Table of contents

The intensity of spontaneous emission by atoms or molecules in a stationary state in contact with a thermal bath at temperature T, is derived up to the fourth-order approximation in electronic charge. The perturbative treatment of the intensity of the stationary spontaneous emission is shown to be valid only if the relaxation rate is much larger than w, the rate of spontaneous emission. A specific model gives the stationary spontaneous emission intensity for all values of and w.

We present the theory of a micromaser operating on a cascade three-level atomic transition, which is coupled to two cavity modes satisfying the resonance condition. A numerical approach is employed to integrate the master equation describing the microwave field, allowing us to obtain the semiclassical regime in the limit of large mean photon numbers. We show that the transfer rate from the excited atomic state is very close to 100% over a large interval of variation of the interaction time. The atom - field interaction time may be chosen so as to avoid transitions to the intermediate atomic state when in steady-state operation. In this case, the two cavity modes have nearly the same photon statistics, and the fluctuations in the difference of intensities may be reduced by up to 50% below the classical limit. The intensity correlation between the two cavity modes originates from the possibility of controlling the interaction time, rather than from the simultaneous generation of `twin' photons in a two-photon transition.

We study the resonant interaction of A initially unexcited two-level atoms with single-mode Fock, coherent and thermal cavity fields of arbitrary intensity. Two mechanisms lead to a spread of the eigenfrequencies: one is due to the photon-number distribution in the initial state and the other reflects the cooperativity of the system. Both affect the evolution of the photon number and photon statistics. We present approximate expressions for the eigenvalues and eigenvectors of the system. Its regular dynamical regions are found and the difference in shape of the collapses and revivals connected with the above mechanisms is discussed.

Relaxation-oscillation (RO) phenomena in a semiconductor diode laser with external optical injection are studied. We extend the concept of `locked dynamics' to include excited ROs. A two-variable scalar function W is constructed, from which the `slow' (transient) dynamics of the RO can be derived as well as an earlier published `potential' model. The function W is used to investigate bifurcations of the RO dynamics in the locking region. The location of the Hopf and the period-doubling bifurcations are in good, respectively fair, agreement with numerical simulations. A bistability is recovered and the dependence on the linewidth enhancement parameter (`the -parameter') is studied.

The two peaks of the vacuum Rabi splitting behave like simple harmonic oscillators for very weak excitation. The transmission spectrum of a cavity filled with two-level atoms shows this doublet at low values of the driving intensity, but only a single peak at high values. The evolution from a doublet to a singlet is governed by the anharmonic response of the system as the driving intensity increases. The anharmonicity can grow to a point where frequency hysteresis appears in the transmission spectrum. This work investigates theoretically with a semiclassical model the transition from the doublet into the singlet. The stability of the different solutions is analysed as the parameters of atomic and cavity detuning vary. The model is extended to include the experimentally relevant transverse profile of the cavity mode as well as the standing wave structure of the field.

We study theoretically the quantized motion of previously cooled atoms in a one-dimensional magneto-optical potential under coherent population trapping (CPT) conditions. We consider atoms with a transition interacting with a lin lin laser field and a static uniform magnetic field in the high-intensity limit. It is shown that if the Rabi frequency is greater than the Zeeman splitting, Doppler shift, natural width and detuning, then atoms are captured in the long-lived CPT state while the excited-state population is small. We do not take into account the incoherent photon scattering and describe the atomic motion by the Schrödinger equation. The oscillation frequency, oscillation damping time and localization size are obtained for atoms moving near the bottom of potential wells in a harmonic approximation. Narrowing of the vibrational spectral lines due to the CPT effect is predicted.

For every real state with photon-number distribution , a virtual state with distribution can be constructed and called a shadow state because it cannot stand by itself. The real state mixed with its shadow state is called a shaded state. This is a systematic way to construct nonclassical states.

The introduction of shadow states makes it much easier to identify, or to isolate, the origin of the nonclassical effects in shaded states. The usefulness of this concept is illustrated by several examples.

Time-dependent analytical solutions for the -system, including detuning of the probe laser, are given. This provides a useful tool for solving various problems in lasing without inversion and electromagnetically induced transparency.

We examine the eight-port homodyne detector when there is a vacuum at two of the input ports. It can then be described as a generalized measurement on the other two fields. We derive the class of two-field operators whose statistics can be deduced from the measurement for different choices of beamsplitters.

Classically eight- and twelve-port homodyne detectors can be used to measure the Stokes parameters of a two-mode field simultaneously. We analyse these schemes in the quantum case as approximate or noisy joint measurements of the noncommuting Stokes operators. The statistics of the measurement are described in terms of these operators and noise. The twelve-port detector is also examined as allowing a noisy simultaneous measurement of the quadratures and intensity of a one-mode field. The vectors governing the statistics of the measurement are found. A simple procedure for obtaining the Wigner function emerges.

We examine the propagation of a pair of electromagnetic pulses through a medium in the adiabatic passage regime in the case of unequal oscillator strengths of two optical transitions in an atom. It is shown that light waves propagating in a nonlinear medium under such conditions are not shape-preserving. We demonstrate that a front sharpening occurs in this case.

The phase properties of states generated by excitations on a coherent state have been studied by evaluating the expression for the phase probability distribution, using the recent formalism of Pegg and Barnett in which the existence of a Hermitian optical phase operator has been shown. This distribution has been further used to evaluate the variance of the phase operator and the number - phase uncertainty product.

Two-photon optical bistability under the influence of transverse effects is considered near the onset of bistability in the weakly dispersive limit. A reduced-field equation of the Swift - Hohenberg type is then obtained, showing the equivalence between two-photon and the usual one-photon optical bistability in the considered limits.

Using the weakly nonlinear theory, we analyse the stability and relative stability of transverse patterns appearing in a passive Kerr cavity. We show that the hexagonal H0 structures are stable in the vicinity of the Turing bifurcation point. Numerical simulations confirm the analytical predictions.

Several methods for eavesdropping on the standard four coherent-state quantum cryptosystem together with a possible countermeasure are analysed and found to place a limit on the tolerable energy disadvantage of the users as compared to the eavesdropper. The possible significant role of the photon-number amplifier and the photon-number duplicator is indicated.

We propose a method to produce superpositions of displaced Fock states via the driven Jaynes - Cummings model. We introduce the dressed-atom representation of the driven Jaynes - Cummings model to investigate the evolution of the state of the system. When the cavity field is in an initial coherent state ( is the amplitude of the classical driving field and g is the coupling constant between the atom and the cavity field), the evolution of the state of the system is similar to the vacuum Rabi oscillation of the normal Jaynes - Cummings model. After a period of interaction, the superposition of displaced Fock states of the cavity field can be generated by a state-selective measurement on the atom.

The effect of detuning on the probe absorption spectra of a two-level system in a squeezed vacuum is investigated, with and without the presence of a classically driven field. For strong squeezing, there is a threshold depending on the squeeze parameter M, which determines the positions and widths of the absorption peaks. For large detunings, the spectra exhibit a close resemblance to Fano spectra and for small detunings there is probe gain. We show that there are marked differences in the spectra between a minimum uncertainty squeezed vacuum and a field state with the maximum classical two-photon correlations . Observation of these features would confirm the essentially quantum-mechanical nature of the squeezed vacuum.

As mentioned in the preface: `This book is a collection of many of the most recent developments in photorefractive effects and materials'. The readers, who, according to the title, would expect to find a broad coverage of the field will be somewhat disappointed. A more appropriate title of this volume would be: `Recent Developments in Photorefractive Effects and Materials'. Within this scope, the book is excellent. The first chapter introduces, briefly but in a very comprehensive manner, the basic mechanisms of photorefractivity and the optical principles that govern wave mixing in these materials. Each of the other chapters covers a selected hot topic and was written by a renowned scientist in the field. Concerning the subject of photorefractive materials, the topics include the recent improvements on by oxide doping and the newly investigated and developed bulk and quantum well semiconductor photorefractive crystals, as well as amorphous photorefractive polymers. With respect to the photorefractive effects, the author discusses the subjects of permanently fixed gratings and spatial solitons.

This book was written for specialists in both optics and condensed matter physics. Since the development of the photorefractive science and technology strongly relies on expertise from both fields, the author made specific efforts in order to provide up-to-date information, in a comprehensive approach for the two groups. This book mainly reports the advancement of photorefractive science, but little was done to discuss the potential applications of these materials and techniques. Therefore, this book is for those interested in the latest developments of this particular field on nonlinear optics, or those involved in the development of photorefractive effects and materials.

In order to complete this review of the important topics in this field, I would have appreciated a chapter on the double phase conjugate mirror which is both of practical interest and still, to some extent, a puzzle for theoreticians. The non-steady-state photoelectromotive force is also a subject that deserves a place in this book.

About this edition, the book is well written and contains pertinent figures and sketches that complete the text. An author index would however have been useful and appreciated.