Self-pulsing in intrinsic optical bistability with two-level molecules (original) (raw)

Transverse effects and self-pulsing in optical bistability

European Physical Journal B, 1983

We consider the problem of optical bistability in a unidirectional ring cavity with spherical mirrors, with an incident field corresponding to a TEM00 mode. In the framework of the one transverse mode model, we analyze the steady state (both in the absorptive and in the dispersive case), and its stability in the absorptive case. We find that when the radius of the cylindrical atomic sample is much larger than the beam waist, no instability arises in the positive slope parts of the steady state curve. This results suggests that in order to observe self-pulsing in absorptive optical bistability it is necessary to fulfil as closely as possible the plane wave condition.

Multimode instability in optical bistability

Physical Review A, 1989

We compare theoretical predictions and experimental data for the multimode instability of optical bistability, which arises from the coherent dynamics of a system of two-level molecules contained in an optical cavity and driven by an external stationary laser field. Considerable insight into this phenomenon is provided by two "rules of thumb" that govern the behavior of the self-pulsing frequency, and establish its relation with the Rabi frequency of the intracavity field. We describe in detail the experimental apparatus and the main features of the experimental findings. The theoretical results are based on the Maxwell-Bloch equations for a ring cavity in the plane-wave approximation. Despite the crudeness of this model, the numerical data display a satisfactory qualitative agreement with the experimental results. Additional period-doubling and chaotic phenomena, predicted by the theory and not observed in the experiment, are presumably washed out by the longitudinal and radial variation of the electric field in the cavity. nally, in condition (2) one must take into account the power broadening in the atomic line. On the other hand, a MM instability can arise only if the power-broadened atomic linewidth is on the order or larger than the free spectral range; this condition requires a large atomic linewidth and/or a long cavity, and is not satisfied in the standard homogeneously broadened alloptical systems which meet the conditions for the twolevel-system description. This feature makes it very difficult to observe experimentally MM instabilities which arise from the interplay of different longitudinal modes, unless one uses a hybrid system which includes a delay line. ' Single-mode and multimode instabilities are linked by precise correspondence principles demonstrated in Ref. 17, which provides a fundamental justification of the socalled "weak-sideband approach, " that is often used in the interpretation and discussion of optical instabilities. ' This approach ascribes the rise of the instability to the gain experienced by the various modes, which 39 703

An organizing center for optical bistability and self-pulsing

Zeitschrift f�r Physik B Condensed Matter, 1983

The problem of self-pulsing in optically bistable systems is discussed within the framework of imperfect bifurcation theory. The joint appearance of a hysteresis cycle in the cw-transmission curve and of transitions to self-pulsing is described as an interaction between steady-state and Hopf bifurcations induced by varying the incident field intensity. The bifurcation equations for the most degenerate case are shown to be determined by a corank-two and codimension-four polynomial normal form. This form can be extracted from analytical and numerical studies on the Maxwell-Bloch equations, and acts as an organizing center for bistable switching and the self-pulsing mechanism. The structurally stable unfolded bifurcation diagrams are analyzed. Besides describing correctly and in a comprehensive way all bifurcations to self-pulsing that have so far been observed, a number of new generic transitions are predicted. These include self-pulsing from the low transmission branch and transitions leading to the formation of islands with self-pulsing behavior.

Optical bistability in lasers induced by active molecules with a large permanent dipole moment

Physical Review A, 2002

We study a single-mode laser system, whose active medium consists of molecules with a large difference between excited and ground electrical permanent-dipole moments. In this case, the Maxwell-Bloch equations are further coupled by nonlinear terms involving the ratio between this difference between the dipoles and the transition dipole moment. It is found that these new terms lead to multiple stationary solutions. From the linear stability analysis, we demonstrate the bistable ͑or multistable͒ character of the lasing solutions.

Quantum analysis of optical bistability and spectrum of fluctuations

Optics Letters, 1978

We discuss the approach to equilibrium and the fluctuations of a bistable system under dynamical conditions such that the field variables can be eliminated adiabatically. The atomic system evolves under the action of the coherent pumping of an external field and of collective and incoherent relaxation processes. The competition between pumping and relaxation effects causes the atomic steady-state configurations to depend discontinuously on the strength of the driving field. We derive an explicit expression for the spectrum of the forward-scattered light, which exhibits hysteresis and a discontinuous dependence on the driving-field amplitude.

Dynamical nonlinear optics and bistability

Applied Physics B Photophysics and Laser Chemistry, 1982

When the Rydberg atoms are prepared in the upper level of a transition resonant with the cavity mode, they amplify the Nackbody radiation at the corresponding frequency, and, above a given threshold, emit a transient maser pulse. We have conted the number n of atoms transferred by this process at time t following the laser pumping pulse in the lower level of the maser transition. We experimentally determine the probability P(n, t) of finding n atoms transferred at time t, n being of course equal to the number of photons in the field at that time. For t short enough, the P(n, t) law is found to be an exponentially decaying function of n, a distribution typical of an amplified blackbody radiation field. At longer times t, the distribution changes its shape and becomes a bell-shaped function centered around a n4;0 value, which is characteristic of a coherent emission. The observed probability laws are in very fair agreement with the theoretical ones [2].

Optical bistability via quantum interference from incoherent pumping and spontaneous emission

Journal of Luminescence, 2011

We theoretically investigate the optical bistability (OB) in a V-type three-level atomic system confined in a unidirectional ring cavity via incoherent pumping field. It is shown that the threshold of optical bistability can be controlled by the rate of an incoherent pumping field and by interference mechanism arising from the spontaneous emission and incoherent pumping field. We demonstrate that the optical bistability converts to optical multi-stability (OM) by the quantum interference mechanism.