Modified optical bistability in two-photon absorption

The effect of level degeneracy of the absorbing atoms on the transmission characteristic of a ring cavity is examined within the mean field approximation. Using a single-mode input field, the possibility of realising a form of tristable behaviour is discussed.     

Stability conditions for two-photon optical bistability in a ring cavity

A stability analysis in the good-cavity and mean-field limits, of two-photon optical bistability arising when two beams at different frequencies interact with a nonlinear medium in a ring cavity, is presented. Another metastable state has been found to occur in the double-absorption case in certain circumstances, and the system may be described as exhibiting a form of tristability.     

On nonclassical effects in two-photon optical bistability and two-photon laser

We analyse the fluctuations at steady state in the good quality cavity case in two-photon lasers with running wave and two-photon absorptive optical bistability in a ring cavity. In the case of two-photon laser we do not find any nonclassical effect, contrary to expectations. On the other hand, in two-photon optical bistability we find squeezing and antibunching in the low transmission branch. The maximum reduction of fluctuations that can be obtained is slightly larger than by a factor of two.     

Double-beam two-photon optical bistability in a Fabry-Perot cavity with polar molecules

Optical bistability in a micrometre-sized Fabry-Perot cavity, filled with appropriate polar molecules, is analysed after two incident beams (with frequenciesgw ₁ andgw ₂) produce in the system a two-photon resonance at frequencygw ₁ +gw ₂. One-photon resonances at the frequenciesgw ₁ andgw ₂ are discarded. It was not necessary to assume a particular relationship betweengw ₁ andgw ₂, and the single-beam two-photon optical bistability whengw ₁ andgw ₂ are of the same order or equal is emphasized.     

Effects of two-photon optical bistability upon phase conjugation

We have investigated phase conjugation by degenerate four-wave mixing, in circumstances where optical bistability can occur by two-photon resonant interaction. The solutions of the probe equation coupled with the two-photon equation of state have been obtained and studied. The two-photon phase-conjugated reflectivity is shown to exhibit multistability as well as hysteresis.     

Propagation of two optical beams in a two-photon resonant medium

Propagation of two-copropagating or counterpropagating beams is considered in a slab of nonlinear dielectric which is in two-photon resonance with respect to the sum of the laser frequencies. The effects of saturated absorption and dispersion of the beam intensities are studied in detail. The slab transmission is shown to be significantly affected by the induced optical Stark-shift.     

Observation of thermal-induced optical guiding and bistability in a mid-IR continuous-wave, singly resonant optical parametric oscillator

We report the observation of thermal-induced optical guiding and bistability in a mid-IR cw, singly resonant optical parametric oscillator (SRO) at approximately 3.2 microm. The SRO employs a MgO:PPLN crystal as the gain medium and a 1-nm-linewidth Yb-fiber laser at 1.064 microm as the pump source. As soon as the pump power reaches the thermal guiding threshold at 16.5 W, the SRO shows a step increase in the parametric efficiency by a factor of 2.5. At 25 W pump power, the SRO generated 5.3 and 1.2 W at 1.58 and 3.23 microm, respectively, with single-longitudinal-mode performance for the 3.23 microm radiation.     

Dichroic bistability caused by the resonant optical orientation of impurity centers

A new optical bistability mechanism for impure cubic crystals in a cavity, the dichroic bistability (DB), is suggested and illustrated by a concrete example. DB is due to the self-induced dichroism that accompanies the nonlinear resonant impurity absorption. The bistability is manifested both in the intensity and in the polarization direction of the radiation passing the ring cavity that contains the crystal.     

富勒烯分子的光学双稳性

本文采用非线性法布里-珀罗腔的全光光学方法,在C_(60)/C_(70)薄膜中首次观测到双稳开关现象,其开关时间为10ns.     

Cavityless optical bistability in a thin semiconductor film upon the resonant excitation of excitons and biexcitons

The bistable properties of a thin semiconductor film under conditions of resonant excitation of coherent excitons and biexcitons by photons in one or two different pulses are studied theoretically. Fiz. Tverd. Tela (St. Petersburg) 40, 932–933 (May 1998)     

Controllable optical bistability in a three-mode optomechanical system with a membrane resonator

We study the optical bistability(OB) in a three-mode cavity optomechanical system, where an oscillating membrane of perfect reflection is inserted between two fixed mirrors of partial transmission. By investigating the behavior of steady state solutions, we find that the left and right cavities will exhibit the bistable behavior simultaneously in this optomechanical system by adjusting the left and right coupling fields. In addition, one can control the OB threshold and the width of the OB curve via adjusting the coupling strength, the detuning, and the decay rate. Moreover, we further illustrate the OB appearing in the cavity by the effective potential as a function of the position.     

Controlling the optical bistability and multistability in a two-level pumped-probe system

We study the behavior of the optical bistability (OB) and multistability (OM) in a two-level pumped-probe atomic system by means of a unidirectional ring cavity. We show that the optical bistability in a two-level atomic system can be controlled by adjusting the intensity of the pump field and the detuning between two fields. We find that applying the pumping field decreases the threshold of the optical bistability.     

Phase-dependent optical bistability and multistability in a semiconductor quantum well system

We theoretically investigate the hybrid absorptive-dispersive optical bistability and multistability in a four-level inverted-Y quantum well system inside a unidirectional ring cavity. We find that the coupling field, the pumping field as well as the cycling field can affect the optical bistability and multistability dramatically, which can be used to manipulate efficiently the threshold intensity and the hysteresis loop. The effects of the relative phase and the electronic cooperation parameter on the OB and OM are also studied. Our study is much more practical than its atomic counterpart due to its flexible design and the wide adjustable parameters. Thus, it may provide some new possibilities for technological applications in optoelectronics and solid-state quantum information science.     

S-shaped current bistability in a bipolar resonant tunneling diode

The bipolar tunneling transport through p–i–n double barrier structures has been studied by means of simultaneous electrical transport measurements and electroluminescence spectroscopy. An “inverted” hysteresis loop is observed at the onset of the first electronic resonance in the current–voltage characteristics with an electrical ON/OFF ratio of more than two orders of magnitude. Relating the different branches of the current–voltage characteristic to the space charges accumulated throughout the structure the inverted hysteresis loop is interpreted in terms of an S-shaped current bistability. The S-shaped current bistability is similar to the current driven negative differential resistivity as known for instance from thyristor action. This analogy between the bipolar double barrier structure with alloyed n-type emitter and the thyristor will be briefly discussed.     

Current bistability in resonant tunneling through a semiconductor quantum dot

We discuss resonant tunneling through quantum dot energy levels considering the charging energy of the dot. The hamiltonian of the system is reduced to a form of the Anderson hamiltonian of resonant tunneling. The mean-field approximation is applied and current–voltage characteristics are evaluated. The self-consistent solution is investigated for the low tunneling rate case in the low-temperature condition. The current bistability and the related current hysteresis are pointed out. The Coulomb staircase is shown in the current–voltage characteristics. These features are all due to Coulomb repulsion within the dot.     

Features of the optical bistability in an exciton-biexciton system

The role of exciton-exciton, exciton-biexciton, and biexciton-biexciton interactions in the nonlinear transmission function of a ring cavity is studied. It is shown that transmission functions both without hysteresis and with one or two hysteresis loops can be obtained by taking into account the elastic interparticle interactions in the exciton-biexciton system. Fiz. Tverd. Tela (St. Petersburg) 40, 927–928 (May 1998)     

Generalised semiclassical formalism for two-photon resonant problems

A general formalism suitable for the semiclassical treatment of many two-photon resonant problems is presented, and the method demonstrated for the specific examples of two-photon self-induced transparency, and third harmonic generation in the cw case.