AN INTRODUCTION TO THE OPTICAL SPECTROSCOPY OF INORGANIC SOLIDS

By Y. DIERR

CONTENTS 1 FUNDAMENTALS 1 1 THE ORIGINS OF SPECTROSCOPY 1 2 THE ELECTROMAGNETIC SPECTRUM AND OPTICAL SPECTROSCOPY 1 3 ABSORPTION 1 3 1 THE ABSORPTION COEF?CIENT 1 3 2 THE MEASUREMENT OF ABSORPTION SPECTRA: THE SPECTROPHOTOMETER 1 3 3 RE?ECTIVITY 1 4 LUMINESCENCE 1 4 1 THE MEASUREMENT OF PHOTOLUMINESCENCE: THE SPECTRO?UORIMETER 1 4 2 LUMINESCENT EF?CIENCY 1 4 3 STOKES AND ANTI-STOKES SHIFTS 1 4 4 TIME-RESOLVED LUMINESCENCE 1 5 SCATTERING: THE RAMAN EFFECT 1 6 ADVANCED TOPIC: THE FOURIER TRANSFORM SPECTROMETER EXERCISES REFERENCES AND FURTHER READING 2 LIGHT SOURCES 2 1 INTRODUCTION 2 1 1 THERMAL RADIATION AND PLANCK’S LAW 2 2 LAMPS 2 2 1 TUNGSTEN AND QUARTZ HALOGEN LAMPS 2 2 2 SPECTRAL LAMPS 2 2 3 FLUORESCENT LAMPS 2 2 4 HIGH-PRESSURE DISCHARGE VAPOR LAMPS 2 2 5 SOLID STATE LAMPS 2 3 THE LASER 2 3 1 LASERS AS LIGHT SOURCES IN SPECTROSCOPY 2 3 2 THE BASIC PRINCIPLES OF LASERS 2 3 3 POPULATION INVERSION: THE THRESHOLD CONDITION 2 3 4 PUMPING TECHNIQUES 2 3 5 THE RESONATOR 2 4 TYPES OF LASERS 2 4 1 THE EXCIMER LASER 2 4 2 GAS LASERS 2 4 3 DYE LASERS 2 4 4 SEMICONDUCTOR LASERS 2 4 5 SOLID STATE LASERS 2 5 THE TUNABILITY OF LASER RADIATION 2 5 1 TUNABLE SOLID STATE LASERS 2 5 2 TUNABLE COHERENT RADIATION BY FREQUENCY-MIXING TECHNIQUES 2 5 3 OPTICAL PARAMETRIC OSCILLATION AND AMPLI?CATION 2 6 ADVANCED TOPICS: SITE SELECTIVE SPECTROSCOPY AND EXCITED STATE ABSORPTION 2 6 1 SITE SELECTIVE SPECTROSCOPY 2 6 2 EXCITED STATE ABSORPTION 3 MONOCHROMATORS AND DETECTORS 3 1 INTRODUCTION 3 2 MONOCHROMATORS 3 3 DETECTORS 3 3 1 BASIC PARAMETERS 3 3 2 TYPES OF DETECTORS 3 4 THE PHOTOMULTIPLIER 3 4 1 THE WORKING PRINCIPLES OF A PHOTOMULTIPLIER 3 4 2 NOISE IN PHOTOMULTIPLIERS 3 5 OPTIMIZATION OF THE SIGNAL-TO-NOISE RATIO 3 5 1 THE AVERAGING PROCEDURE 3 5 2 THE LOCK-IN AMPLI?ER 3 5 3 THE PHOTON COUNTER 3 5 4 THE OPTICAL MULTICHANNEL ANALYZER 3 6 DETECTION OF PULSES 3 6 1 DIGITAL OSCILLOSCOPES 3 6 2 THE BOXCAR INTEGRATOR 3 7 ADVANCED TOPICS: THE STREAK CAMERA AND THE AUTOCORRELATOR 3 7 1 THE STREAK CAMERA 3 7 2 THE AUTOCORRELATOR 4 THE OPTICAL TRANSPARENCY OF SOLIDS 4 1 INTRODUCTION 4 2 OPTICAL MAGNITUDES AND THE DIELECTRIC CONSTANT 4 3 THE LORENTZ OSCILLATOR 4 4 METALS 4 4 1 IDEAL METAL 4 4 2 DAMPING EFFECTS 4 5 SEMICONDUCTORS AND INSULATORS 4 6 THE SPECTRAL SHAPE OF THE FUNDAMENTAL ABSORPTION EDGE 4 6 1 THE ABSORPTION EDGE FOR DIRECT TRANSITIONS 4 6 2 THE ABSORPTION EDGE FOR INDIRECT TRANSITIONS 4 7 EXCITONS 4 7 1 WEAKLY BOUND (MOTT–WANNIER) EXCITONS 4 7 2 TIGHTLY BOUND (FRENKEL) EXCITONS 4 8 ADVANCED TOPIC: THE COLOR OF METALS 5 OPTICALLY ACTIVE CENTERS 5 1 INTRODUCTION 5 2 STATIC INTERACTION 5 2 1 CRYSTALLINE FIELD THEORY 5 2 2 MOLECULAR ORBITAL THEORY 5 3 BAND INTENSITIES 5 3 1 THE ABSORPTION PROBABILITY 5 3 2 ALLOWED TRANSITIONS AND SELECTION RULES 5 3 3 POLARIZED TRANSITIONS 5 3 4 THE PROBABILITY OF SPONTANEOUS EMISSION 5 3 5 THE EFFECT OF THE CRYSTAL ON THE TRANSITION PROBABILITIES 5 3 6 OSCILLATOR STRENGTH: SMAKULA’S FORMULA 5 4 DYNAMIC INTERACTION: THE CON?GURATIONAL COORDINATE DIAGRAM 5 5 BAND SHAPE: THE HUANG–RHYS COUPLING PARAMETER 5 6 NONRADIATIVE TRANSITIONS 5 6 1 MULTIPHONON EMISSION 5 6 2 ENERGY TRANSFER 5 6 3 THE CONCENTRATION QUENCHING OF LUMINESCENCE 5 7 ADVANCED TOPIC: THE DETERMINATION OF QUANTUM EF?CIENCIES 6 APPLICATIONS: RARE EARTH AND TRANSITION METAL IONS, AND COLOR CENTERS 6 1 INTRODUCTION 6 2 RARE EARTH IONS 6 2 1 TRIVALENT RARE EARTH IONS: THE DIEKE DIAGRAM 6 2 2 DIVALENT RARE EARTH IONS 6 3 NONRADIATIVE TRANSITIONS IN RARE EARTH IONS: THE ‘ENERGY-GAP’ LAW 6 4 TRANSITION METAL IONS 6 4 1 3D1 IONS 6 4 2 3DN IONS: SUGANO–TANABE DIAGRAMS 6 5 COLOR CENTERS 6 6 ADVANCED TOPICS: THE JUDD AND OFELT FORMALISM, AND OPTICAL COOLING OF SOLIDS 6 6 1 THE JUDD AND OFELT FORMALISM 6 6 2 OPTICAL COOLING OF SOLIDS 7 GROUP THEORY AND SPECTROSCOPY 7 1 INTRODUCTION 7 2 SYMMETRY OPERATIONS AND CLASSES 7 3 REPRESENTATIONS: THE CHARACTER TABLE 7 4 REDUCTION IN SYMMETRY AND THE SPLITTING OF ENERGY LEVELS 7 5 SELECTION RULES FOR OPTICAL TRANSITIONS 7 6 ILLUSTRATIVE EXAMPLES 7 7 ADVANCED TOPIC: THE APPLICATION TO OPTICAL TRANSITIONS OF KRAMERS IONS