Coherent Nonlinear Optics

Inhaltsverzeichnis

• 1. Coherent Nonlinear Optics.
• 1.1 Introductory Comments.
• References.
• 2. Superradiance.
• 2.1 Background Material.
• 2.2 Physical Principles.
• 2.3 Theoretical Treatments.
• 2.3.1 Initiation of Superradiance: Quantized Field Treatment.
• 2.3.2 Semiclassical Theory.
• 2.4 Results of the Theory.
• 2.4.1 Superradiance in the Ideal Limit.
• 2.4.2 Influence of Quantum Fluctuations.
• 2.4.3 Deviations from Ideal Behavior.
• Finite Inversion Time.
• Uniform Inversion: Cooperation Length.
• Decay and Dephasing Times.
• Feedback Initial Polarization.
• Initial Polarization.
• 2.4.4 Further Discussion of the Basic Assumptions.
• Neglect of Interaction of Forward and Backward Waves.
• Limitations of the Plane Wave Approximation.
• 2.4.5 Point Sample Superradiance.
• 2.5 Relation to Other Coherent Phenomena.
• 2.5.1 Limited Superradiance.
• 2.5.2 Transient Phenomena in Optically Thick Media.
• 2.5.3 Stimulated and Superradiant Emission.
• 2.6 Experiments.
• 2.6.1 Experimental Observation of Superradiance.
• 2.6.2 Recent Experimental Results.
• 2.6.3 Comparison with Theory.
• 2.7 Concluding Remarks.
• 2.7.1 Applications.
• 2.7.2 Summary.
• 3. Coherence in High Resolution Spectroscopy.
• 3.1 Coherent Phenomena in Resonant Processes.
• 3.2 Coherent Phenomena in Saturated Absorption Spectroscopy.
• 3.2.1 Standing Wave.
• 3.2.2 Probe Wave Resonances.
• Oppositely Traveling Waves.
• Unidirectional Waves.
• High-Frequency Stark Effect on Doppler Broadened Transitions.
• Spectroscopic Applications. Measurement of Relaxation Constants.
• Study of Level Structures and Separation of Weak Lines.
• Optical Instability. Generation Stability.
• Recoil Effect.
• 3.2.3 Influence of Collisions on Coherent Processes.
• Study of Relaxation Processes.
• Dipole Scattering.
• Influence of the Elastic Scattering Without Phase Randomization on Resonance Characteristics.
• 3.3 Coherent Phenomena in Multilevel Systems.
• 3.3.1 Resonant Processes in Three-Level Systems.
• 3.3.2 Two-Photon Resonances.
• 3.3.3 Relation to Other Phenomena.
• 3.4 Method of Separated Optical Fields.
• 3.4.1 Two-Photon Resonance in Separated Fields.
• Narrow Two-Photon Absorption Resonances of the Sequence of Supershort Pulses in a Gas.
• 3.4.2 Resonance in Separated Fields for Two-Level Atoms.
• 3.4.3 Coherent Radiation and Macroscopic Polarization Transfer in Separated Fields.
• 3.4.4 Properties of Coherent Radiation in Separated Fields.
• Destruction of an Interference Structure and Attainment of Resonances with a Radiative Width.
• Particle Scattering.
• 3.4.5 Coherent Raman Scattering in Separated Fields.
• 3.4.6 Transient Resonant Coherent Effects.
• 4. Multiphoton Resonant Processes in Atoms.
• 4.1 Various Experimental Aspects of Resonant Multiphoton Transitions in Atoms.
• 4.1.1 Selective Pumping of an Excited Level with Multiphoton Transition.
• 4.1.2 Intermediate Step in Other Processes.
• 4.1.3 Spectroscopy Using Broadband Lasers.
• 4.2 Doppler-Free Two-Photon Experiments.
• 4.2.1 Principle of Doppler-Free Multiphoton Transitions.
• 4.2.2 Experimental Observation of Doppler-Free Two-Photon Transitions.
• Typical Experiment in Sodium.
• Thermoionic Detection.
• 4.2.3 Doppler-Free Two-Photon Transitions in Hydrogen.
• 4.2.4 Other Possibilities of Doppler-Free Two-Photon Transitions.
• 4.2.5 Experiments with Two Different Light Sources.
• 4.3 Theory of Two-Photon Transitions in Atoms.
• 4.3.1 The Effective Hamiltonian.
• 4.3.2 Solution of the Density Matrix Equation.
• 4.3.3 Case of Two Waves with Complex Polarizations.
• 4.3.4 Two-Photon Line Shape in Vapors.
• 4.3.5 Light Shifts.
• Comparison with Experiments.
• 4.3.6 Selection Rules for Two-Photon Transitions.
• 4.4 Multiphoton Transitions.
• 4.4.1 Generalization of the Effective Hamiltonian.
• 4.4.2 Discussion of the Light Shifts.
• Case of a Standing Wave.
• 4.4.3 Application to Multiphoton Ionization.
• 4.4.4 Doppler-Free Three-Photon Transition.
• 4.4.5 Three-Photon Selection Rules.
• 4.5 Dispersion Near a Two-Photon Resonance.
• 4.5.1 Refractive Index for a Travelling Wave.
• 4.5.2 Refractive Indices for Two Waves of Different Frequencies.
• 4.5.3 Refractive Index for a Standing Wave.
• 4.6 Transient Processes Involving Doppler-Free Two-Photon Excitation.
• 4.6.1 Free Induction Transients.
• 4.6.2 Transients in the Driven Regime.
• 5. Coherent Excitation of Multilevel Systems by Laser Light.
• 5.1 Multilevel Molecular Systems.
• 5.1.1 The Schrödinger Equation for Multilevel Systems in the Rotating-Wave Approximation.
• 5.1.2 “Quasi-Energy” or “Dressed-States” Approach for Multilevel Systems.
• Constant Optical Electric Field.
• Adiabatic Switching on of the Field.
• 5.2 Interaction of Equidistant Nondegenerate Multilevel Systems with a Quasi-Resonant Field.
• 5.2.1 Analytical Solutions for an Exactly Resonant Field.
• Harmonic Oscillator.
• Infinite System with Equal Dipole Moments.
• A System with Decreasing Dipole Moments.
• N-Level System with Equal Dipole Moments.
• 5.2.2 Does Resonance Always Result in Effective Excitation?.
• 5.2.3 Nonexact Resonance and Its Compensation by Power Broadening.
• Step-Function Laser Pulse.
• Adiabatically Switched-On Pulse.
• General Estimates for Maximum Detuning.
• 5.3 Interaction of Nonequidistant Multilevel Systems with a Quasi-Resonant Field.
• 5.3.1 Multiphoton Resonances.
• Rabi Frequency for Multiphoton Transitions.
• 5.3.2 Numerical Calculations for Multilevel Systems.
• 5.3.3 Dynamic Stark Effect and Frequency Shifts.
• An Analytically Solvable Example.
• General Approach to an Approximate Description of the Dynamics of Oscillator-Type Systems.
• Upper Subsystem — Harmonic Oscillator.
• Upper Subsystem with Equal Dipole Moments.
• 5.3.4 “Leakage” from the Lower Quantum States into the Upper Levels.
• 5.3.5 Excitation of Multiplet Systems with a Quasi-Continuous Structure of Transitions.
• 5.4 Excitation of Triply-Degenerate Vibrational Modes of Spherical-Top Molecules.
• 5.4.1 Vibrational States and Vibrational Hamiltonian.
• Expression of the Hamiltonian in Terms of Cartesian Creation and Annihilation Operators.
• Orders of Magnitude of Anharmonic Operators.
• Final Form of the Vibrational Hamiltonian.
• Comparison with Hecht’s Hamiltonian.
• The Spherical Vibrational Basis.
• Eigenvalues of the Vibrational Hamiltonian.
• 5.4.2 Physical Significance of Vibrational Anharmonic Parameters.
• 5.4.3 Rotational States and Vibration-Rotation Bases.
• Rigid-Rotor Wave Functions.
• Coupled Vibration-Rotation Basis.
• Symmetry-Adapted Vibration-Rotation Basis.
• 5.4.4 Vibration-Rotation Hamiltonian.
• 5.4.5 Dipole Transition Moments in Spherical-Top Molecules.
• 5.4.6 Experimental Determination of the Anharmonic Parameters of the v3 Mode of SF6.
• Effective-State Models for Molecular Multiphoton Calculations.
• Absorption Strength of an Ensemble of Two-Level Systems.
• Effective-State Equations of Motion.
• Dipole Transition Moments Between Effective States.
• Calculation of Degeneracies and Transition Strengths.
• 5.4.8 Calculation of Multiphoton Excitation Including a Thermal Distribution of Initial State.
• 5.4.9 Numerical Calculations of Multiphoton Excitation of SF6.
• 6. Coherent Picosecond Interactions.
• 6.1 Overview.
• 6.2 Theory of Investigations.
• 6.2.1 Excitation Process.
• 6.2.2 Coherent Probing.
• 6.3 Experimental.
• 6.3.1 Generation of Ultrashort Laser Pulses.
• 6.3.2 Coherent Excitation and Probing Techniques.
• 6.4 Experimental Results and Discussion.
• 6.4.1 Modes with Homogeneous Line Broadening.
• 6.4.2 Modes with Discrete Substructure.
• 6.4.3 Modes with Inhomogeneous Line Broadening.
• 6.4.4 Vibrational Modes in Solids.
• 6.5 Interaction Processes.
• 7. Coherent Raman Spectroscopy.
• 7.1 Historical Background.
• 7.1.1 Prehistory.
• 7.1.2 The Tunable Laser Era.
• 7.2 Theory.
• 7.2.1 Extended Two-Level Model for Coherent Raman Spectroscopy.
• 7.2.2 The Nonlinear Polarization.
• Stimulated Raman Gain and Loss Spectroscopy, and the Raman Induced Kerr Effect.
• Coherent Anti-Stokes and Coherent Stokes Raman Spectroscopy.
• Four-Wave Mixing.
• Photoacoustic Raman Spectroscopy.
• 7.2.3 The Nonlinear Susceptibility Tensor.
• 7.2.4 Doppler Broadening.
• 7.2.5 Symmetry Considerations.
• 7.2.6 Relationship Between xR and the Spontaneous Cross Section.
• 7.2.7 The Coherent Raman Signal.
• 7.2.8 Focusing Considerations.
• 7.2.9 Accentric Crystals and Polaritons.
• 7.2.10 Resonant Effects and Absorbing Samples.
• 7.3 Experimental Techniques.
• 7.3.1 CARS in Liquids and Solids.
• 7.3.2 CARS in Gases: Pulsed Laser Techniques.
• 7.3.3 Multiplex CARS.
• 7.3.4 CW CARS.
• 7.3.5 Nonlinear Ellipsometry.
• 7.3.6 Raman Induced Kerr Effect Spectroscopy (RIKES).
• 7.3.7 Optical Heterodyne Detected RIKES.
• 7.3.8 Stimulated Raman Gain and Loss Spectroscopy.
• 7.3.9 Four-Wave Mixing.
• 7.3.10 Signals, Noise and Sensitivity.
• 7.3.11 Signal Enhancement with Interferometers, Intra-Cavity Techniques and Multipass Cells.
• 7.4 Applications.
• 7.4.1 Combustion Diagnostics: Concentration and Temperature Measurement.
• 7.4.2 Raman Cross Section and Nonlinear Susceptibility Measurements.
• 7.4.3 High-Resolution Molecular Spectroscopy.
• 7.4.4 Raman Spectra of Fluorescent and Resonant Samples.
• 7.4.5 Polariton Dispersion: Spectroscopy in Momentum Space.
• 7.4.6 Low Frequency Modes.
• 7.4.7 Vibrational and Rotational Relaxation Measurements.
• 7.5 Conclusions.
• Additional References with Titles.