Miniaturization of optical components, specifically the reduction in thickness created by using planar optical devices, makes light manipulation by diffraction more and more attractive. Optical gratings based on volume Holographic Optical Elements (vHOEs) have the advantage over surface gratings as they reconstruct only a single diffraction order and hence provide high diffraction efficiencies, selectivity and remain fully transparent in the off-Bragg condition.

Guiding light inside an optically transparent medium by total internal reflection (TIR) is common and useful in thin planar optical devices. vHOEs offer unique ways to create selective in- and out-coupling of TIR light. As such vHOEs typically have to be recorded in an edge-lit configuration as the necessary high diffraction angles could not be generated by two free-space beams outside the medium. To record such an edge-lit vHOE, bulky recording blocks or liquid baths are used in complex and hard to align recording setups.

We present in this paper our findings to use instant-developing photopolymer film (Bayfol® HX) to generate 2^nd harmonics in the index profile of phase gratings while using free-space recording setups. Those 2^nd harmonic components enable the vHOE to diffract at such large angles that they replay in an edge-lit configuration. We will discuss in this paper selected materials and beneficial recording parameters to tune the diffraction efficiency towards 2^nd harmonic replay. By this - in reported specific cases - the cumbersome and complex edge-lit recording can be substituted by easy-to-use free-space setups. This process significantly simplifies master recordings for vHOEs with edge-lit functionalities which later can be used in contact copy schemes for mass replication.

A method is presenting for measuring beam propagation ratios (M2) of laser beam utilizing transmissive liquid crystal spatial light modulator (LC-SLM). In this paper, the function of digital zoom lens (DZL) could be obtained by loading a calculated gray-scale of DZL with desired focal length into the LC-SLM and the accurate focal length of DZL could be gotten by a correction method. By comparing with the standard measuring method provided by ISO (International Standard Organization), through using the transmissive LC-SLM, the beam propagation ratios could be calculated by curve fitting based on the beam spot size collected by digital camera versus the focal length of DZL without any movements in the experiments. The experiment and comparison results have shown that it is effective for us to measure the M2 of Gaussian beam using a transmissive LC-SLM whose experimental setups are simple, relatively.

Novel method is suggested for a hyperspectral wave field holographic recording, based on asymmetrical Fourier spectrometer with a flat microobject placed in one of its arms. The output signal, which is the interference of the reference field with the field diffracted by the object, is registered by CCD. The process of recording is reduced to consecutive registration of two-dimensional interferograms by changing the optical length of the reference arm of the interferometer. One-dimensional Fourier transform of the interferogram in each pixel gives a spatial distribution of the complex amplitude for all spectral components of a hyperspectral object field. Inverse Fresnel transform of this field gives a hyperspectral object field in the object plane. Hyperspectral amplitude and average-phase profile images of standard microscope samples obtained experimentally are presented. Coloring, Fellgett’s advantage and speckle noise reduction are discussed.

An alternative method for phase-shifting interferometry of two steps by using a speckle interferometer is proposed. It is shown that the introduced phase-step could be unknown because the use of an appropriate fringe-pattern processing. The acquired fringe patterns are processed by well established phase-shifting algorithms in order to compare these results with our proposal. Numerical phase difference between two states of phase object is compared with theoretical method using electronic speckle pattern interferometry (ESPI) . Simulated and experimental results are provided.

Here we consider a derivative based method for phase recovery and demonstrate a numerical method that can be described as differentiate and cross multiply operation to obtain the phase gradient. This method uses quadrature phase data that is in sine and cosine form, which is a natural outcome many interferometric measurements including that of digital holographic reconstruction. Since the differentiation is performed on trigonometric functions which are discrete, it is shown that the method of differentiation and the sampling rate are important considerations especially for the noise corrupt signals. The method is initially developed for 1D phase signals, and then later extended to 2D. Noise performance of the method is also investigated, and it is shown that for extremely noisy signals the method can be adapted to an iteration routine which recovers the phase successfully. We present simulations and the experimental results which show the validity of the approach.

We present a theoretical study of amplitude diffraction gratings using computer simulating, which consists of a random sampling of points on the image grating to determine the points to be plotted and the points to remove, to simulate erosion in amplitude on the grating. We show their behavior in the diffraction patterns and the induced noise by limiting the number of points that representing the image of the eroded gratings and their symmetry.

We demonstrate a novel class of elements called Far-Field Geometric Phase Holograms (FGPH) capable of producing far-field output images free of chromatic distortion for a broad range of input wavelengths. The FGPH utilizes the geometric phase which applies the same phase profile to any incident wave regardless of wavelength. Thus, the fidelity of an image produced by an FGPH is the same for all wavelengths. However, being a diffractive element, the FGPH is still dispersive in that the size of a generated image depends on the replay wavelength according to the diffraction equation. In this paper, we give theory for the ideal FGPH element, describing its replay characteristics and unique polarization properties. We experimentally realize an FGPH element using photo-aligned liquid crystals patterned with a direct-write system. We characterize the fabricated element and show the theory to be valid. Generally, this new class of polarization sensitive elements can produce broadband undistorted images with high diffraction efficiency.

We have previously introduced a computational architecture suitable for driving full-color holographic display systems based around anisotropic leaky-mode modulators; this architecture appropriately handles single-sideband modulation and frequency-division multiplexing of spectral bands that correspond to the independent red, green, and blue color channels in the display output. In this paper, we describe an implementation for driving the MIT Mark IV holographic display system with such a computational approach, in cases of both pre-computed Fresnel CGHs and real-time, GPU-based diffraction specific coherent panoramagrams. Real-time holographic images of nearly VGA-resolution (468 lines) are generated via three dual-head NVIDIA GPUs via a CUDA-based implementation that encompasses the requisite orthographic view generation from 3-D data sources, parallel vector-based fringe computation per hogel and per color, single-sideband modulation, and frequency-division multiplexing. We present the first results of this scheme in driving the Mark IV display system and review the resulting holographic video output and performance metrics.

We have achieved real-time dynamic holographic display with holographic response time under an order of a microsecond using super-fast-response liquid crystal films. The hologram formation time and self-erasable time can both reach ~ 1 ms in this film. Holographic video display was realized using it without any cross talk between the holograms. However, the holographic display videos we obtained before need to be improved in image quality. This paper presents improvement of holographic video display of the films, and our achievement may be useful for its potential applications in a large-size, high-definition, and color holographic three-dimensional video display.

Holography is a time-based medium, which uses its own aesthetics and techniques to interpret colour and light. This exclusive descriptive language does not simply represent a particular scenario in the moment of recording, but also documents the performance light during the shooting process.

Nowadays 3D graphic software and Internet offer practitioners greater mobility in both the development and the delivery of their artwork. Furthermore, the diverse web-based social media presents unlimited and various spaces to facilitate artists in the exchange of creative knowledge, it enables them to collaborate on their projects with external connections – audience, specialists, etc.

Within the analogue holography art practice, there is a primary lack of interface, or, in other words, it cannot utilise any digital creative tools. 3D printing makes it possible to bridge the gap between cyber space and the holographic world; even more so, as this emerging technique also becomes a platform, which can connect computational data and light information.

The application of 3D printing in contemporary art will reshape the process of creation, as well as the form of visual narrative itself. New technologies continually and increasingly involve the projection of another artistic dimension, and the term “visual” embarks on challenging the generally accepted notion of understanding art and interacting with it.

As new pathways of practice are established, it will take years to build a complete understanding of this medium in order to be able to take a full advantage of the benefits its use offers. This paper is aimed at looking for the potential new ways of artistic expression, deriving from the interrelation between analogue holography and 3D printing. It will also attempt an articulate assessment of 3D printing within the dynamic holographic aesthetics.

Through two temporal modalities, the time of the holographic image (the performance recorded time) and the performance time of the public, we create “a new space for the image”, whose structure is influenced by the holographic images and the public as performer. In the tension between the action space of the participants and the virtual space of holographic images, it exists the time image that goes beyond the issue of the movement and has a direct relationship with the participant’s thought.

In this series of digital holographic images and lenticulars, we are using an old camera Canon IS3 and a new HD Canon, on the HOLOrail, to capture old fashion scenes and other scenes having a “nowadays” look and put them on the surface of the holographic plate.

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.

The onslaught of big data continues even as growth in data storage density tapers off. Meanwhile, the physics of holography continues to suggest the possibility of digital data storage at densities far exceeding those of today’s technologies. We report on recent results achieved with a demonstrator platform incorporating several new secondgeneration techniques for increasing holographic data storage (HDS) recording density and speed.

Since the highest reported areal densities for hard disk drive products currently hover in the 1 Tbit/in² range, we have adopted 2 Tbit/in² as a milestone likely to generate interest in the technology. The demonstrator is based on an advanced pre-production prototype, and so inherits highly functional electronic, mechanical, and optical subsystems. It employs a high-NA monocular architecture with proven angle-polytopic multiplexing.

The demonstrator design includes several second-generation innovations. The first, dynamic aperture multiplexing, greatly increases the number of multiplexed holograms. The second, the DRED^TM medium formulation, provides dramatically higher dynamic range to record these holograms. These two features alone theoretically allow the demonstrator to exceed 2 Tbit/in². Additionally, it is equipped with the capability of quadrature homodyne detection, permitting phase quadrature multiplexing (QPSK modulation), and the potential to further increase user capacity by a factor of four or more. The demonstrator has thus been designed to achieve densities supporting the multi-terabyte storage capacities required for competitive products, and to demonstrate the potential for Moore’s-Law growth for years to come.

Collinear holographic storage system is one of the advantages of the promising candidate as its unique system design. The wavelength margin is a very important characteristic which can make a laser diode to be used possible as a light source in a holographic storage system, because of the bit-error-rate (BER) of a reconstructed page data pattern will be so high that we cannot decode it correctively, even though the wavelength drift of the diode was small enough. To solve the problem, we studied a method of decreasing BER by adjusting the focal length of the lens to compensate the wavelength drift in the collinear holographic storage system. Once we changed the focal length of the lens, the angles can also be changed to satisfy the Bragg condition. So we find that decreasing the focal length of the lenses can compensate the wavelength drift up effectively and vice versa.

Commercially available ray tracing programs by themselves are not adequate for modelling optical systems with holographic gratings. In this paper, we describe a suite of tools that we have developed specifically for working with volume phase holograms. One tool measures the diffraction efficiency of a grating with respect to angle and position. Our automated measurement process is described. The measured diffraction data is analyzed to extract key grating parameters; such as, grating thickness and index modulation. The theoretical basis for this analysis is described. The extracted grating parameters can be used to ray trace expected performance for comparison with direct measurements. Such a methodology has allowed us to develop modelling capabilities that can be confidently used to compare design options and guide development activities. In our environment, data is collected and grating parameters are extracted using LabView; ray tracing is performed using Zemax. The concepts, however, are quite general. An example of measuring a grating recorded in a photopolymer and extracting its grating parameters is given. Results are compared to published datasheet specifications.

In this paper, the design and produce of the wedge-shaped waveguide head-mounted display (HMD) based on reflection holographic optical element (RHOE) are described. A variety of factors were considered when designing, such as loss of efficiency, volume, wide field of view (FOV), and eye box. The thickness of the designed wedge-shaped waveguide can be reduced to two times in comparison with the system that uses the conventional reflective optics in the waveguide. The measured optical efficiency of the monocular HMD using HOE is 34%, with 15^° FOV and a large eye box. The results confirm that the designed and fabricated waveguide can be employed in future commercial HMD.

A method called the switch-back technique allows us to drastically reduce computation time of occlusion-processing based on the polygon-by-polygon silhouette light-shielding. It is also reported that further reduction of computation time can be achieved by splitting an object to some sub-models along with depth direction. However, computational cost for numerical propagation between the sub-models increases with increasing the number of sub-models. As a result, there is an optimum number of sub-models. In this paper, we propose a technique to predict the optimum number of sub-models by estimating the total computational complexity of the switch-back technique with object splitting.

We present the preliminary results of diffraction gratings, which are made by holographic techniques with NOA65 adhesive as polymer matrix and neon purple food colors photosensitized. Gratings are recorded by diode laser ( λ = 445nm), the resulting intensity vs. exposure time curves are shown. The recorded gratings have a mixed behavior the face and the amplitude and itself-developing.

We propose a technique for optimization of design-wavelengths in trichromatic computer holography. Full color reconstruction of high-definition computer-generated holograms (CGH) is simply realized by combining three primary color images reconstructed by three CGHs. However, chromatic aberrations occur in the reconstruction, because incoherent light sources such as LED are commonly used for the illumination. Since these chromatic aberrations change dependently on the design-wavelengths of CGHs as well as the shape of illumination spectra, optimization techniques based on simulated reconstruction of CGHs is presented to obtain the most unobtrusive color aberration from spectra specific to the light source.

We present preliminary results on diffraction gratings made with holographic techniques using dichromated gelatin (DCG) matrix with edible dyes, the purple red, Layar^® and blue Sabofrut^®. The gratings were recorded with a laser diode, λ = 530nm. Curves show diffracted intensity vs exposure time. The recorded gratings show different diffraction efficiencies of gratings prepared with DCG, purple red + DCG, and blue+ DCG. We observed high diffraction efficiency with purple red. All exposure conditions and reconstruction were therefor for all gratings with the same concentration of dichromate for each one of the photosensitive emulsions prepared.

We present a method to reduce the inherent errors caused by band-pass filter in off-axis quantitative phase microscopy and propose the optimum condition that can minimize these errors. We found that phase information of a sample in frequency domain nonlinearly oscillates as a function of the phase-shift correspond to the sample and its medium and the phase information of a sample inside the band-pass filter can be maximized by a proper phase-shift. Through numerical simulations and actual experiments, we demonstrate that the error in phase volume measurement can be effectively reduced by the enhancement of phase signal inside band-pass region using an optimum amount of phase that can be controlled by either changing medium index or wavelength of illumination.

The stability of holographic gratings recorded on photopolymer films containing acrylamide as a monomer and N,N'- methylenebisacrylamide as a crosslinker was investigated experimentally. The photopolymer films contained acrylamide, N,N'-methylenebisacrylamide, eosin Y, and triethanolamine in polyvinyl alcohol matrices. Four sets of films with different N,N'-methylenebisacrylamide concentrations were fabricated. The concentration of N,N'- methylenebisacrylamide was determined from the relative molar ratio of the crosslinker and the monomer. The relative molar ratio of N,N’-methylenebisacrylamide and acrylamide was set to 0.1, 0.02, 0.004, or 0. The photopolymer films were exposed to two intersecting 532 nm laser beams produced by a YVO laser for 100 s to form a holographic grating with a spatial frequency of 653 lines/mm. Each impinging beam had an intensity of 1.0 mW and a diameter of 2.25 mm. The diffracted intensity was measured during recording using a He-Ne laser at 633 nm and after one, two, and three days of dark storage using a YVO laser. Among the studied photopolymer films, that with a relative molar ratio of 0.1 showed high diffraction efficiency immediately after recording (91%) and the best stability after three days (80%).

Phase liquid crystal (LC) spatial light modulators (SLM) are actively used in various applications. However, majority of scientific applications require stable phase modulation which might be hard to achieve with commercially available SLM due to its consumer origin. The use of digital voltage addressing scheme leads to phase temporal fluctuations, which results in lower diffraction efficiency and reconstruction quality of displayed diffractive optical elements (DOE). Due to high periodicity of fluctuations it should be possible to use knowledge of these fluctuations during DOE synthesis to minimize negative effect. We synthesized DOE using accurately measured phase fluctuations of phase LC SLM “HoloEye PLUTO VIS” to minimize its negative impact on displayed DOE reconstruction. Synthesis was conducted with versatile direct search with random trajectory (DSRT) method in the following way. Before DOE synthesis begun, two-dimensional dependency of SLM phase shift on addressed signal level and time from frame start was obtained. Then synthesis begins. First, initial phase distribution is created. Second, random trajectory of consecutive processing of all DOE elements is generated. Then iterative process begins. Each DOE element sequentially has its value changed to one that provides better value of objective criterion, e.g. lower deviation of reconstructed image from original one. If current element value provides best objective criterion value then it left unchanged. After all elements are processed, iteration repeats until stagnation is reached. It is demonstrated that application of SLM phase fluctuations knowledge in DOE synthesis with DSRT method leads to noticeable increase of DOE reconstruction quality.

Nowadays, there are many types of holographic recording medium some of them are photopolymer systems that generally consist of a polymeric host matrix, photopolymerizable momomer, photosensitizing dye and charge transfer agent but some of them have an undesirable feature, the toxicity of their components. Therefore, the present research study material recording, vinyl acetate is selected as polymeric matrix and natural dye from “muicle plant” is used as the photoinitiation these components are not toxic. The films are fabricated using gravity settling method at room temperature by this method, uniform films is obtained with good optical quality. To characterize the medium, been obtained when the coherent reed light (632.8 nm) was sent normally to the grating.

We have investigated the floating image display, which named computer-generated alcove hologram. The viewing angle was enlarged by changing the shape of the computer-generated hologram from flat to semi-half cylinder. To employ the calculation method of the computer-generated rainbow hologram, the full color floating image which has the wide viewing angle is reconstructed. Since these computer-generated holograms have the wide viewing angle, the correct hidden surface removal method is required.

In our previous work, the computer-generated hologram was calculated by using the large number of object data from different viewpoints. When the fringe pattern was calculated, the calculation area is divided into small segments, and each small segment is calculated from one object data. The reconstructed image of the computer-generated hologram should not show the hole or overlap on the different viewing position. The small segment needs the several viewpoints information, especially the reconstructed image is close to the hologram plane. Therefore, the reconstructed image of the previous computer-generated hologram is concerned about the possibility of the hole or overlap.

In this paper, we have proposed the improved hidden surface removal method which uses the virtual window. The calculation area, which is determined by the virtual window, is added to the object data. To apply the improved hidden surface removal method, we have achieved the more correct reconstructed image.

We propose a new optical one-time password(OTP) authentication method by using digital holography, which enhances security strength in the cryptosystem compared to the conventional electronic OTP method. In this paper, a challenge-response optical OTP authentication based on two-factor authentication is presented by 2-step quadrature phase-shifting digital holography using orthogonal polarization, and two-way authentication is also performed using the challenge-response handshake in both directions. The ID (identification), PW (password) and OTP information are encrypted with a shared key by applying phase-shifting digital holography, and these encrypted information are verified each other by the shared key. Because the encrypted digital holograms which are transmitted to the other party are expressed as random distribution, it guards against a replay attack and results in higher security level. Optically, encrypted digital hologram in our method is Fourier transform hologram and is recorded on CCD with 256 gray-level quantized intensities. The proposed method has an advantage that it does not need a time-synchronized OTP and can be applied to various security services. Computer experiments show that the proposed method is suitable for high secure OTP authentication.

A three-dimensional display using persistence of vision (POV) has its own benefits for natural image expression. Conventional POV display using light emitting diode (LED) array was connected with a high speed motor, so it could be possible to express curved-type two-dimensional display or volumetric three-dimensional display. However, it is necessary to consider interactive three-dimensional display. For example, this kind of volumetric display is hardly applied on interactive display since light emitting parts are placed in the center of a rotating screen. To provide a complementary effort to this need, we propose here a hologram-like interactive volumetric display using LED array type persistence of vision and a pair of parabolic mirrors. We build the volumetric POV display by using small size LED arrays. This POV display is located below a pair of parabolic mirrors so the mirrors make hologram-like volumetric POV images to be reimaged such as 4f system of lenses. Several preliminary experiments will be provided for our proposed method.

Electronic Speckle Pattern Interferometry (ESPI), a non-contact and non-destructive optical techniques, was employed for assessing the conservation state of a XVI Century painting on wood (72x88x1,9 cm). By a long term analysis, the whole structure alterations, induced by the room temperature and relative humidity variations, were evaluated. Measurement of the whole painting structural bends was achieved. Local flaws and hidden detachments of pictorial layers from the support, which cannot be recognized by traditional art-restorer methods, were also revealed. This work was prevalently aimed at achieving a simple approach, in the laboratory practice, to get an intuitively user-friendly method for art conservators, not accustomed to high-tech or math based methods. The results demonstrate that ESPI can largely improve the traditional art conservation survey techniques.

We report on a method for recovering data from a simple portable Digital Speckle Pattern Interferometer intended for utilization outside of laboratory conditions, without anti-vibration devices. We used the system for monitoring the structural behavior of a painting on wood, hanging on a wall. In such a situation, fringes, produced by the object displacements, were affected by random distortions caused by environment noise. However a satisfactory number of undistorted, or barely distorted, fringe patterns were found and utilized for processing.

We performed fast continuous acquisitions of consecutive interferograms, picking usable fringe patterns out of a large amount of recorded frames. This is the crucial task in the measurement procedure. For this purpose we developed a software routine, based on jointly analysis of both spectral content and fringe image sharpne ss, as selection rule. From the selected frames, by using a simple approach based on Hilbert Transform and Phase Unwrapping, via MAx-flow (PUMA) algorithm, we were able to evaluate the painting whole structure deformations, caused by environmental thermo-hygrometric fluctuations.

We performed an experiment on a 3D display by employing spatial cross modulation (SCM) using a random diffuser and phase-only spatial light modulator (SLM). In our experiment, a 3D object, which is constructed using four 2D images acquired from different spatial positions, is generated and the encoded 3D object is then displayed on the SLM. The different object images are observed when the image sensor is moved to different spatial positions. The experimental results revealed that the SCM method allows the generation of arbitrarily complex amplitude fields with high diffraction efficiency and with almost no speckle noise.

We investigate the Gouy phase anomaly of light in the focus of refractive plano-convex microlens arrays by using longitudinal-differential (LD) interferometry and a finite-difference time-domain (FDTD) simulation. We put emphasis on determining the amount of the Gouy phase shift for the line focus of the cylindrical lens and the point focus of the spherical lens. We discuss additional phase structures caused by diffraction, which lead to the discrepancy from the conventional Gouy phase shift.

This PDF file contains the front matter associated with SPIE Proceedings Volume 9386 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.