1. Nonlinear transfer theory of coherent or completly noncoherent scattering. It is well known that due to an interaction of the strong radiation field with a medium the local optical properties of the medium depend on the state of the radiation field. At RTSL a strong radiation field reduces due to the high excitation of atoms and as a result, the absorption capacity of the medium decreases (in a series of the ground state) and the effects of stimulated absorption begin to play a role (negative absorption). Then the transfer equation becomes nonlinear. Nonlinear transfer problems (NLTP) are of great importance not only in astrophysics, but also in the theory of quantum optical generators. Until the 1960s the analytical theory of NLTP was absent. Although in that period the physics of local interaction of the strong radiation field was well known. In 1963 the creation of the nonlinear theory of RTSL was undertaken by Academician V. Ambartsumian and his followers. The investigations were carried out in two basic directions: a) application of the principle of invariance (PI) of Ambartsumian to NLTP; b) development and creation of the method of self-consistent optical depths (SCOD). The basic results due to the method of SCOD were obtained. The idea of this method, which was suggested by V. Ambartsumian in 1964, was based on the possibility of exact linearization of NLTP in a homogeneous plane layer by means
Nonlinear transfer theory of coherent or completly noncoherent scattering. It is well known that due to an interaction of the strong radiation field with a medium the local optical properties of the medium depend on the state of the radiation field. At RTSL a strong radiation field reduces due to the high excitation of atoms and as a result, the absorption capacity of the medium decreases (in a series of the ground state) and the effects of stimulated absorption begin to play a role (negative absorption). Then the transfer equation becomes nonlinear. Nonlinear transfer problems (NLTP) are of great importance not only in astrophysics, but also in the theory of quantum optical generators. Until the 1960s the analytical theory of NLTP was absent. Although in that period the physics of local interaction of the strong radiation field was well known. In 1963 the creation of the nonlinear theory of RTSL was undertaken by Academician V. Ambartsumian and his followers. The investigations were carried out in two basic directions: a) application of the principle of invariance (PI) of Ambartsumian to NLTP; b) development and creation of the method of self-consistent optical depths (SCOD). The basic results due to the method of SCOD were obtained. The idea of this method, which was suggested by V. Ambartsumian in 1964, was based on the possibility of exact linearization of NLTP in a homogeneous plane layer by means
An attempt is made to present a consistent detailed theory of optical phenomena, based on the suggestion recently made by the author in collaboration with Bohr and Kramers. This suggestion is that atoms are radiating or absorbing continuously, during their stationary states, and that transitions influence radiation only in terminating the radiation characteristic of the old state, and substituting that of the new. The atoms, on the other hand, are supposed not to change their energy while radiating, but to change it discontinuously on transition. This necessitates giving up the detailed application of the conservation of energy in interaction between atoms and radiation. In the present paper, an additional suggestion is made, namely that resonance radiation is to be identified with the radiation carried out by the spherical wavelets which, by their interference with the external field, also produce absorption. This is practically a return to the classical picture of resonance radiation. Statement of the theory consists formally of two parts: the description of the behavior of atoms, and of radiation, when the two interact. The first involves the statement of the probabilities of transition of atoms, and is taken without change from Einstein. The probability of interruption of coherent vibrations is also discussed. The second requires the specification of the fields emitted by atoms in any steady state under the influence of any external field. These consist of spherical wavelets of the frequencies of the various quantum lines which the atom can emit or absorb in the stationary state in which it is. For emission frequencies, wavelets are emitted even in the absence of an external field; for absorption frequencies, external fields induce wavelets, similar to the wavelets of linearly bound electrons in electron theory, which on the one hand interfere with the external field to produce the phenomena of dispersion, etc., and on the other carry out the resonance radiation in all directions. Detailed descriptions of these fields are given. In a discussion of the theory, it is first shown that the assumptions which have been made about the field satisfy the correspondence principle, in that for large quantum numbers the field aproaches that which would be emitted classically on account of the interaction of an external field and a multiply periodic atom. On the other hand, it is shown that the field has a character essentially like that of classical electron theory, which is known to be in general agreement with experiments. Next, the energy and momentum relations at interaction of atoms and light are investigated, and it is shown that, although these quantities are not precisely conserved, still the assumptions as to atomic and radiation processes have been so made that they are conserved on an average over a great number of atomic processes. Finally the spectral resolution of emitted and absorbed radiation is considered; the theory gives a minimum breadth for the lines, depending on the finite length of wave trains resulting from the finite life in stationary states, and it is shown that Kirchhoff's law is obeyed, the emission and absorption lines being of the same breadth. By way of illustration, specific application of the theory is made to the simple examples of emission of light by bombardment of electrons at the resonance potential, resonance radiation, its quenching by presence of foreign gases, absorption, scattering, and disperison.
The interaction of intense laser fields with matter is accompanied by a multitude of phenomena, ranging from the generation of coherent radiation across various spectral ranges (from terahertz to soft X-rays) to the creation of beams of accelerated charged particles and micromodification of the volume and surface of various samples.To describe this diversity of phenomena, several theoretical approaches have been developed to date.These approaches utilize different approximations to address this complex nonlinear problem, allowing for the explanation of specific aspects of such interactions.The developed theoretical frameworks consider the interaction at both microscopic and macroscopic levels; at the microscopic level, they investigate the characteristics of single atoms interacting with laser fields, while at the macroscopic level, they analyze nonlinear susceptibilities that describe the nonlinear polarization of the medium during the propagation of laser radiation through it.This work presents an overview of methods describing some of the most commonly employed theoretical approaches to model the response of a medium at a microscopic (quantum-mechanical) level, as well as various methods for controlling the properties of generated coherent radiation.A model for the gas medium is described that accounts for both the response characteristics of individual atoms and allows for consideration of phase and quasiphase matching effects during radiation generation.The influence of medium parameters on the efficiency of generation and polarization properties of generated radiation is analyzed under both phase and quasi-phase matching conditions.A detailed description of an analytical method for calculating the nonlinear susceptibility of a gas medium is provided.The obtained values of nonlinear susceptibility for arbitrary orders may be useful in numerical calculations concerning the propagation of laser radiation in matter.Various channels for radiation generation are analyzed as parameters of the laser field are varied.
There has recently been a rapid growth of activity in nonlinear optics. Effects such as frequency doubling, stimulated Raman scattering, phase conjugation and solitons are of great interest both for their fundamental properties and their many important applications in science and engineering. It is mainly these applications - especially in telecommunications and information processing - that have stimulated the recent surge of activity. This book is a self contained account of the most important principles of nonlinear optics. Assuming only a familiarity with basic mathematics, the fundamentals of nonlinear optics are fully developed from basic concepts. The essential quantum mechanical apparatus is introduced and explained. In later chapters the underlying ideas are illustrated by discussing particular experimental configurations and materials. This book will be an invaluable introduction to the field for beginning graduates in physics or engineering, and will provide an excellent overview and reference work for active researchers in the field.
The ancient laws developed by Snell, Bouguer, Lambert, Fresnel, and Beer, describing the reflection, absorption, and transmission of light by a plane slab of absorbing materials, are applicable only at low irradiances. We have developed new laws that apply at irradiances sufficiently high to produce partial optical saturation of the chromophoric atoms, ions, or molecules of the slab. The radiation field is treated in accordance with the characteristic matrix method of Abelès, based upon Maxwell’s equations. The chromophores are treated in accordance with the optical analogs to the Bloch equations, based upon quantum-statistical mechanics. Our results are presented in the form of an algorithm, by means of which the optical properties are initially estimated assuming no saturation. These properties are then used to compute the field intensities within the medium, and these field intensities are employed in the computation of estimates for the saturated properties. Successive iterations of this procedure are used until the calcuated fields and properties are self-consistent. We show for the first time how to calculate the influence of optical saturation upon the reflectance and angle of refraction of an absorbing sample, and how the method of characteristic matrices can be employed in a problem in nonlinear optics. In addition, the effects of the divergence and finite width of the incident beam, of the cell windows, and the interaction of the forward- and backward-traveling waves to produce a spatial variation in the saturation within the sample, are all treated correctly. The results may therefore be of use to those who wish to design a practical optical memory for a computer, using bistable saturable Fabry-Perot interferometers.
W1 Resonant Pulse Propagation I.- W1-1 Some Nonlinear Properties of Pulse Propagation.- W1-2 Self-Induced Transparency in the Broadline and Narrowline Limits and Applications.- W1-3 Observation of Zero-Degree Pulse Propagation in a Resonant Medium.- W1-4 Higher Conservation Laws and Coherent Pulse Propagation.- W2 Quantum Electrodynamics and Alternative Theories I.- W2-1 Survey of the Present Status of Neoclassical Radiation Theory.- W2-2 A Test of Jaynes' Neoclassical Theory: Incoherent Resonance Fluorescence from a Coherently Excited State.- W2-3 Experimental Limitations to the Validity of Semiclassical Radiation Theories.- W2-4 Time Delay Statistics of Photoelectric Emissions: An Experimental Test of Classical Radiation Theory.- W3 Coherence Effects in Spontaneous Emission I.- W3-1 Non-Linear Radiation Reaction.- W3-2 Master Equations in the Theory of Incoherent and Coherent Spontaneous Emission.- W3-3 Influence of Resonant Frequency Shifts on Superradiant Damping.- W3-4 Spontaneous Emission Rate in the Presence of a Mirror.- W4 Coherence I.- W4-1 Atomic Coherent States in Quantum Optics.- W4-2 Coherent States in Modern Physics.- W4-3 Debye Representation and Multipole Expansion of the Quantized Free Electromagnetic Field.- W4-4 Volume of Coherence.- T1 Quantum Electrodynamics and Alternative Theories II.- T1-1 A Quantum Treatment of Spontaneous Emission without Photons.- T1-2 Finite Quantum and Classical Electrodynamics.- T1-3 The Use of Classical Solutions in Quantum Optics.- T1-4 Raman Effect in Semiclassical Theory.- T2 Light Scattering I.- T2-1 Theory of Resonant Light Scattering Processes in Solids.- T2-2 A Generalized Extinction Theorem and Its Role in Scattering Theory.- T2-3 Mode Analysis and Mode Coupling of Electromagnetic Fields in Spatially Dispersive Media.- T2-4 Amplitude Stabilization of Pulses from a Q-Switched Ruby Laser by Means of Interaction with a Non-Linear Medium.- T3 Correlation and Fluctuation Measurements.- T3-1 Two-Photon Time Distributions in Mixed Light Beams.- T3-2 Photocounting Inversion in Presence of Dead Time Effects.- T3-3 Image Reconstruction from the Modulus of the Correlation Function: A Practical Approach to the Phase Problem of Coherence Theory.- T3-4 Photon-Correlation Spectroscopy.- T3-5 Multi-Time Intervals Distributions of Photoelectrons from Stationary Pseudo-Thermal Light with Gaussian Spectrum.- T4 Light Scattering II.- T4-1 Adventures in Green's Land: Light Scattering in Anisotropic Media.- T4-2 Intensity Fluctuation Techniques in Light Scattering.- T4-3 Coherence Properties of Light through a Liquid Crystal.- T4-4 C. Non-Critical Rayleigh Scattering from Pure Liquids.- T5 Coherence Effects in Spontaneous Emission II.- T5-1 Cooperative Effects in Spontaneous Emission.- T5-2 Amplified Spontaneous Emission.- T5-3 Non-Gaussian Statistics of Superradiant Radiation from Saturated Xenon 3.5?m Laser Amplifier.- T5-4 On the Theory of Radiating Electrons.- T6 Coherent Light Interactions.- T6-1 Atomic and Molecular Spectroscopy by Saturation with Coherent Light.- T6-2 Response Functions for Strongly Driven Systems.- T6-3 Mechanism of Interaction of Picosecond Light Pulses with Matter Yielding Self-Trapping.- T6-4 Resonance Fluorescence Lineshapes with Intense Applied Fields.- T6-5 Electron Beams as Carriers of Optical Coherence.- T7 Lasers.- T7-1 Detuned Single Mode Laser and Detailed Balance.- T7-2 Tunable Raman Lasers.- T7-3 Dye Lasers: Recent Advances in Tunable Systems.- F1 Quantum Electrodynamics and Alternative Theories III.- F1-1 A Theory of Light without Photons: Implications from Fermis to Light Years.- F1-2 Blackbody Heat Capacity and Action-at-a-Distance Electrodynamics.- F1-3 The Implications of Radiative Equilibrium in Jaynes' Extension of Semiclassical Radiation Theory.- F1-4 A Quantum Electrodynamic Investigation of the Jaynes-Crisp-Stroud Approach to Spontaneous Emission.- F1-5 Critical Comments on Radiation Theory.- F2 Resonant Pulse Propagation II.- F2-1 Cooperative Phenomena in Resonant Propagation.- F2-2 Theory of Sub-Cooperation-Limit Optical Pulses in Resonant Absorbers.- F2-3 Multiple Pulse Chirping in Self-Induced Transparency.- F2-4 Coupled Superradiance Master Equations: Application to Fluctuations in Coherent Pulse Propagation in Resonant Media.- F3 Coherence II.- F3-1 The Laser-Phase Transition Analogy - Recent Developments.- F3-2 Multiple-Time-Scale Analysis of Coherent Radiation.- F3-3 Orthogonal Operators and Phase Space Distributions in Quantum Optics.- F4 Coherence Effects in Spontaneous Emission III.- F4-1 Radiation by Many Excited Atoms between Mirrors.- F4-2 Transient Coherent Emission.- F4-3 Superradiance from a System of 3-Level Particles.- F4-4 A Quantum Electrodynamic View of Superradiance as a Competition between Stimulated and Spontaneous Atomic Decay.- F5 Post Deadline Session.- F5-1 Third- and Higher-Order Intensity Correlations in Laser Light.- F5-2 Correlation Function of a Laser Beam near Threshold.- F5-3 Localization of Photons.- F5-4 Adiabatic Following and the Self-Defocusing of Light in Rubidium Vapor.- F5-5 Experimental Evidence of an X-Ray Laser.- F5-6 Quantum Theory of Photodetection and Coherence Properties of Electrons.- F5-7 Statistics of Light Scattered by Non-Gaussian Fluctuations.- F6 Quantum Noise.- F6-1 Unified Thermodynamics of Dissipative Structures and Coherence in Nonlinear Optics.- F6-2 The Approach to Thermal Equilibrium in Systems of Coupled Quantum Oscillators Initially in a Generalized Gaussian State.- F6-3 Comparison between Incoherent and Chaotic Sources: Contribution to the Study of the Origin of Bunching Effect.- F6-4 Self-Pulsing in Laser Amplification of Broadband Noise.- Author Index.
The field acting on the atoms in a medium is different from the averaged macroscopic field. The problem of the effective local field caused by dipole–dipole interaction has been discussed several times since Lorentz. In describing the nonlinear optical properties of optically thin resonant layers, it is of principal importance to take into consideration the dipole–dipole interaction of the atoms. These effects manifest themselves when certain relations between the parameters of the atomic system and the incident field are fulfilled. The presence of the excitonic lines shows that the dipole–dipole interaction is larger than the homogeneous and inhomogeneous broadenings. This gives reason to hope that the required inequalities are satisfied in such systems. The chapter considers boundary value problem and a linearly polarized plane wave, with amplitude slowly varying during one optical period, falls perpendicularly onto the surface of a plane-parallel, optically thin, resonant layer consisting of two-level atoms.