This PDF file contains the front matter associated with SPIE Proceedings Volume 8281, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

PVA (Polyvinyl acetate ) glue is one of the most common forms of adhesive on the market, which is popular because it has an ability to adhere to many different surface, but besides in this research we shown that can be employed as polymeric matrix and is employed for holographic recording when this is doped with ammonium dichromate. Thin, uniform coating of this photopolymer is generated by gravity settling method. The drying time for the photosensitive layers is approximately 24 h. Therefore, we present the experimental results obtained through diffraction gratings were recorded using a laser of He-Cd (442 nm).Furthermore the average results of the diffraction efficiency parameter which is quantified by their two first orders of diffraction. The PVA glue with ammonium dichromate can be considered as versatile holographic recording media due to their good sensitivity low cost and self -developing.

Recent researches have been reported that is possible increase the diffraction efficiency parameter from holographic gratings when photosensitive material (PVA with ammonium dichromate) it is painted after register the hologram with commercial fluorescent ink. In this research we shown that PVA as a binder, with the fluorescent ink and ammonium dichromate, this mixed can be used as recording medium. We characterize this material by implementing holographic films in which holographic gratings are recorded with a He- Cd laser at 442nm, and measuring holographic parameters such as diffraction efficiency. We get increased the diffraction efficiency and also the lifetime of the film.

Photochromic materials can find application in holography, thanks to the peculiar possibility to change reversibly their transparency in the visible (amplitude holography) and their refractive index in the near infrared region (phase holography). The main advantages of such materials are rewritability and self-development. A large change of the key property is crucial to obtain efficient devices and some strategies are followed, accordingly. Production of the holograms have open important issues regarding the film thickness and the nonlinear response to light, because of the strong absorption of the writing light by the material. Results related to these topics, mainly focused on diarylethene-based materials, are reported.

Liquid photopolymers produced by Polygrama-Lynx (SM-532TR and SM-532TRF) have been studied to determine their performances in terms of refractive index modulation, transparency and overall optical quality. Volume phase holographic gratings (VPHGs) based on these materials have been obtained using a 532 DPSS laser and the grating efficiency has been measured at different angles and wavelengths. Using the Kogelnik model and/or the RCWA approach, the thickness and the refractive index modulation has been determined for gratings as function of light exposure, line density, etc. Index modulations up to 0.03 together with good optical quality were obtained.

Phase-shifting digital holography is a hologram capture method used for natural scenes. We propose a method for enlarging the viewing-zone angle for the electronic holography input. During hologram generation, if we use multiple reference beams or multiple object beams whose incident angles differ slightly from each other, the viewing-zone angle of the phase-shifted hologram can be expanded several times compared to the original. In the experiment, a phase-shifted hologram with a viewing-zone angle of 16 degrees was generated using 3 object beams whose incident angles differ from each other by 5.6 degrees.

Because holography can reconstruct the wavefront of the light emitted from an object, eyes might focus on holographically generated three-dimensional (3D) images. Therefore, eye accommodation is considered to function properly for holographic 3D images. However, the measurement of the accommodation responses to 3D images generated by electronic holographic displays have not been reported, because their viewing zone angle and screen size are limited and the observation of the reconstructed 3D images with both eyes is difficult. In the recent study, we have developed a horizontally scanning holographic display that enables the increase of both horizontal viewing zone angle and screen size. The reconstructed images can be observed with both eyes. In this study, we measured the accommodation responses to the 3D images generated by the horizontally scanning holographic display. We found that the accommodation responses to the 3D images were similar to the responses to real objects.

A holographic television system, featuring realtime incoherent 3D capture and live holographic display is used for experiments in depth perception. Holographic television has the potential to provide more complete visual representations, including latency-free motion parallax and more natural affordances for accommodation. Although this technology has potential to improve realism in many display applications, we investigate benefits in uses where direct vision of a workspace is not possible. Applications of this nature include work with hazardous materials, teleoperation over distance, and laparoscopic surgery. In this study, subjects perform manual 3D object manipulation tasks where they can only see the workspace through holographic closed-circuit television. This study is designed to compare performance at manual tasks using holographic television compared to performance with displays that mimic 2D, and stereoscopic television.

Transmission of hologram is very important to realizing the holographic 3D TV. Transmission of Computer Generated Hologram(CGH) data using SSTV wire-less method was tried before and one frame with 76.8k bit data transmitted by 2kbbs was reported1-2). In this research we consider about more high speed transmission and more high resolution hologram data transmission and reconstruction using white LED.

The speed at which our world is changing is reflected in the shifting way artistic images are created and produced. Holography can be used as a medium to express the perception of space with light and colour and to make the material and the immaterial experiments with optical and digital holography. This paper intends to be a reflection on the final product of that process surrounding a debate of ideas for new experimental methodologies applied to holographic images. Holography is a time-based medium and the irretrievable linear flow of time is responsible for a drama, unique to traditional cinematography. If the viewers move to left or right, they see glimpses of the next scene or the previous one perceived a second ago. This interaction of synthetic space arises questions such as: can we see, in "reality", two forms in the same space? Trying to answer this question, a series of works has been created. These concepts are embryonic to a series of digital art holograms and lenticulars technique's titled "Across Light: Through Colour". They required some technical research and comparison between effects from different camera types, using Canon IS3 and Sony HDR CX105.

A holographic video camera with use of a high-power pulsed laser is developed for recording time-sequential 3-D images of moving objects by applying one-shot digital holography. Recorded off-axis holograms are transmitted to a computer where the 0-th order and the conjugate beams are eliminated by fast data processing, and digital output signals from the computer are transmitted to a holographic LCD display system to reconstruct moving 3-D images. Optical experiments demonstrate that complex-amplitude holograms are recorded under room lighting, and that moving 3-D images are reconstructed from the holographic display system in real time.

In Computer Generated Hologram (CGH), the hidden surface removal is needed to display 3D objects. Some methods of the hidden surface removal for a CGH have been proposed. However, these methods are unsuitable to make realistic images that have the complicated reflection, refraction and shadowing. We propose a calculation method of CGH using the ray tracing method. In the ray tracing method, complicated descriptions are expressed with a simple algorithm. The ray tracing method is avoided ever in CGH having a very high resolution because of enormous calculation cost. In order to speed up, we attained improvement of the calculation time using a graphics processing unit (GPU). The ray tracing from one viewpoint is unable to express full parallax CGHs. In this study, a hologram plane is divided into elementary holograms, and the center of each elementary hologram is made the starting point of the ray. Then, sets of point light every elementary hologram are constructed by the ray tracing method. As a result of optical reconstruction, it was confirmed that hidden surface removal was conducted when plural objects were in one scene. Moreover the texture of material and shadows by a front object were expressed.

In off-axis digital holographic microscopy, short coherence length of the source results in an unwanted reduced field of view. A diffractive optical element (DOE) which combines two high efficiency transmission volume phase gratings holographically recorded into a thin photopolymer, is proposed to manipulate the coherence plane tilt of beam containing a plurality of wavelengths simultaneously. The DOE extends the interference pattern between object and reference beams in digital holographic microscope (DHM) over the whole physical beam overlap area. We experimentally demonstrate full field imaging in a commercial, two colors (685 nm and 794 nm) reflection digital holographic microscope (DHM). The synthetic wavelength created by the two colors extends the unambiguous depth range of the DHM from 0.39μm to 2.49μm .

In this paper, a full parallax occlusion algorithm for holographic 3D display is developed and the motion parallax and dynamic occlusion effect of the reconstructed 3D object is successfully demonstrated. The ray-casting, directional clustering and vertical angle marking technologies are integrated with coherent ray tracing (CRT) hologram computation algorithm. By applying the vertical angle marking technology, only a single pass of the entire horizontal viewing angle is needed to compute full parallax occlusion. The complexity of the algorithm is reduced by about one order compared to standard occlusion algorithm which considers the entire range of combination of horizontal and vertical viewing angles for occlusion. Compared to conventional CRT computation which does not consider occlusion effect, the algorithm has also increased the computation speed to about 350%. The algorithm is able to work with any forms of 3D data. The optimal horizontal angular resolution has also been identified as 0.007 degree for our system experimentally which enables the optimization of the algorithm. Various 3D objects with full parallax occlusion effect have been reconstructed optically.

We propose a technique to shade reconstructed images of electronic holography. Our technique modifies the zone plate technique, which represents a three-dimensional object as an aggregate of object points and zone plates, which generate object points, are summed to calculate a hologram. Our technique is based on the Phong reflection model developed for computer graphics, which assumes that light reflected from an object consists of three components: diffuse, specular, and ambient reflection light. Among these components, only the specular component depends on the position of the camera (or the eye). A holographic reconstructed image changes depending on the viewing direction. Therefore, the specular component changes for different viewing directions. Because light modulated by a zone plate converges to an object point, we assumed that light is redirected differently at each point on the zone plate. Therefore, two-dimensional amplitude modulation of the zone plate would generate an object point that emits light with different intensities in different directions. The proposed two-dimensional amplitude modulation comprises variable and constant modulations: the former one controls the specular component and the latter one controls the diffuse and ambient components. We experimentally verified the proposed technique.

The optical imaging takes advantage of coherent optics and has promoted the development of visualization of biological application. Based on the temporal coherence, optical coherence tomography can deliver three-dimensional optical images with superior resolutions, but the axial and lateral scanning is a time-consuming process. Optical scanning holography (OSH) is a spatial coherence technique which integrates three-dimensional object into a two-dimensional hologram through a two-dimensional optical scanning raster. The advantages of high lateral resolution and fast image acquisition offer it a great potential application in three-dimensional optical imaging, but the prerequisite is the accurate and practical reconstruction algorithm. Conventional method was first adopted to reconstruct sectional images and obtained fine results, but some drawbacks restricted its practicality. An optimization method based on 2 l norm obtained more accurate results than that of the conventional methods, but the intrinsic smooth of 2 l norm blurs the reconstruction results. In this paper, a hard-threshold based sparse inverse imaging algorithm is proposed to improve the sectional image reconstruction. The proposed method is characterized by hard-threshold based iterating with shrinkage threshold strategy, which only involves lightweight vector operations and matrix-vector multiplication. The performance of the proposed method has been validated by real experiment, which demonstrated great improvement on reconstruction accuracy at appropriate computational cost.

Using the infrared matrix of pyroelectric or other photodetectors along with THz band pass filters with pulsed or CW sources one can record the 2D intensity distribution of THz radiation with a high degree of monochromatization. This allows one to use various approaches to solving the phase problem which were developed for the visible frequencies. In this contribution we present the results of the numerical investigation of the wavefront reconstruction using THz radiation at several wavelengths and taking the intensity distribution at various distances.

Performance of various holographic techniques can be essentially improved by homogenizing the intensity profile of the laser beam with using beam shaping optics, for example, the achromatic field mapping refractive beam shapers like πShaper. The operational principle of these devices presumes transformation of laser beam intensity from Gaussian to flattop one with high flatness of output wavefront, saving of beam consistency, providing collimated output beam of low divergence, high transmittance, extended depth of field, negligible residual wave aberration, and achromatic design provides capability to work with several laser sources with different wavelengths simultaneously. Applying of these beam shapers brings serious benefits to the Spatial Light Modulator based techniques like Computer Generated Holography or Dot-Matrix mastering of security holograms since uniform illumination of an SLM allows simplifying mathematical calculations and increasing predictability and reliability of the imaging results. Another example is multicolour Denisyuk holography when the achromatic πShaper provides uniform illumination of a field at various wavelengths simultaneously. This paper will describe some design basics of the field mapping refractive beam shapers and optical layouts of their applying in holographic systems. Examples of real implementations and experimental results will be presented as well.

A new numerical method for in-line hologram reconstruction is proposed. It is shown that the object image is successfully recovered by applying Hartley transform to the difference of two phase shifted holograms followed by the application of a phase retrieval type of an algorithm. The algorithm is explained in detail and simulation results are presented.

We describe two novel modulation techniques for collinear holographic data encoding, employing a spatial light modulator (SLM) based on twisted nematic LCD. In the Fourier transform holographic storage system, the reference beam in the outside part and the object beam in the inside part are simultaneously modulated by one single SLM, with different modulation techniques. In one of the modulation methods, the reference beam is phase modulated with a circular blazed grating pattern, and then diffracted into the central part to interfere with the amplitude modulated object beam. Multiple holograms can be recorded on the same location with reference beams of different grating period. Another modulation method is to modulate both the reference beam and the object beam with pure phase modulation by the SLM. The binary ones are encoded with random phase shift from 0 to 2π, while the binary zeroes are encoded with a constant phase of 0. When the dc component of the spatial frequency generated by the binary zeroes is blocked, a homogeneous hologram will be obtained, and the amplitude object will be reconstructed directly. In this paper, both of the two modulation methods are performed theoretically and experimentally. From the experimental results, it can be seen that the blazed-grating modulation technique gets a higher efficiency, while pure phase modulation method can reconstruct the images with more uniform intensity. These techniques are demonstrated to be attractive for applications in data storage and encryption systems.

A computer-generated hologram (CGH) is well-known to reconstruct 3D image truly, and several CGH printers are reported. Since those printers can only output a transmission hologram, the large-scale optical system is necessary to reconstruct the full parallax and full color image. As a method of a simple reconstruction, it is only necessary to use a volume reflection hologram. However, the making of a volume hologram needs to transfer a CGH by use of an optical system. On the other hand, there are the printers which output volume type holographic stereogram reconstructing the full parallax and full color image. However, the reconstructed image whose depth is large gets blurred due to the insufficient sampling rays of a 3D object. In this study, the authors propose the volume hologram printer to record the wavefront of a 3D object. By transferring the CGH which is displayed on the LCoS, the proposed printer can output a volume hologram. In addition, the large volume hologram can be printed by transferring plural CGH that recorded partial 3D object in turn. As a result, the printed volume hologram has been able to reconstruct a monochrome 3D image by white light, and realized the full parallax image.

We introduce and demonstrate a new holographic recording technique based on birefringent prisms for creating polarization gratings (PGs). Conventional holographic arrangements for creating PGs consist of several polarization and collimating optics that are carefully aligned with each other, and often require substantial physical space. Both the size and the relative distance between these optics increase for large exposure areas, that limit the range of grating period achievable. Moreover, the cost and complexity associated with the mounting of the several elements also increases, and therefore such approaches are not viable for large area PGs and large volume manufacturing. To overcome the above limitations, we propose new approach using multiple polarizing prisms to record PGs that is compact, scalable for large areas, and enables easy tuning of the grating period by simple rotation of at most two elements.

In the microwave band, the radiated wave from the pyramidal horn antenna is calculated in the diffracted field by the Fresnel approximation. In addition, the Fresnel approximation has been introduced into the diffracted field with half infinite diffraction plane. This phenomenon is examined compared with the experiment value based on a hologram interpretation. In this report, the electromagnetic diffracted field with the pyramid horn antenna is calculated as the first stage under the Fresnel approximation. As a result, the hologram was made by interfering with the reference wave whose obtained diffracted field and angle of incidence are 60° on the computer. It can be interpreted that this is one computer generated hologram. Moreover, the image that this hologram pattern is reconstructed in optics with the He-Ne laser was obtained.

Today, along with the wider use of high-speed information networks and multimedia, it is increasingly necessary to have higher-density and higher-transfer-rate storage devices. Therefore, research and development into holographic memories with three-dimensional storage areas is being carried out to realize next-generation large-capacity memories. However, in holographic memories, interference between bits, which affect the detection characteristics, occurs as a result of aberrations such as the deviation of a wavefront in an optical system. In this study, we pay particular attention to the nonlinear factors that cause bit errors, where filters with a Volterra equalizer and the morphologies are investigated as a means of signal processing.

A computer generated hologram(CGH) is hologram made by computer simulation. As fast calculation method for CGHs, basic object light method has been proposed. Lightwaves of arbitrary object shapes are calculated by transforming calculation of object light for basic object. And calculation method with spherical basic object light has been proposed to reduce memory capacity. We proposed transformations which are slide, rotation, distance, tilt, scaling and skew with spherical basic object light. This paper shows implementation of these transforming calculation on GPU to accelerate. Memory capacity for basic object light is larger than video memory. We divide data of basic object light and improve the algorithm to enable GPU to calculate at high speed. In the processing speed measurement, processing speed on GPU with basic object light is about 700 times faster than CPU.

The memory system described herein can record multiple holograms by a simple shift of the photopolymer film medium. The primary advantage of this method is that it enables the generation of make a single, large capacity hologram because the corresponding optical system is simpler than the transmission-type recording system, which has generally been studied to date. The experimental results confirm the possibility of multiple recording by medium shift. Furthermore, the results indicate that a large capacity memory system of over 1 Tb/in² can be obtained if a thick medium (about 1 mm) is used.

A computer-generated hologram (CGH) is generated by simulating light waves propagated from virtual objects, and we are able to observe natural 3-D images without feeling tired. However, the resolution of current output devices, liquid crystal displays, is not high enough to display CGH data, so the size of reconstructed images are restricted. To increase image size, a method by using the Fourier transform optical system has been proposed. The Fourier transform optical system converges reconstructed light by arranging a lens between an observer and hologram and reconstructs floating images near the observer. In the system, a reconstruction position is confined around a focal point of the lens because a CGH calculation method had not yet been developed . To solve this problem, this describes a CGH calculation method using a unified formula to reconstruct images at arbitrary depth. This formula is derived by considering image formation of a lens and hologram. Moreover, process for eliminating unnecessary light elimination processing is described in this paper. By changing the elimination process according to the reconstruction position, images are reconstructed without overlapping unnecessary light at arbitrary depth. To confirm the effectiveness of the proposed method, we conducted optical reconstruction experiments. The results show that correctly sized images are reconstructed at correct depth, and unnecessary light is eliminated. It is possible to observe large and free-depth 3-D images with the proposed method.

In this paper, we propose a method of enlarging the visual field for displaying 3-D images of larger objects at wide angles. We also theoretically derived a maximum border for the visual field. Because its viewing zone is close to the lens, we called our method eyepiece-type electro holography. By placing a real image within the focal point of a convex lens, we obtain a 3-D image of the object as a virtual image behind the lens. The range of visual field in this case starts on the lens, continues to infinity on the z-axis, and shapes a truncated cone.

Computer-generated holograms (CGHs), which are generated by simulating the recording process of a hologram in a computer, are noted as an ideal three-dimensional (3D) display technology. However, with CGHs it is necessary to create precise 3D model data based on objects that already exist, and it is difficult to do this. To solve this problem, there has been much research on generating CGHs using multi-view images (MVIs). MVIs make it possible to generate CGHs from real-existing objects in natural light. A method using ordinary digital cameras resulted in high-resolution reconstructed images without the need for any special devices, but with this method it is necessary to capture a huge number of images or to use a huge number of cameras to ensure a sufficient continuous motion parallax. This is simply not realistic for the construction of 3D display applications. In this paper, we describe a method of generating voxel models from captured images and then using the MVIs obtained by the models to generate CGHs. We generate voxel models by SFS, determine voxel value using the captured images, and render voxel models into MVIs. Using this method enables us to arrange holograms at arbitrary positions in the range in which MVIs are generated correctly. We can also obtain a sufficient continuous motion parallax by generating MVIs obtained from voxel models in spite of capturing only a small number of images. Results of optical experiments demonstrated the effectiveness of the proposed method.

Image-type binary CGHs, fabricated by a laser lithography system, commonly lost the object shading and texture. This is caused by the binary amplitude fringe that is unable to reconstruct object brightness because amplitude information of the object field is removed by binarization if the object is too close to the hologram. In this paper, optimized error diffusion is applied to encoding binary-amplitude image-type CGHs in order to improve reconstruction of surface shading and texture. An actual image-type high-definition CGHs is created by the proposed technique and demonstrated to verify that the CGHs can be reconstructed by white light source without much chromatic aberration.

Novel techniques is proposed for rendering specular smooth surfaces in polygon-based computer holography that features reconstruction of fine 3D images accompanied with strong sensation of depth. The technique is an improvement of the conventional technique for rendering flat specular surfaces. In this technique, phase distribution that works as a diffuser is divided into small rectangular segments and the reflection direction is controlled for each segment. In addition, this new method increases freedom for lighting the object. Two high-definition CGHs are calculated by the proposed method. One of them is fabricated and demonstrated for verifying the technique.

We present the performance characterization of photosensitive film emulsions prepared with saccharides like: pectin, fructose and sugar (Glass ®), at certain physicochemical conditions for holographic recording. The photo-oxidation was carried out with concentrations of iron ions, Fe⁺³. We analyzed the parameters of the diffraction efficiencies of each grating constructed with saccharides film. The work was to achieve stability and non-toxicity of the films prepared easily with water-Fe ions. We performed an experimental comparison of the holographic films capacity between the three saccharides.

We present the characterizations of the photosensitive film made with albumins gallus gallus and callipepla cali, with the purpose to make holographic recording. Albumin was combined with propylene glycol, to build colloidal systems by adding the ammonium dichromate solution as photosensitive salt at certain concentrations. Hence, we conducted the photo-oxidation process with laser, λ=442nm. Obtaining holograms that allowed the analysis of the diffraction efficiency parameter. One of the objectives of this work was to obtain some mechanical and chemical stability of films made with albumin when prepared with propylene glycol. At once, experimental studies were performed to compare the results of the holographic recording films between chicken albumin and quail albumin film to prove the recording capabilities and to quantify the diffraction efficiency in holographic grating made with each kind of albumin.

Holographic interferometer is used with a dye-doped photopolymer on one of its arms, the sample is radiated simultaneously with two wavelengths, and measuring the pattern fringe displacement we can calculate the refraction index changes. The photopolymer we use is a mix of Norland Optical Adhesive No. 65 and Crystal Violet dye deposited between two glass plates making a cell of 220 microns thickness. The sample is radiated with a beam from an Ar-ion laser at 515 nm; in the interferometer we employed a He-Ne laser at 633 nm in emission line. We show some experimental results.

We study experimentally the capacity of a transmission in volume holograms, which have a phase and amplitude modulation in a matrix of nitrocellulose. Which is photosensitized with ferric chloride salt FeCl₃. They use different sources of radiation to determine which wavelength is most efficiently achieved registration diffractive holographic elements.

This work presents a study of gum Arabic as holographic recording material, and to quantify the parameter of the diffraction efficiency through holographic diffraction gratings. This material exhibits excellent properties such as transparency, consistency, easy to handle, non toxic, non degradable. It also shows a low moisture absorption environment, hydro-phobic behavior. It is easy to produce a homogeneous thin film layer with a smooth texture on a glass substrate with gravity techniques. It also has adhesive properties. Also shown is a study of the pH behavior of this matrix, related to its viscosity.

Recently, the demand to the diffractive optical element (DOE) is increasing with the developments in the technology. We created a relative large holographic optical element (HOE) with same course of production of the DOE. To make the person who is situated on the long distance recognize image data using the hologram, the hologram must have bright image reconstruction ability and a high SN ratio. Therefore, we made the multi-level phase type hologram for the former and measured the optical intensity of the reproduction image. For an evaluation method of the diffraction efficiency, we used 2-, 4-, and 8-level phase type Fresnel Zone Plate (FZP). Because it supposed that the amount of object was large, it adopted a computer-generated hologram (CGH). Also, it used laser direct write lithography system that has the feature of high-resolution drawing, high-speed drawing, and a high accuracy positioning system, for the making of hologram.

Multi-valued phase patterns were multiply recorded by retardagraphy in order to improve recording density and data transfer rate. In the experiment, the phase pattern consists of four values were recorded on a polarization-sensitive medium by focusing the recording beam, and three patterns were multiply recorded by shifting the focal point. The recorded patterns could be independently reconstructed.