Download or read book Measurements of the Microscopic Properties Contributing to Photorefraction in Barium Titanate written by Gazanfer Unal and published by . This book was released on 1986 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The photorefractive effect is a nonlinear optical phenomena that can produce phase conjugate (complex conjugate) reflection of visible light in a crystalline solid. Very little is known about the microscopic origin of photorefraction; consequently this thesis investigates the following microscopic parameters of barium titante (Barium Titante): the quantum efficiency, charge transport length and the carrier generation rate both theoretically and experimentally. BaTiO3 was chosen because it is a highly nonlinear crystal with large electrooptic coefficients and therefore, is a very efficient photorefractive material. Keywords: Phase Conjugation, Barium Titanate; Photorefraction; Crystals, Lasers.
Download or read book Optical and Photorefractive Properties of Iron doped Barium Titanate written by Ronald Scott Hathcock and published by . This book was released on 1989 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Photorefractive Properties and Applications of Rhodium doped Barium Titanate written by Laura Anne Corner and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identification of Light Induced Charge Transfer Processes in BaTio Sub 3 by Combined ESR and Optical Measurements written by O. F. Schirmer and published by . This book was released on 1992 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: What are the defects responsible for the photorefractive effect in Barium titanate? What charge conversion processes involving these defects are taking place during illumination? Along which energetic paths are charges transported? These questions have to be answered if one wants to understand the outstanding photorefractive properties of BaTiO3 on a microscopic basis. The necessary information can be obtained from ESR studies, if these are combined with optical investigations. We report on such measurements. It was found that the optical behavior of the defects identified by ESR varied from specimen to specimen, even if these were nominally undoped. Even for the same crystal the results depended strongly on the history of illumination and heat treatments. We can give so far only representative results, mostly obtained with crystals cut from one boule, which was nominally undoped. ESR investigations of defects in BaTiO3 in relation to the photorefractive behavior of the material have been performed earlier. We extend such measurements by observing ESR with BaTiO3 single crystals also at low temperatures and by simultaneously monitoring the light induced changes of ESR and optical absorption.
Download or read book Nonlinear Optical Studies of Photorefractive Barium Titanate written by Tallis Young Chang and published by . This book was released on 1986 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photorefractive Properties and Applications of Barium Titanate and Tungsten Bronze Ferroelectrics written by George Anthony Rakuljic and published by . This book was released on 1987 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1987 with total page 964 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photorefractive Properties and Applications of Barium Titanate and Tungsten Bronze Ferroelectrics written by George Anthony Rakuljic and published by . This book was released on 1987 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth and Characterization of High Performance Photorefractive BaTiO3 Crystals written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-08 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Barium titanate has been used for many nonlinear optical applications primarily because it has high grain and high self-pumped phase conjugate reflectivities. However, barium titanate has had a relatively slow response time, and thus low sensitivity. Therefore, it has not been suited to real-time operations. In this report we will describe the modifications in crystal growth, doping, reduction, and poling that have produced barium titanate crystals with the fastest photorefractive response time reported to date, approximately 21 microseconds with a beam-coupling gain coefficient of 38.7 cm(exp -1) and the highest sensitivity reported to date of 3.44 cm(exp 3)/kJ. The sensitivity of these barium titanate crystals is comparable to or greater than other photorefractive oxides. We will show, for the first time, beam-coupling in barium titanate at video frame rates. We infer from response time measurements that barium titanate has a phonon limited mobility. Also, photorefractive response time measurements as a function of the crystallographic orientation and grating wave vector for our cobalt-doped oxygen reduced crystals indicate that their faster response time arise because of an increase in the free carrier lifetime. Warde, C. and Garrett, M. H. and Chang, J. Y. and Jenssen, H. P. and Tuller, H. L. Unspecified Center...
Download or read book Enhanced Photorefractive Effects in Barium Titanate written by and published by . This book was released on 1992 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents investigations of characteristics of secondary centers (shallow traps) in BaTiO3, and the possible utilization of these traps for enhanced photorefractive effects at infrared wavelengths. Secondary centers were characterized by photo-induced absorption and two-beam coupling experiments. Two species were identified, with concentrations of approximately 1.5 x 10(exp 17) cm( -3) and 2 x 10(exp 16) cm( -3). The effect of secondary centers on the sublinear intensity dependence and temperature dependent photorefractive effects were also examined. No enhancements of photorefractive effects were also examined. No enhancements of photorefractive effects from induced population of secondary centers by external pumping were observed ... Photorefraction, Barium titanate.
Download or read book Landmark Papers on Photorefractive Nonlinear Optics written by Pochi Yeh and published by World Scientific. This book was released on 1995 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, intended for students, researchers and engineers, is a collection of classic papers on photorefractive nonlinear optics. Included are landmark papers on fundamental photorefractive phenomena, two-wave mixing, four-wave mixing, phase conjugators and resonators, material growth and physics, and applications in image processing, optical storage and optical computing.
Download or read book Photorefractive and Photochromic Effects in Barium Titanate written by M. H. Garrett and published by . This book was released on 1992 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nominally undoped p-type Barium titanate was grown that exhibits interesting intensity dependent photorefractive and photochromic properties. When its photochromism is activated the absorption increases at the activating wavelength and there is a concurrent and proportional reduction in photorefractive response time. Three photoactivated and thermally reversible absorption conditions and the difference spectra of the photochromic crystal are shown in Figure 1.
Download or read book Synthesis Characterization and Optical Properties of Barium Titanate Films Sputtered Under Various Conditions written by John C. Olson and published by . This book was released on 1981 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data is presented on BaTiO3 films which were rf sputtered on Pt, quartz and sapphire substrates at various temperatures and gas mixtures. Measurements of density, dielectric constant, electrical conductivity, X-ray diffraction, energy band gap from optical absorption and wavelength, and temperature dependence of refractive index are presented. Measurements were also made on a BaTiO3 single crystal and a hot-pressed ceramic pellet for direct comparison of bulk properties to those of the films. The results of this work demonstrate that a transition of the properties occurs between the amorphous and crystalline states depending on the surface temperature during sputtering. The transition is sluggish up to 700 C above which crystalline properties of the films appear rapidly. (Author).
Download or read book Effects of Cobalt doping Oxygen reduction and Crystallographic Orientation on the Photorefractive Properties of Barium Titanate written by Jenq-Yang Chang and published by . This book was released on 1992 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study of Two beam Coupling in Photorefractive Barium Titanate BaTiO3 at 442nm written by Chuong Van Vu and published by . This book was released on 1991 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1987 with total page 1260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Intensity Dependence Absorption and Photorefractive Effects in Barium Titanate written by G. A. Brost and published by . This book was released on 1988 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present experimental data for BaTiO3 that exhibit an intensity dependence in the absorption coefficient and the two-beam coupling coefficient at intensities between 0.002 and 40 S/sq. cm. The effective empty-trap concentration was found to increase with intensity. We present a model, in the spirt of commonly used (photorefractive) theories, for photorefraction and optical absorption that explains these effects. The intensity dependence was attributed to the presence of secondary photorefractive centers. Keywords: Barium titanates, Reprints. (MJM).
