Laser and Coherence Spectroscopy

1 Double-Resonance Spectroscopy.- 1.1. Introduction to Double-Resonance Methods.- 1.1.1. Introduction.- 1.1.2. Dynamics of the Interaction of Radiation and Matter.- 1.1.3. Summary of Molecular Spectroscopy.- 1.1.3.1. Rotational Energy Levels.- 1.1.3.2. Vibrational Energy Levels.- 1.1.3.3. Electronic Energy Levels.- 1.1.4. Definition of Double-Resonance Spectroscopy.- 1.1.5. Historical Survey.- 1.2. Response of a System to Pumping and Analyzing Radiation Fields.- 1.2.1. Saturation of Molecular Absorption Lines.- 1.2.2. Double Resonance in a Three-Level System.- 1.2.3. Rate-Equation Analysis of Double Resonance.- 1.3. Experimental Considerations.- 1.3.1. Radiation Sources.- 1.3.1.1. Klystrons.- 1.3.1.2. Fixed-Frequency Lasers.- 1.3.1.3. Tunable Lasers.- 1.3.2. Signal Detection and Enhancement.- 1.3.2.1. Detectors.- 1.3.2.2. Lock-In Amplifier.- 1.3.2.3. Boxcar Averager.- 1.3.2.4. Transient Recorder.- 1.3.3. Detection by Fluorescence versus Absorption Techniques.- 1.3.4. Experimental Configurations.- 1.4. Microwave-Detected Double Resonance.- 1.4.1. Microwave Pumping.- 1.4.1.1. Carbon Oxysulfide.- 1.4.1.2. Ammonia.- 1.4.1.3. Formaldehyde.- 1.4.1.4. Ethylene Oxide.- 1.4.1.5. Hydrogen Cyanide.- 1.4.1.6. Other Systems.- 1.4.2. Infrared Pumping.- 1.4.2.1. Methyl Halides.- 1.4.2.2. Ammonia.- 1.4.3. Optical Pumping.- 1.5 Infrared-Detected Double Resonance.- 1.5.1. Microwave Pumping.- 1.5.2. Infrared Pumping.- 1.5.2.1. Vibrational Energy Transfer.- 1.5.2.2. Rotational Energy Transfer.- 1.5.2.3. Dephasing, Momentum Transfer, and Molecular Alignment.- 1.5.3. Optical Pumping.- 1.6. Optically Detected Double Resonance.- 1.6.1. Microwave-Optical Double Resonance.- 1.6.1.1. Microwave-Optical Double Resonance in Atoms.- 1.6.1.2. Microwave-Optical Double Resonance in CN.- 1.6.1.3. Microwave-Optical Double Resonance in OH and OD.- 1.6.1.4. Microwave-Optical Double Resonance in CS.- 1.6.1.5. Microwave-Optical Double Resonance in BaO.- 1.6.1.6. Microwave-Optical Double Resonance in NO2.- 1.6.1.7. Microwave-Optical Double Resonance in NH2.- 1.6.1.8. Microwave-Optical Double Resonance in BO2.- 1.6.2. Infrared-Optical Double Resonance.- 1.6.2.1. Infrared-Optical Double Resonance in NH3.- 1.6.2.2. Infrared-Optical Double Resonance in OsO4.- 1.6.2.3. Infrared-Optical Double Resonance in Biacetyl.- 1.6.2.4. Infrared-Optical Double Resonance in F8+.- 1.6.2.5. Infrared-Optical Double Resonance in Coumarin-6.- 1.6.3. Optical-Optical Double Resonance.- 1.6.3.1. Optical-Optical Double Resonance in Atoms.- 1.6.3.2. Optical-Optical Double Resonance in Diatomic Molecules.- 1.6.3.3. Optical-Optical Double Resonance in Polyatomic Molecules.- 1.6.4. Optically Detected Double Resonance in Large Molecules.- 1.7. Molecular Information from Double-Resonance Experiments.- 1.7.1. Spectroscopic Information.- 1.7.2. Energy Transfer and Interaction Potentials.- 1.7.3. Future Directions.- References.- 2 Coherent Transient Microwave Spectroscopy and Fourier Transform Methods.- 2.1. Introduction.- 2.2. Basic Theory and Experiment.- 2.3. Transient Absorption.- 2.4. Transient Emission.- 2.5. Fast Passage.- 2.6. Fourier Transform Microwave Spectroscopy.- 2.7. Molecular Interpretation of T1 and T2.- 2.8. Conclusion.- Appendix A. Solution of the Bloch Equations.- Appendix B. Two-State Relaxation Processes.- References.- 3 Coherent Transient Infrared Spectroscopy.- 3.1. Introduction.- 3.2. Density and Population Matrices.- 3.2.1. Basic Theory.- 3.2.2. Physical Interpretation and Applicability.- 3.3. Absorption and Emission of Radiation.- 3.3.1. Polarization and Reduced Wave Equations.- 3.3.2. Steady-State Absorption: An Example.- 3.4. Solutions of the Population Matrix Equations.- 3.4.1. Introduction.- 3.4.2. Optical Bloch Equations.- 3.4.3. Matrix Solution of the Optical Bloch Equations.- 3.5. Experimental Techniques.- 3.5.1. Pulsed Laser Experiments.- 3.5.2. Stark Switching.- 3.5.3. Frequency Switching.- 3.6. Optical Nutation.- 3.7. Optical Free Induction Decay.- 3.7.1. Theory and Experiment.- 3.7.2. Superradiance.- 3.8. Photon Echo.- 3.8.1. Two-Pulse Echoes.- 3.8.2. Multiple-Pulse Echoes.- 3.9. Measurement of Level Decay Rates.- 3.9.1. Adiabatic Rapid Passage.- 3.9.2. Delayed Optical Nutation.- 3.10. Velocity-Changing Collisions.- 3.10.1. Introduction.- 3.10.2. Brownian Motion and Velocity-Changing Collisions.- 3.10.3. Photon Echoes and Velocity-Changing Collision Measurements.- Appendix A. Justification of the Reduced Wave Equation.- Appendix B. Matrix Formulation of the Bloch Equations.- References.- 4 Coherent Spectroscopy in Electronically Excited States.- 4.1. Introduction.- 4.1.1. Historical Development.- 4.1.2. Recent Advances.- 4.2. Theoretical Considerations.- 4.2.1. General Aspects of Coherence in Excited States.- 4.2.2. Equation of Motion for the Model System.- 4.2.2.1. Basic Torque Equation in the Rotating Frame.- 4.2.2.2. Addition of Feeding and Decay Terms.- 4.2.2.3. Exact Solutions, Including Feeding and Decay.- 4.2.2.4. Addition of Relaxation Terms.- 4.2.2.5. Exact Solutions, Including Feeding, Decay, and Relaxation.- 4.2.2.6. Discussion.- 4.2.2.7. Inhomogeneous Relaxation and Expected Line Shapes.- 4.2.3. Relationship Between the Geometrical Model and Double-Resonance Observables.- 4.2.3.1. Density Matrix and Dipole Emission.- 4.2.3.2. Probe Pulse Method.- 4.2.4. Experiments Utilizing Optically Detected Coherence.- 4.2.4.1. Introduction.- 4.2.4.2. Transient Nutation.- 4.2.4.3. Free Induction Decay and Spin Echo.- 4.2.4.4. Echo Trains and Coherent Averaging.- 4.2.4.5. Spin Locking and Coherent Averaging.- 4.2.4.6. Rotary Echoes and Driving-Field Inhomogeneities.- 4.2.4.7. Adiabatic Demagnetization and Rapid Passage.- 4.3. Experimental Methods.- 4.3.1. Excited Triplet States and Phosphorescence Spectroscopy.- 4.3.2. Conventional Techniques: Optically Detected Magnetic Resonance.- 4.3.3. Pulse Techniques in Optically Detected Magnetic Resonance.- 4.3.3.1. Transient Nutation and Pulse Timing.- 4.3.3.2. Short Coherence Sequences.- 4.3.3.3. Long Coherence Sequences.- 4.3.3.4. Triplet-State Multiplets and Orientation Factors.- 4.4. Applications.- 4.4.1. Preliminaries.- 4.4.2. Addition of Energy Exchange to the Equations of Motion.- 4.4.2.1. Loss of Spin Memory in the Slow Exchange Limit.- 4.4.2.2. Retention of Spin Memory in Scattering in the Fast Exchange Limit.- 4.4.3. Energy Transfer Studies Using Coherent Spectroscopy Techniques.- 4.4.4. Vibrational Relaxation Studies Using Coherence Techniques.- 4.4.5. Energy Transfer Studies Using an Ordered State.- References.- 5 Resonant Scattering of Light by Molecules: Time-Dependent and Coherent Effects.- 5.1. Elementary Time-Dependent Theory Related to Luminescence.- 5.1.1. Introduction.- 5.1.2. Scattering Theory.- 5.1.3. Approximate Model for the Photon States.- 5.1.4. Molecular States.- 5.1.5. Matrix Elements of G(?).- 5.1.6. Excitation of an Isolated Resonant State: A Two-Level System.- 5.1.7. Semiclassical Analogy.- 5.2. Applications of Scattering Theory to Model Systems.- 5.2.1. Three-Level System.- 5.2.2. Scattering of an Exponentially Decaying Pulse.- 5.2.3. Semiclassical Treatment of the Three-Level System.- 5.2.4. Resonance and Near-Resonance Raman Scattering.- 5.3. Nature of the Electromagnetic Field.- 5.3.1. Definition of the Field Variables.- 5.3.2. Radiation-Matter Interaction.- 5.3.3. States of the Radiation Field.- 5.3.4. Measurables of the Field and Photon Experiments.- 5.4. Theory of Light Scattering with Well-Defined Light Sources.- 5.4.1. More General Approach to Light Scattering.- 5.4.2. Spectral Content of a Scattered Coherent Pulse.- 5.4.3. Scattering from a Gaussian Pulse.- 5.4.4. Scattering from a Weak Stationary Light Beam.- 5.5. Effects of Intermolecular Interactions on Luminescence.- 5.5.1. Resonance Scattering (Raman Fluorescence) in the Presence of Fluctuations.- 5.5.2. Random Modulation in Resonance Raman Scattering.- 5.5.3. Classical Character of Fluorescence.- 5.5.4. Absorption and Scattering.- 5.5.5. Spectroscopic Selection Rules for Resonance Raman, Fluorescence, and Phosphorescence.- 5.6. Two-Photon Induced Light Scattering.- 5.6.1. Two-Photon Processes.- 5.6.2. Scattering Induced by Two-Photon Excitation: Hyper Raman Scattering.- 5.7. Recent Resonance Fluorescence Concepts and Experiments.- Appendix. Contour Integration.- References.- Author Index.