Waveguides with photochromic or electro-optic properties have been fabricated by a new technique using spin coating of polymers, or guest/host-polymer systems, on to grooves etched in an indium phosphide wafer. Monomoded waveguides at 633 nm, and at 1320 and 1550 nm (wavelengths of telecommunications interest) have been fabricated. These guides have good quality cleaved ends which allow efficient coupling of light from monomoded standard lensed silica fibers. An example of an electro-optic application is given in the form of a phase modulator. This device uses a side-chain polymer as the waveguide core that develops linear electro-optic properties following an electric field alignment process. It was found to have a switching voltage of 30 V, for a (pi) phase change, and had a total insertion loss of 9.4 dB. Waveguides with photochromic properties have also been produced using Aberchrome 670 (a commercially available fulgide) as a guest in a poly(methyl methacrylate) polymer host. Refractive index, optical loss, photochromic activity, and film forming properties of differing concentrations of guest (up to 20% concentration by weight) have been measured and are reported.

A brief overview of the U.S. Army Strategic Defense Command (USADC) and its relationship with other government agencies is presented. The Advanced Technology Directorate (ATD) and its relationship with the Strategic Defense Initiative (SDI), its participation in and support of Army programs, and its interaction with other government agencies is briefly discussed. A listing of all the contracts in the electronic materials category managed by the ATD is presented. All of these contracts are currently small business innovative research (SBIR) efforts. A more detailed description of the contracts with direct optoelectronic applications concludes the presentation.

Highly ordered phthalocyanine (Pc)/inorganic semiconductor heterojunctions have been created by a process of molecular beam epitaxy in ultrahigh vacuum environments (O/I-MBE). The layered metal dichalcogenides, MoS2, and SnS2, have been used as substrates, either as melt grown crystals or as thin films, created by the MBE process, immediately prior to the deposition of the organic layer. Surface electron diffraction (RHEED) is used to ascertain the type and extent of ordering of the Pc layer. Absorption or reflection spectroscopies are used in the visible wavelength region to characterize the shape and position of the Q-band absorbance of the ordered dye layers, which confirm the ordering seen by RHEED. When deposited on doped SnS2 crystals, and immersed in aqueous electrolytes, the photocurrent yield of these dye layers can also be measured, which provides an alternative means of obtaining the Q-band spectrum for ultrathin dye layers.

Liquid-crystalline elastomers have been investigated with respect to their nonlinear optical and piezoelectric behavior. A liquid-crystalline elastomer with NLO active nitrogroups bonded covalently to a siloxane network was chosen for the NLO experiments. The elastomer exhibits a SA phase and is macroscopically ordered. The elastomer is transparent for wavelengths above 450 nm and the anisotropy of refractive index at room temperature is about 0.1. Applying an external electric poling field breaks centrosymmetry and second harmonic generation similar to crystals can be observed. The poling process is single exponential with an activation energy of 190 KJ/mol and is identified as a (delta) -process. In contrast to low molar mass liquid crystals no director reorientation is observed by the laser field strength. From Maker fringe experiments in the liquid crystalline phase at room temperature the second-order susceptibilities are d3 3 equals 0.92 pm/V and d3 1 equals 0.06 pm/V for a poling field of 19 V/micrometers . Cholesteric elastomers are noncentrosymmetric due to their helicoidal structure. Above a threshold deformation, where the elastomer becomes uniformly aligned with respect to the helicoidal axis, the helicoidal pitch strongly changes with deformation and a piezoelectric voltage of up to 40 mV is observed.

Electro-optical (EO) coefficients are determined for two dye/polymer guest-host systems as a function of the electric field, temperature, and concentration. Above the glass transition temperature, the EO coefficient of methyl nitroaniline in poly(methyl methacrylate) is shown to be due to the Kerr effect. The order parameter induced by the poling field is deduced from the electro-optical coefficient. Interpretation of the order parameter in terms of the Langevin functions alone does not agree with the experimental results.

The orientation of NLO chromophores in a polymer lightguide may be influenced by a ferroelectric sublayer. The multilayer system is investigated towards the in-situ recording of the birefringence introduced by a poling procedure. The ITO electrode is characterized with respect to its losses, the stress induced birefringence during heating is also evaluated.

We present the first time resolved photon echo measurements of homogeneous dephasing of organic dopants in an inorganic sol-gel glass and compare these results with recent hole- burning experiments. In addition, energy transfer mechanisms and chromophore spatial distributions are investigated by time-resolved fluorescence anisotropy measurements.

There is growing interest in developing fabrication methods for optically nonlinear organic materials that are used in integrated optical modulators. Of particular interest are systems in which the NLO moiety is incorporated in a polymer system either as a dopant or chemically attached as a side chain to the polymer backbone. In order to realize the potential of these polymers, much research has been directed toward developing the technology required to form channel waveguides and demonstrate prototype polymeric modulators. Reported here are the fabrication details of a projection printing technique to form channel waveguides and prototype modulators. This technique has been used to characterize the optical properties of the polymers by the fabrication and testing of Mach Zehnder modulators. The projection printing technique forms inverted ribs in optical epoxies by noncontact exposure to a patterned UV light source. These inverted ribs are filled by spin coating with the electro-optic polymers to form channel waveguides. A second buffer layer is coated over the polymer by spinning and poling/device electrodes are added to form the completed modulator. Any spin coatable electro-optic polymer can be used as the active waveguide material by adjusting the inverted rib dimensions for single mode operation depending on the polymer/epoxy index difference. The practical engineering design considerations and fabrication procedures required for single mode channel waveguides and successful modulator construction are discussed in detail.

The applications of lasers in polymer photochemistry spring from the meeting point of two fascinating research fields: photopolymers and development of laser techniques. Lasers can be used as irradiation sources or in probing devices. In the present paper, we mostly discuss the investigation of the primary processes involved in the excited states of photosensitive organic molecules -- photoinitiators, photosensitizers, photoinitiator combinations -- that can be used for laser induced polymerization, laser writing, or holographic recording.

Results of experiments on photoconductivity of one-dimensional bridged polymeric phthalocyanines [PcML]n consisting of different combinations of macrocycles, Pc, bridging ligands, L, and central metal atoms, M, are described. It is shown that the spectral response and photoconductive gain strongly depend on the type of bridging the planar phthalocyanine rings. Therefore, rules for the development of phthalocyanine-based polymeric photoconductors by synthesis, e.g., with significant long wavelength sensitivity, can be outlined.

The photo-oxidation of certain polyimides has been found to be extremely efficient provided that the photolysis is conducted in the presence of oxygen. The apparent rate of decomposition depends on the chemical composition of the components composing the polyimide backbone as well as the spectral properties of the light source. In the case of polyimides which are made from a hexafluorinated dianhydride and a hexafluorinated diamine, the photo-oxidation process is extremely rapid. The photolysis mechanism is quite complicated, but analysis of model compound photochemistry by conventional methods indicates that a variety of products, which themselves are photolabile, are generated in the primary photochemical process.

This paper presents the study of the photoinduced refractive index change and birefringence in a nonlinear optical polymer --polyester with disperse red 19 side groups. Polyester with disperse red 19 side groups showed sizable second-order nonlinear optical properties when poled under intense electric field. In addition, under ultra-violet or short wavelength visible light illumination, large photoinduced refractive index changes were measured in the near infrared region. Furthermore, with linearly polarized light illumination large photoinduced birefringence was also exhibited in the thin films of this polymer. Some device structures, such as birefringent gratings, thin film waveplates, and optical waveguides, were generated by photo exposure method. A simple theoretical model is also presented to investigate the relation between the photoinduced birefringence and the refractive index change.

Attenuated total reflection (ATR) is commonly used for measuring small variations of the index of refraction of thin polymeric films. We show that a careful analysis of reflectivity dips, due to the excitation of guided modes in the film, allows a precise measurement of very small variations of the anisotropic index of refraction and of the thickness of the film. This is very useful for studying a wide variety of physical phenomena such as electro-optic effects, piezoelectricity, electrostriction, mechanical and thermal strains inducing elasto-optic effects (i.e., photoelasticity), and photochromism. In this paper we particularly emphasize the measurement of some components of the photoelastic tensor and of the index variations associated with cis-trans photoisomerization of azo dyes which have been clearly demonstrated in doped polymeric films. Kinetics of cis-trans optical pumping and of relaxation in darkness have been studied. It is noticeable that the layered configuration of samples and the guided waves excited by ATR are quite similar to the structure and to the propagation conditions of integrated optics devices.

Triphenylsulfonium salts (TPS) have been formulated with polymers to make photosensitive systems for optical and optoelectronic applications. Photolysis of these salts generates strong acid which has been used in cross-linking reactions, deprotection reactions, and depolymerization reactions for photosensitive polymers, photodeformable polymers, and photo-doped conducting polymers. In addition, materials best described as polymeric sulfonium salts have been found to become conducting after photolysis. We have studied the photochemistry of TPS in polymer films and in solution. TPS photodecomposes by a mechanism that gives both in-cage recombination reactions and cage-escape products, and by reaction with solvent or polymer matrix. These products give cage/escape (C/E) ratios which are sensitive to the viscosity, rigidity, and polarity of the environment, and also the excited state from which the photochemistry occurs. Details of the reactivity and C/E ratios from photolysis of TPS salts in solution, have made it possible to determine their reactivity in polymers. In some cases the polymer behaves as a viscous solvent leading to high C/E ratios and in other systems the polymer excited state can sensitize the decomposition of TPS salts to give lower C/E ratios. Fluorescence studies on these polymers and quenching studies with TPS salts have helped to determine which excited states of the polymer and TPS salts are involved, and whether there is static or dynamic quenching in these systems. The photochemistry of model compounds for the polymeric sulfonium salts is also described.

We present the electrochromic properties of dodecylbenzenesulfonate-doped poly(pyrrole). The galvanostatic synthesis on ITO electrodes produces homogeneous films which show a transmittance change from 80% to 40% at 700 nm when cycled in aqueous KC1 between -0.75 and 1.00 V (SCE). These films are stable to 3.5 X 103 potential redox steps from -0.6 to 0.4 V (SCE).

Using the TRMC technique, small transient changes in the microwave conductivity (dielectric loss) of a medium that occur on laser flash-photolysis can be monitored with nanosecond time- resolution. The method is described. Its application is illustrated with results on photo-induced charge separation in the singlet and triplet excited states of dilute solutions of donor-spacer- acceptor molecules. Both conjugated $PI-bond and nonconjugated (sigma) -bond spacers have been investigated. Particular attention is paid to the extension of the lifetime of the highly dipolar excited states formed on photolysis either by the formation of metastable triplet states or by intramolecular `through-bond' electron tunneling. The results could be relevant to the design of molecular optoelectric devices.

The process of photochemical hole burning in rigidly coupled polyacenes is discussed. Photochemical mechanisms in these systems are conducive to low temperature spectral hole burning. Several factors which determine the shape and width of spectral holes are discussed. Prospects for use in information storage applications are presented.

This paper is a brief review of original results of investigations and developments of some organic light-sensitive media which provide realization of photoinduced dichroism and birefringence, their applications in optical recording and processing of information, and phototechnology of manufacturing optical elements.

A new photosensitive memory device with semiconductor-thin polymer-semiconductor (STPS) structure is described. A `writing' light pulse drastically changes a basic current mechanism. As a result, the dark current increases many times. Moreover, new quality phenomena appears, such as photocurrent amplification and photo-induced self-oscillations.

During the past few years we have conducted extensive analysis of the laser-initiated polymerization of acrylate type monomers which polymerize by a free-radical mechanism. In this paper we report on the dependence of the rate of polymerization of a variety of monofunctional and multifunctional monomers on the intensity of pulses produced from an excimer laser. In the case of multifunctional systems, the rates of certain monomers show an absence of dependence on the laser intensity over a selected range while others are highly dependent on the laser intensity over a broad range. It appears that the ability to exhibit rapid rates when high intensities are employed is influenced by the mechanism of the macrogelation process which occurs during the polymerization. Also, the photoinitiator type and concentration can play a major role in the dependence of the rate on the pulse light intensity.

Triarylsulfonium salts are used for both curing and microelectronic imaging of polymer films. The major products from the photodecomposition of sulfonium salts are a Broensted acid along with a mixture of diarylsulfides. The amount of acid which is produced on irradiation of polymer films containing triarylsulfonium salts is dependent on the structures of both the polymer and sulfonium salt. The results from both electron beam and ultraviolet experiments suggest that polarity effects are very important factors in determining how much acid is produced. The effect of sulfonium salt loading percentage was also studied. Thermal analysis of polymer films has shown greater plasticization effects for sulfonium salts in polar polymer films indicating that the interaction between sulfonium salts and polymers is better for polar polymers. ESR experiments have determined the nature of the radicals which are produced following irradiation and these results suggest a mechanistic understanding of the polymer structural effects. In the case of acid-sensitive polymers, it has been possible to determine the extent of acid-catalyzed chemistry which, in turn, provides a means of estimating the acid diffusion range in this polymer film.

Binary optics reflective gratings and micro mirrors are studied for integrated planar optical interconnect applications. The staircase profile surface relief gratings have high efficiency at small diffraction angles. The micro mirrors provide larger deflection angles. Fabrication of both elements is discussed and experimented on a photoresist layer.

Mass-producible optical waveguide devices and their fabrication method for integrated optics are described. Single-mode polymer rib waveguides and grating couplers in planar polymer waveguides which are a key component for organic integrated optical devices have been successfully developed by using photopolymerization (2P) method. The method is based on an electron-beam lithography technique for writing original patterns and a replicating technique using a molding stamper.

Phenosafranin is shown to have an intense triplet-triplet absorption band in the 600 - 850 nm spectral region. This absorption was investigated in samples prepared by doping PVA films or by doping solgel glasses. The resulting optical samples are shown to have an intensity depending absorption upon pumping by an Ar+ laser. This nonlinear optical absorption can be utilized for construction of optical bistable devices, such as spatial light modulators. In addition, this absorption is manifested in photorefractivity of the samples.

A review of work of Soviet scientists in development and utilization of photopolymerizable compositions in the various fields of applied optics is presented.

Polymeric materials that exhibit a controlled change in refractive index upon irradiation with UV light are promising candidates for the development of polymeric optical interconnects. We have demonstrated that polymers containing nitrone functional groups can be spatially patterned for single-mode waveguide devices using both laser direct writing and traditional photolithographic techniques.

An important signature of material properties is the absorption spectrum. However, for weak absorption in thin films or for subtle spectral features, standard measurement techniques are inadequate. Ideally suited for this regime is photothermal deflection spectroscopy (PDS) which can give several orders of magnitude greater sensitivity than transmission techniques. With the sensitivity of PDS, it is possible to detect features that cannot be observed by other means, such as singlet-triplet transitions, weak charge-transfer bands, and weak photo-chemical changes at the surface. The films studied were those commonly used as charge transport materials in organic photoconductors, and are comprised of a small organic molecule and a polymer binder. The PDS spectra indicate the formation of charge transfer complexes between the two components, in the solid state. The strength depends on the various combinations and can be correlated to relative energy level offsets between the HOMO of the small molecule and the LUMO of the polymer binder. Reversible photochemistry resulting from UV exposure can also be detected at the surface. In addition, using PDS, it has been possible to obtain, for the first time, the vibrational overtone spectra in the range from the near IR to the visible (0.4 - 2 eV) for polymeric thin films. The absorption spectra of polycarbonate, for instance, exhibits C-H stretch modes for (Delta) n > 1 where n is the vibrational quantum level. Previous measurements were constrained to either long fibers, which pose the problem of scattering, or to a restricted wavelength region in the visible accessible by dye laser sources. The unparalleled sensitivity of PDS allows precise determination of frequency, lineshape, and intensity of the various modes, even for films just a few microns thick over a very broad energy range. The overtone spectra can be used as a probe of various basic molecular properties such as bond energy, anharmonicity, and vibrational energy localization. In a manner similar to NMR spectroscopy, it is possible to study specific atomic bonds.

Optical technology is now established as the basis of a future integrated broadband communication network (IBCN). The capacity of an optical system can be increased by the development of transmission and switching facilities of the coherent multicarrier (CMC) technique. This contribution concentrates on the structure and technology of a CMC crossconnect, which may be realized as an integrated optical polymer circuit. The manufacture of passive polymer waveguide devices is presented. Further electro-optical polymer devices and erbium-doped PMMA applications are discussed.

It is known that for given recording and reconstruction geometries, the wavelength of light for which a volume reflection hologram recorded in the dichromated gelatin has the highest efficiency can be adjusted by suitable preparation, sensitization, exposure, and processing of the DCG layer. Unfortunately, reliable data on these factors is very limited; thus a detailed experimental study on the relations between exposure, sensitizer concentration in the gelatin, and position of the efficiency peak has been undertaken. The sensitizer concentration in the gelatin can be adjusted by variation of its concentration in the sensitizing bath. The dependence is studied for variation of the latter in the range of 0.5% to 5%. The final sensitizer concentration in the gelatin is measured with the spectrophotometric method. The results obtained show, even for low temperature processing, that by proper combination of concentration and exposure, it is possible to create holograms with peak efficiency shifted in any (blue or red) direction by a strictly controlled amount.

In this paper, we present a methodology for analyzing the characteristics of a photosensitive material for holography. When two Gaussian beams of equal intensities are exactly superimposed on the recording material, the modulation of the interference pattern is equal to unity. When they are no longer exactly superimposed, this modulation varies from one to zero depending on the analyzed point. On the other hand, the modulation is constant in a direction perpendicular to the incident plane. Therefore, it is possible to consider a complete analysis (point by point) of only one holographic grating in order to measure the diffraction efficiency (eta) at a given modulation versus exposure or for varying modulation for a given exposure. We present the results obtained with an experimental setup devised for that purpose. The tested recording material is a film of dichromated poly(-vinyl alcohol) (DC-PVA).

An optical correlator system that employs photopolymer materials fabricated to form holographic optical elements and multiple matched filter memories is described. The photopolymer media offer some distinct advantages over other materials; in particular, these are in situ operations, high-efficiency one-step dry chemistry, and ease of operation. By comparison, silver-halide media in general require off-line multistep wet chemistry processing which is slow and inconvenient; the resultant holographic element exhibits low efficiency. To be sure, the use of photopolymers for holographic elements has its shortcomings, being several orders of magnitude less sensitive, with spatial frequency limits at the low end and somewhat limited wavelength operation. In this paper a comparison is made of two Van der Lugt architectures, one being an all-photopolymer element system and the second a benchmark correlator system employing silver-halide materials. Representative correlation objects were prepared and processed for each medium. This was followed by a series of test measurements for peak levels, signal-to-clutter, and tracking response. For a wider range of applications, filter impulse responses are examined and compared for the classic Van der Lugt filter and binary-phase-only-filter-type elements. It is shown that when care is taken in processing, the photopolymers can offer an extremely convenient and effective medium for in situ recording of both amplitude and phase filter elements, while providing significantly more versatility than the silver halides and, generally, with higher efficiency and system throughput.

The applicability of holographic optical elements (HOE) in the IR depends upon the achievable bandwidth, operating central wavelength, dispersion characteristics, and transmissivity. Dichromated gelatin layers (DCG) are well suited for such applications because of their light weight, excellent optical quality, and high diffraction efficiency. The research efforts reported here are aimed at the realization and evaluation of dichromated gelatin films of very high optical quality, i.e., films with very low scattering losses and uniform layer thickness over the entire aperture that possess the capacity for large modulation of the refractive index. These properties ensure the attainment of the desired operational characteristics such as high diffraction efficiency, large bandwidth, and a central wavelength that may be freely selected over a wide spectral range. These objectives are achieved by means of precise control of the thickness of the holographic layer while maintaining simultaneously the capability to modify the refractive index modulation over a wide range. The required large modulation range of the refractive index is realized by means of precise control of the flow velocity and of the water evaporation rate during the drying of the film.The subsequent thermal after-treatment of the film permits the realization of an overall hardness that facilitates the attainment of the desired modulation characteristics.

Results of theoretical and experimental investigations, devoted to the analysis and optimization of optoelectronic image formation devices (IFD) on the basis of deformable polymer films (DPF) at the expense of choice of the polymer material rheology, electric field distribution in DPF by means of electrode raster and heat deformation regime is presented. For DPF structure investigations the tunnel electron microscopy technique has been used.

Poly-(methyl-methacrylate) (PMMA) on different substrates was implanted by He+ ions of energies between 50 keV and 250 keV as well as 1 MeV and 2 MeV. The ion doses varied between 1012/cm2 and 1015/cm2. We have studied the increase of the refractive index in the implanted surface layer, which acts as an optical waveguide, by measuring the effective index of refraction neff for different optical modes. According to the range of ions in the polymer, surface waveguides and buried waveguides can be generated. The number of modes a waveguide is carrying depends on the ion doses. For single mode waveguides low doses must be used. Waveguides with losses below 1 dB/cm were obtained. The chemical effects caused by the implantation are measured by IR spectroscopy and residual gas analysis (RGA), physical modifications of the surface were studied by scanning electron microscopy (SEM). The refractive index profiles are discussed using simulation calculations.

Photopolymers are used in printing, electronics, solid imaging, and holography. In typical applications the illumination from one side, normal to the surface of these materials, initiates a chemical sequence that records the incident light pattern in the polymer. The high optical density of the film and the unidirectional illumination leads to a concentration gradient of the reacting species and their consequent migration toward the illuminated surface from the bulk of the film. As such, one also sees migration from the dark regions of the pattern to the illuminated ones. As a result, the photopolymerization rate and yield vary greatly with the depth and location in the pattern creating a spatially anisotropic distribution of reactants and products. The presence of atmospheric oxygen in the system adds to nonuniformities of imaging. Using the fluorescence based technique for kinetic measurement, optical microscopy, and semiempirical finite element model computations we reconstruct the spatial dependence of photopolymerization in photopolymer films. The model assumes the mobility of every reactive species in photopolymer formulation including oxygen. We propose to control image uniformity by selecting the reactants with predetermined mobility in polymer film and by controlling the oxygen content of the material during imaging.

A new theory is presented that describes the writing and readout of polarization volume holograms in dynamic photoanisotropic organic materials (DPOMs). Based on the coupled mode theory, the stationary coupled differential equations, which incorporate self diffraction, of two recording beams are derived in the slowly varying amplitude approximation. From these equations, the intensity and phase of the recording beams at steady state can be studied so that the final recorded polarization hologram can be described. The analytic solutions are presented for orthogonal linear and orthogonal circular recording geometries. Under the assumption of a weak probe beam, the readout equations are derived and the diffraction efficiency of polarization volume holograms is analytically solved. Numerical simulation results are provided and compared with the analytic solutions.

Picosecond degenerate four-wave mixing in a planar quasi-waveguide made of poly(vinyl alcohol) film doped with rhodamine 6G dye is reported. The four-wave mixing geometry consists of a probe beam incident from above a prism-film structure which is pumped by two oppositely propagating quasi-guided or evanescent waves. Such fourwave mixing signals are obtained both in reflection and in transmission. It is shown that the reflected signal can be optimized by varying both the pump and the probe angles. With this configuration four-wave mixing reflectivities of nearly 0.1 percent were obtained.

We succeeded in characterizing by long-wavelength neutron diffraction light-induced volume phase holograms which have been recorded in photopolymers. The samples were prepared from protonated and deuterated poly-(methylmethacrylate). They initially contained about 10 - 15% monomers and a photo-initiator. Discs of about 2 mm thickness and 2 to 3 cm diameter were exposed, in a conventional two-beam interference setup, to a periodic light intensity pattern, with fringe spacings between 120 and 390 nm. The illumination modulated the neutron optical refractive index. This was due to a density variation that was introduced by a diffusion-controlled photopolymerization, within the light regions, of the residual monomers. The neutron diffraction has been observed using the full length of the 80 m small-angle camera D11 at the High-Flux Reactor, Grenoble, France. The primary neutron beam was monochromatized at around (lambda) equals 1 nm within (Delta) (lambda) /(lambda) equals 18% full width and collimated within 0.75 mrad. The amplitude of the neutron refractive index modulation of the protonated samples was by 105 smaller than the light refractive index modulation if using a helium-neon laser beam of (lambda) equals 633 nm. The neutron reflectivity of the fully deuterated samples, 1.4%, was by a factor 40 larger than that of the protonated samples; this makes these gratings valuable etalons for neutron small-angle cameras. Possible further applications of our research include the study of light-induced neutron refractive index changes and photochemical processes in situ using a radiation which does not alter the structure; investigation of the factors that influence the regularity and stability of the holographic gratings; development of neutron optical devices as beam splitters, mirrors, and lenses; and, in the more distant future, the construction of instruments, e.g., neutron interferometers and neutron microscopes.

A new holographic recording medium based on poly-2-Hydroxyethyl Methacrylate (HEMA) and visible light sensitizer is investigated. The holographic recordings are based on photo- induced polymerization of HEMA, using Camphorquinone as a visible light sensitizer. The medium has several advantages. Namely, it does not require extensive processing and survives high humidity conditions, including water immersion. Several experiments have been conducted to analyze the behavior of this medium, including analysis of recording parameters using a real-time holographic recording/playback setup, precuring, swelling, and water survivability tests. Water-immersion survivability of our material is a unique characteristic that can be incorporated in novel holographic and optical systems, such as water immersed holographic optical elements. New possibilities and applications are discussed.

A two-step procedure is described where a photosensitive layer of doped PMMA is spin- coated on a glass substrate, exposed to a UV pattern, and, finally, covered in a second spin- coating procedure. The result is a thickness pattern that follows the UV image. The obtained waveguides are characterized with respect to their effective indices as a function of UV exposure and spinning speed. Simple elements like lenses or beam splitters are discussed.

A fast method of diagnosing a phase characteristic curve for a variety of phase recording materials is proposed. A sinusoidal test pattern is printed onto a phase recording material that is illuminated through a continuous neutral density filter. The sample is then placed at the entrance of a 2-F coherent system, and the intensities of selected diffraction orders are observed. By comparison of the output intensity distribution with a predicted one, a curve of phase vs. exposure energy for the photosensitive material can be immediately calculated. This paper considers both surface relief modulation materials and volume optical index modulation media. Experimental measurements on DCG material show that extremely high input dynamic range (up to 3 orders of magnitude) can be obtained with standard processing.

The present work is an experimental study of the speed of hologram recording in dichromated polyvinyl alcohol films (DC-PVA) and DYE-DC-PVA films. Real-time recordings give high diffraction efficiency and low signal-to-noise ratio holograms without any chemical development. The dyes studied here are MALACHITE GREEN, EOSIN Y, and ROSE BENGAL introduced in DC-PVA films having a thickness of 60 - 62 micrometers . The best of these DYE-DC-PVA systems is a good candidate for holographic optical elements fabrication.

Metal ions such as Ferric [(Fe(III)] and Dichromate [Cr(IV)] have been used in conjunction with Polyvinyl alcohol for recording holograms in real time. Experiments have been performed to optimize the various parameters influencing the holographic performance of these materials. High real-time diffraction efficiency of 80% and 60% have been obtained in Ferric chloride Polyvinyl alcohol (FePVA) and Dichromated Polyvinyl alcohol (DCPVA), respectively.

A novel collinear polymer waveguide modulator was successfully demonstrated. A 36 dB modulation depth was observed with the combination of current induced absorption (3 dB) and phase-matched cross coupling (33 dB). The experimental data shows that the modulator is insensitive to beam polarization. Only 0.1 dB difference was observed between the transverse electric (TE) and transverse magnetic (TM) modes. The theoretical calculation projects a modulation bandwidth of multi gigabit/sec. The polymer microstructure film (PMSF) demonstrated an index tunability from a stepped-index profile to a graded-index (GRIN) profile. GRIN profiles have been produced using the swelling and dehydration process. High- quality waveguides have been generated on an array of optoelectronic substrates, including semiconductors, conductors, insulators, and ceramics. As a result, the demonstrated polymer waveguide modulator can be implemented on any system application where passive and active guided wave devices are employed. Besides the aforementioned universality, the ingenuity of the proposed device provides us with an extremely large dynamic range of the suitable waveguide effective index for waveguide-to-waveguide coupling, which is not achievable through any existing electro-optic devices. Drive power, fabrication cost, and interaction length are expected to be drastically reduced.

Thin films of a liquid crystalline polyaryl cinnamate have been irradiated at (lambda) > 400 nm in the presence of ketocoumarin triplet sensitizers. The aryl cinnamate chromophore disappears upon irradiation with concomitant loss of solubility attributed to cross-linking by interchain cyclobutane photoproduct formation. Competing loss of sensitizer absorption also occurs during irradiation. Up to ca. 80% of the aryl cinnamate chromophores in amorphous films can be destroyed using high weight percentages (>= 5%) of sensitizer. At low concentrations of sensitizer (0.5 wt.%), approximately 80 cinnamate chromophores are photolyzed for each sensitizer molecule initially present, despite the competing photolysis of sensitizer during the course of irradiation. The ketocoumarins are insoluble in the glassy (frozen) nematic films of the polymer and thus are ineffective in sensitizing photolysis in this more organized phase.

Coupled-wave analysis of laser beam interaction in electro-optic sillenite crystals with bipolar photoconductivity, optical activity, linear birefringence, and anisotropic diffraction is given. The optimum holographic readout performance of a dynamic interferometric system has been obtained. The construction of devices in nondestructive testing and some applications are presented.

To solve non-linear problem. by means of experimental simulation, the polycrystalline photoplastic material - Silver Chlorider(AGCL), has been systematically investigated, including the determination of the mechanical and optical behaviour of AGCL. A number of experimental results has been presented in order to simulate experimentally non- linear problems. Finally, the problems in experimental technique are pointed out and the prospect of application in simulating non-linear problems is illustrated.

A very useful technology for monomode waveguide production by etching SiO2 substrate material and covering it with organic polymeric materials is reported. An integrated dual-beam interferometer is presented which serves efficiently for electro-optical material parameter determination for polymers. An opto-optical beam scanner based on a grating coupler was realized. Output coupling angle modulation up to 0.1 rad was obtained by illuminating the grating with low intensity (2) laser radiation. A new waveguiding principle in which light is guided in a low refractive index region, a so called ARROW, was realized using polymer in combination with SiO2Si3N4.

We have demonstrated for the first time board-to-board optical interconnection having a 60 GHz bandwidth with a signal-to-noise ratio of 22 dB at 60 0Hz. Board-to-board optical interconnection was realized using microprisms which had a measured coupling bandwidth of more than 250 nm. The graded index (GRIN) of the polymer waveguide allows us to implement such an interconnection scheme on an array of substrates. The implementation of a high speed on-board transceiver in connection with a polymer waveguide lens will generate a fully on-board optical interconnect involving modulation/demodulation.