An ideal material for the application of holography would be defined as a material that has a sensitivity suited to existing lasers, a high resolution, a linear transfer function, and a low noise ; it is also indefinetely recyclable, and it is relatively cheap. Numerous efforts have been made to produce this sort of material. We examine the principal recording materials used in holography that now exist.

We developed a new holographic material: polyvinyl carbazore material. The advantage or the material over conventional DCC material is that it has high durability against humidity and transparency. Some optical properties of the material and some applications are presented. We have already installed the holographic display element using polyvinyl carbazole in a commercialized 8mm movie camera. The letters "END" are displayed on an imaging plane of the finder system by using an image plane hologram. We also present the holographic lens of which aberration is well corrected at laser diode wavelength. We made this holographic lens using a new aberration correcting method.

A volume phase holographic recording material with high diffraction efficiency and high durability against humidity has been developed. The holographic material consists of Poly-N-vinylcarbazole (PVCz) as a base polymer, camphorquinone as an initiator and thioflavine-T as a sensitizer. This film is sensitive to argon ion laser light, and exposure energy of 500 mJ/cm2 is required to realize high diffraction efficiency. After recording a latent image of a fringe pattern by exposure, a hologram was developed by swelling and shrinking of the film with two sorts of solvent. The thickness of the hologram could be reduced to 2.5 μm, because the PVCz hologram has a large amplitude of the refractive index modulation related with the crystallinity modulation. The high diffraction efficiency coupled with the thin layer made an incident light angle wide enough to maintain a high diffraction efficiency around the Bragg angle.

We describe and analyse the use of the photoelectrochemical etching technique to create holographic relief gratings and patterns in semiconductors such as GaAs. Images and wavefront diffracted in the visible and the I.R. will be shown.

The interaction of two incident plane waves in a photorefractive material is discussed both in the transient and in the stationary case. Preliminary results of a study are presented which solves numerically the transient equations in conjunction with the field equations including optical activity. Comparisons with experimental results show good agreement.

Powered reflection HOES, both spherical and aspherical have been constructed in dichromated gelatin on flat substrates using the back mirror method. Examples of this type of HOE have been investigated inteferometrically and the results compared with theoretical predictions. Some effects of construction geometry and film swelling are discussed.

Holographic Optical Elements operating on light by diffraction are beginning to find a role in optics complementary to those of mirrors and lenses, that is reflective and refractive optics. Holographic elements working in either transmission or reflection can be made.

Thanks to numerous progress particulary in chemical technology, computer automatic design, Computer Generated Holograms (C.G.H), and industrial means, diffractive optics can be used widely.

This paper looks at the production of achromatic reflection holograms in dichromated gelatin. By using a double exposure technique we can produce two reflection bands in the same emulsion with complementary dominant wavelengths. This results in the colour mixture being close to the achromatic point on a chromaticity diagram.

Embossing of replica holograms at the Polaroid Corporation is being done in two major areas: crossed grating arrays for development of new types of photographic films and holographic optical elements; and the production of white-light viewable display holograms of various types for many diverse applications.

A review is given of image blurring mechanisms in reflection and transmission holograms for both monochromatic and white-light replay. A theoretical model based on ray-tracing and locally-planar grating 2-beam coupled-wave theory is used to analyse dispersion blurring in white-light holograms as a function of wavelength in terms of the angular blur of an image-point seen by an observer. Methods of minimizing the blur are given, and the significant reduction achieved by recording reflection holograms with a tilt is explained and illustrated by experimental results. The use of a thick recording material is proposed as a method of producing full-parallax transmission holograms which can be replayed with white-light without dispersion compensation, and some preliminary results are given. The theoretical model used can also be applied to the analysis of the imaging properties of holographic optical elements.

After a short review of diffractive optics, three display applications of Has are considered : helmet mounted displays, holographic night vision goggles and holographic head up displays. Possible future research fields are introduced.

Some initial research results are reported toward developing holographic optical elements for use as beam corrector-collimators for diode laser arrays in an inter-satellite data link. Holograms have been made in 649F emulsions with 633 nm radiation from a He-Ne laser under conditions which simulate a hologram made in an IR-sensitive emulsion with a diode laser. Such holograms have been copied into dichromated gelatin emulsions with 488 nm radiation from an Ar + laser. The copies have shown up to 94% efficiency when reconstructed as optical elements at 633 nm. Some difficulties in obtaining efficient holograms that do not introduce significant wave-front aberrations are discussed and possible solutions described.

A two dimensional optical switching device for fiber array has been investigated. The spatial commutation of an infrared beam from an optical fiber is produced in an entirely optical way : a photoinduced dynamic grating in a photorefractive crystal diffracts this beam assuring deflection in a given direction. Bragg condition is automatically matched. The large capacities thus obtained make this system attractive for its use in the optical networks.

The coupling in the Holocoupler-Selfoc fiber system is studied using a new matrix method, which may be applied to arbitrary x,y,z - varying structures. The properties of the spatial transfer function for invariant linear system are used.

Two methods performing wavelength division multiplexing or wavelength division demultiplexing in the near infrared region and using volume transmission holographic optical element are presented. In the first one, the holographic optical element converts collimated light beams (output beam of optical fiber coupled with a GRIN lens) and the second method handles direct output beam of the fiber. Advantages and drawbacks of the methods are investigated.

A new holographic interferometer concept for novel applications in integrated optic grating device manufacturing has been developed. The spatial filters have been substituted by two special monomode fibers with a core diameter below 5 μm. Only the finite size of the fiber mounts limits now the beam interference angle, thus leading to great flexibility in design of the desired curved or chirped grating groove formation.

A discussion is given of certain aspects of hologram recording using computer control. The computer link is sometimes via direct computation of the fringe pattern of the hologram. This paper discusses the more simplistic and pragmatic use of the computer to control the position of a spot of light thus in effect creating images by point-by-point drawing. It is pointed out that the method has distinct advantages over simultaneous (coherent) recording if certain points of detail are attended to. A method is proposed for the recovery of images of large number of sequentially recorded luminous points.

Copying of holograms using laser light in a contact situation is a commonplace technique. This paper discusses the use of simplistic incoherent light sources and filters to achieve the same result. Results are reported of test experiments which show that existing holographic recording emulsions are barely adequate in structure and performance. Theoretical criteria are reported which offer guidance for the optimised use of the recording media.

We describe a high-luminosity holographic system which allows the recording of large volumes at a long distance. A high-resolution image is reconstructed, which allows accurate measurements to he achieved in the object. The arrangement is adapted to double-exposure recording with two separate references. An application to ballistics is presented.

In contrast with ordinary photographic techniques, a three dimensional analysis of transparent or opaque objects can be obtained by holographic technique, with combined properties which are not obtainable simultaneously by classical optics, namely: high resolution, wide field of view, large frontal distance. The last property is very useful in the case of difficult access to the object plane for any reason such as: cumbersome mechanics, safety considerations... A holographic device has been built for the investigation of the rectilinear discharge propagation on a surface intended to simulate, in the laboratory, the natural leader lightning phenomenon. The apparatus was designed in order to achieve both high temporal and spatial resolution, without neglecting the necessity of a minimum value of forty centimeters for the distance between the set-up and the electric phenomenon (120 kV). wo optical component is placed between the object plane and the hologram plate. ado, the resolution of the record only depends on the angle substending the holographic plate as measured from the object. A single exposure is used for the record of a hologram providing the shadowgraphy of the channel (optical phase object). The interferometric examination is also possible by means of the double exposure holographic method. With just a few minor modifications, the holographic set-up was also used for the study of the structure of a turbulent flame, for the high resolution record of opaqueobjects and the interferometric examination of their deformations. The reconstruction, from the holograhic plate, of a high resolution real image at the same size of the object is achieved by means of another especially designed set-up. this three dimensional image can be easily observed by means of a microscope, unlike the phenomenon itself which is brief and/or inaccessible. The two optical devices are described and various examples of applications are given.

The following paper will attempt to highlight the need for security in all walks of life. It will show how holography in general will thwart the conventional counterfeiter, and reflection holography in particular from the Holocopier system will further confound the more determined forger. Mention will be made of the restrictions on copying reflection holograms, and brief mention will be made to the advances to produce such a system. Graphical evidence will be presented to show the degree of control that can and needs to be achieved to ensure high quality, high efficiency copies of original masters by the Holo-copier system.

A holographic recording with a filter is studied. In particular, influences of the hologram finite aperture on filtered images are considered. Irradiance distribution in defocused image is calculated. Furthermore in application an instrument measuring the diameter and 3-D position of a glass fiber is described.

A 3-D holographic miniprojector on the basis of holographic (optical element) screens using for integrated circuits assembly and quality control is described. This is a compact, professional projection-type microscope using hybrid technique combing the advantages of both ste-reoscopy and holography. The optical principle and system of this miniprojector, recording scheme of holographic diffusing screen, improvement of chromatic dispersion of screen and characteristics of projection system are discussed.

Using the coherence function of a multimode laser source, a technique is presented that produces rainbow holographic images without employing a slit for recording. A slit-shaped pupil is though synthetically produced whose extent and position can be controlled by the experimental parameters.

The holographic material Agfa 8E75HD sheet film is used in a Denisyuk-like type recording set-up, in conjunction with a pulsed ruby laser. A relatively simple production method is outlined, attention being given to some practical problems : sensitivity, processing, polarisation and color.

A new optical design of a 60° x 30° holographic display is demonstrated. The arrangement uses two holograms, a relay lens and a Schmidt plate. The first hologram is used as collimator and combiner and gives complete see trough capability. The second hologram is a field hologram. Ray traces and spot diagrams are shown, which have been obtained with a computer program especially developed for this analysis.

Two important progresses were achieved for the first time: 1) recording of single exposure cineholograms of living bodies on a 126-mm film, at a frequency of 25 holograms per second. Limitations of 3-D movies by holography are described. 2) recording of double-exposure cineholograms of reflecting objects, a loudspeaker membrane and the vertex cranii of a bald-headed man. These experiments show the interest of interferometric cineholography for industrial applications.

Up to now holographic interferometry did not allow the study of an object motion generating too many interference fringes. Our method is general and resolves this problem in all cases. This paper gives some new developments and applications of this technique.

The problems of recording holograms through optical fibers are discussed. A holographic arrangement is tested; it is composed of: - a c.w.- or pulse-laser, - one or several multimode fibers and an imaging fiber bundle for the object beam, - a monomode fiber for the reference beam. Various holograms of a small object were recorded and some reconstructed images are shown.

A simple, low-cost, versatile holographic scanning system was developed for use with dichromated gelatin holograms or similar high-quality copies made by hologram techniques. The fabrication of the disk holographic scanner is described in detail. The optical configurations of several high-density scan patterns were generated, and they are applicable to commercial scanning requirements.