Optical Properties of Excited States in Solids, 1992 NATO Science Series B: Series, Vol. 301

This book presents an account of the course "Optical Properties of Excited States in Solids" held in Erice, Italy, from June 16 to 3D, 1991. This meeting was organized by the International School of Atomic and Molecular Spectroscopy of the "Ettore Majorana" Centre for Scientific Culture. The purpose of this course was to present physical models, mathematical formalisms and experimental techniques relevant to the optical properties of excited states in solids. Some active physical species, such as ions or radicals, could survive indefinitely if they were completely 'isolated in space. Other active species, such as excited molecular and solid-state systems, are inherently unstable, even in isolation, due to the spontaneous mechanisms that may convert their excitation energies into radiation or heat. Physical parameters that may be used to characterize these excited systems are the localization or delocalization, and the coherence or incoherence, of their state excitations. In solids the excited states, whether they are localized (as for impurities in insulators) or delocalized (as they may occur in semiconductors), are relevant in several regards. Their de-excitation is extremely sensitive to the nature of the excitations of the systems, and a study of the de-excitation processes can yield a variety of information. For example, the excited states may represent the initial condition of the onset of such processes as Stokes-shifted emission, hot luminescence, symmetry-dependent Jahn-Teller and scattering processes, tunneling processes, energy transfer to like and unlike centers, superradiance, coherent radiation, and excited state absorption.

The Nature of the Electronic Excited States of Molecular Systems.- Properties of the Excited States of Complex Molecules: What Can We Learn for Solids.- Rates of Processes Involving Excited States.- Excited States in Semiconductors.- Advances in the Characterization of Excited States of Luminescent Ions in Solids.- Relaxed Excited States of Color Centers.- Properties of Highly Populated Excited States in Solids: Superfluorescence, Hot Luminescence, Excited State Absorption.- Advances in the Sensitization of Phosphors.- Laser Spectroscopy Inside Inhomogeneously Broadened Lines.- Excited-State Dynamics and Energy Transfer in Doped-Substituted Garnets.- Studies of the Charge Transfer States of Certain Rare-Earth Activators in Yttrium and Lanthanum Oxysulfides.- Photochemistry, Charge Transfer States and Laser Applications of Small Molecules in Rare Gas Crystals.- The Study of Paramagnetic Excited States by Electron Paramagnetic Resonance.- The Jahn-Teller Effect in the Optical Spectra of Impurities.- Spectral properties of excited states in restricted Geometries.- Excited State Interactions in Stabilized Lasers.- Semiconductors Quantum Dots in Amorphous Materials.- New Crystals for Laser Applications (Abstract Only).- Excited States and Reorientational Properties of Color Centers with Axial Symmetry.- De-Excitation Processes of the Optically Excited States of the F Centers (Abstract Only).- Two-Photon Spectroscopy in Insulating Crystals.- Particles and Elementary Excitations.- Superconductivity.- The Luminescent Excited State of The Vanadate Ion Studied by Optically-Detected Magnetic Resonance.- Rare Earth Spectroscopy in Glasses, a Fraction.- The Influence of Impurities on the Quantum Yeild of Y2O:3%Eu3+.- Fluorescence Mechanisms of Mixed Crystals Sr1-xBaxF2:Eu2+.- Spectroscopy of Er3+:Ggg and Calculation of the Judd-Ofelt Lifetime Parameters.- Laser Spectroscopic Studies of Solid State Defect Chemistry in Perovskites.- Picosecond Time-Resolved Cars: Application to Vibrons in Molecular Crystals.- Experimental Studies of Upconversion Laser Materials and Upconversion Lasers.- Luminescence of the Eu3+ Ion in Calcium Compounds.- Theoretical Study of Ultra-Fast Dephasing by Four-Wave Mixing.- A New Way to the Relaxed Excited State in Localized Centers: The Pulse Model.- Proposition of Effective Wavefunction for 2deg Within Modfet Heterostructures.- Epitaxy of Cds-Thin Films by Pulsed Laser Evaporation (PLE).- Growth and Optical Properties of Thin Cds Films.- Luminescence of New Storage Phosphors: Alkaline Earth Fluorohalides Doped with Divalent Ytterbium.- Application of Phosphors in X-Ray Computed Tomography.- Dissociation of Polyatomic Molecules by Infrared Lasers.- A Quantitative Analytic Theory of the Spectra of Diatomic Olecules.- Thermal Behavior of Spectral Line Positions and Widths of Nd3+ in GSGG.- Comparison of Er3+ Spectroscopy in Doped Glass Fibers and in Glass Bulk Samples.- Passive Intracavity Stabilization of Wide Gain Laser by Er3+- Doped Materials.- Optical Properties of F3+ Center In Lif (Triplet State).- Two-Photon Spectroscopy in the F-Shell.- Two-Photon Transition Intensities Within Symmetry-Adapted Eigenvector Approach: Ni2+ in Oh Symmetry.- Characteristic Electroluminescence at the Semiconductor Electrolyte Interface.- Localized 3??? Excitations of [Rh(phpy)2bipy]PF6 (phpy = 2-phenylpyridine, bipy = 2,2’-bipyridine).- Cross Relaxation of Excited States in a One-Dimensional Compound.- Luminescence of the % MathType!MTEF!2!1!+- % feaagCart1ev2aaatCvAUfKttLearuavP1wzZbItLDhis9wBH5garm %Wu51MyVXgaruWqVvNCPvMCaebbnrfifHhDYfgasaacH8srps0lbbf9 % q8WrFfeuY-Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0-yr0RYxir % -Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGacaGa % aeqabaWaaeaaeaaakeaaqaaaaaaaaaWdbiabdAfawjabg2da9iabd+ % eapjabbccaGiqbdAfawzaaryaaDaaaaa!3528! $$ V = O{\text{ }}{\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{\bar{V}}} $$ Complex.- Radiationless Vibronic Relaxation and Electron Transfer of the F-Center in NaBr.- Luminescence of Broad Bands in Mn-Doped n-Type GaP.- Optical Spectroscopy of the Matrix-Isolated Nh Radical.- Interaction Between Color Center and Dislocation in Alkali Halides.- Summary of the Meeting.- Picture of the Participants.- Participants.