[en] This book reports on: Diamond films, Synthesis of optical materials, Structure related optical properties, Radiation effects in optical materials, Characterization of optical materials, Deposition of optical thin films, and Optical fibers and waveguides

[en] ZnO layers were grown by organometallic chemical vapor deposition. Films were deliberately doped with nitrogen by incorporating ammonia into the ambient during growth. The resistivity of the films depended strongly on the ammonia partial pressure. The layers were n-type with resistivities in the range of 0.1 - 360 ohm-cm. The films exhibited strong ultraviolet nearbandedge photoluminescent emission. Emission was ascribed to recombination of bound excitons at neutral acceptors, presumably involving substitutional nitrogen

[en] The fine probe forming capabilities of an analytical electron microscope combined with the development of related spectroscopies, diffraction and imaging techniques, makes it possible to obtain structural and chemical information from multiphase materials at high spatial resolution. These microanalytical methods are described with relevant examples from our studies of compounds in the Al₂O₃-AIN pseudo binary system, a potential window material, low-pressure synthesized diamond, diamond-like carbon and hydrocarbon films. A comprehensive example of the characterization of a novel AlON poltypoid structure (32H), level of resolution and the need to employ all the complementary methods of analysis, is discussed. Efforts to characterize a variety of diamond-like carbon films by the measurements of both the low-loss plasmon resonances and the fine structure in the core-loss edges observable in the energy-loss spectrum, to obtain sp₃/sp₂ ratios are outlined. The electronic structure of thin film diamonds, synthesized by a plasma enhanced chemical vapor deposition method, has been shown to be in agreement with band structure calculations

[en] The microstructure and optical properties of vacuum evaporated coatings are a sensitive function of the deposition conditions. In recent years, ion bombardment has been sued increasingly for the production of denser, more stable coatings of oxides and other materials. In addition to modifying the microstructure, ion bombardment is emerging as a valuable tool for altering the composition (and hence the optical properties) of thin films. A discussion of the effects of ion beam processing and the methods used to analyze the changes in these films is presented

[en] To a greater or lesser extent, all alkaline-earth oxide crystals contain hydrogen. Thermochemical reduction (TCR) of MgO and CaO crystals at high temperatures (∼2000K) and high pressures (4 to 7 atmospheres) of the metallic cation vapor (Mg and Ca respectively) results in a stoichiometric deficiency of oxygen ions, creating F centers (oxygen vacancies each with two electrons) and H_- ions (protons in the anion sublattice, each occupied by two electrons)> The positively-charged H^- ions serve as traps for electrons excited from the F centers. Steady-state photo-excitation of the F absorption band results in F luminescence which typically extends to several minutes. This photoluminescence is detrimental for certain applications, such as tunable lasers. The authors have been able to reduce the hydrogen concentration prior to TCR of MgO and during TCR of CaO. The result is that the oxygen vacancies are predominately in the one-electron F₊ charge state

[en] Recent efforts to engineer new nonlinear optical materials with specific desired characteristics has engendered a need for a theoretical description of optical properties which is readily accessible to chemists, yet correctly treats the essential physics of dielectric response. This paper describes a simple empirical molecular orbital model which gives useful insights into the relationship between chemical composition, crystalline structure, and optical susceptibilities. The authors compare the probabilities of finding new harmonic generators in various chemical classes. Rigorous bounds on the magnitudes of linear and nonlinear optical coefficients and their anisotropies are also discussed

[en] KNbO₃ is a strong candidate as a material for use as channel waveguides due to a high electrooptic figure of merit. High quality single crystals are difficult to obtain due to incongruent melting of the compound. Control of cation concentration and oxygen incorporation are problems encountered in current thin film processing routes. In order to overcome the problems discussed above, an ion beam deposition system featuring a computer-controlled rotatable target holder and quartz crystal resonator (QCR) feedback loop has been developed. Multicomponent films are produced via sputtering from elemental or compound targets sequentially exposed to an ion beam. Initial results are presented on the use of this new technique for the deposition of KNbO₃. Pressed KNbO₃, Nb₂O₅, and KO₂ powders were used as sputtering targets. By varying the programmed thickness of deposited film from each target being sputtered, the ration of K:Nb could be reproducibly controlled. The variation in sticking coefficients due to substrate temperature was also compensated for in this manner

[en] LiNbO₃ is a relevant material to prepare a number of electrooptic (bulk and waveguide) devices. Moreover, its photorefractive (PR) behavior is also potentially useful for optoelectronic applications such as holographic storage and coherent optical amplification. For a full understanding and optimization of the PR effect, the lattice location and valence state of the active impurities is essential, since they determine the ionization and trapping capabilities for free carriers. So far, the information obtained with spectroscopic techniques (EPR, ENDOR, Mossbauer, optical) is not conclusive, except manganese and possible iron. In this paper the authors report on an investigation of the lattice location of Eu by ion-channeling techniques. They provide a rather direct method, largely relying on geometrical considerations, which is very adequate for semiquantitative analysis. Eu has been chosen because its heavy mass produces a RBS peak well separated from the host contributions. Results conclusively show that Eu³⁺ lies partly on both Li and Nb sites (36% 64%, respectively), but not on the intrinsic vacant lattice sites

[en] The microstructural development of Ti:LiNbO₃ optical waveguides as a function of annealing time and temperature was studied using transmission electron microscopy. The morphological evolution of the deposited Ti film can be characterized by three stages: oxidation beginning at low temperatures, coarsening and secondary grain growth of the oxide film at higher temperatures and eventual film breakup and void formation. Secondary grain growth is driven by minimization of interfacial energy of grains which have a special epitaxial relationship with respect to the LiNbO₃ substrate

[en] The authors' recent report of epitaxial single crystal growth of C₊ ion-beam-deposited diamond films on (111) single crystals of silicon is shown to be incorrect. The authors briefly describe the circumstances leading to this revision (and to our earlier finding) and discuss the possible structure of these films based on preliminary synchrotron x-ray data and on the Raman spectrum