Persistent Spectral Hole Burning Science And Applications

Almost fifteen years have now elapsed since the first observations of per sistent spectral hole-burning in inhomogeneously broadened absorption lines in solids. The fact that the spectral shape of an inhomogeneously broadened line can be locally modified for long periods of time has led to a large number of investigations of low-temperature photophysics and photochemistry that would not have been possible otherwise. Using hole burning, important information has been obtained about a variety of in teractions, including excited-state dephasing processes, host-guest dynam ics, proton tunnelling, low-frequency excitation in amorphous hosts, relaxation mechanisms for vibrational modes, photochemical mechanisms at liquid helium temperatures, and external field perturbations. At the same time, the possibility that persistent spectral holes might be used to store digital information has led to the study of materials and configura tions for frequency-domain optical storage and related possible applica tions. This is the first full-length book on persistent spectral hole-burning. The goal is to provide a broadly based survey of the scientific principles and applications of persistent spectral hole-burning. Since the topic is quite interdisciplinary, the book is intended for researchers, graduate stu dents, and advanced undergraduates in the fields of chemical physics, solid-state physics, laser spectroscopy, solid-state photochemistry, and high-performance optical storage and optical processing.

This book describes the underlying scientific fundamentals and principal phenomena associated with persistent spectral hole-burning in solids, and presents an overview of possible future applications to optical storage of digital data and optical signal processing. Organization of the material is by the general physical mechanism responsible for the formation of persistent spectral holes. After a description of the basic principles and methods of hole-burning, with examples from photochemical processes in crystalline and amorphous hosts, the unusual proton tunneling phenomena that occur in hydrogen-bonded polymers and glasses are described. Persistent spectral hole-burning in inorganic materials due either to photoionization or to photophysical effects is then summarized, followed by a detailed discussion of nonphotochemical hole-burning mechanisms for electronic transitions in amorphous solids. The book concludes with a description of potential applications to data storage and optical processsing using frequency-domain, holographic, and electric field techniques. Readers of this volume will gain a detailed appreciation of both the generality of the persistent spectral hole-burning phenomenon and the power of the technique in studying microscopic dynamics and mechanisms of phototransformation in low-temperature solids.

Since Dr. Disiich of Germany prepared a glass lens by the sol-gel method around 1970, sol-gel science and technology has continued to develop. Since then this field has seen remarkable technical developments as well as a broadening of the applications of sol-gel science and technology. There is a growing need for a comprehensive reference that treats both the fundamentals and the applications, and this is the aim of "Handbook of Sol-Gel Science and Technology."The primary purpose of sol-gel science and technology is to produce materials, active and non-active including optical, electronic, chemical, sensor, bio- and structural materials. This means that sol-gel science and technology is related to all kinds of manufacturing industries. Thus Volume 1, "Sol-Gel Processing," is devoted to general aspects of processing. Newly developed materials such as organic-inorganic hybrids, photonic crystals, ferroelectric coatings, photocatalysts will be covered. Topics in this volume include: Volume 2, "Characterization of Sol-Gel Materials and Products, "highlights the important fact that useful materials are only produced when characterization is tied to processing. Furthermore, characterization is essential to the understanding of nanostructured materials, and sol-gel technology is a most important technology in this new field. Since nanomaterials display their functional property based on their nano- and micro-structure, "characterization" is very important. Topics found in Volume 2 include: Sol-gel technology is a versatile technology, making it possible to produce a wide variety of materials and to provide existing substances with novel properties. This technology was applied to producingnovel materials, for example organic-inorganic hybrids, which are quite difficult to make by other fabricating techniques, and it was also applied to producing materials based on high temperature superconducting oxides. "Applications of Sol-Gel Technology," (Volume 3), will cover applications such as:

This completely updated and expanded second edition stands as a comprehensive knowledgebase on both the fundamentals and applications of this important materials processing method. The diverse, international team of contributing authors of this reference clarify in extensive detail properties and applications of sol-gel science and technology as it pertains to the production of substances, active and non-active, including optical, electronic, chemical, sensor, bio- and structural materials. Essential to a wide range of manufacturing industries, the compilation divides into the three complementary sections: Sol-Gel Processing, devoted to general aspects of processing and recently developed materials such as organic-inorganic hybrids, photonic crystals, ferroelectric coatings, and photocatalysts; Characterization of Sol-Gel Materials and Products, presenting contributions that highlight the notion that useful materials are only produced when characterization is tied to processing, such as determination of structure by NMR, in-situ characterization of the sol-gel reaction process, determination of microstructure of oxide gels, characterization of porous structure of gels by the surface measurements, and characterization of organic-inorganic hybrid; and Applications of Sol-Gel Technology, covering applications such as the sol-gel method used in processing of bulk silica glasses, bulk porous gels prepared by sol-gel method, application of sol-gel method to fabrication of glass and ceramic fibers, reflective and antireflective coating films, application of sol-gel method to formation of photocatalytic coating films, and application of sol-gel method to bioactive coating films. The comprehensive scope and integrated treatment of topics make this reference volume ideal for R&D scientists and engineers across a wide range of disciplines and professional interests.