual to a family of field theories parameterized by a relevant coupling. They combine a non-trivial scalar field profile with a naked singularity. The naked singularity is necessary to preserve Lorentz invariance along the boundary directions. The singularity is however excised by introducing an infrared cutoff in the geometry. The holographic dictionary associated to the infrared boundary is developed. We implement quenches between two different values of the coupling. This requires considering time dependent boundary conditions for the scalar field both at the AdS boundary and the infrared wall.
Persistent superconductor currents in holographic lattices.
Iizuka, Norihiro; Ishibashi, Akihiro; Maeda, Kengo
2014-07-04
We consider a persistent superconductor current along the direction with no translational symmetry in a holographic gravity model. Incorporating a lattice structure into the model, we numerically construct novel solutions of hairy charged stationary black branes with momentum or rotation along the latticed direction. The lattice structure prevents the horizon from rotating, and the total momentum is only carried by matter fields outside the black brane horizon. This is consistent with the black hole rigidity theorem, and it suggests that in dual field theory with lattices, superconductor currents are made up of "composite" fields, rather than "fractionalized" degrees of freedom. We also show that our solutions are consistent with the superfluid hydrodynamics.
Holographic Lattices Give the Graviton a Mass
Blake, Mike; Vegh, David
2014-01-01
We discuss the DC conductivity of holographic theories with translational invariance broken by a background lattice. We show that the presence of the lattice induces an effective mass for the graviton via a gravitational version of the Higgs mechanism. This allows us to obtain, at leading order in the lattice strength, an analytic expression for the DC conductivity in terms of the size of the lattice at the horizon. In locally critical theories this leads to a power law resistivity that is in agreement with an earlier field theory analysis of Hartnoll and Hofman.
Holographic Investigation of Solid Propellant Combustion
1988-12-01
IITLE (B=m* £Se-T) CaruatwICi, HOLOGRAPHIC INIL’ESTIGWI’ION OF SOLZ ’PROPELLANT COMBUSTION 12 PERSONAL AUTHOR(S) -Butler, Albert G. 13a TYPE OF REPORT...Speckle 19 ABSTRACT (Ccin1,rn WI ree~rse if IlCCenr~y anld ,dentify by blod number) An Investigcation into the behavior of aissmnied solid propellant...required to obtain a good quality hologram. Nuetral density filters, :3 placed in the scene beam for collimated type transmission holograms or in the
Holographic Quark Matter and Neutron Stars.
Hoyos, Carlos; Jokela, Niko; Rodríguez Fernández, David; Vuorinen, Aleksi
2016-07-15
We use a top-down holographic model for strongly interacting quark matter to study the properties of neutron stars. When the corresponding equation of state (EOS) is matched with state-of-the-art results for dense nuclear matter, we consistently observe a first-order phase transition at densities between 2 and 7 times the nuclear saturation density. Solving the Tolman-Oppenheimer-Volkov equations with the resulting hybrid EOSs, we find maximal stellar masses in excess of two solar masses, albeit somewhat smaller than those obtained with simple extrapolations of the nuclear matter EOSs. Our calculation predicts that no quark matter exists inside neutron stars.
Heavy quarkonium in a holographic basis
Directory of Open Access Journals (Sweden)
Yang Li
2016-07-01
Full Text Available We study the heavy quarkonium within the basis light-front quantization approach. We implement the one-gluon exchange interaction and a confining potential inspired by light-front holography. We adopt the holographic light-front wavefunction (LFWF as our basis function and solve the non-perturbative dynamics by diagonalizing the Hamiltonian matrix. We obtain the mass spectrum for charmonium and bottomonium. With the obtained LFWFs, we also compute the decay constants and the charge form factors for selected eigenstates. The results are compared with the experimental measurements and with other established methods.
The Volume Holographic Optical Storage Potential in Azobenzene Containing Polymers
DEFF Research Database (Denmark)
Hvilsted, Søren; Sanchez, Carlos; Alcalá, Rafael
2009-01-01
to be suitable for holographic storage applications. However, they still present several problems, mainly those related with light sensitivity, response time and stability of the stored information. In this article we review the work performed on volume holographic storage using azobenzene containing polymers......Volume holographic data storage is one of the most promising techniques to improve both the storage capacity of devices and the transfer data rate. Among the materials proposed as storage data media, azobenzene containing polymers have received much attention. Some of their properties seem...
Volume holographic storage in photorefractives: material peculiarities and memory performances
Tao, Shiquan
1998-08-01
In this paper we review the currently achievable performances of holographic memories stored in photorefractive crystals. We discuss the dependence of the memory performances on the material peculiarities in three major aspects: storage capacity, data transfer rate,and image fidelity. In the recent years the research at Beijing Polytechnic University on the photorefractive holographic storage has been focused to the optimization of the storage capacity and diffraction efficiency, as well as the influence of noises on the fidelity of reconstructed images. Our research shows again that the realization of volume holographic storage technology requests materials with perfect properties.
Inflation via logarithmic entropy-corrected holographic dark energy model
Energy Technology Data Exchange (ETDEWEB)
Darabi, F.; Felegary, F. [Azarbaijan Shahid Madani University, Department of Physics, Tabriz (Iran, Islamic Republic of); Setare, M.R. [University of Kurdistan, Department of Science, Bijar (Iran, Islamic Republic of)
2016-12-15
We study the inflation in terms of the logarithmic entropy-corrected holographic dark energy (LECHDE) model with future event horizon, particle horizon, and Hubble horizon cut-offs, and we compare the results with those obtained in the study of inflation by the holographic dark energy HDE model. In comparison, the spectrum of primordial scalar power spectrum in the LECHDE model becomes redder than the spectrum in the HDE model. Moreover, the consistency with the observational data in the LECHDE model of inflation constrains the reheating temperature and Hubble parameter by one parameter of holographic dark energy and two new parameters of logarithmic corrections. (orig.)
Lifshitz holographic superconductor in Hořava–Lifshitz gravity
Energy Technology Data Exchange (ETDEWEB)
Luo, Cheng-Jian, E-mail: rocengeng@hotmail.com [Department of Physics, Nanchang University, Nanchang, 330031 (China); Center for Relativistic Astrophysics and High Energy Physics, Nanchang University, Nanchang 330031 (China); Kuang, Xiao-Mei, E-mail: xmeikuang@gmail.com [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile); Shu, Fu-Wen, E-mail: shufuwen@ncu.edu.cn [Department of Physics, Nanchang University, Nanchang, 330031 (China); Center for Relativistic Astrophysics and High Energy Physics, Nanchang University, Nanchang 330031 (China)
2016-08-10
We study the holographic phase transition of superconductor dual to a Lifshitz black brane probed by an anisotropic scalar field in the probe limit in Hořava–Lifshitz gravity. With the use of numerical and analytical method, we investigate how the critical temperature of the condensation is affected by the Lifshitz exponent z, α-correction term in the action as well as the dimensions of the gravity. We also numerically explore the condensation of the dual operator and optical conductivity of the holographic system. Various interesting properties of the holographic condensation affected by the parameters of model are discussed.
The holographic Hadamard condition on asymptotically anti-de Sitter spacetimes
Wrochna, Michał
2017-12-01
In the setting of asymptotically anti-de Sitter spacetimes, we consider Klein-Gordon fields subject to Dirichlet boundary conditions, with mass satisfying the Breitenlohner-Freedman bound. We introduce a condition on the b-wave front set of two-point functions of quantum fields, which locally in the bulk amounts to the usual Hadamard condition, and which moreover allows to estimate wave front sets for the holographically induced theory on the boundary. We prove the existence of two-point functions satisfying this condition and show their uniqueness modulo terms that have smooth Schwartz kernel in the bulk and have smooth restriction to the boundary. Finally, using Vasy's propagation of singularities theorem, we prove an analogue of Duistermaat and Hörmander's theorem on distinguished parametrices.
Holographic s+p insulator/superconductor phase transition at zero temperature
Directory of Open Access Journals (Sweden)
Ran Li
2017-03-01
Full Text Available We study the holographic s+p insulator/superconductor phase transition at zero temperature by using the model with a scalar triplet charged under an SU(2 gauge field in anti-de Sitter (AdS soliton background. In this model, besides the insulator phase, s-wave condensate phase and p-wave condensate phase, the s+p coexisting condensate phase is found numerically when operator dimension Δ is greater than a critical value Δc. We also construct the complete phase diagram in Δ−μ plane, which shows the s+p coexisting region is very narrow. Furthermore, we calculate the corresponding conductivities for different phases. The delta function support for the real part of conductivity of the spontaneous breaking phases is also revealed numerically as expected for the superconducting phases.
Solitonic approach to holographic nuclear physics
Baldino, Salvatore; Bolognesi, Stefano; Gudnason, Sven Bjarke; Koksal, Deniz
2017-08-01
We discuss nuclear physics in the Sakai-Sugimoto model in the limit of a large number Nc of colors and large 't Hooft coupling λ . In this limit the individual baryons are described by classical solitons whose size is much smaller than the typical distance at which they settle in a nuclear bound state. We can thus use the linear approximation outside the instanton cores to compute the interaction potential. We find the classical geometry of nuclear bound states for baryon number up to 8. One of the interesting features that we find is that holographic nuclear physics provides a natural description for lightly bound states when λ is large. For the case of two nuclei, we also find the topology and metric of the manifold of zero modes and, quantizing it, we find that the ground state can be identified with the deuteron state. We discuss the relations with other methods in the literature used to study Skyrmions and holographic nuclear physics. We discuss 1 /Nc and 1 /λ corrections and the challenges to overcome to reach the phenomenological values to fit with real QCD.
Holographic superconductor on a novel insulator
Ling, Yi; Liu, Peng; Wu, Jian-Pin; Wu, Meng-He
2018-01-01
We construct a holographic superconductor model, based on a gravity theory, which exhibits novel metal-insulator transitions. We investigate the condition for the condensation of the scalar field over the parameter space, and then focus on the superconductivity over the insulating phase with a hard gap, which is supposed to be Mott-like. It turns out that the formation of the hard gap in the insulating phase benefits the superconductivity. This phenomenon is analogous to the fact that the pseudogap phase can promote the pre-pairing of electrons in high {T}{{c}} cuprates. We expect that this work can shed light on understanding the mechanism of high {T}{{c}} superconductivity from the holographic side. Supported by Natural Science Foundation of China (11575195, 11775036, 11305018), Y.L. also acknowledges the support from Jiangxi young scientists (JingGang Star) program and 555 talent project of Jiangxi Province. J. P. Wu is also supported by Natural Science Foundation of Liaoning Province (201602013)
Holographic Dynamics from Multiscale Entanglement Renormalization Ansatz
Chua, Victor; Tiwari, Apoorv; Ryu, Shinsei
2016-01-01
The Multiscale Entanglement Renormalization Ansatz (MERA) is a tensor network based variational ansatz that is capable of capturing many of the key physical properties of strongly correlated ground states such as criticality and topological order. MERA also shares many deep relationships with the AdS/CFT (gauge-gravity) correspondence by realizing a UV complete holographic duality within the tensor networks framework. Motivated by this, we have re-purposed the MERA tensor network as an analysis tool to study the real-time evolution of the 1D transverse Ising model in its low energy excited state sector. We performed this analysis by allowing the ancilla qubits of the MERA tensor network to acquire quantum fluctuations, which yields a unitary transform between the physical (boundary) and ancilla qubit (bulk) Hilbert spaces. This then defines a reversible quantum circuit which is used as a `holographic transform' to study excited states and their real-time dynamics from the point of the bulk ancillae. In the ga...
The holographic dual of the Penrose transform
Neiman, Yasha
2018-01-01
We consider the holographic duality between type-A higher-spin gravity in AdS4 and the free U( N) vector model. In the bulk, linearized solutions can be translated into twistor functions via the Penrose transform. We propose a holographic dual to this transform, which translates between twistor functions and CFT sources and operators. We present a twistorial expression for the partition function, which makes global higher-spin symmetry manifest, and appears to automatically include all necessary contact terms. In this picture, twistor space provides a fully nonlocal, gauge-invariant description underlying both bulk and boundary spacetime pictures. While the bulk theory is handled at the linear level, our formula for the partition function includes the effects of bulk interactions. Thus, the CFT is used to solve the bulk, with twistors as a language common to both. A key ingredient in our result is the study of ordinary spacetime symmetries within the fundamental representation of higher-spin algebra. The object that makes these "square root" spacetime symmetries manifest becomes the kernel of our boundary/twistor transform, while the original Penrose transform is identified as a "square root" of CPT.
Random holographic "large worlds" with emergent dimensions
Trugenberger, Carlo A.
2016-11-01
I propose a random network model governed by a Gaussian weight corresponding to Ising link antiferromagnetism as a model for emergent quantum space-time. In this model, discrete space is fundamental, not a regularization; its spectral dimension ds is not a model input but is, rather, completely determined by the antiferromagnetic coupling constant. Perturbative terms suppressing triangles and favoring squares lead to locally Euclidean ground states that are Ricci flat "large worlds" with power-law extension. I then consider the quenched graphs of lowest energy for ds=2 and ds=3 , and I show how quenching leads to the spontaneous emergence of embedding spaces of Hausdorff dimension dH=4 and dH=5 , respectively. One of the additional, spontaneous dimensions can be interpreted as time, causality being an emergent property that arises in the large N limit (with N the number of vertices). For ds=2 , the quenched graphs constitute a discrete version of a 5D-space-filling surface with a number of fundamental degrees of freedom scaling like N2 /5, a graph version of the holographic principle. These holographic degrees of freedom can be identified with the squares of the quenched graphs, which, being triangle-free, are the fundamental area (or loop) quanta.
Archiving Saudi heritage using the holographic medium
Althagafi, A.; Richardson, M.
2015-03-01
This paper focuses on the use of the Yuri Nikolaevich DENISYUK holographic recording process to document, archive and display Saudi heritage. The goal of this research is to develop a technique of archiving heritage by using a high-tech holographic process to capture a three-dimensional presentation of ancient jewelry artifacts of the Saudi Heritage in particular. This study concentrates on five particular items of handmade authentic ancient metal jewelry from different parts of Saudi Arabia. When conducting this research experiments were conducted using both red-green sensitive plates sensitive to 633 nm and 532 nm respectively. Material thickness ranged between 1.5 and 3 millimeters were used, consequently in the dark room, varied chemicals for developing the holograms were employed. Red and green laser devices were also used with exposure times between 8 to 18 seconds of laser light dispersion through diffused surfaces in reflection holography. The outcome in each case was varied. The holograms captured the jewelry pieces with all the engravings and minute details, thus archiving the Saudi Heritage of that time. What makes holograms a revolutionary method for presenting valuable and/or ancient artifacts is the fact that they offer a more practical and convenient solution to travel around the world than displaying the originals items. Thus, museum visitors can enjoy and appreciate the precious artifacts otherwise unseen and lost without holography.
Setting up of holographic optical tweezer arrays
Gupta, Deepak K.; Tata, B. V. R.; Ravindran, T. R.
2017-05-01
Optical tweezers use tightly focused laser beams to hold and move microscopic objects in a solvent. However, many applications require simultaneous control over multitude of particles, positioning them in 3D space at desired locations with desired symmetry, which is made possible by the use of holographic optical tweezers using the technique of beam shaping and holography. We have designed and developed a holographic optical tweezer set-up using a phase only liquid crystal, reflective spatial light modulator. We employ the technique of phase modulation to modulate the phase of the beam by generating holograms using Random Superposition (RS) and weighted Gerchberg Saxton algorithm (WGS) algorithm for generating desired patterns of light at the trapping plane. A 4×4 array of beams with square symmetry was generated using WGS algorithm and trapped polystyrene particles of size 1.2 micron in a 4×4 two dimensional array. There were uniformity issues among the trap intensities, as we move away from the zeroth order spot. This was corrected by taking into account diffraction effects due to the pixelated nature of SLM modulating the intensity of the trap spots and the ghost order suppression by spatial disorder.
Holographic superconductor on Q-lattice
Energy Technology Data Exchange (ETDEWEB)
Ling, Yi [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing, 100049 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences, Beijing, 100190 (China); Liu, Peng; Niu, Chao [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing, 100049 (China); Wu, Jian-Pin [Department of Physics, School of Mathematics and Physics, Bohai University,Jinzhou, 121013 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences, Beijing, 100190 (China); Xian, Zhuo-Yu [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing, 100049 (China)
2015-02-10
We construct the simplest gravitational dual model of a superconductor on Q-lattices. We analyze the condition for the existence of a critical temperature at which the charged scalar field will condense. In contrast to the holographic superconductor on ionic lattices, the presence of Q-lattices will suppress the condensate of the scalar field and lower the critical temperature. In particular, when the Q-lattice background is dual to a deep insulating phase, the condensation would never occur for some small charges. Furthermore, we numerically compute the optical conductivity in the superconducting regime. It turns out that the presence of Q-lattice does not remove the pole in the imaginary part of the conductivity, ensuring the appearance of a delta function in the real part. We also evaluate the gap which in general depends on the charge of the scalar field as well as the Q-lattice parameters. Nevertheless, when the charge of the scalar field is relatively large and approaches the probe limit, the gap becomes universal with ω{sub g}≃9T{sub c} which is consistent with the result for conventional holographic superconductors.
Sonorous images through digital holographic images
Azevedo, Isabel; Sandford-Richardson, Elizabeth
2017-03-01
The art of the last fifty years has significantly surrounded the presence of the body, the relationship between human and interactive technologies. Today in interactive art, there are not only representations that speak of the body but actions and behaviours that involve the body. In holography, the image appears and disappears from the observer's vision field; because the holographic image is light, we can see multidimensional spaces, shapes and colours existing on the same time, presence and absence of the image on the holographic plate. And the image can be flowing in front of the plate that sometimes people try touching it with his hands. That means, to the viewer will be interactive events, with no beginning or end that can be perceived in any direction, forward or backward, depending on the relative position and the time the viewer spends in front of the hologram. To explore that feature we are proposing an installation with four holograms, and several sources of different kind of sounds connected with each hologram. When viewers will move in front of each hologram they will activate different sources of sound. The search is not only about the images in the holograms, but also the looking for different types of sounds that this demand will require. The digital holograms were produced using the HoloCam Portable Light System with the 35 mm camera Canon 700D to capture image information, it was then edited on computer using the Motion 5 and Final Cut Pro X programs.
Holographic free energy and thermodynamic geometry
Energy Technology Data Exchange (ETDEWEB)
Ghorai, Debabrata [S.N. Bose National Centre for Basic Sciences, Kolkata (India); Gangopadhyay, Sunandan [Indian Institute of Science Education and Research, Kolkata, Nadia (India); West Bengal State University, Department of Physics, Barasat (India); Inter University Centre for Astronomy and Astrophysics, Pune (India)
2016-12-15
We obtain the free energy and thermodynamic geometry of holographic superconductors in 2 + 1 dimensions. The gravitational theory in the bulk dual to this 2 + 1-dimensional strongly coupled theory lives in the 3 + 1 dimensions and is that of a charged AdS black hole together with a massive charged scalar field. The matching method is applied to obtain the nature of the fields near the horizon using which the holographic free energy is computed through the gauge/gravity duality. The critical temperature is obtained for a set of values of the matching point of the near horizon and the boundary behaviour of the fields in the probe limit approximation which neglects the back reaction of the matter fields on the background spacetime geometry. The thermodynamic geometry is then computed from the free energy of the boundary theory. From the divergence of the thermodynamic scalar curvature, the critical temperature is obtained once again. We then compare this result for the critical temperature with that obtained from the matching method. (orig.)
Agour, Mostafa; Falldorf, Claas; Bergmann, Ralf B
2016-06-27
We present a new method for the generation of a dynamic wave field with high space bandwidth product (SBP). The dynamic wave field is generated from several wave fields diffracted by a display which comprises multiple spatial light modulators (SLMs) each having a comparably low SBP. In contrast to similar approaches in stereoscopy, we describe how the independently generated wave fields can be coherently superposed. A major benefit of the scheme is that the display system may be extended to provide an even larger display. A compact experimental configuration which is composed of four phase-only SLMs to realize the coherent combination of independent wave fields is presented. Effects of important technical parameters of the display system on the wave field generated across the observation plane are investigated. These effects include, e.g., the tilt of the individual SLM and the gap between the active areas of multiple SLMs. As an example of application, holographic reconstruction of a 3D object with parallax effects is demonstrated.
Holographic butterfly effect and diffusion in quantum critical region
Ling, Yi; Xian, Zhuo-Yu
2017-09-01
We investigate the butterfly effect and charge diffusion near the quantum phase transition in holographic approach. We argue that their criticality is controlled by the holographic scaling geometry with deformations induced by a relevant operator at finite temperature. Specifically, in the quantum critical region controlled by a single fixed point, the butterfly velocity decreases when deviating from the critical point. While, in the non-critical region, the behavior of the butterfly velocity depends on the specific phase at low temperature. Moreover, in the holographic Berezinskii-Kosterlitz-Thouless transition, the universal behavior of the butterfly velocity is absent. Finally, the tendency of our holographic results matches with the numerical results of Bose-Hubbard model. A comparison between our result and that in the O( N ) nonlinear sigma model is also given.
Exploring Neural Cell Dynamics with Digital Holographic Microscopy
Marquet, Pierre
2013-04-21
In this talk, I will present how digital holographic microscopy, as a powerful quantitative phase technique, can non-invasively measure cell dynamics and especially resolve local neuronal network activity through simultaneous multiple site optical recording.
Quantitative measurement of holographic image quality using Adobe Photoshop
Wesly, E.
2013-02-01
Measurement of the characteristics of image holograms in regards to diffraction efficiency and signal to noise ratio are demonstrated, using readily available digital cameras and image editing software. Illustrations and case studies, using currently available holographic recording materials, are presented.
A novel collinear optical setup for holographic data storage system
Horimai, Hideyoshi; Li, Jun
2004-09-01
In this paper, A novel collinear optical setup for holographic data storage system is presented. Simulated/experimental results are given. Combined with sub-page based data format, the system is simple and robust.
Holographic Gratings in Azobenzene Side-Chain Polymethacrylates
DEFF Research Database (Denmark)
Andruzzi, Luisa; Altomare, Angelina; Ciardelli, Francesco
1999-01-01
Optical storage properties of thin unoriented liquid crystalline and amorphous side-chain azobenzene polymethacrylate films are examined by polarization holographic measurements. The investigated materials are free radical copolymers derived from two photochromic monomers, 6-(4-oxy-4...
Review of Random Phase Encoding in Volume Holographic Storage
Directory of Open Access Journals (Sweden)
Wei-Chia Su
2012-09-01
Full Text Available Random phase encoding is a unique technique for volume hologram which can be applied to various applications such as holographic multiplexing storage, image encryption, and optical sensing. In this review article, we first review and discuss diffraction selectivity of random phase encoding in volume holograms, which is the most important parameter related to multiplexing capacity of volume holographic storage. We then review an image encryption system based on random phase encoding. The alignment of phase key for decryption of the encoded image stored in holographic memory is analyzed and discussed. In the latter part of the review, an all-optical sensing system implemented by random phase encoding and holographic interconnection is presented.
Reflection mode holographic recording in methylene blue-sensitized ...
Indian Academy of Sciences (India)
2014-02-13
out rates has increased considerably. Thus, in recent years much attention has been centred on three-dimensional (3D) holographic disks [1,2]. Many recent studies have focussed on the characterization and optimization of ...
Holographic Renormalization of general dilaton-axion gravity
Papadimitriou, Ioannis
2011-01-01
We consider a very general dilaton-axion system coupled to Einstein-Hilbert gravity in arbitrary dimension and we carry out holographic renormalization for any dimension up to and including five dimensions. This is achieved by developing a new systematic algorithm for iteratively solving the radial Hamilton-Jacobi equation in a derivative expansion. The boundary term derived is valid not only for asymptotically AdS backgrounds, but also for more general asymptotics, including non-conformal branes and Improved Holographic QCD. In the second half of the paper, we apply the general result to Improved Holographic QCD with arbitrary dilaton potential. In particular, we derive the generalized Fefferman-Graham asymptotic expansions and provide a proof of the holographic Ward identities.
Holographic entanglement entropy in 2D holographic superconductor via AdS3/CFT2
Directory of Open Access Journals (Sweden)
Davood Momeni
2015-07-01
Full Text Available The aim of the present letter is to find the holographic entanglement entropy (HEE in 2D holographic superconductors (HSC. Indeed, it is possible to compute the exact form of this entropy due to an advantage of approximate solutions inside normal and superconducting phases with backreactions. By making the UV and IR limits applied to the integrals, an approximate expression for HEE is obtained. In case the software cannot calculate minimal surface integrals analytically, it offers the possibility to proceed with a numerical evaluation of the corresponding terms. We'll understand how the area formula incorporates the structure of the domain wall approximation. We see that HEE changes linearly with belt angle. It's due to the extensivity of this type of entropy and the emergent of an entropic force. We find that the wider belt angle corresponds to a larger holographic surface. Another remarkable observation is that no “confinement/deconfinement” phase transition point exists in our 2D dual field theory. Furthermore, we observe that the slope of the HEE with respect to the temperature dSdT decreases, thanks to the emergence extra degree of freedom(s in low temperature system. A first order phase transition is detected near the critical point.
Kim, Sun Il; Choi, Chil-Sung; An, Jungkwuen; Song, Hoon; Kim, Yunhee; Kim, Young; Sung, Geeyoung; Seo, Wontaek; Seo, Juwon; Kim, Yun-Tae; Kim, Hojung; Kim, Yongkyu; Lee, Hong-Seok; Hwang, Sungwoo
2017-03-01
We propose the coherent backlight unit (BLU) using Holographic Optical Element (HOE) for full-color flat-panel holographic display. The HOE BLU consists of two reflective type HOEs that change the optical beam path and shape by diffraction. The diverging incident beam is transformed to the collimated beam which has a very small diffraction angle (7.5°) by HOE 1 (H1) in order to illuminate the whole display. This collimated beam is converged to a point at a distance from the glass substrate by HOE 2 (H2). As a result, the diverging incident beam is converted to a point light by H1 and H2. When the high resolution Spatial Light Modulator (SLM) displaying Computer Generated Hologram (CGH) is illuminated by HOE BLU, the hologram image is displayed at a view point near focal point. Practically, we fabricated the full color HOE BLU for 5.5" flat panel holographic display by using the proposed design. At least 5.5" size of HOE is required to illuminate the whole panel. For this reason, we recorded 150 mm x 90 mm size HOE on the 10 mm thickness glass substrate. This HOE BLU exhibits a total efficiency of 8.0% at Red (660 nm), 7.7% at Green (532 nm), 3.2% at Blue (460 nm) using optimized recording conditions for each wavelength. Finally, a bright full color hologram image was achieved.
Holographic model for dilepton production in p-p collisions
Energy Technology Data Exchange (ETDEWEB)
Ballon Bayona, C.A., E-mail: c.a.m.ballonbayona@durham.ac.uk [Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150, RJ 22290-180 (Brazil); Centre for Particle Theory, University of Durham, Science Laboratories, South Road, Durham DH1 3LE (United Kingdom); Boschi-Filho, Henrique, E-mail: boschi@if.ufrj.br [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, RJ 21941-972 (Brazil); Braga, Nelson R.F., E-mail: braga@if.ufrj.br [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, RJ 21941-972 (Brazil)
2011-10-01
We propose a holographic model for dilepton production in proton-proton collisions through the exchange of vector mesons. The holographic hard wall model is used to describe the dynamics and interactions of vector mesons and baryons. We estimate the parameters {lambda}, {mu}, {nu} that characterize the angular distribution of the produced dileptons in a region of q{sub T}{sup 2}<
Note on the butterfly effect in holographic superconductor models
Ling, Yi; Liu, Peng; Wu, Jian-Pin
2017-05-01
In this note we remark that the butterfly effect can be used to diagnose the phase transition of superconductivity in a holographic framework. Specifically, we compute the butterfly velocity in a charged black hole background as well as anisotropic backgrounds with Q-lattice structure. In both cases we find its derivative to the temperature is discontinuous at critical points. We also propose that the butterfly velocity can signalize the occurrence of thermal phase transition in general holographic models.
Clocks, computers, black holes, spacetime foam, and holographic principle
Ng, Y. Jack
2000-01-01
What do simple clocks, simple computers, black holes, space-time foam, and holographic principle have in common? I will show that the physics behind them is inter-related, linking together our concepts of information, gravity, and quantum uncertainty. Thus, the physics that sets the limits to computation and clock precision also yields Hawking radiation of black holes and the holographic principle. Moreover, the latter two strongly imply that space-time undergoes much larger quantum fluctuati...
Note on the butterfly effect in holographic superconductor models
Directory of Open Access Journals (Sweden)
Yi Ling
2017-05-01
Full Text Available In this note we remark that the butterfly effect can be used to diagnose the phase transition of superconductivity in a holographic framework. Specifically, we compute the butterfly velocity in a charged black hole background as well as anisotropic backgrounds with Q-lattice structure. In both cases we find its derivative to the temperature is discontinuous at critical points. We also propose that the butterfly velocity can signalize the occurrence of thermal phase transition in general holographic models.
Note on the butterfly effect in holographic superconductor models
Energy Technology Data Exchange (ETDEWEB)
Ling, Yi, E-mail: lingy@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai 200444 (China); School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Peng, E-mail: liup51@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wu, Jian-Pin, E-mail: jianpinwu@mail.bnu.edu.cn [Institute of Gravitation and Cosmology, Department of Physics, School of Mathematics and Physics, Bohai University, Jinzhou 121013 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai 200444 (China)
2017-05-10
In this note we remark that the butterfly effect can be used to diagnose the phase transition of superconductivity in a holographic framework. Specifically, we compute the butterfly velocity in a charged black hole background as well as anisotropic backgrounds with Q-lattice structure. In both cases we find its derivative to the temperature is discontinuous at critical points. We also propose that the butterfly velocity can signalize the occurrence of thermal phase transition in general holographic models.
Holographic Refraction and the Measurement of Spherical Ametropia.
Nguyen, Nicholas Hoai Nam
2016-10-01
To evaluate the performance of a holographic logMAR chart for the subjective spherical refraction of the human eye. Bland-Altman analysis was used to assess the level of agreement between subjective spherical refraction using the holographic logMAR chart and conventional autorefraction and subjective spherical refraction. The 95% limits of agreement (LoA) were calculated between holographic refraction and the two standard methods (subjective and autorefraction). Holographic refraction has a lower mean spherical refraction when compared to conventional refraction (LoA 0.11 ± 0.65 D) and when compared to autorefraction (LoA 0.36 ± 0.77 D). After correcting for systemic bias, this is comparable between autorefraction and conventional subjective refraction (LoA 0.45 ± 0.79 D). After correcting for differences in vergence distance and chromatic aberration between holographic and conventional refraction, approximately 65% (group 1) of measurements between holography and conventional subjective refraction were similar (MD = 0.13 D, SD = 0.00 D). The remaining 35% (group 2) had a mean difference of 0.45 D (SD = 0.12 D) between the two subjective methods. Descriptive statistics showed group 2's mean age (21 years, SD = 13 years) was considerably lower than group 1's mean age (41 years, SD = 17), suggesting accommodation may have a role in the greater mean difference of group 2. Overall, holographic refraction has good agreement with conventional refraction and is a viable alternative for spherical subjective refraction. A larger bias between holographic and conventional refraction was found in younger subjects than older subjects, suggesting an association between accommodation and myopic over-correction during holographic refraction.
Holographic superconductors in Einstein-æther gravity
Lin, Kai; Wu, Yumei
2017-11-01
In this paper, we apply Anti-de Sitter (AdS) black hole solution of the Einstein-æther theory to the study of the holographic superconductor and show that the AdS black hole solution can be rewritten in some very simple forms, from which it is easy to identify the locations of various killing horizons. Then, we investigate the different effects of these horizons on the holographic superconductor.
Automated PCB Inspection System
Directory of Open Access Journals (Sweden)
Syed Usama BUKHARI
2017-05-01
Full Text Available Development of an automated PCB inspection system as per the need of industry is a challenging task. In this paper a case study is presented, to exhibit, a proposed system for an immigration process of a manual PCB inspection system to an automated PCB inspection system, with a minimal intervention on the existing production flow, for a leading automotive manufacturing company. A detailed design of the system, based on computer vision followed by testing and analysis was proposed, in order to aid the manufacturer in the process of automation.
Directory of Open Access Journals (Sweden)
Stanislav Absolon
2015-10-01
Full Text Available This article discusses the use of the RPAS for the inspection of the airport operating areas. The paper compares the current process of the inspection of the airport operating areas by the airport staff with the possibilities which are offered by the use of the modern technology RPAS. The following text also describes how to inspect airport operating areas by the RPAS, specific technical possibilities and the applicable technical solutions. Furthermore there are variants of piloting the RPAS, comparing usable equipment, equipment for video recording and the possibility of using thermal imaging camera in the article.
Holographic renormalization group and cosmology in theories with quasilocalized gravity
Energy Technology Data Exchange (ETDEWEB)
Csaki, Csaba; Erlich, Joshua; Hollowood, Timothy J.; Terning, John
2001-03-15
We study the long distance behavior of brane theories with quasilocalized gravity. The five-dimensional (5D) effective theory at large scales follows from a holographic renormalization group flow. As intuitively expected, the graviton is effectively four dimensional at intermediate scales and becomes five dimensional at large scales. However, in the holographic effective theory the essentially 4D radion dominates at long distances and gives rise to scalar antigravity. The holographic description shows that at large distances the Gregory-Rubakov-Sibiryakov (GRS) model is equivalent to the model recently proposed by Dvali, Gabadadze, and Porrati (DGP), where a tensionless brane is embedded into 5D Minkowski space, with an additional induced 4D Einstein-Hilbert term on the brane. In the holographic description the radion of the GRS model is automatically localized on the tensionless brane, and provides the ghostlike field necessary to cancel the extra graviton polarization of the DGP model. Thus, there is a holographic duality between these theories. This analysis provides physical insight into how the GRS model works at intermediate scales; in particular it sheds light on the size of the width of the graviton resonance, and also demonstrates how the holographic renormalization group can be used as a practical tool for calculations.
Noncommutative effects of spacetime on holographic superconductors
Directory of Open Access Journals (Sweden)
Debabrata Ghorai
2016-07-01
Full Text Available The Sturm–Liouville eigenvalue method is employed to analytically investigate the properties of holographic superconductors in higher dimensions in the framework of Born–Infeld electrodynamics incorporating the effects of noncommutative spacetime. In the background of pure Einstein gravity in noncommutative spacetime, we obtain the relation between the critical temperature and the charge density. We also obtain the value of the condensation operator and the critical exponent. Our findings suggest that the higher value of noncommutative parameter and Born–Infeld parameter make the condensate harder to form. We also observe that the noncommutative structure of spacetime makes the critical temperature depend on the mass of the black hole and higher value of black hole mass is favourable for the formation of the condensate.
Noncommutative effects of spacetime on holographic superconductors
Energy Technology Data Exchange (ETDEWEB)
Ghorai, Debabrata, E-mail: debanuphy123@gmail.com [S.N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700098 (India); Gangopadhyay, Sunandan, E-mail: sunandan.gangopadhyay@gmail.com [Department of Physics, West Bengal State University, Barasat (India); Inter University Centre for Astronomy & Astrophysics, Pune (India)
2016-07-10
The Sturm–Liouville eigenvalue method is employed to analytically investigate the properties of holographic superconductors in higher dimensions in the framework of Born–Infeld electrodynamics incorporating the effects of noncommutative spacetime. In the background of pure Einstein gravity in noncommutative spacetime, we obtain the relation between the critical temperature and the charge density. We also obtain the value of the condensation operator and the critical exponent. Our findings suggest that the higher value of noncommutative parameter and Born–Infeld parameter make the condensate harder to form. We also observe that the noncommutative structure of spacetime makes the critical temperature depend on the mass of the black hole and higher value of black hole mass is favourable for the formation of the condensate.
Holographic bulk reconstruction with α' corrections
Roy, Shubho R.; Sarkar, Debajyoti
2017-10-01
We outline a holographic recipe to reconstruct α' corrections to anti-de Sitter (AdS) (quantum) gravity from an underlying CFT in the strictly planar limit (N →∞ ). Assuming that the boundary CFT can be solved in principle to all orders of the 't Hooft coupling λ , for scalar primary operators, the λ-1 expansion of the conformal dimensions can be mapped to higher curvature corrections of the dual bulk scalar field action. Furthermore, for the metric perturbations in the bulk, the AdS /CFT operator-field isomorphism forces these corrections to be of the Lovelock type. We demonstrate this by reconstructing the coefficient of the leading Lovelock correction, also known as the Gauss-Bonnet term in a bulk AdS gravity action using the expression of stress-tensor two-point function up to subleading order in λ-1.
Towards a Holographic Marginal Fermi Liquid
Energy Technology Data Exchange (ETDEWEB)
Jensen, Kristan; Kachru, Shamit; Karch, Andreas; Polchinski, Joseph; Silverstein, Eva
2011-08-15
We present an infinite class of 2+1 dimensional field theories which, after coupling to semi-holographic fermions, exhibit strange metallic behavior in a suitable large N limit. These theories describe lattices of hypermultiplet defects interacting with parity-preserving supersymmetric Chern-Simons theories with U(N) x U(N) gauge groups at levels {+-}k. They have dual gravitational descriptions in terms of lattices of probe M2 branes in AdS{sub 4} x S{sup 7}/Z{sub k} (for N >> 1,N >> k{sup 5}) or probe D2 branes in AdS{sub 4} x CP{sup 3} (for N >> k >> 1,N << k{sup 5}). We discuss several challenges one faces in maintaining the success of these models at finite N, including backreaction of the probes in the gravity solutions and radiative corrections in the weakly coupled field theory limit.
Digital holographic interferometer with correction of distortions
Sevryugin, A. A.; Pulkin, S. A.; Tursunov, I. M.; Venediktov, D. V.; Venediktov, V. Y.
2015-10-01
The paper considers the use of holographic interferometer for hologram re-recording with correction of distortions. Each optical system contains some beam path deviations, called aberrations of the optical system. They are seen in the resulting interference pattern as a distortion of fringes. While increasing the sensitivity of the interference pattern by N times at the same time we introduce new aberrations, caused by re-recording setup in addition to aberrations that are already presented on the interferogram, caused by initial recording, also multiplied by N times. In this experiment we decided to use a modified setup with spatially combined interferograms with use of matrix spatial light modulator and digital image processing of the interferograms recorded by CCD or CMOS camera.
Photovoltaic concentrator using a holographic optical element.
Zhang, Y W; Ih, C S; Yan, H F; Chang, M J
1988-08-15
A photovoltaic concentrator is proposed that uses equatorial tracking (the rotation axis of a concentrator points to the North Star), so that the change of the sun's altitude angle is minimized. The solar concentrator consists of a Fresnel lens (objective), a holographic optical element made on photoresist with 90% diffraction efficiency, and a field lens (making the sunlight come from different fields of view uniformly falling on the solar cell). The accuracy of the original 2-D tracking is reduced several orders over previous methods; however, it may be that only 1-D tracking is needed. A theoretical analysis and a study model have been made, and a reasonable concentration ratio has been obtained. Therefore, it can be expected that the cost will be much lower than an accurate 2-D tracking system.
Holographic superconductivity from higher derivative theory
Wu, Jian-Pin; Liu, Peng
2017-11-01
We construct a 6 derivative holographic superconductor model in the 4-dimensional bulk spacetimes, in which the normal state describes a quantum critical (QC) phase. The phase diagram (γ1 ,Tˆc) and the condensation as the function of temperature are worked out numerically. We observe that with the decrease of the coupling parameter γ1, the critical temperature Tˆc decreases and the formation of charged scalar hair becomes harder. We also calculate the optical conductivity. An appealing characteristic is a wider extension of the superconducting energy gap, comparing with that of 4 derivative theory. It is expected that this phenomena can be observed in the real materials of high temperature superconductor. Also the Homes' law in our present models with 4 and 6 derivative corrections is explored. We find that in certain range of parameters γ and γ1, the experimentally measured value of the universal constant C in Homes' law can be obtained.
Quantum corrections to holographic mutual information
Energy Technology Data Exchange (ETDEWEB)
Agón, Cesar A. [Martin Fisher School of Physics, Brandeis University,Waltham, MA 02453 (United States); Faulkner, Thomas [University of Illinois, Urbana-Champaign,Urbana, IL 61801-3080 (United States)
2016-08-22
We compute the leading contribution to the mutual information (MI) of two disjoint spheres in the large distance regime for arbitrary conformal field theories (CFT) in any dimension. This is achieved by refining the operator product expansion method introduced by Cardy http://dx.doi.org/10.1088/1751-8113/46/28/285402. For CFTs with holographic duals the leading contribution to the MI at long distances comes from bulk quantum corrections to the Ryu-Takayanagi area formula. According to the FLM proposal http://dx.doi.org/10.1007/JHEP11(2013)074 this equals the bulk MI between the two disjoint regions spanned by the boundary spheres and their corresponding minimal area surfaces. We compute this quantum correction and provide in this way a non-trivial check of the FLM proposal.
Asymmetric dense matter in holographic QCD
Directory of Open Access Journals (Sweden)
Shin Ik Jae
2012-02-01
Full Text Available We study asymmetric dense matter in holographic QCD.We construct asymmetric dense matter by considering two quark flavor branes with dierent quark masses in a D4/D6/D6 model. To calculate the symmetry energy in nuclear matter, we consider two quarks with equal masses and observe that the symmetry energy increases with the total charge showing the stiff dependence. This behavior is universal in the sense that the result is independent of parameters in the model. We also study strange (or hyperon matter with one light and one intermediate mass quarks. In addition to the vacuum properties of asymmetric matter, we calculate meson masses in asymmetric dense matter and discuss our results in the light of in-medium kaon masses.
Holographic construction of excited CFT states
Energy Technology Data Exchange (ETDEWEB)
Christodoulou, Ariana; Skenderis, Kostas [STAG Research Centre and Mathematical Sciences, University of Southampton,High-field, Southampton SO17 1BJ (United Kingdom)
2016-04-15
We present a systematic construction of bulk solutions that are dual to CFT excited states. The bulk solution is constructed perturbatively in bulk fields. The linearised solution is universal and depends only on the conformal dimension of the primary operator that is associated with the state via the operator-state correspondence, while higher order terms depend on detailed properties of the operator, such as its OPE with itself and generally involve many bulk fields. We illustrate the discussion with the holographic construction of the universal part of the solution for states of two dimensional CFTs, either on R×S{sup 1} or on R{sup 1,1}. We compute the 1-point function both in the CFT and in the bulk, finding exact agreement. We comment on the relation with other reconstruction approaches.
Collinear technology for a holographic versatile disk
Horimai, Hideyoshi; Tan, Xiaodi
2006-02-01
A novel reading and writing technology for a holographic versatile disk (HVD) system called collinear technology is developed. With this method a two-dimensional data page can be recorded as volumetric holograms generated by a reference beam and a signal beam that are bundled on the same axis and that are irradiated on the recording medium through a single objective lens. The multiplex recording and reconstruction process is demonstrated, and it is shown that the optical configuration and the dichroic medium disk structure are suitable for a compact system. With the HVD's special structure, the system can use a servo to focus, track, and locate the reading and writing addresses. A unique selectable-capacity recording format of a HVD and its standardization activity are also introduced. This method will enable us to construct a small HVD system with CD and DVD upper compatibilities.
A Comment on Holographic Luttinger Theorem
Hashimoto, Koji
2012-01-01
Robustness of the Luttinger theorem for fermionic liquids is examined in holography. The statement of the Luttinger theorem, the equality between the fermion charge density and the volume enclosed by the Fermi surface, can be mapped to a Gauss's law in the gravity dual, a la Sachdev. We show that various deformations in the gravity dual, such as inclusion of magnetic fields, a parity-violating theta-term, dilatonic deformations, and higher-derivative corrections, do not violate the holographic derivation of the Luttinger theorem, as long as the theory is in a confining phase. Therefore a robustness of the theorem is found for strongly correlated fermions coupled with strongly coupled sectors which admit gravity duals. On the other hand, in the deconfined phase, we also show that the deficit appearing in the Luttinger theorem is again universal. It measures a total deficit which measures the charge of the deconfined ("fractionalized") fermions, independent of the deformation parameters.
Holographic Polytropic f(T Gravity Models
Directory of Open Access Journals (Sweden)
Surajit Chattopadhyay
2015-01-01
Full Text Available The present paper reports a study on the cosmological consequences arising from reconstructing f(T gravity through new holographic polytropic dark energy. We assume two approaches, namely, a particular form of Hubble parameter H and a solution for f(T. We obtain the deceleration parameter and effective equation of state, as well as torsion equation of state parameters from total density and pressure in both cases. It is interesting to mention here that the deceleration and torsion equation of state represent transition from deceleration to acceleration phase. We study the statefinder parameters under both approaches which result in the fact that statefinder trajectories are found to attain ΛCDM point. The comparison with observational data represents consistent results. Also, we discuss the stability of reconstructed models through squared speed of sound which represents stability in late times.
Holograph in noncommutative geometry: Part 1
Wang, Jingbo
2010-01-01
In this paper, we consider the holograph principle emergent from noncommutative geometry, based on the spectral action principle. We show that under some appropriate conditions, the gravity theory on a manifold with boundary could be equivalent to a gauge theory $SU(N)$ on the boundary. Then an expression for $N$ with the geometrical quantities of the manifold is given. Based on this result, we find that the volume of the manifold and the boundary have some discrete structure. Applying the result to the black hole, we get that the radium of the Schwarzschild black hole is quantized. We also find an explanation why the extremal RN-black hole has zero temperature but with finite entropy.
Linearized holographic isotropization at finite coupling
Energy Technology Data Exchange (ETDEWEB)
Atashi, Mahdi; Fadafan, Kazem Bitaghsir [Shahrood University of Technology, Physics Department (Iran, Islamic Republic of); Jafari, Ghadir [Institute for Research in Fundamental Sciences (IPM), School of Physics, Tehran (Iran, Islamic Republic of)
2017-06-15
We study holographic isotropization of an anisotropic homogeneous non-Abelian strongly coupled plasma in the presence of Gauss-Bonnet corrections. It was verified before that one can linearize Einstein's equations around the final black hole background and simplify the complicated setup. Using this approach, we study the expectation value of the boundary stress tensor. Although we consider small values of the Gauss-Bonnet coupling constant, it is found that finite coupling leads to significant increasing of the thermalization time. By including higher order corrections in linearization, we extend the results to study the effect of the Gauss-Bonnet coupling on the entropy production on the event horizon. (orig.)
Holographic superconductivity from higher derivative theory
Directory of Open Access Journals (Sweden)
Jian-Pin Wu
2017-11-01
Full Text Available We construct a 6 derivative holographic superconductor model in the 4-dimensional bulk spacetimes, in which the normal state describes a quantum critical (QC phase. The phase diagram (γ1,Tˆc and the condensation as the function of temperature are worked out numerically. We observe that with the decrease of the coupling parameter γ1, the critical temperature Tˆc decreases and the formation of charged scalar hair becomes harder. We also calculate the optical conductivity. An appealing characteristic is a wider extension of the superconducting energy gap, comparing with that of 4 derivative theory. It is expected that this phenomena can be observed in the real materials of high temperature superconductor. Also the Homes' law in our present models with 4 and 6 derivative corrections is explored. We find that in certain range of parameters γ and γ1, the experimentally measured value of the universal constant C in Homes' law can be obtained.
Understanding the holographic principle via RG flow
Mukhopadhyay, Ayan
2016-01-01
This is a review of some recent works which demonstrate how the classical equations of gravity in AdS themselves hold the key to understanding their holographic origin in the form of a strongly coupled large $N$ QFT whose algebra of local operators can be generated by a few (single-trace) elements. I discuss how this can be realised by reformulating Einstein's equations in AdS in the form of a non-perturbative RG flow that further leads to a new approach towards constructing strongly interacting QFTs. In particular, the RG flow can self-determine the UV data that are otherwise obtained by solving classical gravity equations and demanding that the solutions do not have naked singularities. For a concrete demonstration, I focus on the hydrodynamic limit in which case this RG flow connects the AdS/CFT correspondence with the membrane paradigm, and also reproduces the known values of the dual QFT transport coefficients.
Digital Holographic Microscopy Principles, Techniques, and Applications
Kim, Myung K
2011-01-01
Digital holography is an emerging field of new paradigm in general imaging applications. By replacing the photochemical procedures with electronic imaging and having a direct numerical access to the complex optical field, a wide range of new imaging capabilities become available, many of them difficult or infeasible in conventional holography. An increasing number of researchers—not only in optical physics and optical engineering, but also in diverse applications areas such as microbiology, medicine, marine science, particle analysis, microelectromechanics, and metrology—are realizing and exploiting the new capabilities of digital holography. Digital Holographic Microscopy: Principles, Techniques, and Applications, by Dr. Myung K. Kim, is intended to provide a brief but consistent introduction to the principles of digital holography as well as to give an organized overview of the large number of techniques and applications being developed. This will also shed some light on the range of possibilities for f...
Signal Station Inspection Reports
National Oceanic and Atmospheric Administration, Department of Commerce — Handwritten reports resulting from detailed inspections of US Army Signal Service Stations, 1871-1889. Features reported included instrument exposure and condition,...
Wheel inspection system environment.
2008-11-18
International Electronic Machines Corporation (IEM) has developed and is now marketing a state-of-the-art Wheel Inspection System Environment (WISE). WISE provides wheel profile and dimensional measurements, i.e. rim thickness, flange height, flange ...
Synfograms: a new generation of holographic applications
Meulien Öhlmann, Odile; Öhlmann, Dietmar; Zacharovas, Stanislovas J.
2008-04-01
The new synthetic Four-dimensional printing technique (Syn4D) Synfogram is introducing time (animation) into spatial configuration of the imprinted three-dimensional shapes. While lenticular solutions offer 2 to 9 stereoscopic images Syn4D offers large format, full colors true 3D visualization printing of 300 to 2500 frames imprinted as holographic dots. This past 2 years Syn4D high-resolution displays proved to be extremely efficient for museums presentation, engineering design, automobile prototyping, and advertising virtual presentation as well as, for portrait and fashion applications. The main advantages of syn4D is that it offers a very easy way of using a variety of digital media, like most of 3D Modelling programs, 3D scan system, video sequences, digital photography, tomography as well as the Syn4D camera track system for life recording of spatial scenes changing in time. The use of digital holographic printer in conjunction with Syn4D image acquiring and processing devices separates printing and imaging creation in such a way that makes four-dimensional printing similar to a conventional digital photography processes where imaging and printing are usually separated in space and time. Besides making content easy to prepare, Syn4D has also developed new display and lighting solutions for trade show, museum, POP, merchandising, etc. The introduction of Synfograms is opening new applications for real life and virtual 4D displays. In this paper we will analyse the 3D market, the properties of the Synfograms and specific applications, the problems we encounter, solutions we find, discuss about customers demand and need for new product development.
Holographic spin networks from tensor network states
Singh, Sukhwinder; McMahon, Nathan A.; Brennen, Gavin K.
2018-01-01
In the holographic correspondence of quantum gravity, a global on-site symmetry at the boundary generally translates to a local gauge symmetry in the bulk. We describe one way how the global boundary on-site symmetries can be gauged within the formalism of the multiscale renormalization ansatz (MERA), in light of the ongoing discussion between tensor networks and holography. We describe how to "lift" the MERA representation of the ground state of a generic one dimensional (1D) local Hamiltonian, which has a global on-site symmetry, to a dual quantum state of a 2D "bulk" lattice on which the symmetry appears gauged. The 2D bulk state decomposes in terms of spin network states, which label a basis in the gauge-invariant sector of the bulk lattice. This decomposition is instrumental to obtain expectation values of gauge-invariant observables in the bulk, and also reveals that the bulk state is generally entangled between the gauge and the remaining ("gravitational") bulk degrees of freedom that are not fixed by the symmetry. We present numerical results for ground states of several 1D critical spin chains to illustrate that the bulk entanglement potentially depends on the central charge of the underlying conformal field theory. We also discuss the possibility of emergent topological order in the bulk using a simple example, and also of emergent symmetries in the nongauge (gravitational) sector in the bulk. More broadly, our holographic model translates the MERA, a tensor network state, to a superposition of spin network states, as they appear in lattice gauge theories in one higher dimension.
1983-01-01
Engineers from the Power Authority of the State of New York use a Crack Growth Analysis Program supplied by COSMIC (Computer Software Management and Information Center) in one stage of nuclear plant inspection. Welds of the nuclear steam supply system are checked for cracks; radiographs, dye penetration and visual inspections are performed to locate cracks in the metal structure and welds. The software package includes three separate crack growth analysis models and enables necessary repairs to be planned before serious problems develop.
Digital holographic microscopy for detection of Trypanosoma cruzi parasites in fresh blood mounts
Romero, G. G.; Monaldi, A. C.; Alanís, E. E.
2012-03-01
An off-axis holographic microscope, in a transmission mode, calibrated to automatically detect the presence of Trypanosoma cruzi in blood is developed as an alternative diagnosis tool for Chagas disease. Movements of the microorganisms are detected by measuring the phase shift they produce on the transmitted wave front. A thin layer of blood infected by Trypanosoma cruzi parasites is examined in the holographic microscope, the images of the visual field being registered with a CCD camera. Two consecutive holograms of the same visual field are subtracted point by point and a phase contrast image of the resulting hologram is reconstructed by means of the angular spectrum propagation algorithm. This method enables the measurement of phase distributions corresponding to temporal differences between digital holograms in order to detect whether parasites are present or not. Experimental results obtained using this technique show that it is an efficient alternative that can be incorporated successfully as a part of a fully automatic system for detection and counting of this type of microorganisms.
Scattering vector mesons in D4-D8 holographic QCD
Energy Technology Data Exchange (ETDEWEB)
Boschi-Filho, Henrique; Braga, Nelson; Ballon Bayona, C.A.; Torres, Marcus A.C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)
2009-07-01
Full text. Sakai and Sugimoto authored one of the most successful string top-down models in describing real QCD, the D4-D8 brane model of holographic QCD. This model succeeds in exhibiting chiral symmetry breaking and confinement.A drawback of this model is that all massive hadrons have their masses set by the Kaluza-Klein compactification scale and we would have to work at energy scales below 1 GeV in order to describe a four dimensional physics. Still, they were able to find pion form factors and pion in agreement with experiment at scale of 1 GeV and above. They also calculate pion quadratic square radius in check with experiment, from a formula that depends on the entire Kaluza-Klein tower of excited pion states. Their model also realizes vector meson dominance (VMD) in electromagnetic interaction as proposed by Sakurai in the sixties. 5D gauge fields from flavor symmetry provides a zoo of mesons (scalar, pseudo-scalar, vector and pseudo-vector) and instanton configurations of such fields are interpreted as baryon fields. Inspired by the results of pion form factors and pion quadratic radius predicted in close agreement with experiment, we further calculate vector and axial vector mesons {psi}(z) wave functions, form factors, we discuss about its Q{sup -2} power behavior at large virtuosity (Q{sup 2}), and we check necessary relations between coupling constants and masses (superconvergence) that grants such power behavior of form factors. We compare our results with what is found in bottom-up hard wall and soft wall models and discuss the problems of the D4-D8 model. (author)
Ultrasonic inspection of AA6013 laser welded joints
Directory of Open Access Journals (Sweden)
Adriano Passini
2011-09-01
Full Text Available Interest in laser beam welding for aerospace applications is continuously growing, mainly for aluminum alloys. The joints quality is usually assessed by non-destructive inspection (NDI. In this work, bead on plate laser welds on 1.6 mm thick AA6013 alloy sheets, using a 2 kW Yb-fiber laser were obtained and inspected by pulse/echo ultrasonic phased-array technique. Good and poor quality welds were inspected in order to verify the limits of inspection, comparing also to X-ray radiography and metallographic inspections. The results showed that ultrasonic phased array technique was able to identify the presence of grouped porosity, through the attenuation of the amplitude of the echo signal. This attenuation is attributed to the scattering of the waves caused by micro pores, with individual size below the resolution limit of the equipment, but when grouped, can cause a perceptive effect on the reflection spectra.
Inspection Strategies for Concrete Bridges
DEFF Research Database (Denmark)
Sørensen, John Dalsgaard; Thoft-Christensen, Palle
1989-01-01
In this paper an optimal inspection strategy for concrete bridges based on periodic routine and detailed inspections is presented. The failure mode considered is corrosion of the reinforcement due to chlorides. A simple modelling of the corrosion and of the inspection strategy is presented....... The optimal inspection strategy is determined from an optimization problem, where the design variables are time intervals between detailed inspections and the concrete cover. The strategy is illustrated on a simple structure, namely a reinforced concrete beam....
Energy Technology Data Exchange (ETDEWEB)
Heasler, P.G.; Doctor, S.R. [Pacific Northwest National Lab., Richland, WA (United States)
1996-04-01
The piping inspection round robin was conducted in 1981 at the Pacific Northwest National Laboratory (PNNL) to quantify the capability of ultrasonics for inservice inspection and to address some aspects of reliability for this type of nondestructive evaluation (NDE). The round robin measured the crack detection capabilities of seven field inspection teams who employed procedures that met or exceeded the 1977 edition through the 1978 addenda of the American Society of Mechanical Engineers (ASME) Section 11 Code requirements. Three different types of materials were employed in the study (cast stainless steel, clad ferritic, and wrought stainless steel), and two different types of flaws were implanted into the specimens (intergranular stress corrosion cracks (IGSCCs) and thermal fatigue cracks (TFCs)). When considering near-side inspection, far-side inspection, and false call rate, the overall performance was found to be best in clad ferritic, less effective in wrought stainless steel and the worst in cast stainless steel. Depth sizing performance showed little correlation with the true crack depths.
Development of an optoelectronic holographic platform for otolaryngology applications
Harrington, Ellery; Dobrev, Ivo; Bapat, Nikhil; Flores, Jorge Mauricio; Furlong, Cosme; Rosowski, John; Cheng, Jeffery Tao; Scarpino, Chris; Ravicz, Michael
2010-08-01
In this paper, we present advances on our development of an optoelectronic holographic computing platform with the ability to quantitatively measure full-field-of-view nanometer-scale movements of the tympanic membrane (TM). These measurements can facilitate otologists' ability to study and diagnose hearing disorders in humans. The holographic platform consists of a laser delivery system and an otoscope. The control software, called LaserView, is written in Visual C++ and handles communication and synchronization between hardware components. It provides a user-friendly interface to allow viewing of holographic images with several tools to automate holography-related tasks and facilitate hardware communication. The software uses a series of concurrent threads to acquire images, control the hardware, and display quantitative holographic data at video rates and in two modes of operation: optoelectronic holography and lensless digital holography. The holographic platform has been used to perform experiments on several live and post-mortem specimens, and is to be deployed in a medical research environment with future developments leading to its eventual clinical use.
Energy analysis of holographic lenses for solar concentration
Marín-Sáez, Julia; Collados, M. Victoria; Chemisana, Daniel; Atencia, Jesús
2017-05-01
The use of volume and phase holographic elements in the design of photovoltaic solar concentrators has become very popular as an alternative solution to refractive systems, due to their high efficiency, low cost and possibilities of building integration. Angular and chromatic selectivity of volume holograms can affect their behavior as solar concentrators. In holographic lenses, angular and chromatic selectivity varies along the lens plane. Besides, considering that the holographic materials are not sensitive to the wavelengths for which the solar cells are most efficient, the reconstruction wavelength is usually different from the recording one. As a consequence, not all points of the lens work at Bragg condition for a defined incident direction or wavelength. A software tool that calculates the direction and efficiency of solar rays at the output of a volume holographic element has been developed in this study. It allows the analysis of the total energy that reaches the solar cell, taking into account the sun movement, the solar spectrum and the sensitivity of the solar cell. The dependence of the recording wavelength on the collected energy is studied with this software. As the recording angle is different along a holographic lens, some zones of the lens could not act as a volume hologram. The efficiency at the transition zones between volume and thin behavior in lenses recorded in Bayfol HX is experimentally analyzed in order to decide if the energy of generated higher diffraction orders has to be included in the simulation.
Holographic display system for restoration of sight to the blind
Goetz, G. A.; Mandel, Y.; Manivanh, R.; Palanker, D. V.; Čižmár, T.
2013-10-01
Objective. We present a holographic near-the-eye display system enabling optical approaches for sight restoration to the blind, such as photovoltaic retinal prosthesis, optogenetic and other photoactivation techniques. We compare it with conventional liquid crystal displays (LCD) or digital light processing (DLP)-based displays in terms of image quality, field of view, optical efficiency and safety. Approach. We detail the optical configuration of the holographic display system and its characterization using a phase-only spatial light modulator. Main results. We describe approaches to controlling the zero diffraction order and speckle related issues in holographic display systems and assess the image quality of such systems. We show that holographic techniques offer significant advantages in terms of peak irradiance and power efficiency, and enable designs that are inherently safer than LCD or DLP-based systems. We demonstrate the performance of our holographic display system in the assessment of cortical response to alternating gratings projected onto the retinas of rats. Significance. We address the issues associated with the design of high brightness, near-the-eye display systems and propose solutions to the efficiency and safety challenges with an optical design which could be miniaturized and mounted onto goggles.
Holographic display system for restoration of sight to the blind.
Goetz, G A; Mandel, Y; Manivanh, R; Palanker, D V; Čižmár, T
2013-10-01
We present a holographic near-the-eye display system enabling optical approaches for sight restoration to the blind, such as photovoltaic retinal prosthesis, optogenetic and other photoactivation techniques. We compare it with conventional liquid crystal displays (LCD) or digital light processing (DLP)-based displays in terms of image quality, field of view, optical efficiency and safety. We detail the optical configuration of the holographic display system and its characterization using a phase-only spatial light modulator. We describe approaches to controlling the zero diffraction order and speckle related issues in holographic display systems and assess the image quality of such systems. We show that holographic techniques offer significant advantages in terms of peak irradiance and power efficiency, and enable designs that are inherently safer than LCD or DLP-based systems. We demonstrate the performance of our holographic display system in the assessment of cortical response to alternating gratings projected onto the retinas of rats. We address the issues associated with the design of high brightness, near-the-eye display systems and propose solutions to the efficiency and safety challenges with an optical design which could be miniaturized and mounted onto goggles.
AdS{sub 2} holographic dictionary
Energy Technology Data Exchange (ETDEWEB)
Cvetič, Mirjam [Department of Physics and Astronomy, University of Pennsylvania,Philadelphia, PA 19104-6396 (United States); Center for Applied Mathematics and Theoretical Physics,University of Maribor, SI2000 Maribor (Slovenia); Papadimitriou, Ioannis [SISSA and INFN - Sezione di Trieste,Via Bonomea 265, 34136 Trieste (Italy)
2016-12-02
We construct the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions. This specific model ensures that the dual theory has a well defined ultraviolet completion in terms of a two dimensional conformal field theory, but our results apply qualitatively to a wider class of two dimensional dilaton gravity theories. For each type of solutions we perform holographic renormalization, compute the exact renormalized one-point functions in the presence of arbitrary sources, and derive the asymptotic symmetries and the corresponding conserved charges. In both cases we find that the scalar operator dual to the dilaton plays a crucial role in the description of the dynamics. Its source gives rise to a matter conformal anomaly for the running dilaton solutions, while its expectation value is the only non trivial observable for constant dilaton solutions. The role of this operator has been largely overlooked in the literature. We further show that the only non trivial conserved charges for running dilaton solutions are the mass and the electric charge, while for constant dilaton solutions only the electric charge is non zero. However, by uplifting the solutions to three dimensions we show that constant dilaton solutions can support non trivial extended symmetry algebras, including the one found by Compère, Song and Strominger http://dx.doi.org/10.1007/JHEP05(2013)152, in agreement with the results of Castro and Song http://arxiv.org/abs/1411.1948. Finally, we demonstrate that any solution of this specific dilaton gravity model can be uplifted to a family of asymptotically AdS{sub 2}×S{sup 2} or conformally AdS{sub 2}×S{sup 2} solutions of the STU model in four dimensions, including non extremal black holes. The four dimensional solutions obtained by uplifting the running dilaton
Holographic duality from random tensor networks
Energy Technology Data Exchange (ETDEWEB)
Hayden, Patrick; Nezami, Sepehr; Qi, Xiao-Liang; Thomas, Nathaniel; Walter, Michael; Yang, Zhao [Stanford Institute for Theoretical Physics, Department of Physics, Stanford University,382 Via Pueblo, Stanford, CA 94305 (United States)
2016-11-02
Tensor networks provide a natural framework for exploring holographic duality because they obey entanglement area laws. They have been used to construct explicit toy models realizing many of the interesting structural features of the AdS/CFT correspondence, including the non-uniqueness of bulk operator reconstruction in the boundary theory. In this article, we explore the holographic properties of networks of random tensors. We find that our models naturally incorporate many features that are analogous to those of the AdS/CFT correspondence. When the bond dimension of the tensors is large, we show that the entanglement entropy of all boundary regions, whether connected or not, obey the Ryu-Takayanagi entropy formula, a fact closely related to known properties of the multipartite entanglement of assistance. We also discuss the behavior of Rényi entropies in our models and contrast it with AdS/CFT. Moreover, we find that each boundary region faithfully encodes the physics of the entire bulk entanglement wedge, i.e., the bulk region enclosed by the boundary region and the minimal surface. Our method is to interpret the average over random tensors as the partition function of a classical ferromagnetic Ising model, so that the minimal surfaces of Ryu-Takayanagi appear as domain walls. Upon including the analog of a bulk field, we find that our model reproduces the expected corrections to the Ryu-Takayanagi formula: the bulk minimal surface is displaced and the entropy is augmented by the entanglement of the bulk field. Increasing the entanglement of the bulk field ultimately changes the minimal surface behavior topologically, in a way similar to the effect of creating a black hole. Extrapolating bulk correlation functions to the boundary permits the calculation of the scaling dimensions of boundary operators, which exhibit a large gap between a small number of low-dimension operators and the rest. While we are primarily motivated by the AdS/CFT duality, the main
Advances in inspection automation
Weber, Walter H.; Mair, H. Douglas; Jansen, Dion; Lombardi, Luciano
2013-01-01
This new session at QNDE reflects the growing interest in inspection automation. Our paper describes a newly developed platform that makes the complex NDE automation possible without the need for software programmers. Inspection tasks that are tedious, error-prone or impossible for humans to perform can now be automated using a form of drag and drop visual scripting. Our work attempts to rectify the problem that NDE is not keeping pace with the rest of factory automation. Outside of NDE, robots routinely and autonomously machine parts, assemble components, weld structures and report progress to corporate databases. By contrast, components arriving in the NDT department typically require manual part handling, calibrations and analysis. The automation examples in this paper cover the development of robotic thickness gauging and the use of adaptive contour following on the NRU reactor inspection at Chalk River.
Holographic recording of volume phase Fresnel lenses in ZnSe semiconductor material.
Krivoshlykov, Sergei G
2017-03-10
Holographic recording of the relief-free volume phase Fresnel lenses in polycrystalline ZnSe semiconductor material, which is transparent from the visible to long-wave infrared wavelengths, is demonstrated. The room-temperature process of photomodification, which changes the refractive index of the semiconductor material dramatically (Δn=0.74-1.2) under illumination with low-intensity light, is used for recording the Fresnel lens employing a computer-generated photomask in the proximity configuration. The thin-plate volume phase diffractive optics offers broader functionality and at least three-fold cost reduction due to the saving of expensive material and labor. The possibility of recording of the volume phase diffraction gratings also in the active Cr-doped ZnSe material opens a door to the fabrication of mid-infrared lasers with narrowed and tunable emission spectra.
Ellabban, Mostafa A.; Glavan, Gašper; Flauger, Peter; Klepp, Jürgen; Fally, Martin
2017-05-01
We investigated recording and readout of transmission gratings in composites of poly(ethylene glycol) dimethacrylate (PEGDMA) and ionic liquids (IL) in detail. Gratings were recorded using a two-wave mixing technique for different grating periods, exposures and a series of film thicknesses. The recording kinetics as well as the post-exposure behavior of the gratings were studied by diffraction experiments. We found that - depending on the parameters - different grating types (pure phase or mixed) are generated, and at elevated thicknesses strong light-induced scattering develops. Gratings with thicknesses up to 85 micrometers are of the required quality with excellent optical properties, thicker gratings exhibit strong detrimental light-induced scattering. The obtained results are particularly valuable when considering PEGDMA-ionic liquid composites for applications as e.g., holographic storage materials or as neutron optic diffractive elements.
Holographic reconstruction of sound fields based on the acousto-optic effect
DEFF Research Database (Denmark)
Fernandez Grande, Efren; Torras Rosell, Antoni; Jacobsen, Finn
2013-01-01
yielding a full characterization of the sound field. In this study, a direct projection of the Radon transform from one plane to another and into the space domain, based on an elementary wave expansion is proposed. The relationship between the Radon and the wavenumber domains is examined......Recent studies have shown that it is possible to measure a sound field using acousto-optic tomography. Theacousto-optic effect, i.e., the interaction between sound and light, can be used to measure an arbitrary soundfield by scanning it with a laser Doppler vibrometer (LDV) over an aperture......; This can be described mathematically by means of the Radon transform of the acoustic field. An interesting feature of this Measurement technique is that the spatial characteristics of the sound field are captured in the measurement. Therefore, the technique has an inherent holographic potential, implicitly...
Holographic 3D imaging through diffuse media by compressive sampling of the mutual intensity
Falldorf, Claas; Klein, Thorsten; Agour, Mostafa; Bergmann, Ralf B.
2017-05-01
We present a method for holographic imaging through a volume scattering material, which is based on selfreference and light with good spatial but limited temporal coherence. In contrast to existing techniques, we do not require a separate reference wave, thus our approach provides great advantages towards the flexibility of the measurement system. The main applications are remote sensing and investigation of moving objects through gaseous streams, bubbles or foggy water for example. Furthermore, due to the common path nature, the system is also insensitive to mechanical disturbances. The measurement result is a complex amplitude which is comparable to a phase shifted digital hologramm and therefore allows 3D imaging, numerical refocusing and quantitative phase contrast imaging. As an example of application, we present measurements of the quantitative phase contrast of the epidermis of an onion through a volume scattering material.
Analytical study of holographic superconductor in Born–Infeld electrodynamics with backreaction
Directory of Open Access Journals (Sweden)
A. Sheykhi
2016-03-01
Full Text Available We extend the analytical studies on the properties of s-wave holographic superconductors in the presence of Born–Infeld nonlinear electrodynamics by taking the backreaction into account. We find that even in the case of nonlinear electrodynamics, one can still employ the analytical method when the backreaction is turned on. In our calculations, we use the variational method which is based on the Sturm–Liouville eigenvalue problem. For this system, we obtain the relation between the critical temperature and the charge density. We find that both backreaction and Born–Infeld parameters decrease the critical temperature of the superconductor and make the condensation harder. Finally, we compute the critical exponent associated with the condensation near the critical temperature and find that it equals 1/2 which is the universal value in the mean field theory.
Analytical study of holographic superconductor in Born–Infeld electrodynamics with backreaction
Energy Technology Data Exchange (ETDEWEB)
Sheykhi, A., E-mail: asheykhi@shirazu.ac.ir [Physics Department and Biruni Observatory, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of); Shaker, F. [Physics Department and Biruni Observatory, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)
2016-03-10
We extend the analytical studies on the properties of s-wave holographic superconductors in the presence of Born–Infeld nonlinear electrodynamics by taking the backreaction into account. We find that even in the case of nonlinear electrodynamics, one can still employ the analytical method when the backreaction is turned on. In our calculations, we use the variational method which is based on the Sturm–Liouville eigenvalue problem. For this system, we obtain the relation between the critical temperature and the charge density. We find that both backreaction and Born–Infeld parameters decrease the critical temperature of the superconductor and make the condensation harder. Finally, we compute the critical exponent associated with the condensation near the critical temperature and find that it equals 1/2 which is the universal value in the mean field theory.
Bubble nucleation dynamics in 3He/4He mixture by holographic interferometry
Morikawa, M.; Abe, H.; Nomura, R.; Okuda, Y.
2009-02-01
We were able to nucleate a gas bubble in the diluted phase of 3He-4He mixture by a 1 ms width strong sound pulse. The nucleated bubble became large and detached from the bottom transducer and was pushed out to the bulk liquid by the acoustic wave pulse. The bubble then repeatedly expanded and contracted a few times and finally disappeared. The overall motion of the bubble was traced by a high speed camera with a time resolution of 1 ms. We are attempting to investigate the small density fluctuation around the bubble by incorporating holographic interferometry technology. The measurement was done at T=0.35 K for the phase separated mixture at saturated vapor pressure. An acoustic wave transducer was located at the bottom of the cell, so the bubble was nucleated in the dilute phase of the mixture. We resolved the density fluctuation as small as Δρ/ρ = 2 × 10-6 in the dilute phase with the sample width of 25 mm, which could not be obtained by other methods. It was found that there appeared a less dense region of —Δρ/ρ approx 1.46 × 10-3 just above the bubble. The bubble appeared just after the pulse was turned off, but this less dense region appeared prior to the emergence of the bulk bubble. It should be an important information about the bubble nucleation mechanism. This very high sensitivity of holographic interferometry with respect to the density fluctuation could be widely used in quantum liquid.
Holographic equilibration under external dynamical electric field
Directory of Open Access Journals (Sweden)
M. Ali-Akbari
2017-10-01
Full Text Available The holographic equilibration of a far-from-equilibrium strongly coupled gauge theory is investigated. In particular, the dynamics of a probe D7-brane in an AdS-Vaidya background is studied in the presence of an external time-dependent electric field. Defining the equilibration times teqc and teqj, at which condensation and current relax to their final equilibrated values, receptively, the smallness of transition time kM or kE is enough to observe a universal behaviour for re-scaled equilibration times kMkE(teqc−2 and kMkE(teqj−2. kM(kE is the time interval in which the temperature (electric field increases from zero to finite value. Moreover, regardless of the values for kM and kE, teqc/teqj also behaves universally for large enough value of the ratio of the final electric field to final temperature. Then a simple discussion of the static case reveals that teqc≤teqj. For an out-of-equilibrium process, our numerical results show that, apart from the cases for which kE is small, the static time-ordering, that is teqc≤teqj, persists.
A holographic model for quantum critical responses
Energy Technology Data Exchange (ETDEWEB)
Myers, Robert C. [Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2L 2Y5 (Canada); Sierens, Todd [Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2L 2Y5 (Canada); Department of Physics & Astronomy and Guelph-Waterloo Physics Institute,University of Waterloo,Waterloo, Ontario N2L 3G1 (Canada); Witczak-Krempa, William [Department of Physics, Harvard University,Cambridge, MA 02138 (United States)
2016-05-12
We analyze the dynamical response functions of strongly interacting quantum critical states described by conformal field theories (CFTs). We construct a self-consistent holographic model that incorporates the relevant scalar operator driving the quantum critical phase transition. Focusing on the finite temperature dynamical conductivity σ(ω,T), we study its dependence on our model parameters, notably the scaling dimension of the relevant operator. It is found that the conductivity is well-approximated by a simple ansatz proposed in http://dx.doi.org/10.1103/PhysRevB.90.245109 for a wide range of parameters. We further dissect the conductivity at large frequencies ω≫T using the operator product expansion, and show how it reveals the spectrum of our model CFT. Our results provide a physically-constrained framework to study the analytic continuation of quantum Monte Carlo data, as we illustrate using the O(2) Wilson-Fisher CFT. Finally, we comment on the variation of the conductivity as we tune away from the quantum critical point, setting the stage for a comprehensive analysis of the phase diagram near the transition.
Holographic quenches in a confined phase
Myers, Robert C.; Rozali, Moshe; Way, Benson
2017-12-01
We investigate quenches of holographic theories in a confined phase, where the energy injected is insufficient to reach the deconfined phase. In such quenches, thermalization is not associated with gravitational collapse and the formation of a black hole. Nevertheless, we attempt to characterize the late-time state of this scenario. We check a number of notions of thermalization that do not require horizon formation, and find no evidence for thermalization, or even equilibration, for our chosen parameters and initial states. We find that the post-quench behaviour of both local and nonlocal observables exhibit oscillatory behaviour rather than decaying towards equilibrium. We generally find that the response of the nonlocal observables is smoother than that of the local ones. We discuss mechanisms which generate such smoothing, as well as ‘beats’ which appear in the time-dependence of the nonlocal operators for certain classes of quenches. When tuning the quench parameters such that the smoothing is ineffective, we are able to perform ‘entanglement spectroscopy, recovering the spectrum of the confined phase of the theory from the time dependence of the entanglement entropy, as well as other nonlocal observables.
Scanning for piecewise holographic grating generation
Miler, Miroslav; Kostka, František; Dvořák, Martin
2006-03-01
Holographic gratings that are recorded as a whole in a single exposition are limited in size because of the available power of suitable laser sources and nonlinear response of and/or reciprocity effects in a recording medium. A sequential-illumination technique can help in this case. This technique relies on piecewise grating recording that consists in scanning with a relatively narrow laser beam, a pencil, across the grating surface employing an appropriate optical set up. The contribution describes a method utilizing a small parallel displacement of the laser pencil by turning a plane-parallel plate, which is then transferred to a larger angular deflection by a short focus lens. Simultaneously, the beam is expanded angularly. This all can take place either before light enters the beam-splitter or along paths of both the interfering beams. In this way, uniform diffraction efficiency gratings that are much larger than the cross-section of the beam can be achieved. The laser pencil can be moved in polar or rectangular coordinates. Recording of larger gratings supposes large precise collimating mirrors. If they are not available e.g. due to their high price, they can be replaced by long propagating homocentric beams with their origins in the same distance from the recording plate.
Unitarity and the Holographic S-Matrix
Energy Technology Data Exchange (ETDEWEB)
Fitzpatrick, A.Liam; /Stanford U., Phys. Dept.; Kaplan, Jared; /SLAC
2012-08-28
The bulk S-Matrix can be given a non-perturbative definition in terms of the flat space limit of AdS/CFT. We show that the unitarity of the S-Matrix, ie the optical theorem, can be derived by studying the behavior of the OPE and the conformal block decomposition in the flat space limit. When applied to perturbation theory in AdS, this gives a holographic derivation of the cutting rules for Feynman diagrams. To demonstrate these facts we introduce some new techniques for the analysis of conformal field theories. Chief among these is a method for conglomerating local primary operators O{sub 1} and O{sub 2} to extract the contribution of an individual primary O{sub {Delta},{ell}} in their OPE. This provides a method for isolating the contribution of specific conformal blocks which we use to prove an important relation between certain conformal block coefficients and anomalous dimensions. These techniques make essential use of the simplifications that occur when CFT correlators are expressed in terms of a Mellin amplitude.
Thermalization in a holographic confining gauge theory
Energy Technology Data Exchange (ETDEWEB)
Ishii, Takaaki [Crete Center for Theoretical Physics, Department of Physics, University of Crete,71003 Heraklion (Greece); Kiritsis, Elias [Crete Center for Theoretical Physics, Department of Physics, University of Crete,71003 Heraklion (Greece); APC, University Paris Diderot, Sorbonne Paris Cité, UMR 7164 CNRS,10, rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); Rosen, Christopher [Crete Center for Theoretical Physics, Department of Physics, University of Crete,71003 Heraklion (Greece)
2015-08-03
Time dependent perturbations of states in the holographic dual of a 3+1 dimensional confining theory are considered. The perturbations are induced by varying the coupling to the theory’s most relevant operator. The dual gravitational theory belongs to a class of Einstein-dilaton theories which exhibit a mass gap at zero temperature and a first order deconfining phase transition at finite temperature. The perturbation is realized in various thermal bulk solutions by specifying time dependent boundary conditions on the scalar, and we solve the fully backreacted Einstein-dilaton equations of motion subject to these boundary conditions. We compute the characteristic time scale of many thermalization processes, noting that in every case we examine, this time scale is determined by the imaginary part of the lowest lying quasi-normal mode of the final state black brane. We quantify the dependence of this final state on parameters of the quench, and construct a dynamical phase diagram. Further support for a universal scaling regime in the abrupt quench limit is provided.
Harmonic resolution as a holographic quantum number
Energy Technology Data Exchange (ETDEWEB)
Bousso, Raphael
2004-01-31
The Bekenstein bound takes the holographic principle into the realm of flat space, promising new insights on the relation of non-gravitational physics to quantum gravity. This makes it important to obtain a precise formulation of the bound. Conventionally, one specifies two macroscopic quantities, mass and spatial width, which cannot be simultaneously diagonalized. Thus, the counting of compatible states is not sharply defined. The resolution of this and other formal difficulties leads naturally to a definition in terms of discretized light-cone quantization. In this form, the area difference specified in the covariant bound converts to a single quantum number, the harmonic resolution K. The Bekenstein bound then states that the Fock space sector with K units of longitudinal momentum contains no more than exp(2 pi^2 K) independent discrete states. This conjecture can be tested unambiguously for a given Lagrangian, and it appears to hold true for realistic field theories, including models arising from string compactifications. For large K, it makes contact with more conventional but less well-defined formulations.
Holographic free-electron light source
Li, Guanhai; Clarke, Brendan P.; So, Jin-Kyu; MacDonald, Kevin F.; Zheludev, Nikolay I.
2016-12-01
Recent advances in the physics and technology of light generation via free-electron proximity and impact interactions with nanostructures (gratings, photonic crystals, nano-undulators, metamaterials and antenna arrays) have enabled the development of nanoscale-resolution techniques for such applications as mapping plasmons, studying nanoparticle structural transformations and characterizing luminescent materials (including time-resolved measurements). Here, we introduce a universal approach allowing generation of light with prescribed wavelength, direction, divergence and topological charge via point-excitation of holographic plasmonic metasurfaces. It is illustrated using medium-energy free-electron injection to generate highly-directional visible to near-infrared light beams, at selected wavelengths in prescribed azimuthal and polar directions, with brightness two orders of magnitude higher than that from an unstructured surface, and vortex beams with topological charge up to ten. Such emitters, with micron-scale dimensions and the freedom to fully control radiation parameters, offer novel applications in nano-spectroscopy, nano-chemistry and sensing.
Analyticity and the Holographic S-Matrix
Energy Technology Data Exchange (ETDEWEB)
Fitzpatrick, A.Liam; /Stanford U., Phys. Dept.; Kaplan, Jared; /SLAC
2012-04-03
We derive a simple relation between the Mellin amplitude for AdS/CFT correlation functions and the bulk S-Matrix in the flat spacetime limit, proving a conjecture of Penedones. As a consequence of the Operator Product Expansion, the Mellin amplitude for any unitary CFT must be a meromorphic function with simple poles on the real axis. This provides a powerful and suggestive handle on the locality vis-a-vis analyticity properties of the S-Matrix. We begin to explore analyticity by showing how the familiar poles and branch cuts of scattering amplitudes arise from the holographic description. For this purpose we compute examples of Mellin amplitudes corresponding to 1-loop and 2-loop Witten diagrams in AdS. We also examine the flat spacetime limit of conformal blocks, implicitly relating the S-Matrix program to the Bootstrap program for CFTs. We use this connection to show how the existence of small black holes in AdS leads to a universal prediction for the conformal block decomposition of the dual CFT.
Exploring neural cell dynamics with digital holographic microscopy
Marquet, Pierre
2013-07-11
In this review, we summarize how the new concept of digital optics applied to the field of holographic microscopy has allowed the development of a reliable and flexible digital holographic quantitative phase microscopy (DH-QPM) technique at the nanoscale particularly suitable for cell imaging. Particular emphasis is placed on the original biological ormation provided by the quantitative phase signal. We present the most relevant DH-QPM applications in the field of cell biology, including automated cell counts, recognition, classification, three-dimensional tracking, discrimination between physiological and pathophysiological states, and the study of cell membrane fluctuations at the nanoscale. In the last part, original results show how DH-QPM can address two important issues in the field of neurobiology, namely, multiple-site optical recording of neuronal activity and noninvasive visualization of dendritic spine dynamics resulting from a full digital holographic microscopy tomographic approach. Copyright © 2013 by Annual Reviews.
Covariant generalized holographic dark energy and accelerating universe
Energy Technology Data Exchange (ETDEWEB)
Nojiri, Shin' ichi [Nagoya University, Department of Physics, Nagoya (Japan); Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya (Japan); Odintsov, S.D. [ICREA, Barcelona (Spain); Institute of Space Sciences (IEEC-CSIC), Barcelona (Spain); National Research Tomsk State University, Tomsk (Russian Federation); Tomsk State Pedagogical University, Tomsk (Russian Federation)
2017-08-15
We propose the generalized holographic dark energy model where the infrared cutoff is identified with the combination of the FRW universe parameters: the Hubble rate, particle and future horizons, cosmological constant, the universe lifetime (if finite) and their derivatives. It is demonstrated that with the corresponding choice of the cutoff one can map such holographic dark energy to modified gravity or gravity with a general fluid. Explicitly, F(R) gravity and the general perfect fluid are worked out in detail and the corresponding infrared cutoff is found. Using this correspondence, we get realistic inflation or viable dark energy or a unified inflationary-dark energy universe in terms of covariant holographic dark energy. (orig.)
Future of photorefractive based holographic 3D display
Blanche, P.-A.; Bablumian, A.; Voorakaranam, R.; Christenson, C.; Lemieux, D.; Thomas, J.; Norwood, R. A.; Yamamoto, M.; Peyghambarian, N.
2010-02-01
The very first demonstration of our refreshable holographic display based on photorefractive polymer was published in Nature early 20081. Based on the unique properties of a new organic photorefractive material and the holographic stereography technique, this display addressed a gap between large static holograms printed in permanent media (photopolymers) and small real time holographic systems like the MIT holovideo. Applications range from medical imaging to refreshable maps and advertisement. Here we are presenting several technical solutions for improving the performance parameters of the initial display from an optical point of view. Full color holograms can be generated thanks to angular multiplexing, the recording time can be reduced from minutes to seconds with a pulsed laser, and full parallax hologram can be recorded in a reasonable time thanks to parallel writing. We also discuss the future of such a display and the possibility of video rate.
Holographic stereogram using camera array in dense arrangement
Yamamoto, Kenji; Oi, Ryutaro; Senoh, Takanori; Ichihashi, Yasuyuki; Kurita, Taiichiro
2011-02-01
Holographic stereograms can display 3D objects by using ray information. To display high quality representations of real 3D objects by using holographic stereograms, relatively dense ray information must be prepared as the 3D object information. One promising method of obtaining this information uses a combination of a camera array and view interpolation which is signal processing technique. However, it is still technically difficult to synthesize ray information without visible error by using view interpolation. Our approach uses a densely arranged camera array to reduce this difficulty. Even though view interpolation is a simple signal processing technique, the synthesized ray information produced by this camera array should be adequate. We designed and manufactured a densely arranged camera array and used it to generate holographic stereograms.
Interacting holographic dark energy models: A general approach
Som, S
2014-01-01
Dark energy models inspired by the cosmological holographic principle are studied in homogeneous isotropic spacetime with a general choice for the dark energy density $\\rho_d=3(\\alpha H^2+\\beta\\dot{H})$. Special choices of the parameters enable us to obtain three different holographic models, including the holographic Ricci dark energy(RDE) model. Effect of interaction between dark matter and dark energy on the dynamics of those models are investigated for different popular forms of interaction. It is found that crossing of phantom divide can be avoided in RDE models for $\\beta>0.5$ irrespective of the presence of interaction. A choice of $\\alpha=1$ and $\\beta=2/3$ leads to a varying $\\Lambda$-like model introducing an IR cutoff length $\\Lambda^{-1/2}$. It is concluded that among the popular choices an interaction of the form $Q\\propto H\\rho_m$ suits the best in avoiding the coincidence problem in this model.
Diffraction model of peristrophic multiplexing with spherical reference wave.
Yoshida, Shuhei; Takahata, Yosuke; Horiuchi, Shuma; Yamamoto, Manabu
2015-02-01
Multiplexing recording is a primary contributor to determining the recording density in holographic data storage. Therefore, many different kinds of recording methods have been proposed. Among them, the method that utilizes spherical waves as reference waves is characterized by the ability to enable multiplexing recording only by moving (shifting or rotating) the recording medium. In our research, we propose a theoretical diffraction model of peristrophic multiplexing with a spherical reference wave and evaluate the diffraction efficiency; this multiplexing recording method has incorporated spherical reference waves in rotation of the media. Additionally, we verify the effectiveness of the model by comparing it with experimental results.
Subsea Infrastructure Inspection
DEFF Research Database (Denmark)
Mai, Christian; Pedersen, Simon; Hansen, Leif
2016-01-01
of the offshore pipeline inspections are currently committed using Towed or Remotely Operated Vehicle (ROV) systems. It is well-known that the ROVs are very time-consuming and expensive to operate, with respect to the fact that they require a relatively large support ship to accommodate the equipment as well...
A pre-demolition inspection may be one of the most helpful and cost-efficient steps you can take to identify materials that should (or must) be removed from buildings prior to demolition. In some cases it may be required by regulation.
Automatic Inspection During Machining
Ransom, Clyde L.
1988-01-01
In experimental manufacturing process, numerically-controlled machine tool temporarily converts into inspection machine by installing electronic touch probes and specially-developed numerical-control software. Software drives probes in paths to and on newly machined parts and collects data on dimensions of parts.
Innovative Inspection Techniques
1993-01-01
Shearography ...................................... 45 5.14 Vibration M onitoring . ................................ 46 5.15 NDT Summary...41 Figure 15 Acoustic Emissions System for Experiments ..................... 42 Figure 16 X-Ray Test Equipment...equipment needed for a remote video system that could be used in marine inspection. ix Executive Summary This report provides the results of a three phase
Imaging and Measuring Electron Beam Dose Distributions Using Holographic Interferometry
DEFF Research Database (Denmark)
Miller, Arne; McLaughlin, W. L.
1975-01-01
Holographic interferometry was used to image and measure ionizing radiation depth-dose and isodose distributions in transparent liquids. Both broad and narrowly collimated electron beams from accelerators (2–10 MeV) provided short irradiation times of 30 ns to 0.6 s. Holographic images...... and measurements of absorbed dose distributions were achieved in liquids of various densities and thermal properties and in water layers thinner than the electron range and with backings of materials of various densities and atomic numbers. The lowest detectable dose in some liquids was of the order of a few k...
Holographic Ward identities for symmetry breaking in two dimensions
Energy Technology Data Exchange (ETDEWEB)
Argurio, Riccardo [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Giribet, Gaston [Martin Fisher School of Physics, Brandeis University,Waltham, Massachusetts 02453 (United States); Physics Department, University of Buenos Aires FCEN-UBA and IFIBA-CONICET,Ciudad Universitaria, Pabellón I, 1428, Buenos Aires (Argentina); Marzolla, Andrea; Naegels, Daniel [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Sierra-Garcia, J. Anibal [Department of Particle Physics and IGFAE, University of Santiago de Compostela,E-15782 Santiago de Compostela (Spain)
2017-04-03
We investigate symmetry breaking in two-dimensional field theories which have a holographic gravity dual. Being at large N, the Coleman theorem does not hold and Goldstone bosons are expected. We consider the minimal setup to describe a conserved current and a charged operator, and we perform holographic renormalization in order to find the correct Ward identities describing symmetry breaking. This involves some subtleties related to the different boundary conditions that a vector can have in the three-dimensional bulk. We establish which is the correct prescription that yields, after renormalization, the same Ward identities as in higher dimensions.
Generalized holographic dark energy model described at the Hubble length
Malekjani, M
2012-01-01
We generalize the holographic dark energy model described in Hubble length IR cutoff by assuming a slowly time varying function for holographic parameter $c^2$. We calculate the evolution of EoS parameter and the deceleration parameter as well as the evolution of dark energy density in this generalized model. We show that the phantom line is crossed from quintessence regime to phantom regime which is in agreement with observation. The evolution of deceleration parameter indicates the transition from decelerated to accelerated expansion. Eventually, we show that the GHDE with HIR cutoff can interpret the pressureless dark matter era at the early time and dark energy dominated phase later.
Holographic entanglement entropy close to quantum phase transitions
Energy Technology Data Exchange (ETDEWEB)
Ling, Yi [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing 100049 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences, Beijing 100190 (China); Liu, Peng; Niu, Chao [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing 100049 (China); Wu, Jian-Pin [Institute of Gravitation and Cosmology, Department of Physics,School of Mathematics and Physics, Bohai University, Jinzhou 121013 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences, Beijing 100190 (China); Xian, Zhuo-Yu [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing 100049 (China)
2016-04-19
We investigate the holographic entanglement entropy (HEE) of a strip geometry in four dimensional Q-lattice backgrounds, which exhibit metal-insulator transitions in the dual field theory. Remarkably, we find that the HEE always displays a peak in the vicinity of the quantum critical points. Our model provides the first direct evidence that the HEE can be used to characterize the quantum phase transition (QPT). We also conjecture that the maximization behavior of HEE at quantum critical points would be universal in general holographic models.
Big Lake Dam Inspection Report
US Fish and Wildlife Service, Department of the Interior — This report summarizes an inspection of the Big Lake Dam that was done in September of 1983. The inspection did not reveal any conditions that constitute and...
Guide for Ship Structural Inspections
1990-08-02
000- 1000, Naval Ship Systems Command, 1968. (7) "IH1 SPAIS - The Shipbuilding Process and Inspection Standard", Ishikawajima - Harima Heavy Industries Co...each subsequent special survey. IHI Japanese shipyard: " Ishikawajima Harima Heavy Industries " "In-Service" Inspection Inspections performed on the...specifying inspections in excess of what is necessary to ensure structural integrity of the completed vessel, an extra heavy cost burden may be imposed
Phase transitions in a holographic s + p model with back-reaction
Energy Technology Data Exchange (ETDEWEB)
Nie, Zhang-Yu [Kunming University of Science and Technology, Kunming (China); Chinese Academy of Sciences, State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); Shanghai Jiao Tong University, INPAC, Department of Physics, and Shanghai Key Laboratory of Particle Physics and Cosmology, Shanghai (China); Cai, Rong-Gen [Chinese Academy of Sciences, State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); Gao, Xin [Virginia Tech, Department of Physics, Blacksburg, VA (United States); Li, Li [University of Crete, Department of Physics, Crete Center for Theoretical Physics, Heraklion (Greece); Zeng, Hui [Kunming University of Science and Technology, Kunming (China); Chinese Academy of Sciences, State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China)
2015-11-15
In a previous paper (Nie et al. in JHEP 1311:087, arXiv:1309.2204 [hep-th], 2013), we presented a holographic s + p superconductor model with a scalar triplet charged under an SU(2) gauge field in the bulk. We also study the competition and coexistence of the s-wave and p-wave orders in the probe limit. In this work we continue to study the model by considering the full back-reaction. The model shows a rich phase structure and various condensate behaviors such as the ''n-type'' and ''u-type'' ones, which are also known as reentrant phase transitions in condensed matter physics. The phase transitions to the p-wave phase or s + p coexisting phase become first order in strong back-reaction cases. In these first order phase transitions, the free energy curve always forms a swallow tail shape, in which the unstable s + p solution can also play an important role. The phase diagrams of this model are given in terms of the dimension of the scalar order and the temperature in the cases of eight different values of the back-reaction parameter, which show that the region for the s + p coexisting phase is enlarged with a small or medium back-reaction parameter but is reduced in the strong back-reaction cases. (orig.)
Optimal Risk-Based Inspection Planning for Offshore Wind Turbines
DEFF Research Database (Denmark)
Rangel-Ramirez, Jose G.; Sørensen, John Dalsgaard
2008-01-01
, inspection and maintenance activities are developed. This paper considers aspects of inspection and maintenance planning of fatigue prone details in jacket and tripod types of wind turbine support structures. Based oil risk-based inspection planning methods used for oil & gas installations, a framework......Wind turbines for electricity production have increased significantly the last years both in production capability and size. This development is expected to continue also in the coining years. The Support structure for offshore wind turbines is typically a steel structure consisting of a tower...... for optimal inspection and maintenance planning of offshore wind turbines is presented. Special aspects for offshore wind turbines are considered: usually the wind loading are dominating the wave loading, wake effects in wind farms are important and the reliability level is typically significantly lower than...
Development of integral holographic motion pictures
Alexander, P.
1995-02-01
In 1985 Anne-Marie Christakis selected me to make the first pulse holographic feature-fiction movie. Up to that time, the process had only been used for laboratory tests. The running time for the movie was to be 1 minute 20 seconds. Apparently quite long compared with previous tests, but an extremely short time in which to tell a story. I chose the characters of Beauty and the Beast. A lot of time was spent in preparatory work: triple distilling the scenario to get it down to 80 seconds; paintings and masks, and I extracted the music from a suite I had already written in medieval style. The movie was made in 1986 in the laboratory of Professeur Smigielsky, which was located in the Franco-German Defense Research Establishment, at St. Louis in France. Prof. Smigielsky's staff operated all the equipment and Anne-Marie Christakis coordinated everything, as she had done throughout the project. As soon as we arrived at the laboratory, we were told not to look beyond a certain angle towards the laser, otherwise we could be blinded for life. With all that dangerous power however, it was only possible to illuminate a volume for the set of half a meter wide by half a meter deep by one third of a meter high. Such a set gives real meaning to the expression `cramp one's style.' The layout used was, in principle, the same as for making a simple hologram. A pulsed YAG laser was used and each pulse was synchronized with a new frame to be exposed in the camera. When the movie was finished, it was not very bright, and one had to look through a small aperture to view it.
Overview of the software inspection process
Energy Technology Data Exchange (ETDEWEB)
Lane, G.L.; Dabbs, R. [Sandia National Labs., Albuquerque, NM (United States)
1997-11-01
This tutorial introduces attendees to the Inspection Process and teaches them how to organize and participate in a software inspection. The tutorial advocates the benefits of inspections and encourages attendees to socialize the inspection process in their organizations.
Track inspection planning and risk measurement analysis.
2014-11-01
This project models track inspection operations on a railroad network and discusses how the inspection results can : be used to measure the risk of failure on the tracks. In particular, the inspection times of the tracks, inspection frequency of the ...
THz imaging techniques for nondestructive inspections
Kawase, Kodo; Shibuya, Takayuki; Hayashi, Shin'ichiro; Suizu, Koji
2010-08-01
We have suggested a wide range of real-life applications using novel terahertz imaging techniques. A high-resolution terahertz tomography has been demonstrated by ultra short terahertz pulses using optical fiber and a nonlinear organic crystal. We also describe a nondestructive inspection system that can monitor the soot distribution in a ceramic filter using millimeter-to-terahertz wave computed tomography. Further, we report on the thickness measurement of very thin films using high-sensitivity metal mesh filter. These techniques are directly applicable to the nondestructive testing in industries.
Cleareye In-Ground and In-Concrete DIV Inspections: FY11 Final Report
Energy Technology Data Exchange (ETDEWEB)
Braatz, Brett G.; Tedeschi, Jonathan R.; Denslow, Kayte M.; Morra, Marino; Knopik, Clint D.; Severtsen, Ronald H.; Jones, Anthony M.; Lechelt, Wayne M.; McMakin, Douglas L.; Good, Morris S.; Sorensen, Jerry B.; Hall, Thomas E.
2012-01-23
This report summarizes the results of a series of feasibility testing studies for in-ground and in-concrete imaging/detection technologies including radar imaging and acoustic time-of flight method. The objectives of this project are: (1) Design Information Verification (DIV) Tools for In-Concrete Inspections - To determine the feasibility of using holographic radar imaging (HRI), radar imaging, and acoustic time-of-flight (TOF) non-destructive evaluation technologies to detect, locate and identify pipes and voids embedded in standard-density and high-density concrete walls that typify those the IAEA will need to verify during field inspections; (2) DIV Tools for In-Ground Inspections - To determine the feasibility of using HRI and radar imaging non-destructive evaluation technologies to detect, locate, and identify objects buried at various depths made of various materials (metal, plastic, wood, and concrete) and representing geometries that typify those the IAEA will need to verify during field inspections; and (3) Based on the results of the studies, recommend the next steps needed to realize fieldable tools for in-concrete and in-ground inspections (including detection of deeply buried polyvinyl chloride [PVC] pipes) that employ the technologies shown to be feasible.
Inspection tester for explosives
Haas, Jeffrey S.; Simpson, Randall L.; Satcher, Joe H.
2007-11-13
An inspection tester that can be used anywhere as a primary screening tool by non-technical personnel to determine whether a surface contains explosives. It includes a body with a sample pad. First and second explosives detecting reagent holders and dispensers are operatively connected to the body and the sample pad. The first and second explosives detecting reagent holders and dispensers are positioned to deliver the explosives detecting reagents to the sample pad. A is heater operatively connected to the sample pad.
A Position, Scale, and Rotation Invariant Holographic Associative Memory
1988-12-01
printed on the Imagen Laser printer. An example is seen in Figure 20. A photographic negative of this laser plot was obtained from the Base Photo Lab...22. White, H. J. et al. " Digital and Analogue Holographic Associative Memories," Optics Letters, 11: 30-37 (January 1988). 23. Walrond, Capt Thomas
Expressions for third-order aberration theory for holographic images
Indian Academy of Sciences (India)
Expressions for third-order aberration theory for holographic images. S K Tripathy S Ananda Rao. Brief Reports Volume 60 Issue 1 January 2003 pp 151-157 ... Author Affiliations. S K Tripathy1 S Ananda Rao1. Department of Physics, Jagannath Institute for Technology and Management, Parlakhemundi 761 200, India ...
Evolution of holographic dark energy with interaction term Q ...
Indian Academy of Sciences (India)
Abstract. A flat FLRW Universe with dark matter and dark energy, which are interacting with each other, is considered. The dark energy is represented by the holographic dark energy model and the interaction term is taken as proportional to the dark energy density. We have studied the cosmological evolution and analysed ...
Digital wavelength-multiplexed holographic data storage system
Lande, David; Heanue, John F.; Bashaw, Matthew C.; Hesselink, Lambertus
1996-11-01
We present a novel digital holographic data storage system based on wavelength multiplexing in 90 degrees geometry, using an automated tunable diode laser and a lithium niobate crystal. The automatic storage and retrieval of a 60-kbyte data file, as well as the limitations and future implementations of the system, are discussed.
Massive pions, anomalies and baryons in holographic QCD
Energy Technology Data Exchange (ETDEWEB)
Domenech, O. [Departament de Fisica and IFAE, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Panico, G., E-mail: panico@phys.ethz.c [Institute for Theoretical Physics, ETH Zurich, 8093 Zurich (Switzerland); Wulzer, A. [Institut de Theorie des Phenomenes Physiques, EPFL, CH-1015 Lausanne (Switzerland)
2011-03-01
We consider a holographic model of QCD, obtained by a very simple modification of the original construction, which describes at the same time the pion mass, the QCD anomalies and the baryons as topological solitons. We study in detail its phenomenological implications in both the mesonic and baryonic sectors and compare with the observations.
A 3D acquisition method for holographic display
Yue, Weirui; Liu, Jingdan; Situ, Guohai
2014-11-01
It is well known that holographic display can provide 3D scenes with continuous viewpoints and is free of accommodation-convergence conflict. So far most of the research in this area focuses on the display end, leaving the acquisition end merely explored. For holographic content acquisition, one needs to capture the scene in 3D. Ways to do this include the traditional optical holography and integral imaging. However, optical holography suffers from serious speckle while integral imaging has a long march to increase the resolution. In this paper, we propose a technique based on a variation of the transport of intensity equation to calculate the "phase" information of a scene from its defocusd intensity captured by a color camera under white light illumination. With the defocused phase and intensity data at hand, we can calculate the infocused wavefront of the scene, and further encode it into a computer generated hologram for subsequent holographic display. We demonstrate the proposed technique by simulation and experimental results. Compared with existing 3D acquisition techniques for holographic display, our method may provide better viewing experience due to the free of speckle in the acquisition stage, as well as the fact that the resolution does not limited by the microlenslet.
Relaxation effect of stilbene azobenzene derivatives on their holographic properties
Energy Technology Data Exchange (ETDEWEB)
Saharov, D; Ozols, A; Kokars, V; Kampars, V; Mezinskis, G; Maleckis, A; Pludons, A; Jansone, M [Riga Technical University, Faculty of Material Science and Applied Chemistry, Azenes 14/24, LV-1048, Riga (Latvia)
2007-12-15
The material relaxation effect on holographic properties of stilbene azobenzene derivatives in the form of glassy films has been experimentally studied. Holographic grating recording with the period of 2 {mu}m was made by a He-Ne laser at 633 nm in the self-diffraction mode. The readout was made simultaneously in order to follow the fast self-diffraction efficiency changes. The existence of the optimal material storage time (6-51 day) is established enabling the most efficient recording. Material relaxation amplitude and the holographic recording efficiency increased when the chromophore concentration was increased, especially above the threshold of about 70 mass %. It is also found that 633 nm recording due to the modulation of refraction and absorption indices is accompanied by the formation of surface relief grating. The conclusion is made that holographic recording in stilbene azobenzene derivatives at 633 nm is due to the chromophore reorientation by linearly polarized light possibly including trans-cis-trans transformations.
Prospects of linear reconstruction in atomic resolution electron holographic tomography
Energy Technology Data Exchange (ETDEWEB)
Krehl, Jonas, E-mail: Jonas.Krehl@triebenberg.de; Lubk, Axel
2015-03-15
Tomography commonly requires a linear relation between the measured signal and the underlying specimen property; for Electron Holographic Tomography this is given by the Phase Grating Approximation (PGA). While largely valid at medium resolution, discrepancies arise at high resolution imaging conditions. We set out to investigate the artefacts that are produced if the reconstruction still assumes the PGA even with an atomic resolution tilt series. To forego experimental difficulties the holographic tilt series was simulated. The reconstructed electric potential clearly shows peaks at the positions of the atoms. These peaks have characterisitic deformations, which can be traced back to the defocus a particular atom has in the holograms of the tilt series. Exchanging an atom for one of a different atomic number results in a significant change in the reconstructed potential that is well contained within the atom's peak. - Highlights: • We simulate a holographic tilt series of a nanocrystal with atomic resolution. • Using PGA-based Holographic Tomography we reconstruct the atomic structure. • The reconstruction shows characteristic artefacts, chiefly caused by defocus. • Changing one atom's Z produces a well localised in the reconstruction.
Realization of an optical interferometer based on holographic optics ...
Indian Academy of Sciences (India)
Keywords. Interferometry; holography; optical testing instruments. Abstract. The paper describes a simple and cost effective method for the realization of an optical interferometer based on holographic optics, which use minimal bulk optical components. The optical arrangement in the proposed method involves a very simple ...
Multispectral digital holographic microscopy with applications in water quality assessment
Kazemzadeh, Farnoud; Jin, Chao; Yu, Mei; Amelard, Robert; Haider, Shahid; Saini, Simarjeet; Emelko, Monica; Clausi, David A.; Wong, Alexander
2015-09-01
Safe drinking water is essential for human health, yet over a billion people worldwide do not have access to safe drinking water. Due to the presence and accumulation of biological contaminants in natural waters (e.g., pathogens and neuro-, hepato-, and cytotoxins associated with algal blooms) remain a critical challenge in the provision of safe drinking water globally. It is not financially feasible and practical to monitor and quantify water quality frequently enough to identify the potential health risk due to contamination, especially in developing countries. We propose a low-cost, small-profile multispectral (MS) system based on Digital Holographic Microscopy (DHM) and investigate methods for rapidly capturing holographic data of natural water samples. We have developed a test-bed for an MSDHM instrument to produce and capture holographic data of the sample at different wavelengths in the visible and the near Infra-red spectral region, allowing for resolution improvement in the reconstructed images. Additionally, we have developed high-speed statistical signal processing and analysis techniques to facilitate rapid reconstruction and assessment of the MS holographic data being captured by the MSDHM instrument. The proposed system is used to examine cyanobacteria as well as Cryptosporidium parvum oocysts which remain important and difficult to treat microbiological contaminants that must be addressed for the provision of safe drinking water globally.
Realization of an optical interferometer based on holographic optics ...
Indian Academy of Sciences (India)
holographic exposures, in conjunction with the common beam O2 for the formation of two different but overlapped .... used for Agfa-Gevaert 8E75HD plates to give high efficiency and low noise grating holograms on H1 and H2. ... of India, New Delhi for the financial support for carrying out this work. One of the authors (AKS) ...
Digital holographic 3D imaging spectrometry (a review)
Yoshimori, Kyu
2017-09-01
This paper reviews recent progress in the digital holographic 3D imaging spectrometry. The principle of this method is a marriage of incoherent holography and Fourier transform spectroscopy. Review includes principle, procedure of signal processing and experimental results to obtain a multispectral set of 3D images for spatially incoherent, polychromatic objects.
Simplified Approach to Inspection Planning
DEFF Research Database (Denmark)
Bloch, Allan; Sørensen, John Dalsgaard; Faber, Michael Havbro
2000-01-01
structural details and thereby develop pre-made inspection plans in tables which depend on relative cost of inspections, repairs and failures. Due to the simplicity of the format of the developed inspection plans the proposed approach has a high potential in code making for the design and maintenance......A simplified and practically applicable approach for risk based inspection planning of fatigue sensitive structural details is presented. The basic idea behind the approach is that the fatigue sensitive details are categorized according to their stress intensity factors and their design fatigue...... of steel structures. The validity of the proposed approach is illustrated through a study regarding inspection planning of offshore structures....
Microscopic Mapping of Subnanometric Motion with Multiple-Beam Differential Holographic Technique
Lin, Hungyi
The measurement of ultrasmall displacement is usually performed by laser interferometry. In most cases, this method is specified for the surface measurement and requires a relatively smooth surface capable of reflecting light. In this research, a newly developed method, mutiple -beam microdifferential holography, is introduced to measure a small configuration change. This configuration change can happen on the surface of an object or inside a semitransparent object. In the experiment, two reference beams are used to record a pair of phase biased holographic images simultaneously. During the image reconstruction, the CCD image acquisition system is employed to record the pair of images one at a time and then process them digitally. The subtraction image intuitively shows that the deformation of tested object occurs between the double exposures applied during the holographic recording. A second object beam, usually a plane wave, is added to the imaging system for the purpose of image registration, which is required for the image processing. Several developments upgraded the system performance. The calibration was done with an extremely consistent moving object, a small air bubble drifting in a glycerine-filled capillary. Displacements as small as 0.4 nanometer are reported. In application, a living cell, a single frog muscle fiber, was under examination. This part of the research focused mainly on the crossbridge mechanism of striated muscle contraction. The images made at the plateau of tetanus suggest either that the cycling time constant is much longer than 10 msec, that the displacement for a power stroke is substantially less than 12 nanometer, or that the crossbridge is not cycling during the isometric force generation. The images made at the initial state of force development suggest that a large number of crossbridges shift toward the actin filament at the onset of the force development and stay there (at least without large scale rotation) even when the
Real-time, auto-focusing digital holographic microscope using graphics processors.
Doğar, Mert; İlhan, Hazar A; Özcan, Meriç
2013-08-01
The most significant advantage of holographic imaging is that one does not need to do focusing alignment for the scene or objects while capturing their images. To focus on a particular object recorded in a digital hologram, a post-processing on the recorded image must be performed. This post-processing, so called the reconstruction, is essentially the calculation of wave propagation in free space. If the object's optical distance to the recording plane is not known a priori, focusing methods are used to estimate this distance. However, these operations can be quite time consuming as the hologram sizes increase. When there is a time constraint on these procedures and the image resolution is high, traditional central processing units (CPUs) can no longer satisfy the desired reconstruction speeds. Then, especially for real-time operations, additional hardware accelerators are required for reconstructing high resolution holograms. To this extend, today's commercial graphic cards offer a viable solution, as the holograms can be reconstructed tens of times faster with a graphics processing unit than with the state-of-the-art CPUs. Here we present an auto-focusing megapixel-resolution digital holographic microscope (DHM) that uses a graphics processing unit (GPU) as the calculation engine. The computational power of the GPU allows the DHM to work in real-time such that the reconstruction distance is estimated unsupervised, and the post-processing of the holograms are made completely transparent to the user. We compare DHM with GPU and CPU and present experimental results showing a maximum of 70 focused reconstructions per second (frps) with 1024 × 1024 pixel holograms.
Holographic quantitative imaging of sample hidden by turbid medium or occluding objects
Bianco, V.; Miccio, L.; Merola, F.; Memmolo, P.; Gennari, O.; Paturzo, Melania; Netti, P. A.; Ferraro, P.
2015-03-01
Digital Holography (DH) numerical procedures have been developed to allow imaging through turbid media. A fluid is considered turbid when dispersed particles provoke strong light scattering, thus destroying the image formation by any standard optical system. Here we show that sharp amplitude imaging and phase-contrast mapping of object hidden behind turbid medium and/or occluding objects are possible in harsh noise conditions and with a large field-of view by Multi-Look DH microscopy. In particular, it will be shown that both amplitude imaging and phase-contrast mapping of cells hidden behind a flow of Red Blood Cells can be obtained. This allows, in a noninvasive way, the quantitative evaluation of living processes in Lab on Chip platforms where conventional microscopy techniques fail. The combination of this technique with endoscopic imaging can pave the way for the holographic blood vessel inspection, e.g. to look for settled cholesterol plaques as well as blood clots for a rapid diagnostics of blood diseases.
Shell Inspection History and Current CMM Inspection Efforts
Energy Technology Data Exchange (ETDEWEB)
Montano, Joshua Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-01-26
The following report provides a review of past and current CMM Shell Inspection efforts. Calibration of the Sheffield rotary contour gauge has expired and the primary inspector, Matthew Naranjo, has retired. Efforts within the Inspection team are transitioning from maintaining and training new inspectors on Sheffield to off-the-shelf CMM technology. Although inspection of a shell has many requirements, the scope of the data presented in this report focuses on the inner contour, outer contour, radial wall thickness and mass comparisons.
Comparative study of Palito inspection and MFL Inspection
Energy Technology Data Exchange (ETDEWEB)
Araujo, Anne A. de; Miranda, Ivan Vicente Janvrot; Silva, Jose Augusto Pereira da [Pipeway Engenharia, Rio de Janeiro, RJ (Brazil); Guimaraes, Frederico S.; Magalhaes, Joao Alfredo P. [Minds at Work, Rio de Janeiro, RJ (Brazil); Sabino, Joao Marcos [Petroleo Brasileiro S.A. (PETROBRAS/UN-RN/CE), Natal, RN (Brazil). Unidade de Negocios Rio Grande do Norte e Ceara
2009-07-01
A 16 inches oil pipeline was surveyed with MFL and Palito pig in 2007. The MFL inspection was performed by Pipeway Engenharia while Palito inspection was performed by PETROBRAS. A comparison between the results of these two ILI inspections has been made to validate Palito Pig and to assess main characteristics and differences between the two techniques. The purpose of this paper is to detail the methodology applied to perform the comparison and to present a comparative study of results registered in the MFL and Palito inspections by Pipeway Engenharia, PETROBRAS/CENPES and CPTI/PUC-Rio. (author)
Zhang, Zhen; Chen, Siqing; Zheng, Huadong; Zeng, Zhenxiang; Gao, Hongyue; Yu, Yingjie; Asundi, Anand K
2017-07-10
The fractional Fourier transform (FRT) has been used for computing holograms in holographic displays due to its continuity of describing wave diffraction in the near field and far field. In this study, we propose a method to realize a full-color holographic 3D display with combined use of the FRT and the free-space Fresnel diffraction. A slice-based optical configuration and the calculation algorithm of the FRT are proposed for generating phase-only holograms of full-color 3D objects. Sequential phase-only holograms are generated for reducing the speckle noise of reconstructed images by the time-averaging effect. Free-space Fresnel diffraction is used for 3D image reconstruction from the generated holograms. The relationship between the fractional orders of different color channels and the free-space Fresnel diffraction distance is analyzed. Chromatic aberrations caused by different wavelengths of RGB lasers are also compensated. A full-color holographic display system using a reflective phase-only spatial light modulator (SLM) is established. Both the numerical and optical reconstruction results demonstrate the feasibility of the proposed method.
Lin, Qiaowen; Wang, Dayong; Wang, Yunxin; Guo, Sha; Panezai, Spozmai; Ouyang, Liting; Rong, Lu; Zhao, Jie
2017-03-01
A super-resolution quantitative phase-contrast imaging method using high refractive index microsphere is developed to overcome the diffraction limit of optical field, which is produced by the object in the digital holographic microscopy. A microsphere placed on the surface of the object can collect the underlying near-field information, which appears as the evanescent waves and transforms them into propagating waves. Due to the spherical symmetry provided by the microsphere, the super-resolution of the imaging system can be realized in all directions at the same time with one-shot recording. The experiments are carried out for a cosine grating with the line width of 255 nm as the object, which confirms that the lateral resolution can be less than λ/2. Meanwhile, the quantitative phase-contrast image is experimentally obtained. The reconstructed complex field distribution provides the great flexibility with the digital processing for the microscope imaging, such as the ability of refocusing and numerical reconstruction.
3D displacement measurements of the tympanic membrane with digital holographic interferometry.
Solís, S Muñoz; Santoyo, F Mendoza; Hernández-Montes, M del Socorro
2012-02-27
A digital holographic interferometry (DHI) system with three object-illumination beams is used for the first time to measure micro-deformations along the x, y and z axes (3D) on the tympanic membrane (TM) surface of a post-mortem cat. In order to completely and accurately measure the TM surface displacements its shape is required to map on it the x, y and z micro-deformations. The surface contour is obtained by applying small shifts to the object illumination source position. A cw laser in stroboscopic mode and a CCD camera were used and synchronized to the acoustic excitation wave that produces a resonant vibration mode on the tympanic membrane surface. This research work reports on the 3D full field of view response of the TM to sound pressure, and has as its main goal the presentation of DHI as an alternative technique to study the TM real displacement behavior when subjected to sound waves, so it can be used as a diagnostic tool to prevent and treat TM diseases.
Comments on the Chiral Symmetry Breaking in Soft Wall Holographic QCD
DEFF Research Database (Denmark)
Bechi, Jacopo
2009-01-01
In this paper we describe qualitatively some aspects of the holographic QCD. Inspired by a successfull 4D description, we try to separate the Confinement and the Chiral Symmetry Breaking dynamics. We also discuss the realization of the baryons as skyrmions in Soft Wall Holographic QCD, and the is......In this paper we describe qualitatively some aspects of the holographic QCD. Inspired by a successfull 4D description, we try to separate the Confinement and the Chiral Symmetry Breaking dynamics. We also discuss the realization of the baryons as skyrmions in Soft Wall Holographic QCD...
Complex wavefront modulation and holographic display using single spatial light modulator
Kong, Dezhao; Cao, Liangcai; Shen, Xueju; Zhang, Hao; Zong, Song; Jin, Guofan
2017-08-01
A holographic display method based on complex wavefront modulation using single spatial light modulator is proposed. The holographic display is achieved from complex wavefront encoded by double phase hologram. The modulated beam by single phase-only spatial light modulator passes through a 4f optical system to synthesize the expected complex modulated wavefront on the output plane, with a low-pass filter in the Fourier plane. The performance of holographic display is also improved by complex wavefront modulation, compared with the holographic display based on phase-only wavefront modulation. The proposed encoding and display technique is theoretically demonstrated, as well as validated in numerical simulations.
Robotic Platform for Internal Inspection
Cope, Brian Alexander
2013-01-01
This thesis describes the design of a robotic inspection tool which is based on a differential track-drive platform. The robotic inspection tool is a one man-portable UGV that has been developed for the purpose of non-destructive evaluation (NDE) and internal inspection of environments where human penetration may be difficult or hazardous. Various NDE and sensing techniques are described in this paper but the focus is on the mechanical and electrical design of the platform itself. The platfor...
Waste inspection tomography (WIT)
Energy Technology Data Exchange (ETDEWEB)
Bernardi, R.T. [Bio-Imaging Research, Inc., Lincolnshire, IL (United States)
1995-10-01
Waste Inspection Tomography (WIT) provides mobile semi-trailer mounted nondestructive examination (NDE) and assay (NDA) for nuclear waste drum characterization. WIT uses various computed tomography (CT) methods for both NDE and NDA of nuclear waste drums. Low level waste (LLW), transuranic (TRU), and mixed radioactive waste can be inspected and characterized without opening the drums. With externally transmitted x-ray NDE techniques, WIT has the ability to identify high density waste materials like heavy metals, define drum contents in two- and three-dimensional space, quantify free liquid volumes through density and x-ray attenuation coefficient discrimination, and measure drum wall thickness. With waste emitting gamma-ray NDA techniques, WIT can locate gamma emitting radioactive sources in two- and three-dimensional space, identify gamma emitting, isotopic species, identify the external activity levels of emitting gamma-ray sources, correct for waste matrix attenuation, provide internal activity approximations, and provide the data needed for waste classification as LLW or TRU.
C324 Study of micro-underwater shock waves induced by Q-switched Ho : YAG laser focusing
S. H. R., Hosseini; T., Hirano; K., Takayama; Department of Neurosurgery. School of Medicine. Tohoku University; Shock Wave Research Center. Institute of Fluid Science. Tohoku University
2002-01-01
Paper reports a quantitative study of underwater shock waves and cavity bubbles induced by direct irradiation of pulse laser beam. Energy source was a Q-switched Ho : YAG laser. The laser beam was focused and transmitted through an optical fiber. Double exposure holographic interferometry was used for flow visualization. The whole sequences of underwater shock waves generation and propagation were observed. The laser interaction produced micro plasma. which drove spherical shock wave in water...
Verification of Remote Inspection Techniques for Reactor Internal Structures of Liquid Metal Reactor
Energy Technology Data Exchange (ETDEWEB)
Joo, Young Sang; Lee, Jae Han
2007-02-15
The reactor internal structures and components of a liquid metal reactor (LMR) are submerged in hot sodium of reactor vessel. The division 3 of ASME code section XI specifies the visual inspection as major in-service inspection (ISI) methods of reactor internal structures and components. Reactor internals of LMR can not be visually examined due to opaque liquid sodium. The under-sodium viewing techniques using an ultrasonic wave should be applied for the visual inspection of reactor internals. Recently, an ultrasonic waveguide sensor with a strip plate has been developed for an application to the under-sodium inspection. In this study, visualization technique, ranging technique and monitoring technique have been suggested for the remote inspection of reactor internals by using the waveguide sensor. The feasibility of these remote inspection techniques using ultrasonic waveguide sensor has been evaluated by an experimental verification.
Finite temperature holographic duals of 2-dimensional BCFTs
Estes, J.
2015-07-01
We consider holographic duals of 2-dimensional conformal field theories in the presence of a boundary, interface, defect and/or junction, referred to collectively as BCFTs. In general, the presence of a boundary reduces the SO(2, 2) conformal symmetry to SO(2, 1) and the dual geometry is realized as a warped product of the form , where is not compact. In particular, it will contain points where the warp factor of the AdS 2 space diverges, leading to asymptotically AdS 3 regions. We show that the AdS 2 space-time may always be replaced with an AdS 2-"black-hole" space-time. We argue the resulting geometry describes the BCFT at finite temperature. To motivate this claim, we compute the entanglement entropy holographically for a segment centered around the defect or ending on the boundary and find agreement with a known universal formula.
Comments on entanglement negativity in holographic field theories
Rangamani, Mukund; Rota, Massimiliano
2014-10-01
We explore entanglement negativity, a measure of the distillable entanglement contained in a quantum state, in relativistic field theories in various dimensions. We first give a general overview of negativity and its properties and then explain a well known result relating (logarithmic) negativity of pure quantum states to the Rényi entropy (at index 1/2), by exploiting the simple features of entanglement in thermal states. In particular, we show that the negativity of the thermofield double state is given by the free energy difference of the system at temperature T and 2 T respectively. We then use this result to compute the negativity in the vacuum state of conformal field theories in various dimensions, utilizing results that have been derived for free and holographic CFTs in the literature. We also comment upon general lessons to be learnt about negativity in holographic field theories.
Wavelength-coded volume holographic imaging endoscope for multidepth imaging.
Howlett, Isela D; Han, Wanglei; Rice, Photini; Barton, Jennifer K; Kostuk, Raymond K
2017-10-01
A wavelength-coded volume holographic imaging (WC-VHI) endoscope system capable of simultaneous multifocal imaging is presented. The system images light from two depths separated by 100 μm in a tissue sample by using axial chromatic dispersion of a gradient index probe in combination with two light-emitting diode sources and a multiplexed volume hologram to separate the images. This system is different from previous VHI systems in that it uses planar multiplexed gratings and does not require curved holographic gratings. This results in improved lateral imaging resolution from 228.1 to 322.5 lp/mm. This letter describes the design and fabrication of the WC-VHI endoscope and experimental images of hard and soft resolution targets and biological tissue samples to illustrate the performance properties. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).
Nopal Cactus (Opuntia Ficus-Indica) as a Holographic Material
Olivares-Pérez, Arturo; Toxqui-López, Santa; Padilla-Velasco, Ana L.
2012-01-01
The nopal cactus (Opuntia ficus-indica) releases a substance through its mucilage, which comes from the degradation of pectic substances and chlorophyll. Combined in a polyvinyl alcohol matrix, this substance can be used as a recording medium. The resulting extract material has excellent photosensitizer properties, is easy to handle, has a low cost, and low toxicity. This material has the property of self-developing, and it can be used in holographic applications. The polyvinyl alcohol and extract from the nopal cactus was deposited by a gravity technique on a glass substrate, which dried to form a photosensitive emulsion. We show experimental results on a holographic grating using this material, written by a He-Cd laser (442 nm). We obtained diffraction gratings by transmission with a diffraction efficiency of approximately 32.3% to first order.
Read-only high accuracy volume holographic optical correlator
Zhao, Tian; Li, Jingming; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2011-10-01
A read-only volume holographic correlator (VHC) is proposed. After the recording of all of the correlation database pages by angular multiplexing, a stand-alone read-only high accuracy VHC will be separated from the VHC recording facilities which include the high-power laser and the angular multiplexing system. The stand-alone VHC has its own low power readout laser and very compact and simple structure. Since there are two lasers that are employed for recording and readout, respectively, the optical alignment tolerance of the laser illumination on the SLM is very sensitive. The twodimensional angular tolerance is analyzed based on the theoretical model of the volume holographic correlator. The experimental demonstration of the proposed read-only VHC is introduced and discussed.
Impact of electron irradiation on electron holographic potentiometry
Energy Technology Data Exchange (ETDEWEB)
Park, J. B.; Niermann, T.; Lehmann, M. [Technische Universität Berlin, Institut für Optik und Atomare Physik, Straße des 17. Juni 135, 10623 Berlin (Germany); Berger, D. [Technische Universität Berlin, Zentraleinrichtung für Elektronenmikroskopie, Strae des 17. Juni 135, 10623 Berlin (Germany); Knauer, A.; Weyers, M. [Ferdinand-Braun-Institut, Leibnitz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Koslow, I.; Kneissl, M. [Ferdinand-Braun-Institut, Leibnitz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstr. 36, 10623 Berlin (Germany)
2014-09-01
While electron holography in the transmission electron microscope offers the possibility to measure maps of the electrostatic potential of semiconductors down to nanometer dimensions, these measurements are known to underestimate the absolute value of the potential, especially in GaN. We have varied the dose rates of electron irradiation over several orders of magnitude and observed strong variations of the holographically detected voltages. Overall, the results indicate that the electron beam generates electrical currents within the specimens primarily by the photovoltaic effect and due to secondary electron emission. These currents have to be considered for a quantitative interpretation of electron holographic measurements, as their negligence contributes to large parts in the observed discrepancy between the measured and expected potential values in GaN.
Holographic and light-field imaging for augmented reality
Lee, Byoungho; Hong, Jong-Young; Jang, Changwon; Jeong, Jinsoo; Lee, Chang-Kun
2017-02-01
We discuss on the recent state of the augmented reality (AR) display technology. In order to realize AR, various seethrough three-dimensional (3D) display techniques have been reported. We describe the AR display with 3D functionality such as light-field display and holography. See-through light-field display can be categorized by the optical elements which are used for see-through property: optical elements controlling path of the light-fields and those generating see-through light-field. Holographic display can be also a good candidate for AR display because it can reconstruct wavefront information and provide realistic virtual information. We introduce the see-through holographic display using various optical techniques.
Compact lensless off-axis transmission digital holographic microscope.
Rostykus, Manon; Moser, Christophe
2017-07-10
Current compact lensless holographic microscopes are based on either multiple angle in-line holograms, multiple wavelength illumination or a combination thereof. Complex computational algorithms are necessary to retrieve the phase image which slows down the visualization of the image. Here we propose a simple compact lensless transmission holographic microscope with an off-axis configuration which simplifies considerably the computational processing to visualize the phase images and opens the possibility of real time phase imaging using off the shelf smart phone processors and less than $3 worth of optics and detectors, suitable for broad educational dissemination. This is achieved using a side illumination and analog hologram gratings to shape the reference and signal illumination beams from one light source. We demonstrate experimentally imaging of cells with a field of view (FOV) of ~12mm2, and a resolution of ~3.9μm.
A Virtual Holographic Display Case for Museum Installations
Directory of Open Access Journals (Sweden)
Manuela Chessa
2015-12-01
Full Text Available Today, it is important in society to make artworks accessible to mass audiences and to widen participation in culture. In such a context, virtual reality is one of the areas of greatest interest: new devices and new techniques are affordable for many users, and virtual and real worlds are often mixed together. In this paper, we propose a "virtual holographic" display, i.e. a stereoscopic virtual reality system that is able to replicate the behavior of a real showcase for exhibitions. It works in a completely virtual manner and it can yield to a new generation of entertainment "holographic" installations. We evaluate such a system through an experimental session with 20 users. In particular, we compare the proposed system, based on a stereoscopic technique (TD3D, with respect to a standard motion parallax technique in terms of the users' perceptual experience.
Multimodal holographic microscopy: distinction between apoptosis and oncosis.
Directory of Open Access Journals (Sweden)
Jan Balvan
Full Text Available Identification of specific cell death is of a great value for many scientists. Predominant types of cell death can be detected by flow-cytometry (FCM. Nevertheless, the absence of cellular morphology analysis leads to the misclassification of cell death type due to underestimated oncosis. However, the definition of the oncosis is important because of its potential reversibility. Therefore, FCM analysis of cell death using annexin V/propidium iodide assay was compared with holographic microscopy coupled with fluorescence detection - "Multimodal holographic microscopy (MHM". The aim was to highlight FCM limitations and to point out MHM advantages. It was shown that the annexin V+/PI- phenotype is not specific of early apoptotic cells, as previously believed, and that morphological criteria have to be necessarily combined with annexin V/PI for the cell death type to be ascertained precisely. MHM makes it possible to distinguish oncosis clearly from apoptosis and to stratify the progression of oncosis.
Stiff phases in strongly coupled gauge theories with holographic duals
Ecker, Christian; Hoyos, Carlos; Jokela, Niko; Fernández, David Rodríguez; Vuorinen, Aleksi
2017-11-01
According to common lore, Equations of State of field theories with gravity duals tend to be soft, with speeds of sound either below or around the conformal value of υ_s=1/√{3} . This has important consequences in particular for the physics of compact stars, where the detection of two solar mass neutron stars has been shown to require very stiff equations of state. In this paper, we show that no speed limit exists for holographic models at finite density, explicitly constructing examples where the speed of sound becomes arbitrarily close to that of light. This opens up the possibility of building hybrid stars that contain quark matter obeying a holographic equation of state in their cores.
Conductivity tensor in a holographic quantum Hall ferromagnet
Directory of Open Access Journals (Sweden)
Joel Hutchinson
2014-11-01
Full Text Available The Hall and longitudinal conductivities of a recently studied holographic model of a quantum Hall ferromagnet are computed using the Karch–O'Bannon technique. In addition, the low temperature entropy of the model is determined. The holographic model has a phase transition as the Landau level filling fraction is increased from zero to one. We argue that this phase transition allows the longitudinal conductivity to have features qualitatively similar to those of two dimensional electron gases in the integer quantum Hall regime. The argument also applies to the low temperature limit of the entropy. The Hall conductivity is found to have an interesting structure. Even though it does not exhibit Hall plateaux, it has a flattened dependence on the filling fraction with a jump, analogous to the interpolation between Hall plateaux, at the phase transition.
Holographic metal-insulator transition in higher derivative gravity
Energy Technology Data Exchange (ETDEWEB)
Ling, Yi, E-mail: lingy@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai, 200444 (China); Liu, Peng, E-mail: liup51@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wu, Jian-Pin, E-mail: jianpinwu@mail.bnu.edu.cn [Institute of Gravitation and Cosmology, Department of Physics, School of Mathematics and Physics, Bohai University, Jinzhou 121013 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai, 200444 (China); Zhou, Zhenhua, E-mail: zhouzh@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)
2017-03-10
We introduce a Weyl term into the Einstein–Maxwell-Axion theory in four dimensional spacetime. Up to the first order of the Weyl coupling parameter γ, we construct charged black brane solutions without translational invariance in a perturbative manner. Among all the holographic frameworks involving higher derivative gravity, we are the first to obtain metal-insulator transitions (MIT) when varying the system parameters at zero temperature. Furthermore, we study the holographic entanglement entropy (HEE) of strip geometry in this model and find that the second order derivative of HEE with respect to the axion parameter exhibits maximization behavior near quantum critical points (QCPs) of MIT. It testifies the conjecture in that HEE itself or its derivatives can be used to diagnose quantum phase transition (QPT).
Nopal Cactus (Opuntia Ficus-Indica as a Holographic Material
Directory of Open Access Journals (Sweden)
Santa Toxqui-López
2012-11-01
Full Text Available The nopal cactus (Opuntia ficus-indica releases a substance through its mucilage, which comes from the degradation of pectic substances and chlorophyll. Combined in a polyvinyl alcohol matrix, this substance can be used as a recording medium. The resulting extract material has excellent photosensitizer properties, is easy to handle, has a low cost, and low toxicity. This material has the property of self-developing, and it can be used in holographic applications. The polyvinyl alcohol and extract from the nopal cactus was deposited by a gravity technique on a glass substrate, which dried to form a photosensitive emulsion. We show experimental results on a holographic grating using this material, written by a He-Cd laser (442 nm. We obtained diffraction gratings by transmission with a diffraction efficiency of approximately 32.3% to first order.
Digital Holographic Capture and Optoelectronic Reconstruction for 3D Displays
Directory of Open Access Journals (Sweden)
Damien P. Kelly
2010-01-01
Full Text Available The application of digital holography as a viable solution to 3D capture and display technology is examined. A review of the current state of the field is presented in which some of the major challenges involved in a digital holographic solution are highlighted. These challenges include (i the removal of the DC and conjugate image terms, which are features of the holographic recording process, (ii the reduction of speckle noise, a characteristic of a coherent imaging process, (iii increasing the angular range of perspective of digital holograms (iv and replaying captured and/or processed digital holograms using spatial light modulators. Each of these challenges are examined theoretically and several solutions are put forward. Experimental results are presented that demonstrate the validity of the theoretical solutions.
Non-thermal fixed point in a holographic superfluid
Energy Technology Data Exchange (ETDEWEB)
Ewerz, Carlo [Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg,Philosophenweg 16, 69120 Heidelberg (Germany); ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung,Planckstraße 1, 64291 Darmstadt (Germany); Gasenzer, Thomas [Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg,Philosophenweg 16, 69120 Heidelberg (Germany); ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung,Planckstraße 1, 64291 Darmstadt (Germany); Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg,Im Neuenheimer Feld 227, 69120 Heidelberg (Germany); Karl, Markus; Samberg, Andreas [Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg,Philosophenweg 16, 69120 Heidelberg (Germany); ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung,Planckstraße 1, 64291 Darmstadt (Germany)
2015-05-14
We study the far-from-equilibrium dynamics of a (2+1)-dimensional superfluid at finite temperature and chemical potential using its holographic description in terms of a gravitational system in 3+1 dimensions. Starting from various initial conditions corresponding to ensembles of vortex defects we numerically evolve the system to long times. At intermediate times the system exhibits Kolmogorov scaling the emergence of which depends on the choice of initial conditions. We further observe a universal late-time regime in which the occupation spectrum and different length scales of the superfluid exhibit scaling behaviour. We study these scaling laws in view of superfluid turbulence and interpret the universal late-time regime as a non-thermal fixed point of the dynamical evolution. In the holographic superfluid the non-thermal fixed point can be understood as a stationary point of the classical equations of motion of the dual gravitational description.
Holographic entanglement entropy of N =2* renormalization group flow
Pang, Da-Wei
2015-10-01
The N =2* theory is obtained by deforming N =4 supersymmetric Yang-Mills theory with two relevant operators of dimensions 2 and 3. We study the holographic entanglement entropy of the N =2* theory along the whole renormalization group flow. We find that in the UV the holographic entanglement entropy for an arbitrary entangling region receives a universal logarithmic correction, which is related to the relevant operator of dimension 3. This universal behavior can be interpreted on the field theory side by perturbatively evaluating the entanglement entropy of a conformal field theory (CFT) under relevant deformations. In the IR regime, we obtain the large R behavior of the renormalized entanglement entropy for both a strip and a sphere entangling region, where R denotes the size of the entangling region. A term proportional to 1 /R is found for both cases, which can be attributed to the emergent CFT5 in the IR.
Consistency relations and conservation of ζ in holographic inflation
Energy Technology Data Exchange (ETDEWEB)
Garriga, Jaume [Departament de Física Fonamental i Institut de Ciències del Cosmos,Universitat de Barcelona,Martí i Franquès 1, 08028 Barcelona (Spain); Institute of Cosmology, Department of Physics and Astronomy, Tufts University,Medford, MA 02155 (United States); Urakawa, Yuko [Department of Physics and Astrophysics, Nagoya University,Chikusa, Nagoya 464-8602 (Japan)
2016-10-18
It is well known that, in single clock inflation, the curvature perturbation ζ is constant in time on superhorizon scales. In the standard bulk description this follows quite simply from the local conservation of the energy momentum tensor in the bulk. On the other hand, in a holographic description, the constancy of the curvature perturbation must be related to the properties of the RG flow in the boundary theory. Here, we show that, in single clock holographic inflation, the time independence of correlators of ζ follows from the absence of the anomolous dimension of the energy momentum tensor in the boundary theory, and from the so-called consistency relations for vertex functions with a soft leg.
Holographic metal-insulator transition in higher derivative gravity
Directory of Open Access Journals (Sweden)
Yi Ling
2017-03-01
Full Text Available We introduce a Weyl term into the Einstein–Maxwell-Axion theory in four dimensional spacetime. Up to the first order of the Weyl coupling parameter γ, we construct charged black brane solutions without translational invariance in a perturbative manner. Among all the holographic frameworks involving higher derivative gravity, we are the first to obtain metal-insulator transitions (MIT when varying the system parameters at zero temperature. Furthermore, we study the holographic entanglement entropy (HEE of strip geometry in this model and find that the second order derivative of HEE with respect to the axion parameter exhibits maximization behavior near quantum critical points (QCPs of MIT. It testifies the conjecture in [1,2] that HEE itself or its derivatives can be used to diagnose quantum phase transition (QPT.
Supersymmetric holographic dual of a fractional topological insulator
Ammon, Martin; Gutperle, Michael
2012-07-01
We construct a supersymmetric generalization of the holographic dual of a fractional topological insulator found in . This is accomplished by introducing a nontrivial gauge field on the world volume of the probe D7-brane. The Bogomol’nyi-Prasad-Sommerfeld monopoles (BPS) equations are derived from the κ-symmetry transformation of the probe brane. The BPS equations are shown to reduce to two first-order nonlinear partial differential equations. Solutions of the BPS equations correspond to a probe brane configuration which preserves four of the 32 supersymmetries of the AdS5×S5 background. Solutions of the BPS equations which correspond to a holographic fractional topological insulator are obtained numerically.
Magnetic phenomena in holographic superconductivity with Lifshitz scaling
Directory of Open Access Journals (Sweden)
Aldo Dector
2015-09-01
Full Text Available We investigate the effects of Lifshitz dynamical critical exponent z on a family of minimal D=4+1 holographic superconducting models, with a particular focus on magnetic phenomena. We see that it is possible to have a consistent Ginzburg–Landau approach to holographic superconductivity in a Lifshitz background. By following this phenomenological approach we are able to compute a wide array of physical quantities. We also calculate the Ginzburg–Landau parameter for different condensates, and conclude that in systems with higher dynamical critical exponent, vortex formation is more strongly unfavored energetically and exhibits a stronger Type I behavior. Finally, following the perturbative approach proposed by Maeda, Natsuume and Okamura, we calculate the critical magnetic field of our models for different values of z.
Holographic fluctuations and the principle of minimal complexity
Energy Technology Data Exchange (ETDEWEB)
Chemissany, Wissam [Institut für Theoretische Physik, Leibniz Universität Hannover,Appelstr. 2, 30167 Hannover (Germany); Department of Mechanical Engineering, MIT,Cambridge MA 02139 (United States); Osborne, Tobias J. [Institut für Theoretische Physik, Leibniz Universität Hannover,Appelstr. 2, 30167 Hannover (Germany)
2016-12-14
We discuss, from a quantum information perspective, recent proposals of Maldacena, Ryu, Takayanagi, van Raamsdonk, Swingle, and Susskind that spacetime is an emergent property of the quantum entanglement of an associated boundary quantum system. We review the idea that the informational principle of minimal complexity determines a dual holographic bulk spacetime from a minimal quantum circuit U preparing a given boundary state from a trivial reference state. We describe how this idea may be extended to determine the relationship between the fluctuations of the bulk holographic geometry and the fluctuations of the boundary low-energy subspace. In this way we obtain, for every quantum system, an Einstein-like equation of motion for what might be interpreted as a bulk gravity theory dual to the boundary system.
Phase transition of holographic entanglement entropy in massive gravity
Directory of Open Access Journals (Sweden)
Xiao-Xiong Zeng
2016-05-01
Full Text Available The phase structure of holographic entanglement entropy is studied in massive gravity for the quantum systems with finite and infinite volumes, which in the bulk is dual to calculating the minimal surface area for a black hole and black brane respectively. In the entanglement entropy–temperature plane, we find for both the black hole and black brane there is a Van der Waals-like phase transition as the case in thermal entropy–temperature plane. That is, there is a first order phase transition for the small charge and a second order phase transition at the critical charge. For the first order phase transition, the equal area law is checked and for the second order phase transition, the critical exponent of the heat capacity is obtained. All the results show that the phase structure of holographic entanglement entropy is the same as that of thermal entropy regardless of the volume of the spacetime on the boundary.
Accelerated optical holographic recording using bis-DNO
DEFF Research Database (Denmark)
Rasmussen, Palle H.; Ramanujam, P.S.; Hvilsted, Søren
1999-01-01
The design, synthesis and optical holographic recording properties of bis-DNO are reported. Bis-DNO is composed of two identical azobenzene oligoornithine segments (DNO) connected via a dipeptide linker. The two segments were assembled in a parallel fashion at the two amino groups of the dipeptide...... linker by Merrifield synthesis. Surprisingly, the response time of films of bis-DNOs was found to be much faster than that of their linear counterparts. (C) 1999 Elsevier Science Ltd. All rights reserved....
Universal Charge Diffusion and the Butterfly Effect in Holographic Theories
Blake, Mike
2016-08-01
We study charge diffusion in holographic scaling theories with a particle-hole symmetry. We show that these theories have a universal regime in which the diffusion constant is given by Dc=C vB2/(2 π T ), where vB is the velocity of the butterfly effect. The constant of proportionality C depends only on the scaling exponents of the infrared theory. Our results suggest an unexpected connection between transport at strong coupling and quantum chaos.
Charge diffusion and the butterfly effect in striped holographic matter
Energy Technology Data Exchange (ETDEWEB)
Lucas, Andrew [Department of Physics, Harvard University,Cambridge, MA 02138 (United States); Department of Physics, Stanford University,Stanford, CA 94305 (United States); Steinberg, Julia [Department of Physics, Harvard University,Cambridge, MA 02138 (United States)
2016-10-26
Recently, it has been proposed that the butterfly velocity — a speed at which quantum information propagates — may provide a fundamental bound on diffusion constants in dirty incoherent metals. We analytically compute the charge diffusion constant and the butterfly velocity in charge-neutral holographic matter with long wavelength “hydrodynamic' disorder in a single spatial direction. In this limit, we find that the butterfly velocity does not set a sharp lower bound for the charge diffusion constant.
Charge diffusion and the butterfly effect in striped holographic matter
Lucas, Andrew; Steinberg, Julia
2016-10-01
Recently, it has been proposed that the butterfly velocity — a speed at which quantum information propagates — may provide a fundamental bound on diffusion constants in dirty incoherent metals. We analytically compute the charge diffusion constant and the butterfly velocity in charge-neutral holographic matter with long wavelength "hydrodynamic" disorder in a single spatial direction. In this limit, we find that the butterfly velocity does not set a sharp lower bound for the charge diffusion constant.
Holographic cosmology and its relevant degrees of freedom
Dawid, Richard
1999-01-01
We reconsider the options for cosmological holography. We suggest that a global and time--symmetric version of the Fischler-Susskind bound is the most natural generalization of the holographic bound encountered in AdS and De Sitter space. A consistent discussion of cosmological holography seems to imply an understanding of the notion of ``number of degrees of freedom'' that deviates from its simple definition as the entropy of the current state. The introduction of a more adequate notion of d...
Holographic polymer dispersed liquid crystal enhanced by introducing urethane trimethacrylate.
Nataj, Nahid Hosein; Mohajerani, Ezeddin; Jashnsaz, Hossein; Jannesari, Ali
2012-02-20
This work characterizes holographic polymer dispersed liquid crystals (HPDLC) composite material based on a new monomer, urethane trimethacrylate, by fabricating switchable diffraction grating. The highest diffraction efficiency achieved was 90.3%. Details of the fabrication and preliminary results of electro-optical switching of the HPDLC diffraction gratings are presented and discussed based on the functionality of the monomer. These experimental results are explained by means of morphological scanning electron microscopy analyses. © 2012 Optical Society of America
Holographic tool kit for optical communication beyond orbital angular momentum
Trichili, Abderrahmen; Rosales-Guzmán, Carmelo; Dudley, Angela; Ndagano, Bienvenu; Salem, Amine Ben; Zghal, Mourad; Forbes, Andrew
2016-01-01
Mode division multiplexing (MDM) is mooted as a technology to address future bandwidth issues, and has been successfully demonstrated in free space using spatial modes with orbital angular momentum (OAM). To further increase the data transmission rate, more degrees of freedom are required to form a densely packed mode space. Here we move beyond OAM and demonstrate multiplexing and demultiplexing using both the radial and azimuthal degrees of freedom. We achieve this with a holographic approac...
Holographic study of the QCD matter under external conditions
Directory of Open Access Journals (Sweden)
Katanaeva Alisa
2017-01-01
We use methods of the bottom-up AdS/QCD approach to bring out the phase structure of several holographic models in which transition to a deconfined phase is related to a (first order Hawking-Page phase transition. The impact of phenomenological model parameters on the critical temperature and chemical potential is studied in detail. Comparison of the model predictions with results of experimental investigations, lattice QCD simulations and other methods is also done.
Holographic Data Storage with a Digital Micromirror Device
Bullock, Daniel; Sauncy, Toni; Allen, Charles; Dallas, Tim
2007-10-01
A holographic data system writes bits by recording the interference between a reference beam and an object beam containing data as a diffraction grating onto a photosensitive disc. The purpose of this research is to evaluate current designs and consider improvements such as the use of a digital micromirror device (DMD) as a spatial light modulator. Other factors addressed are multiple incident angles for volume layering and improving bit contrast.
Holographic quark-gluon plasmas at finite quark density
Energy Technology Data Exchange (ETDEWEB)
Bigazzi, F. [Dipartimento di Fisica e Astronomia, Universita di Firenze, Sesto Fiorentino (Firenze), Pisa (Italy); INFN, Sezione di Torino (Italy); Cotrone, A. [Dipartimento di Fisica, Universita di Torino (Italy); Mas, J. [Departamento de Fisica de Particulas, Universidade de Santiago de Compostela (Spain); Instituto Galego de Fisica de Altas Enerxias (IGFAE), Santiago de Compostela (Spain); Tarrio, J. [Institute for Theoretical Physics and Spinoza Institute, Universiteit Utrecht, 3584 CE, Utrecht (Netherlands); Mayerson, D. [Institute for Theoretical Physics, University of Amsterdam (Netherlands)
2012-07-15
Gravity solutions holographically dual to strongly coupled quark-gluon plasmas with non-zero quark density are reviewed. They are motivated by the urgency of finding novel tools to explore the phase diagram of QCD-like theories at finite chemical potential. After presenting the solutions and their regime of validity, some of their physical properties are discussed. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Guided wave travel time tomography for bends
Volker, A.W.F.; Bloom, J.G.P.
2010-01-01
The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections. Guided wave tomography has been developed to map the wall thickness using the travel times of guided waves. The method
Guided Wave Travel Time Tomography for Bends
Volker, A.W.F.; Zon, A.T. van
2012-01-01
The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections. Guided wave tomography has been developed to map the wall thickness using the travel times of guided waves. The method
Plane wave imaging using phased array
Volker, A.W.F.
2014-01-01
Phased arrays are often used for rapid inspections. Phased arrays can be used to synthesize different wave fronts. For imaging, focused wave fronts are frequently used. In order to build an image, the phased array has to be fired multiple times at the same location. Alternatively, different data
Study of human cardiac cycle using holographic interferometry
Brown, Glen; Boxler, Lawrence H.; Chun, Patrick K. C.; Western, Arthur B.
1991-03-01
A study using holographic interferometry (HI) to examine human body surface motion has been done. Skin surface motion resulting from the pumping action of the heart is detectable with holographic methods. We have examined the skin motion in the neck area in detail. The interferograms obtained using a double pulsed ruby laser system provide an image of the human subjects with a fringe pattern superimposed upon that image. The fringe patterns correspond to the motion of the skin during the time between the two laser pulses. These fringe patterns were analyzed and correlated with several known cardiac phenomena. The patterns show a high degree of intra- and inter-subject consistency for healthy male subjects. To determine direction (sign) of skin displacement from standard interferograms a method of introducing reference fringes was incorporated into the system. To confirm that the fringe patterns yield accurate displacement data a point sensor was utilized to directly measure skin movement. Holographic interferometry''s future value as a clinical tool warrants further detailed investigation. 1.
Holographic non-Gaussianities in general single-field inflation
Energy Technology Data Exchange (ETDEWEB)
Isono, Hiroshi [Department of Physics, Faculty of Science,Chulalongkorn University, Bangkok 10330 (Thailand); Noumi, Toshifumi [Department of Physics and Jockey Club Institute for Advanced Study,Hong Kong University of Science and Technology (Hong Kong); Department of Physics,Kobe University, Kobe 657-8501 (Japan); Shiu, Gary [Department of Physics and Jockey Club Institute for Advanced Study,Hong Kong University of Science and Technology (Hong Kong); Department of Physics, University of Wisconsin-Madison,Madison, WI 53706 (United States); Wong, Sam S.C.; Zhou, Siyi [Department of Physics and Jockey Club Institute for Advanced Study,Hong Kong University of Science and Technology (Hong Kong)
2016-12-07
We use holographic techniques to compute inflationary non-Gaussianities for general single-field inflation, including models with a non-trivial sound speed. In this holographic approach, the inflationary dynamics is captured by a relevant deformation of the dual conformal field theory (CFT) in the UV, while the inflationary correlators are computed by conformal perturbation theory. In this paper, we discuss the effects of higher derivative operators, such as (∂{sub μ}ϕ∂{sup μ}ϕ){sup m}, which are known to induce a non-trivial sound speed and source potentially large non-Gaussianities. We compute the full inflationary bispectra from the deformed CFT correlators. We also discuss the squeezed limit of the bispectra from the viewpoint of operator product expansions. As is generic in the holographic description of inflation, our power spectrum is blue tilted in the UV region. We extend our bispectrum computation to the IR region by resumming the conformal perturbations to all orders. We provide a self-consistent setup which reproduces a red tilted power spectrum, as well as all possible bispectrum shapes in the slow-roll regime.
Experimental teaching and training system based on volume holographic storage
Jiang, Zhuqing; Wang, Zhe; Sun, Chan; Cui, Yutong; Wan, Yuhong; Zou, Rufei
2017-08-01
The experiment of volume holographic storage for teaching and training the practical ability of senior students in Applied Physics is introduced. The students can learn to use advanced optoelectronic devices and the automatic control means via this experiment, and further understand the theoretical knowledge of optical information processing and photonics disciplines that have been studied in some courses. In the experiment, multiplexing holographic recording and readout is based on Bragg selectivity of volume holographic grating, in which Bragg diffraction angle is dependent on grating-recording angel. By using different interference angle between reference and object beams, the holograms can be recorded into photorefractive crystal, and then the object images can be read out from these holograms via angular addressing by using the original reference beam. In this system, the experimental data acquisition and the control of the optoelectronic devices, such as the shutter on-off, image loaded in SLM and image acquisition of a CCD sensor, are automatically realized by using LabVIEW programming.
Holographic conductivity for logarithmic charged dilaton-Lifshitz solutions
Directory of Open Access Journals (Sweden)
A. Dehyadegari
2016-07-01
Full Text Available We disclose the effects of the logarithmic nonlinear electrodynamics on the holographic conductivity of Lifshitz dilaton black holes/branes. We analyze thermodynamics of these solutions as a necessary requirement for applying gauge/gravity duality, by calculating conserved and thermodynamic quantities such as the temperature, entropy, electric potential and mass of the black holes/branes. We calculate the holographic conductivity for a (2+1-dimensional brane boundary and study its behavior in terms of the frequency per temperature. Interestingly enough, we find out that, in contrast to the Lifshitz–Maxwell-dilaton black branes which have conductivity for all z, here in the presence of nonlinear gauge field, the holographic conductivity does exist provided z≤3 and vanishes for z>3. It is shown that independent of the nonlinear parameter β, the real part of the conductivity is the same for a specific value of frequency per temperature in both AdS and Lifshitz cases. Besides, the behavior of real part of conductivity for large frequencies has a positive slope with respect to large frequencies for a system with Lifshitz symmetry whereas it tends to a constant for a system with AdS symmetry. This behavior may be interpreted as existence of an additional charge carrier rather than the AdS case, and is due to the presence of the scalar dilaton field in model. Similar behavior for optical conductivity of single-layer graphene induced by mild oxygen plasma exposure has been reported.
Holographic deep learning for rapid optical screening of anthrax spores.
Jo, YoungJu; Park, Sangjin; Jung, JaeHwang; Yoon, Jonghee; Joo, Hosung; Kim, Min-Hyeok; Kang, Suk-Jo; Choi, Myung Chul; Lee, Sang Yup; Park, YongKeun
2017-08-01
Establishing early warning systems for anthrax attacks is crucial in biodefense. Despite numerous studies for decades, the limited sensitivity of conventional biochemical methods essentially requires preprocessing steps and thus has limitations to be used in realistic settings of biological warfare. We present an optical method for rapid and label-free screening of Bacillus anthracis spores through the synergistic application of holographic microscopy and deep learning. A deep convolutional neural network is designed to classify holographic images of unlabeled living cells. After training, the network outperforms previous techniques in all accuracy measures, achieving single-spore sensitivity and subgenus specificity. The unique "representation learning" capability of deep learning enables direct training from raw images instead of manually extracted features. The method automatically recognizes key biological traits encoded in the images and exploits them as fingerprints. This remarkable learning ability makes the proposed method readily applicable to classifying various single cells in addition to B. anthracis, as demonstrated for the diagnosis of Listeria monocytogenes, without any modification. We believe that our strategy will make holographic microscopy more accessible to medical doctors and biomedical scientists for easy, rapid, and accurate point-of-care diagnosis of pathogens.
Collinear technology for holographic versatile disc (HVD) system
Tan, Xiaodi; Horimai, Hideyoshi; Shimura, Tsutomu; Ichimura, Shotaro; Fujimura, Ryushi; Kuroda, Kazuo
2006-09-01
Holographic Versatile Disc (HVD TM) using Collinear TM Technologies is proposed by OPTWARE Corporation, in which the information and reference beams are displayed co-axially by the same SLM. With this unique configuration the optical pickup can be designed as small as the DVD's, and can be placed on one side of the recording disc. In HVD TM structure, the pre-formatted meta-data reflective layer is used for the focus/tracking servo and reading address information, and the dichroic mirror layer is used for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increased recording density of HVD TM. Experimental and theoretical studies suggest that the holographic material is very effective to increased recording density of the system. As the servo technology is being introduced to control the objective lens to be maintained precisely to the disc in the recording and the reconstructing process, a vibration isolator is no longer necessary. HVD TM will be compatible with existing disc storage systems, like CD and DVD, and enable us to expand its applications into other optical information storage systems.
Holographic space and time: Emergent in what sense?
Vistarini, Tiziana
2017-08-01
This paper proposes a metaphysics for holographic duality. In addition to the AdS/CFT correspondence I also consider the dS/CFT conjecture of duality. Both involve non-perturbative string theory and both are exact dualities. But while the AdS/CFT keeps time at the margins of the story, the dS/CFT conjecture gives to time the "space" it deserves by presenting an interesting holographic model of it. My goals in this paper can be summarized in the following way. First, I argue that the formal structure and physical content of the duality do not support the standard philosophical reading of the relation in terms of grounding. Second, I put forward a philosophical scheme mainly extrapolated from the double aspect monism theory. I read holographic duality in this framework as it seems to fit the mathematical and physical structure of the duality smoothly. Inside this framework I propose a notion of spacetime emergence alternative to those ones commonly debated in the AdS/CFT physics and philosophy circles.
Holographic entanglement entropy for the most general higher derivative gravity
Energy Technology Data Exchange (ETDEWEB)
Miao, Rong-Xin [Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Mühlenberg 1, 14476 Golm (Germany); Guo, Wu-zhong [Kavli Institute for Theoretical Physics, Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yukawa Institute for Theoretical Physics (YITP), Kyoto University, Kyoto 606-8502 (Japan)
2015-08-07
The holographic entanglement entropy for the most general higher derivative gravity is investigated. We find a new type of Wald entropy, which appears on entangling surface without the rotational symmetry and reduces to usual Wald entropy on Killing horizon. Furthermore, we obtain a formal formula of HEE for the most general higher derivative gravity and work it out exactly for some squashed cones. As an important application, we derive HEE for gravitational action with one derivative of the curvature when the extrinsic curvature vanishes. We also study some toy models with non-zero extrinsic curvature. We prove that our formula yields the correct universal term of entanglement entropy for 4d CFTs. Furthermore, we solve the puzzle raised by Hung, Myers and Smolkin that the logarithmic term of entanglement entropy derived from Weyl anomaly of CFTs does not match the holographic result even if the extrinsic curvature vanishes. We find that such mismatch comes from the ‘anomaly of entropy’ of the derivative of curvature. After considering such contributions carefully, we resolve the puzzle successfully. In general, we need to fix the splitting problem for the conical metrics in order to derive the holographic entanglement entropy. We find that, at least for Einstein gravity, the splitting problem can be fixed by using equations of motion. How to derive the splittings for higher derivative gravity is a non-trivial and open question. For simplicity, we ignore the splitting problem in this paper and find that it does not affect our main results.
Holographic torus entanglement and its renormalization group flow
Bueno, Pablo; Witczak-Krempa, William
2017-03-01
We study the universal contributions to the entanglement entropy (EE) of 2 +1 -dimensional and 3 +1 -dimensional holographic conformal field theories (CFTs) on topologically nontrivial manifolds, focusing on tori. The holographic bulk corresponds to anti-de Sitter-soliton geometries. We characterize the properties of these regulator-independent EE terms as a function of both the size of the cylindrical entangling region, and the shape of the torus. In 2 +1 dimensions, in the simple limit where the torus becomes a thin one-dimensional ring, the EE reduces to a shape-independent constant 2 γ . This is twice the EE obtained by bipartitioning an infinite cylinder into equal halves. We study the renormalization group flow of γ by defining a renormalized EE that (1) is applicable to general QFTs, (2) resolves the failure of the area law subtraction, and (3) is inspired by the F-theorem. We find that the renormalized γ decreases monotonically at small coupling when the holographic CFT is deformed by a relevant operator for all allowed scaling dimensions. We also discuss the question of nonuniqueness of such renormalized EEs both in 2 +1 dimensions and 3 +1 dimensions.
System for coherence-controlled holographic microscopy of living cells
Antoš, Martin; Čolláková, Jana; Veselý, Pavel; Chmelík, Radim; Křížová, Aneta
2012-01-01
Coherence Controlled Holographic Microscopy (CCHM) is a novel holographic technique for quantitative-phasecontrast (QPC) biological observations particularly of living cells. Owing to the ordinary (low coherence) illumination source, the CCHM images are of low noise, deprived of coherence noise (speckles) and the lateral resolution is improved by a factor of 2 compared to classic holographic microscopes. Long-lasting time-lapse experiments require elimination of the CCHM optical system instability in order to achieve precise QPC measurement and to maintain correct CCHM adjustment for its low-coherence operation. The critical part of CCHM is the interferometer, which is very sensitive to temperature fluctuations and air turbulences. The temperature stabilization of the whole microscope without air turbulences is therefore required to provide stability for long-term observations of living cells. Novel heated microscope box and stage designed and constructed for this purpose are described in the paper. The system maintains a constant temperature of both the microscope and of the sample set to 37 °C thus providing optimal living conditions for living human and animal cells. The system is completed with a novel flow-chamber for living-cells accommodation during observation. A service of the system to CCHM is demonstrated by a series of pictures of growing cells.
Holographic deep learning for rapid optical screening of anthrax spores
Jo, YoungJu; Park, Sangjin; Jung, JaeHwang; Yoon, Jonghee; Joo, Hosung; Kim, Min-hyeok; Kang, Suk-Jo; Choi, Myung Chul; Lee, Sang Yup; Park, YongKeun
2017-01-01
Establishing early warning systems for anthrax attacks is crucial in biodefense. Despite numerous studies for decades, the limited sensitivity of conventional biochemical methods essentially requires preprocessing steps and thus has limitations to be used in realistic settings of biological warfare. We present an optical method for rapid and label-free screening of Bacillus anthracis spores through the synergistic application of holographic microscopy and deep learning. A deep convolutional neural network is designed to classify holographic images of unlabeled living cells. After training, the network outperforms previous techniques in all accuracy measures, achieving single-spore sensitivity and subgenus specificity. The unique “representation learning” capability of deep learning enables direct training from raw images instead of manually extracted features. The method automatically recognizes key biological traits encoded in the images and exploits them as fingerprints. This remarkable learning ability makes the proposed method readily applicable to classifying various single cells in addition to B. anthracis, as demonstrated for the diagnosis of Listeria monocytogenes, without any modification. We believe that our strategy will make holographic microscopy more accessible to medical doctors and biomedical scientists for easy, rapid, and accurate point-of-care diagnosis of pathogens. PMID:28798957
Notes on theta dependence in holographic Yang-Mills
Energy Technology Data Exchange (ETDEWEB)
Bigazzi, Francesco [INFN - Sezione di Pisa,Largo B. Pontecorvo 3, I-56127 Pisa (Italy); Cotrone, Aldo L. [Dipartimento di Fisica e Astronomia, Università di Firenze and INFN - Sezione di Firenze,Via G. Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Sisca, Roberto [Università di Pisa, Dipartimento di Fisica “E. Fermi' ,Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy)
2015-08-18
Effects of the θ parameter are studied in Witten’s model of holographic 4d Yang-Mills, where θ is the coefficient of the CP-breaking topological term. First, the gravity background, including the full backreaction of the RR form dual to the θ parameter, is revisited. Then, a number of observables are computed holographically: the ground-state energy density, the string tension, the ’t Hooft loop, the light scalar glueball mass, the baryon mass scale, the critical temperature for deconfinement — and thus the whole (T,θ) phase diagram — and the entanglement entropy. A simple rule is provided to derive the θ corrections to (at least) all the CP-neutral observables of the model. Some of the observables we consider can and have been in fact studied in pure 4d Yang-Mills on the lattice. In that framework the results, obtained in the small θ regime, are given up to very few powers of θ{sup 2}. The corresponding holographic results agree qualitatively with available lattice data and signal an overall mass scale reduction by θ. Moreover, being exact in θ, they provide a benchmark for higher order corrections in Yang-Mills.
Smartphone-based quantitative measurements on holographic sensors.
Directory of Open Access Journals (Sweden)
Gita Khalili Moghaddam
Full Text Available The research reported herein integrates a generic holographic sensor platform and a smartphone-based colour quantification algorithm in order to standardise and improve the determination of the concentration of analytes of interest. The utility of this approach has been exemplified by analysing the replay colour of the captured image of a holographic pH sensor in near real-time. Personalised image encryption followed by a wavelet-based image compression method were applied to secure the image transfer across a bandwidth-limited network to the cloud. The decrypted and decompressed image was processed through four principal steps: Recognition of the hologram in the image with a complex background using a template-based approach, conversion of device-dependent RGB values to device-independent CIEXYZ values using a polynomial model of the camera and computation of the CIEL*a*b* values, use of the colour coordinates of the captured image to segment the image, select the appropriate colour descriptors and, ultimately, locate the region of interest (ROI, i.e. the hologram in this case, and finally, application of a machine learning-based algorithm to correlate the colour coordinates of the ROI to the analyte concentration. Integrating holographic sensors and the colour image processing algorithm potentially offers a cost-effective platform for the remote monitoring of analytes in real time in readily accessible body fluids by minimally trained individuals.
The future of holographic technologies and their use by artists
Oliveira, S.; Richardson, M.
2013-02-01
The use of holographic technologies in the past has faced resistance in the artistic field. The most conservative artists and critiques saw the term "holographic" more as a technical subject than an artistic one. Nevertheless, to explore new forms to create art has been a constant challenge for any artist, whatever their field. At the end of the 20-century the concept that art can explore any field or subject, create a vision that is somehow technological, is part of the evolving artistic world. In the last two decades, in the search for new terminologies, scientists and artists have used the expression "Holographic" as a synonym of evolution, but with different meanings. Artists are using it as a new form of art call "Holo Art"; scientists see it as a "new" science technique where light takes an important part in the process, and can be used in various aspects of daily life, such as, security and medicine. This paper will explore artists who take the challenge of combining their art with new technologies and how they are viewed in a world where the question of 'what is and what isn't art' is very debatable. Other questions that will be explored are 'How can these techniques be useful to artists?' and 'How do artists challenge themselves to analyse the pros and cons of the results that can be obtained?'
Stuerwald, S.; Schmitt, R.
2010-08-01
Digital holographic microscopy (DHM) is utilized for quantitative phase contrast microscopy in optical testing of reflective or transparent specimens and allows altering the focus numerically by propagating the complex wave. Especially for compensation of deformations or displacements and for long-term investigations of living cells, a reliable region selective numerical readjustment of the focus is of particular interest in digital holographic microscopy. Since this method is time consuming, a Halton point set with low discrepancy has been chosen. By this, the effective axial resolution can be enhanced numerically by post processing of complex wave fronts without narrowing the field of view leading to a loss of information around the focus plane by blurring. The concept of numerical parametric lenses is another key feature in DHM and used to correct aberrations in the reconstructed wave front caused by the setup. To reduce the number of parameters for parametric lenses, the polynomial basis by Forbes is applied for the needs of DHM. Both numerical approaches have been characterized and adapted to the requirements of DHM. The applicability is demonstrated by results of investigations of engineered surfaces and biological cells.
Energy Technology Data Exchange (ETDEWEB)
Betin, A Yu; Bobrinev, V I; Verenikina, N M; Donchenko, S S; Odinokov, S B [Research Institute ' Radiotronics and Laser Engineering' , Bauman Moscow State Technical University, Moscow (Russian Federation); Evtikhiev, N N; Zlokazov, E Yu; Starikov, S N; Starikov, R S [National Reseach Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)
2015-08-31
A multiplex method of recording computer-synthesised one-dimensional Fourier holograms intended for holographic memory devices is proposed. The method potentially allows increasing the recording density in the previously proposed holographic memory system based on the computer synthesis and projection recording of data page holograms. (holographic memory)
Holographic 3D tracking of microscopic tools
DEFF Research Database (Denmark)
Glückstad, Jesper; Villangca, Mark Jayson; Bañas, Andrew Rafael
2015-01-01
We originally proposed and experimentally demonstrated the targeted-light delivery capability of so-called Wave-guided Optical Waveguides (WOWs) three years ago. As these WOWs are maneuvered in 3D space, it is important to maintain efficient light coupling through their integrated waveguide...... demonstrated dynamic tracking and coupling for both lateral and axial displacements of the WOWs. The ability to switch from on-demand to continuous addressing with efficient illumination leverages our WOWs for potential applications in near-field stimulation and nonlinear optics at small scales....
Holographic spectrum-splitting optical systems for solar photovoltaics
Zhang, Deming
Solar energy is the most abundant source of renewable energy available. The relatively high cost prevents solar photovoltaic (PV) from replacing fossil fuel on a larger scale. In solar PV power generation the cost is reduced with more efficient PV technologies. In this dissertation, methods to improve PV conversion efficiency with holographic optical components are discussed. The tandem multiple-junction approach has achieved very high conversion efficiency. However it is impossible to manufacture tandem PV cells at a low cost due to stringent fabrication standards and limited material types that satisfy lattice compatibility. Current produced by the tandem multi-junction PV cell is limited by the lowest junction due to series connection. Spectrum-splitting is a lateral multi-junction concept that is free of lattice and current matching constraints. Each PV cell can be optimized towards full absorption of a spectral band with tailored light-trapping schemes. Holographic optical components are designed to achieve spectrum-splitting PV energy conversion. The incident solar spectrum is separated onto multiple PV cells that are matched to the corresponding spectral band. Holographic spectrum-splitting can take advantage of existing and future low-cost technologies that produces high efficiency thin-film solar cells. Spectrum-splitting optical systems are designed and analyzed with both transmission and reflection holographic optical components. Prototype holograms are fabricated and high optical efficiency is achieved. Light-trapping in PV cells increases the effective optical path-length in the semiconductor material leading to improved absorption and conversion efficiency. It has been shown that the effective optical path length can be increased by a factor of 4n2 using diffusive surfaces. Ultra-light-trapping can be achieved with optical filters that limit the escape angle of the diffused light. Holographic reflection gratings have been shown to act as angle