Dichromated gelatin (DCG) is nov well established as the preferred material for quality holographic optical elements in avionic applications. DCC is an extremely flexible holographic material and a wide range of properties can be achieved, however, associated with this flexibility is a considerable degree of process sensitivity. In this paper we discuss some of the process control and monitoring techniques used to help establish a production viable process and achieve the high performance and tolerance requirements of avionic holographic optical elements. The range of holographic optical element properties that can now be achieved in production volumes across a film range from 4 microns to several hundred microns is reviewed.

Enhancement of color, bandwidth and diffraction efficiency of volume reflection holograms recorded in photopolymers is discussed and demonstrated. A method of increasing.the bandwidth while shifting the center frequency toward the red is given for special cases in two well known photopolymers. Computer modelling gives clues to what has happened to the structures in some cases. Many more adjustment recipes than those given appear to be possible and are likely to work as well or better.

Photosensitive films composed of dye, initiator, acrylic monomers, and polymeric film-forming binder, and their use in recording volume phase transmission and reflection holograms are described. Systematic variation of monomer-binder combinations reveals that the maximum attainable index modulation (hologram efficiency) increases with increasing difference between the refractive indices of monomer and binder. Addition of plasticizer is also useful for increasing index modulation. Thermal and wet chemical processing methods for altering hologram properties are described.

New families of transmission and reflection holographic photopolymer materials and their performance are described. The materials are composed of polymeric binders, monomers, initiation system, and sensitizing dyes. The physical and holographic properties may be controlled by choice of components. Photopolymerization and diffusion of monomers is the proposed mechanism for recording of refractive index modulation. The materials are sensitized from the Uv to the red with typical exposure energies form 10 to 100 mJ/cm2. Hologram recording consists of exposure, UV cure, and heat processing. Significant refractive index modulation occurs during exposure. Processed holograms are insensitive to humidity and temperature. Holographic properties and performance of various formulations are discussed, as well as applications of these materials.

The sensitivity and the diffraction efficiency of the Lippmann hologram recorded in methylene blue sensitized dichromated gelatin increases for red light when the moisture of the plate is properly controlled during the exposure. The exposure required to obtain the diffraction efficiency of 70% is 25OmJ/cm2 for 45% moisure for 647.lnm red light. The photochemical reaction of the plate is briefly discussed and the experimental results of multicolor recording using this method are presented for Lippmann hologram.

Mass produced silver halide Lippman holograms have tended to suffer from two drawbacks. Firstly reflectivity has been low due to the removal of silver halide at the bleach stage and secondly the replay wavelength has tended to be green owing to the difficulty of maintaining colour consistency in the yellow region for a process in which the colour is exposure dependent. A new, machine compatible, rehalogenating bleach now makes replay colour independent of exposure and gives brighter holograms. The methods of preparation and disposal of the new bleach also make it more environmentally acceptable and contribute to cost reduction in the manufacture of the holograms. The new bleach is part of film, developer, bleach system which can be used either for room temperature dish processing, desk top machine processing or mass production.

A factorial design approach to optimizing rehalogenating bleaches for silver-halide holograms is presented. An advantage of this technique is that it allows simultaneous improvement to a number of hologram performance characteristics as a function of several input parameters. Interactive effects of combinations of input parameters can also be examined. A specific experiment is described in which diffraction efficiency, average light loss, thickness change, and noise grating efficiency are optimized as a function of the rehalogenating agent, oxiding agent, and acid concentrations of a rehalogenating bleach. Results for both Agfa 8E75HD and Ilford SP673 films are presented.

Lippmann photography and reflection holography is based on Bragg diffraction from photographically recorded volume gratings, where the index and absorption variations occur mainly in the direction normal to the film plane. A first Born analysis provides a simple physical description of the reconstruction process. Computer simulations, based on the theory of wave propagation in a stratified medium, confirm the predictions and enables modelling of situations where the first Born analysis breaks down. A number of computed spectral response curves are used to illustrate the color and tone reproduction properties of the processes.

New visibile llight sensitive positive type resists have been developed. The chemistry is based on the hydrolysis of polymers catalyzed by acid which is generated on sensitized photodecomposition of diphenyliodonium (DPI) salt. Dimethoxybenzhydryl methacrylate (DMOBHMA)-phenyl methacrylate (PhMA) copolymer was the best acid sensitive polymer tested, producing photoresists with sensitivity to an argon ion laser light and good holographic properties.

Many studies have focused on the use of Dichromated Gelatin (DCG) to make primary harmonic holograms. The use of second harmonics in the visible region of the spectrum yields high efficiency Lippmann holograms with a single processing. The reconstruction wavelength can be equal to or shorter than the construction wavelength and is easily controlled in this method. Such units offer the benefits of high efficiency and controllable bandwidths for applications in the visible spectrum.

This paper proposes a holographic printer, which produces 3-D hard copies of computer processed objects. For the purpose of automatic making of 3-D hard copies of distortion free, a new method to synthesize holographic stereogram is proposed. It is is flat format and lippmann type holographic stereogram which can be printed by one optical step. The proposed hologram has not only horizontal parallax but vertical parallax, so that the reconstructed image is completely free from distortions. Though a basic experiment, a holographic stereogram of 8.Ox6.4cm2 was synthesized and a 3-D image is correctly reconstructed. In this paper the principle and the method of the new technique are described, and the system constitution' and the problems with the holographic 3-D printer are also discussed.

Measure to evaluate holograms recorded with spatial light modulator(SLM), and optical systems to implement quantitative evaluation of the image quality are presented. We propose utilizing a pseudo-random diffuser with SLM to suppress speckle noise. High quality holograms have been obtained by using a high performance liquid-crystal display panel with a maximum contrast ratio as high as six hundred.

In biological systems 3-D data is often collected as serial sections, but reconstruction of 3-D models of the original object by computer can be very timeconsuming. Conventional holography produces excellent 3-D images quickly, but images are the same size as the object. However, multiplex holography uses photographically scaled images as the "object", eliminating the problems with objects too small or too large for conventional holography. A rectangular box of square steel tubing was used to mount optical components for a multiplex holography rig. Coherent light at 514.5 rim was provided by an argon-ion laser. The object beam illuminated 35mm transparencies of serial sections whose magnified images were projected onto a ground-glass screen, and thence to the film. The reference beam was spread by a spatial filter and reflected by a mirror onto the film. Exposures of each serial section were made using a moveable "cage" containing film holder and reference mirror to vary the screen/film distance for each exposure. Beam paths formed a parallelogram so that movements of the film/mirror cage changed reference and object beams by the same amount. The rig could be configured for reflection or transmission holograms. Both serial micrographs and computerized tomograms gave holograms where 3-D relationships between structures could be visualized. Although the range of perspectives with these holograms is less than that with some computer reconstructions, the time for hologram production with this rig (about 30 minutes) makes it an attractive addition to laboratories and hospitals where serial sections or computerized tomograms are used for 3-D reconstructions.

In this paper we discuss what is required for the accurate and complete display of three-dimensional tomographic medical data. Both holographic stereograms and volumetric-multiplexed holograms have been used for the display of such data. We describe these two kinds of hologram, and compare them with several other display techniques including conventional two-dimensional images and pseudo-three-dimensional pictures generated using computers. The suitability of dispersion-compensated volumetric-multiplexed holography for the display of tomographic medical data derives from its ability to provide near-range physical depth cues, its ability to show all of the information in a volume without obscuration, its inherent geometric and photometric accuracy, and its similarity to conventional film-based hard copies. The showing of all information within a volume is a fundamental requirement for the display of soft tissues in tomographic medical data, but is generally undesirable for certain other three-dimensional display purposes such as Computer Aided Design. The combined effect of having the near-range physical depth-cues and showing all of the volume information provides a solution to the so-called "cloud-in-a-cloud" problem which has been significant for other display techniques.

The plane type white light reconstructed holographic stereograi ( PWHS ) is made from the element holograms using the photograph of many different viewpoints. It is useful when we take hologram of object which can not taken hologram directly. On the other hand we want to see the inside of human body visually in the 3-D image. For these reasons we apply the technique of holographics tereogram( US ) to the ultrasound B-mode images and display 3-D image directly. Moreover we consider the distortion of the reconstructed image and consider (4)-('l') the method of distortion correction. Finally we want to apply this system to the medical fetus diagonosis.

We suggest several ideas for imaging either through or into inhomogeneities, all based on essentially coherent techniques in which the coherence of the illumination, either spatial or temporal or both, is reduced in some specially designed way.

A three-step technique produces rainbow holograms that can be illuminated through the edge of their substrates with highly divergent illumination, permitting very compact integral hologram and illumination display units.

We were the first-ever 'Artists in Residence' at the Royal Greenwich Observatory, producing a series of holographic artworks based on our artistic 'researches' there during 1987 and 1988. For the purposes of art we appropriated visual fragments from old optical experiments, including some by Sir Isaac Newton, which we recreated in our studio with a laser. We explain how our experience exhibiting in museums and art galleries since 1984 has influenced the way we make and display holograms.

The hologram reconstructed by white light is very advantageous for us to record the important cultural properties. There are many properties to be recorded in Japan. A tea cup for teacereinony in ancient time is shown in Fig.1. This kind is easily recorded in Lippman hologram. Especially,color Lippman holography is very useful to do so. A 'ooderi statue of Buddha in Fig.2 isn't removed for the purpose of recording. The holographic streogram (H.S.) and the reflected ho1ographic stereograni (R.H.S.) are useful. H.S.& R.H.S.are very interesting because of this ability to render a wide range of input formats,such as photographic, C.G.,movie and video images. Our experiments are constructed with Lippman hologram and R.H.S.(flat type). To repair these important cultural. properties will come to be remarkably advanced by making use of our method. So in this paper, it is considerd about the distortion which appears in the images with rotation method of the experiments. FinaiJy it will be tried to reconstruct distortionless 3D images by R.H.S. with this way.

We present an electro-optical apparatus capable of displaying a computer generated hologram (CGH) in real time. The CGH is calculated by a supercomputer, read from a fast frame buffer, and transmitted to a high-bandwidth acousto-optic modulator (AOM). Coherent light is modulated by the AOM and optically processed to produce a three-dimensional image with horizontal parallax.

An interferometric, holographic instrument has been developed by the authors which can precisely characterize the entire corneal surface with submicron accuracy. An air-cooled argon ion laser was run at all wavelengths to construct the hologram and an interference filter picked out a single wavelength for reconstruction and viewing. The holograms were recorded by a holographic camera on a thermoplastic recording medium. The laser and optics were layed out in a modified Twyman-Green interferometer setup. A CCD camera imaged the resulting hologram on a video screen and fringe analysis software subsequently digitized and analyzed the data. Head and eye movement were minimized by the use of a rigid head and chin rest, a fixation light, and a short exposure time. This technique was completely noninvasive in that no physical alien surface made contact with the corneal surface. The amount of optical radiation which entered the eye was orders of magnitude lower than the exposure limit standards set by ANSI Z-136.1 guidelines.

Two holographic methods suited for the measurement of flatness deviation are presented. The first one takes advantage of the basic holographic interferometry arrangement usually meant for deformation analysis of rough bodies. Simple modifications allow flatness measurements of polished surfaces with sub-wavelength sensitivity. Secondly, a new desensitized interferometer is described allowing the measurement of rougher objects, more frequently encountered in engineering practice. The key component of this interferometer is a diffractive optical element produced by recording two wave interference patterns. Desensitization factors ranging from 1 to 100 with respect to a Fizeau interferometer can be achieved. Harness checks of computer disks demonstrate the possibilities of both interferometers. Deformation measurements performed with the desensitized interferometer are presented.

Described are the techniques employed to produce a transmissive holographic optical element which precisely replicates the function of a precision cylindrical lens. It is hoped that the results of this work will be of benefit to image holographers wishing to replicate optics whose costs would be otherwise prohibitive.

The application of high energy lasers for material processing requires a high beam quality. This is e. g. determined by the image quality of the optical elements used for beara guidance and shaping. Up to now in the construction of the elements several influencing parameters that occur during laser processing were largely neglected. Reasons for this are the lindted knowledge about the operational performance of optical elements for high power lasers (up to 25 kW) and the difficult measurement of the accuring deformations and displacements . Responsible for the deterioration of the desired image properties of the optical elements are on the one hand manufacturing inaccuracies and on the other hand statical, dynamical, and thermal process forces. Statical forces result from the mounting of the optical components and the applied coolant pressure. Dynamical forces can occur due to vibrations of the mechanical components of the beam guidance and fluctuations of the coolant pressure. The absorption of a small part of the incident laser radiation leads to a heat-up of the optical element, resulting in a time and space-dependent deformation of the optics. The statical, dynamical and thermal deformations and displacements occur simultaneously. A systematic analysis of the operational behavior requires a separated consideration of these parameters. Only this proceeding can lead to a weighting of the influencing parameters. Using holographic interferometry such a separated consideration of the different influences becomes possible. It also allows not only the investigation of the optical component (e. g. mirror) but also the other components of the optical element. The results of this investigation lead to first conclusions about the operational behavior of the considered optical elements. Mainly responsible for the occuring deviations is the applied coolant pressure. The deviations due to absorbed beam power have a smaller significance.

By combination with digital image analysis already known optical methods can get totally new field of application. With holographic and speckle-interferometry for deformation- and vibration analysis fringe images are evaluated which represent deformations or vibration amplitudes very exactly. With projection- or moire techniques micro- and macro-structures of the surface, as f. ex. 3-dimensional shape can be analyzed very exactly. Appropriate evaluation makes a partial frequency analysis of vibration forms induced by operation possible. The applications are described with concrete examples from car construction, in some cases with harder conditions as rotating components.

Telescopes, microscopes, and similar compound systems often require achromats for objectives, since the longitudinal chromatic aberration from a singlet objective is so large that eyepieces cannot easily correct it. Such achromats can limit large-aperture systems because the curvatures required of their components are much stronger than the curvatures of singlets with the same net optical power. The hybrid diffractive-refractive telescope formed by combining a diffractive eyepiece with an unachromatized refractive objective is shown to eliminate the need for such bulky objectives, since a diffractive eyepiece is capable of correcting the large longitudinal chromatic aberrations of singlet refractive objectives. By splitting the holographic eyepiece into two elements, paraxial lateral color may also be corrected. First-order design considerations in these hybrid telescopes are presented, and a practical hybrid telescope layout is developed in which 1) primary chromatic aberration is eliminated, 2) paraxial lateral color is corrected, and 3) a useful eye relief is obtained.

Conjugate wave holographic interferaretry was rent1y proposed by the author for the measurerrent , in real irre, of the in-plane ccxriponents of deformation. Basical , the technique consists of recording holographical ly two syrrnetrical waves scattered by a frontally illuminated object. If the conjugates of these waves are produced and irringe on the deformed object, the in-plane displaciient fringes can be observed on its surface. After a short review of the principles of the technique , the paper presents sane examples of implementation and a number of applications. Various practical details which are relevant for the performance of the technique are pointed out and discussed.

We present experimental results of an infrared (IR) volume holographic grating operating in the Littrow configuration. This grating can achieve better than 9 1 % efficiency over a greater than lSOnm bandwidth for unpolarized light.

The value of the market for display holograms in the USA and Europe in the period 1980-1989 inclusive is estimated, showing a much greater rate ofgrowth in Europe than the USk Ftors affecting this growth are identified and their impt assessed. This suggests consiructive precedents for market development in newer markets.

Experimental results of a high resolution holographic imaging system using lensless geometry are demonstrated. A master mask is imaged on a photopolymer and is recorded as a volume hologram, which is then employed as the hologrphic mask. Formation of a 0.5un resolution image was consistently observed in a large field with illumination by an Argon laser operating at 457 nm, and the pattern was successfully recorded on photoresist.

Holographic optical elements (HOE) are finding increasing interest for optical systems where special functions or light weight and compactness are required. A holographic optical element (HOE) is fabricated by recording in a photosensitive material the interference pattern, which is obtained by the superposition of two coherent waves. A HOE which functions as a lens corresponds to a hologram with point sources as object and reference. This paper presents the design and manufacture of transmission type HOEs which were developed at CSEM for applications with diode lasers.

A new optical switch design is reported consisting of two sets of parallel channel waveguides intersecting at right angles. Arrays based on Ti:LiNbO3 technology, with waveguide intersections iron doped to provide photorefractive sensitivity, have been fabricated. Interfering guided beams are used to write index gratings at the waveguide intersections, which in turn diffract a portion of an incident signal beam into the crossing waveguide. Arrays ranging from 15 x 15 up to 50 x 50 waveguides are constructed in an active area of 5 mm square. Diffraction efficiency and writing time measurements are reported along with a brief theoretical analysis. A proposal for a practical architecture offering nondestructive readout is described.

Two holographic methods are presented which permit the determination of the Poisson 's ratio. The limits and application ranges of each method are outlined. Results for filled epoxy and composite materials (prepregs) are presented.

A method to calculate the data necessary to make a computer generated hologram (CGH) without using the fast Fourier transform is developed. Using this method, a supercomputer calculated the data necessary to make a CGH. The results of this method are then used to drive an electron-beam lithography machine which places the interference fringes on a glass plate.

A volume hologram has an advantage in regard to productivity and diffraction efficiency for a holographic optical element (HOE). However, reconstruction beam characteristics for the hologram are influenced by product process conditions, and they deteriorate when keep illuminating by high power light and held in a high temperature ambient. For this reason, the volume hologram has not been used for the HOE practically. This paper report the causes of these probrems and their countermeasures. First, a reconstructed beam angle from the hologram was measured very accurately by a newly designed instrument. From this measurement result, it was found that there was a difference between diffraction angle value, estimated from Kogelnik's theory, and the measured value in an off-Bragg's incident beam angle condition. Next, a variation between hologram characteristics was assumed to be caused by recording emulsion deformation in a development process. The deformation was measured, using a spectrometer and a scanning tunneling microscope (STM) . To improve the efficiency deterioration, haloid gas was permeated into the emulsion, and the emulsion was sealed between glass plates. Finaly, the authors attempted to make a laser scanner with the volume hologram. Due to the improvements, beam spot size became below 200,urn through a 200mm scanning range.

The phase values in binary phase only filters cannot be directly calculated to give the highest correlation peaks. We show the condition for which the optimum binary phase is it,and the condition for which it is not it.Computer simulation shows that for a BPOF encoded with the simulated annealing algorithm, its binary phase is other than iv andthe correlation peak of a given pattern is increased by more that 35%, compared with the correlation peaks of the BPOFs encoded by the conventional methods.

For sometime now, holographic interferometry (HI) has been in use as a nondestructive inspection (NDI) tool at many manufacturing facilities. However, because of its sensitivity to external vibrations, the technique's full potential as a quality control tool cannot be realized in total. To overcome this problem, another technique called shearography is being explored by many. Unlike holography, shearography is immune to environmental vibration. In this presentation, we will explore the principle behind shearography, its applicability as an NDI tool and how it can be adapted to carry out on-site inspection.

It has been a long and elusive goal of display holographers to produce true multicolored images closely matched to that o the objects. ,21uch progress has been reported recently by K. Bazargan l , T. Kubo ", P. M. Hubel and A. A. Ward ' ' ' , and H. Owen and A. E. Hurst ". However, most of the works reported require sandwiches of different materials independently exposed. Herein we report our recent work in "true color" holography using single e],ents of silver halide, dichromated gelatin (as proposed by J . Blyth ' ) ) , and the Du Pont photopolymer material . 1 new sandwich combinations are reported.

Bright and scatter-free reflection holograms of about 4 cm. diameter can now be made in DCG using a 10mw HeNe laser and a one minute exposure. This breakthrough in DCG technology comes from the discovery of a new electron donor compound (tetramethylguanidine) used in conjunction with methylene blue. Other dyes will allow much greater sensitivity to green light than normally exists in DCG. This can lead to both easier fabrication of HOE's and full color DCG holograms. Furthermore, the high alkalinity of the system allows the unexposed coated material to have an effective lifetime at room temperature of weeks rather than hours. It has a much lower quantity of hexavalent chromium than normal unexposed DCG, thus making its toxicity comparatively much lower.

A fundamental investigation on the influence of deformation on the anodic dissolution behavior, i.e., corrosion, of metallic electrodes in aqueous solution has been conducted. The investigation was successful in developing a novel experimental method for studying the effects of deformation on corrosion. The development of the new method is established based on incorporating electrochemical techniques with those of holographic interferometry. In other words, the new method is capable of measuring microscopic deformation and the anodic dissolution current of the surface of metallic electrodes, simultaneously. Consequently, data on a stress corrosion test of Molybdenum in 0.75 N KCI is given in the present paper.