Proceedings Volume 6136

Practical Holography XX: Materials and Applications

Hans I. Bjelkhagen, Roger A. Lessard
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Proceedings Volume 6136

Practical Holography XX: Materials and Applications

Hans I. Bjelkhagen, Roger A. Lessard
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 22 February 2006
Contents: 8 Sessions, 41 Papers, 0 Presentations
Conference: Integrated Optoelectronic Devices 2006 2006
Volume Number: 6136

Table of Contents

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Table of Contents

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  • Materials I
  • Can We Do Business With Holography?
  • Applications of Holography I
  • Materials II
  • Applications of Holography II
  • Digital and Computer Holography
  • Display
  • Posters
Materials I
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Engineering applications of HOEs manufactured with enhanced performance DCG films.
The objective of this research program was the development of the technology for the industrial manufacturing of high efficiency holographic optical elements (HOEs) with predetermined spectral characteristics ranging in format from few square millimeters to square meters. The desired optical properties of holographic materials for specific engineering applications are determined during the making of the film and are modified during the exposure, the development and the post-treatment of the HOE. This technology includes the machine fabrication of precision holographic films with 1 to 50 micron thickness on glass or plastic substrata, the use of filler material to modify the spectral characteristics of HOEs, multiple exposure techniques, contact-copying procedures and chemically and thermally adapted hologram development and post-treatment processes. The technology extends the use of dichromated gelatin (DCG) into the blue and infrared spectral domains and is a viable tool in the control of the holographic properties of the manufactured HOEs. The usefulness of the technology is illustrated with results obtained from existing HOE installations. Design and performance information is presented for manufactured reflection and transmission HOEs that are used in a variety of technical applications, such as: holographic concentrators for photo-voltaic and thermal energy conversion, special collectors for solar photo-chemistry, holographic stacks for day-lighting, glazing and shading in buildings, optical interconnects in multi-chip modules, robotic sensors and holographic beam forming optics for LED applications. Multiple exposures technique is used to record up to four holograms in the same DCG film that are used to generate simultaneously several monochrome or RGB beams.
High spatial resolution measurement of volume holographic gratings
Gregory J. Steckman, Frank Havermeyer
The conventional approach for measuring volume holographic gratings typically requires measuring the transmitted and diffracted beams simultaneously while varying the angle of incidence. To obtain the spectral response a tunable laser is used with a fixed angle of incidence. In the former case, the motion of the diffracted beam from reflection gratings requires the detector to move with it, or otherwise the range of angles must be limited. Furthermore it is often difficult to separate the diffraction from the specular surface reflections, increasing the error of the measurement. In the latter case, a high cost tunable laser is required. We describe methods for the measurement of volume holographic gratings with high spatial resolution. A fixed wavelength laser in conjunction with a high-resolution digital camera is used to measure the angle selectivity of the transmitted beam only. The measured data are fit to a model of the grating diffraction combined with the cyclical interference from the surface reflections in order to increase the accuracy when measuring uncoated gratings. The system is capable of simultaneously measuring diffraction efficiency, loss, surface reflectivity, Bragg angle, and grating tilt in one plane, with a resolution of better than 250 micrometers over the area of a 45 mm by 35 mm wafer. Through a transformation utilizing the de-phasing term of the coupled wave analysis of thick hologram gratings, the wavelength selectivity is also obtained.
Holograms in acrylic copolymer adhesive
S. Toxqui-López, A. Olivares-Pérez, A. Padilla V, et al.
Replicated holograms with high diffraction efficiency can be generated into acrylic copolymer adhesive coating by applying heat, the principal characteristics from this material are nontoxic, soluble-water, clear and cheap, we show a technique to obtain holograms replication and some experimental results.
Transparent acrylic enamel slide holograms
We present holograms generated in a computer to an acrylic enamel slide (Comex(R)), getting phase holograms. The information in the mask is transferred to the material by temperature gradients generated by rubbing. The refraction index is transformed at each material point by the temperature changes, thus the film is recorded and developed by itself. this material can be used for soft lithography.
Can We Do Business With Holography?
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Managing and directing innovation in the holography business
Joseph E. Gortych, Harold Abilock
The intellectual property (IP) space associated with core high-tech innovations, such as holography, tends to rapidly expand in many directions as new applications and improvements to the core technology are realized. Patents soon start to quickly fill regions of the IP space to varying densities, often before any commercial product is available. Complicating matters is the fact that the patents typically range wildly in quality and business value for a host of reasons, not the least of which is that many high-tech companies lack an IP strategy designed to drive their R and D and patenting efforts. IP-savvy high-tech companies are relying more and more on some type of IP space analysis to more fully understand the IP landscape in which they do business. However, after an IP space analysis is performed, it needs to be integrated into a larger IP management system driven by an IP strategy. This paper examines the role of a best-practice IP management system in a high-tech business and how it can be used in conjunction with a holography IP space analysis to strategically manage and direct innovation in the holography business.
Intellectual property analysis of holographic materials business
Nadya Reingand, David Hunt
The paper presents an overview of intellectual property in the field of holographic photosensitive materials and highlights the possibilities offered by patent searching and analysis. Thousands of patent documents relevant to holographic materials have been uncovered by the study. The search was performed in the following databases: U.S. Patent Office, European Patent Office, and Japanese Patent Office for the time frame of 1971 through November 2005. The patent analysis has unveiled trends in patent temporal distribution, leading IP portfolios, companies competition within the holographic materials market and other interesting insights.
Intellectual property licensing issues in the holography business
Increasingly, many high-tech companies are acquiring or transferring "leases" to the innovations used to make products. In legal parlance, these innovations-which may include new manufacturing methods, applications, devices or improvements-are considered "intellectual property" (IP), and the "leases" are referred to as "licenses." The holography business, like many other high-tech businesses, has evolved over many decades and consists of many densely packed IP subspaces. However, the IP space is constantly expanding through the development of new innovations and applications, such as security and storage applications, and new materials. Additionally, like most IP, the quality and business value of holographic IP ranges widely, which makes for a challenging IP licensing environment. This paper addresses IP licensing issues in the holography business, including some basics about the forms of IP and the basic types of IP licenses, the role of an IP space analysis in licensing activities, best-practice management of licensing activities, and how IP is properly scrutinized to assess licensing potential. The concept of the patent pool is discussed in connection with security holograms as well as other technologies.
Intellectual property analysis of embossed hologram business
David Hunt, Nadya Reingand, Robert Cantrell
This paper presents an overview of patents and patent applications on security embossed holograms, and highlights the possibilities offered by patent searching and analysis. Thousands of patent documents relevant to embossed holograms were uncovered by the study. The search was performed in the following databases: U.S. Patent Office, European Patent Office, Japanese Patent Office and Korean Patent Office for the time frame from 1971 through November 2005. The patent analysis unveils trends in patent temporal distribution, patent families formation, significant technological coverage within the embossed holography market and other interesting insights.
Applications of Holography I
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Bronze rainbow hologram mirrors
This project draws on holographic embossing techniques, ancient artistic conventions of bronze mirror design and modelling and casting processes to accomplish portraiture of reflection. Laser scanning, 3D computer graphics and holographic imaging are employed to enable a permanent 3D static holographic image to appear integrated with the real-time moving reflection of a viewer's face in a polished bronze disc. The disc and the figure which holds it (caryatid) are cast in bronze from a lost wax model, a technique which has been used for millennia to make personal mirrors. The Caryatid form of bronze mirror which went through many permutations in ancient Egyptian, Greece and Rome shows a plethora of expressive figure poses ranging from sleek nudes to highly embellished multifigure arrangements. The prototype of this series was made for Australian choreographer Graeme Murphy, Artistic Director of the Sydney Dance Company. Each subsequent mirror will be unique in figure and holographic imagery as arranged between artist and subject. Conceptually this project references both the modern experience of viewing mirrors retrieved from ancient tombs, which due to deterioration of the surface no longer reflect, and the functioning of Chinese Magic mirrors, which have the ability to project a predetermined image. Inspired by the metaphorical potential of these mirrors, which do not reflect the immediate reality of the viewer, this bronze hologram mirror series enables each viewer to reflect upon himself or herself observing simultaneously the holographic image and their own partially obliterated reflection.
Physical aspects of digital synthesis and reconstruction of the multiview diffractive images
Ilya S. Borisov, Valeriy I. Grygoruk, Sergey A. Kostyukevych
The present research deals with the digital synthesis of the multiview diffractive image elements, or simply the Multiview Diffractive Images (MDIs), also known as stereographic diffractive images or holographic stereograms. These images are designed to be included in Diffractive Optically Variable Image Devices (DOVIDs) in order to make them more spectacular and visually impressive and to improve their security properties. In the present paper there are considered the computation of parameters for Diffractive Gratings (DGs) composing the MDI topology. The innovative DGs based on the curvilinear strokes are offered. They provide larger diffraction efficiency and better integrity of the scene for any variant of the Lighting and Observation (LO) as well as for the arbitrary parameters of LO geometry. There are described the original approach for computation and estimation of the polychromatic DGs intended to reproduce the complex spectral distribution of the diffracted light. There are proposed the powerful and flexible techniques for Diffractive Images (DIs) encoding and for uniting different DIs within multichannel one. The distinctions in the modes of the MDI observation, which were escaping anyone's attention until now, are discussed. The physical aspects of visual perception for diffractive images are also concerned. So, the present investigations elucidate the main topics pertinent to the diffractive images synthesis and approach to master the creation of striking ones, particularly the multiview images.
Optimal design and evaluation of a color separation grating using rigorous coupled wave analysis
Mayumi Nagayoshi, Keiko Oka, Werner Klaus, et al.
In recent years, the technology which separates white light into the three primary colors of Red (R), Green (G) and Blue (B) and adjusts each optical intensity and composites R, G and B to display various colors is required in the development and spread of color visual equipments. Various color separation devices have been proposed and have been put to practical use in color visual equipments. We have focused on a small and light grating-type device which has the possibility of reduction in cost and large-scale production and generates only the three primary colors of R, G and B so that a high saturation level can be obtained. To perform a rigorous analysis and design of color separation gratings, our group has developed a program that is based on the Rigorous Coupled Wave Analysis (RCWA). We then calculated the parameters to obtain a diffraction efficiency of higher than 70% and the color gamut of about 70%. We will report on the design, fabrication and evaluation of color separation gratings that have been optimized for fabrication by laser drawing.
Recording and reconstruction of 3D color images by phase-shifting in-line holography
Hideto Fujiwara, Kunihiro Sato, Masakazu Morimoto, et al.
A phase-shifting holographic system for recording 3D color images is developed with a color CCD, and red (R), green (G), and blue (B) lasers. The phase of reference lights in this recording system is precisely shifted by moving the diffraction grating displayed on a high-resolution reflective LCD panel. Measurement of the phase shift of the diffracted light demonstrates the feasibility of the phase-shifting method. RGB in-line holograms can be recorded at the same time for a practical color object by adopting a high-resolution color CCD. Color images in the wide visual field are recorded by adopting a multi-channel CCD and are reconstructed from the recorded hologram by adopting a multi-channel LCD modulator. Holograms for reconstruction of RGB images are obtained from recorded in-line holograms by the phase-shifting holography, and fine color images of high quality are reconstructed from recorded phase-shifting holograms. The visual field or the viewing zone of the holographic system is enlarged by adopting a multi-channel color CCD and a multi-channel LCD panel.
3D display with wide viewing zone using holograms with reduced information
Shingo Hamada, Kunihiro Sato, Masakazu Morimoto, et al.
The superimposing method for information reduction in hologram is compared with the sampling method to clarify their features. 3D images with motion parallax are reproduced in the wide viewing zone from holograms with reduced information. The visual field is divided in several fields for displaying visual depth of the image under reduced information, and partial images in divided visual fields are separately recorded on several Fourier transform holograms (FTHs). A time-sharing display system is developed to reconstruct the 3D image in real time from several FTHs. Experiments are carried out for reconstruction of the practical 3D image from recorded holograms. Results show that resolution of the image is improved, and the speckle noise is suppressed by the superimposing method. Observer can perceive motion parallax of the image with wide viewing zone by viewing a pair of stereoscopic images from right-eye and left-eye positions. Observer can also perceive the correct visual depth of images through a parallax-fusing perceptual phenomenon.
Materials II
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Advances with holographic DESA emulsions
Lothar Dünkel, Jürgen Eichler, Claudia Schneeweiss, et al.
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.
Lactose holograms
The study and optimization of new materials for holographic recording open new applications about these, we find the biopolymer, which offer a high response at the same way, the lactose present this characteristic, Preliminary studies shows, some properties with the ability to storage information, these can be used for holographic recording medium. In this present manuscript we made on analysis of its optical and chemical properties as: refraction index, diffraction efficiency, technique to obtain hologram and experimental replication results of computer holograms. The advantage that this material it is that does not need developed process of developed at environment conditions.
Polymerization-induced diffusion as a tool to generate periodic relief structures: a combinatorial study
Carlos Sánchez, Berend-Jan de Gans, Dimitri Kozodaev, et al.
Polymeric relief structures are extensively used in display technology due to their ability to redirect light in a controlled way. Photo-embossing is a new photo-lithographic technique to generate surface relief structures using photopolymers. In the present paper we show a combinatorial methodology to explore this technique. We have prepared and evaluated (using automated atomic force microscopy) 2-dimensional libraries of photo-embossed gratings, each library with a gradient in period and a gradient in either exposure energy or development temperature or film thickness or photoinitiator concentration or monomer to binder ratio. We show how this combinatorial approach helps us to better understand the photo-embossing process. In addition, we show that this methodology is an effective tool to identify processing conditions resulting in optimum shape and height of the polymeric relief micro-structures to be used in specific applications.
Pineapple holograms
S. Toxqui-López, L. Calixte, A. Olivares-Pérez, et al.
We show that juice pineapple can be considering as new unconventional holographic recorded medium, because it has good chemical and optical properties. Some structures of computers phase holograms are copied into this material by thermo-polymerization therefore in this research we present a preliminary analysis and experimental results. The major improvements from our material are: good diffraction efficiency, reduced cost, easily to apply on any substrate and the hologram is making with out develop process. the nature sweetener from pineapple can be applied for the food industry mainly in the candy industry.
The recent holographic material: Konica P7000
Masashi Iwasaki, Toshihiro Kubota, Masachika Watanabe, et al.
A newly developed silver halide material, KONIKA MINOLTA OPTO P7000, was examined its holographic characteristics. The commercially available material, KONIKA P5600, is blue-green sensitive but the new P7000 shows enough sensitivity to red light for practical use. We recorded holograms with He-Ne laser light on P7000 plates and evaluated the holographic characteristics such as diffraction efficiency and reconstructed wavelength. The results are discussed comparing with those of former Agfa products.
Applications of Holography II
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An application of polymer holographic grating with the frustrated-total-internal-reflection coupling structure to wavelength-band selection for optical wireless communication
Seunghwan Chung, Dongil Yeom, Seyoon Kim, et al.
Spatial confinement of paths in wireless optical communication enables bandwidth and resources reuse in adjacent environments. This property can also result in undesirable shadowing that occurs whenever an obstacle blocks signal paths between transceivers. Shadowing can result in service interruption and increased error rate. Spatial coding is possible to improve link performance and alleviate shadowing effect in wireless communication environment. In this paper, we propose an application of polymer holographic grating with the frustrated-total-internal-reflection (FTIR) structure to wavelength-band selection for optical wireless communication. A polymer holographic grating is fabricated by two beam interference at the wavelength of 532 nm. In the system, a multi-channel source is incident to the FTIR coupling structure which is made by a prism and polymer holographic gratings and acts as a wavelength-band selective filter. This scheme can be used in various systems which need flexible optical path and relative time delay according to each wavelength-band.
A PMMA-metal lamella grating based surface plasmon resonance device
Yongjun Lim, Kyongsik Choi, Hwi Kim, et al.
Recently, a lot of interests have been focused on surface plasmon resonance (SPR), generated by the charge density oscillation existing on the interface between dielectric and metal surface. This particular surface wave has been widely used for sub-wavelength scale photonic circuits, fluorescence microscopy, bio-sensing devices, and photonic display applications. Also, it has a lot of potentials from holographic optical devices to holographic display applications. The measurement of SPR can be simply evaluated by the well-known Kretchmann-Raether attenuated total reflection geometry using angle multiplexing of the incident wave. Based on these concepts, we propose and analyze a plasmon-coupled waveguide and a polymethyl-methacrylate (PMMA) metal thin film grating structure for optical beam coupling and splitting applications. For efficient beam coupling and splitting, we analyze the SPR phenomenon and design plasmon-coupled waveguide structures and the grating structures. To form the PMMA-metal lamella grating structure, we inscribe the grating on the PMMA layer by using excimer laser with the wavelength of 244nm. Then, we deposit gold on the PMMA grating. Finally some experimental results, discussion, and its practical photonic applications are provided.
A Ulexite-based animation recording system by random reference patterns
Yuko Ishii, Misako Irisawa, Yoshihisa Takayama, et al.
We propose a simple, compact and high-security holographic optical memory system using Ulexite in order to produce random patterns of reference beam. 100 hologram multiplexing was achieved by multiplexing exposure, rotating Ulexite by 0.2 degrees every time with LiNbO3 crystal as a recording medium. Moreover, with this system, animation readout images can play for approximately 8 seconds by continuous rotation of Ulexite. As a natural stone, the exactly same Ulexite is very difficult to be found or replicated. Basic experimental results show that Ulexite can be used as a security key for its image-reproducibility and BER calculations.
Digital and Computer Holography
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Impact measurements using double pulse digital holography
J. Müller, J. Geldmacher, C. König, et al.
In this work an analysis of impacts on carbon fibre structures using holographic interferometry is presented. Impacts are caused e.g. by stones or hail at high motion speeds of vehicles. An impact is defined as a load having a duration that is shorter than the travelling time of the impact waves through the structure. The measurements are therefore performed using a pulsed ruby laser, making it possible to record digital interferograms at different times after the impact [1]. The impact is excited by an air-driven projectile and the holograms are stored digitally using a CCD camera. The holograms are reconstructed numerically and the phase difference between the unloaded state before the impact and the loaded state at a predefined time after the impact is calculated. The out-of-plane displacement can then be extracted from these phase differences. The experiments cover the influence of different parameters. Investigated are the occurring wave forms and their group velocities. Results of experiments on the effect of different composite designs on the shape of the wavefront are presented. Due to the anisotropic properties of carbon fibre composites not much is known about the damage tolerance and failure limits especially in the dynamical case. Therefore the goal of these experiments is to gain a deeper understanding of the dynamical behaviour of these materials and to provide the dynamical material parameters which can be used for numerical simulations on one hand and for design and construction on the other hand.
3D CGH registration on organic and non-organic resists: comparative analysis
3D computer-synthesized hologram - is one of the most promising technologies that today is used in modern optical protection elements. Usage of 3D CGH as hologram component allows not only to increase the level of their authenticity but also expand the field of designer solutions, which is very important for increase of hologram quality. Without completely substitute of classical 2D/3D elements 3D CGH technology allows to provide them with especial visual effects.
Applications of the high resolution optical reconstruction of digital holograms
Günther Wernicke, Johannes Frank, Hartmut Gruber, et al.
Adressable spatial light modulators with as much as possible ideal phase modulation are the precondition for their application in digital holography. An adapted driver electronics for the modulator and a correct knowledge of the modulation behavior can lead to a dynamic phase modulating device with nearly linear characteristic curve and a maximum phase range of 2π. We show a system for recording and reconstruction of digital holograms applying a spatial light modulator for the optical reconstruction and the digital processing of the holograms. The data of a CCD-camera are taken to a PC and sent to a spatial light modulator. In that sense we realised an analog-digital converter for recording and a digital-analog converter for the optical hologram reconstruction. We discuss the resolution of the reconstruction and their applications, especially possibilities for the manipulation with the reconstructed wave field.
Display
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Real time calculation for holographic video display
For practical holographic video system, it is important to generated holographic fringe as fast as possible. We have proposed an approximation method that can calculate the hologram faster. However, for the full parallax Fresnel hologram, the speed is not enough for real-time calculation. In this paper, we change the type of hologram from Fresnel to image. Since the object points of the image hologram are located very close to the hologram, calculations for single object point require only fractional part of the hologram. This also makes computation quite fast. The image hologram with 1.47 million pixels hologram, the speed of ten frames per second is obtained with the object consists of 7,000 points. Experimental results demonstrate that the interactive computation of complex object can be generated with conventional PC. We also investigated rainbow hologram for both full-color reconstruction and fast calculation. Reconstructed image prove that the color registration is good thorough the view zone. From the experimental results, compared with the image hologram, we could achieve about two times calculation speed when the number of the object point is more than 17,000. This results demonstrate that the interactive computation of full-color object can be generated with conventional PC.
Holographic stereogram using graphic accelerator
A holographic stereogram is one of methods for displaying 3-D image data from multiple-view images. In this paper, we propose a method for computing holographic stereogram using graphic accelerator. We use graphic accelerator at two stages of method. One is creating Multiple-view images, and another is synthesizing holographic stereogram. To create and rasterize multiple-view images, we use CG rendered from the point of view on the projection plain of hologram. This CG makes effect like ray tracing. In rendering, we use vertex-transforming rebuiled by VertexShader for the negative parallax. This vertex transforming makes negative near clipping possible. And To Synthesize holographic stereogram, we use texture mapping feature of graphic accelerator. This method befits raster output device, because this method output raster data sequentially. And this method befits also PC, because this method doesn't need memory that buffers all multiple-view images, needs processing power for rendering and sampling and synthesizing for each unit of projection plain.
Reconstruction of color images of high quality by a holographic display
Kunihiro Sato, Atsuhiko Sugita, Masakazu Morimoto, et al.
A time-sharing holographic color display system is developed using a high-resolution reflective liquid-crystal display (LCD) panel that consists of a 1920x1080 array of square pixels with the pixel pitch of 8.1 micron. Red, green and blue high-resolution images are reconstructed from the holographic display system with a red laser diode (LCD), a green diode-pumped laser and a blue diode-pumped laser. The reconstructed color image can clearly be observed under the room light. The image exhibits a large color gamut good color expression. High-quality color images of the practical object are reconstructed from recorded holograms by using the developed holographic display system. The viewing zone or the visual field of the holographic display is enlarged by adopting a multi-channel LCD modulator. The viewing zone angle or the visual field angle of color images is enlarged up to about 20 degrees by adopting a 6-channel LCD modulator.
Hologram technology in the display field
Luis M. Murillo-Mora, Hideaki Honma, Fujio Iwata
A review of the applications of holography to commercial products is presented. This review is performed on application on display devices such as liquid crystal display devices where the inclusion of holographic optical elements has been successful. Works are focused on light coupling, reflectors, diffusers and light guides.
Posters
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Electro-holography system using an array of water particle 3D screen
Koki Sato, Takumi Kanaoka, Toshimichi Okumura, et al.
Recently, many type 3D display are now being developed. We have developed a electro-holographic display system using water particle 3D screen. However, a reconstructed image on water particle 3D screen was not clear because it was flickered by gravity and flow. By our research, flicker was reduced using flow controlled nozzle. We want to watch 3D moving image with little distortion and more expanded depth, hence, we have developed an array of water particle 3D screen.
Photoinduced birefringence and cooperative molecular reorientation in azo copolymer: optical characterization for rewritable memory application
In this paper, new azobenzene copolymers (PCDY and PPDY) with large photoinduced birefringence and good long-term stability of a recorded data have been introduced. The largest photoinduced value of 0.289 was obtained on the PCDY50 at 458 nm light irradiation. This value was brought about a result of molecular cooperative reorientation of cyanoazo and bisazobenzene moieties. It should be noted that the PCDY50 exhibited quite stable characteristics on the archival viewpoint. Furthermore, if we can optimize experimental conditions, more than 105 cycles of reversible data storage could be achieved. Making use of these superior characteristics of the PCDY50, an application for rewritable holographic memory and/or other optical addressable devices is anticipated.
Optical characteristics of holographic input-beam coupler using a photopolymer
Holographic gratings with asymmetric structure are widely used to couple light into and out of waveguides due to their high diffraction efficiencies and planar packaging. In this paper, a holographic grating coupler based on the photopolymer has been designed and experimentally demonstrated at wavelength of 405nm. To achieve the high diffraction efficiencies in the structure, we investigated the optical properties of the coupler according to the exposure energy at the 405nm wavelength. In the holographic recording for the asymmetrical geometry, we researched the optical characteristics of the Dupont photopolymer HRF150-38 as the correction of the Bragg angles shift because of shrinkage factor and the diffraction efficiency. The performance and the optical characteristics of the coupler using volume holographic grating will discussed in detail.
Stability of holographic gratings recorded on photopolymer using different dyes
In this study, stability of holographic gratings recorded in four photopolymer films with different dyes was experimentally examined. Also, dye concentration was optimized to get high diffraction efficiency. Each film contains triethanolamine and acrylamide in polyvinyl alcohol matrix, and one type of dye: eosin Y, methyl violet, rhodamine B or rose bengal. Dye concentrations were adjusted so that transmittances of the four films 60 μm thick were approximately 94%. The photopolymer films were exposed by two intersecting beams of a YVO laser at 532 nm to form holographic grating with spatial frequency of 653 line/mm until the diffraction efficiency reached its maximum. The power of each recording beam was 10 mW, and its diameter was 2.25 mm each. Diffraction efficiency was measured using a YVO laser beam for the recorded films undergoing either 300 sec reconstruction or 5-day dark storage. The photopolymer film containing eosin Y showed the best stability both for a 300 sec reconstruction and for 5-day storage. Regarding optimization of dye concentration, the diffraction efficiencies of more than 60 % were obtained when an amount of eosin Y is between 1 mg and 50 mg, which was solved in 9.1 % polyvinyl alcohol aqueous solution of 110 g.
Real-time holographic gratings recorded in Norland Optical Adhesive 65 and crystal violet dye
M. Ortíz-Gutiérrez, A. M. Martínez-Basurto, J. C. Ibarra, et al.
We recorded real time holographic gratings in a photosensitive liquid material. This material is Norland Optical Adhesive (NOA 65(R) ) mixed with crystal violet dye (CV). The NOA 65(R) is a clear, colorless, liquid photopolymer that cures when is exposed to ultraviolet light (UV) but when is mixed with crystal violet becomes sensitive to visible region of the electromagnetic spectrum. To record the gratings we used the interference between two beams from a He-Ne, obtaining phase modulation gratings by refraction index changes. We use three different wavelength, λ = 633 nm, 612 nm and 594 nm for recording the gratings and its highest diffraction efficient was obtained when the grating was illuminated with a wavelength λ= 594 nm whose value was of 10.76 %. This mixture of NOA 65(R) and CV open the possibility to make diffractive elements.
Properties comparison of holograms using PVA doped with MgCl2 as conductor polymer
Metallic salt MgCl2 as dopant, its concentration, and electro-chemical behaviour, as the physico-chemicals changes in the doped process; these are elements determinant to obtain a final conductive polymer product. We present some results from properties electro-optics of the PVA doped with MgCl2, for this form will be use as conductive polymer and holographic material, we present the diffraction efficiency parameter from the gratings made with our conductor polymer material.
Holograms using PVA doped with CoCl2 as conductor polymer
We used CoCl2 as dopant with PVA, to do holograms for different concentrations and process as photo and thermo-polymerizations under environmental conditions. We present the quantitative results of the diffraction efficiency parameter from digital holograms storage, bearing in mind variable so much physical and chemical to different concentrations.
Epoxy resin holograms
B. Ruiz-Limón, G. B. J. Wetzel, A. Olivares-Pérez, et al.
We observed that a commercial epoxy resin (Comex(R) is enable to record images by means of lithography techniques. We can generate a hologram using a digital image and a computer simulation program and transferred it on our resin by microlithography techniques to get a phase hologram and increase its efficiency. The exposition to the heat produce temperature gradients and the information in the mask is transferred to the material by the refraction index changes, thus the film is recorded. At the same time the hologram is cured.
Successive encryption and transmission with phase-shifting digital holography
Sang Keun Gil, Seok Hee Jeon, Nam Kim, et al.
We present a novel information or key encryption and transmission technique based on phase-shifting digital holography for a security system. Phase-shifting digital holography is used for recording phase and amplitude information on CCD device. 4-step phase-shifting is implemented by moving the PZT mirror with equidistant phase steps of π/2. The information and the key are converted to random phase patterns. Digital hologram in this method is Fourier transform hologram and quantized with 256 gray-level. The basic idea is that we reuse a 256 gray-level digital hologram to encrypt the information or the key with 4-step phase-shifting digital holography. The encrypted binary data/image in the form of digital hologram can be transmitted through communication network, and is reconstructed and decrypted digitally. The simulation shows that the proposed method gives good results for a successive encryption/transmission.
A high-resolution fringe printer for studying synthetic holograms
K. Matsushima, S. Kobayashi, H. Miyauchi
A high resolution fringe printer developed for driving the research in computer-generated holograms is presented. This fringe printer consists of a rotation drum and a laser diode and is capable of printing elliptical dots of 1.5 times 3.0 microns in diameter on photosensitive films. These dot sizes are approximately converted into resolutions of 17,000dpi × 8,500dpi. The horizontal and vertical angles of viewing-zone of holograms printed by the printer reach 24 and 12 degrees, respectively. The designed maximum scan speed is more than 200mm/s, and at current stage of development, a hologram of approximately 50 mm square can be printed in approximately 2 hours.
Data compression for transmission of holographic 3D images using digital SSTV
Kunihiko Takano, Koki Sato, Toshimichi Okumura, et al.
In this paper, the quality of recovered holographic images produced by CGH adopted JPEG2000 is investigated. As a result, it is observed that this process gives nice 3D reconstructed images. It appears to show that a transmission of 3D holographic images can be possible.
Development of interactive tabletop hologram
Kunio Sakamoto, Tsukasa Nishida, Tsutomu Morii
Many applications for 3D imaging are proposed. We developed a prototype interactive tabletop holographic display system. This system consists of the object recognition system and the spatial imaging system. In this paper, we describe the recognition system using a QR Code label or RFID tag and a 3D display system using a holographic technology.
Color evaluation of full color hologram
Tomoko Kumasawa, Akiko Tanaka, Tsuyoshi Yamauchi, et al.
This paper concerns the new full color mastering process in order to obtain full color three-dimensional Lippmann holograms with flipping effect. As holographic recording materials, both newly developed red-sensitized silver halide P7000 and photopolymer were appropriated. In this study, the color reproduction and the viewable zone in vertical and horizontal directions of resulting full color Lippmann holograms were examined. The angle dependence of the reproduced colors of the holograms with both the new H1H2 mastering method and the previously reported modified Denisyuk mastering method were evaluated. The holograms using the new method showed better color reproduction and were brighter than the holograms using the modified Denisyuk method. To combine above mastering technology with mass-production technology and layer structure technology, we have succeeded in the mass-production of full color holograms with flipping effect.