Type Of Optical Bistability Research Articles

Optical bistability in electromagnetically induced grating

Abstract We explore a new type of optical bistability (OB) based on electromagnetically induced grating (EIG) and discuss the factors that affect the instability of this system. The stability of each branch of the solution is analyzed.

Structural dependence of optical bistability of In 0.52Al 0.48As/InP type II MQW diodes grown by gas source molecular beam epitaxy

The structural dependence of optical bistability was studied for the In 0.52Al 0.48As/InP type II multiple quantum well diodes grown by gas source molecular beam epitaxy. Two types of optical bistability were observed. One of them shows a sudden increase of light output with increasing injection current, while the other shows a sudden decrease of light output with increasing injection current. The former is considered to be induced by holes tunneling in the valence band, while the latter is considered to be induced by the resonant tunneling effect of electrons in the conduction band.

Dynamic transmission properties of a nonlinear fiber ring resonator

We present a method for calculating the dynamic input–output characteristics of a nonlinear fiber ring resonator caused by a change in input intensity. It is based on an original method developed by Bischofberger and Shen [Phys. Rev. A 19, 1169 (1979)] to study a transient nonlinear Fabry–Perot resonator. We treat a double-coupler fiber ring resonator, in which two types of optical bistability (transmission bistability and reflection bistability) are available and present the illustrative numerical results for a few cavity parameters. This analysis will be useful for a future experimental verification of optical bistability in fiber ring resonators and for the design of fiber bistable devices.

Two-photon optical bistability in polar molecules: vibrational coupling effects

Single-beam two-photon optical bistability in a two-level system where the levels have unequal electric dipole moments is analyzed theoretically. By means of unitary transformations the system is transformed into a two-level nonpolar system with a field-dependent effective transition dipole moment. Two-photon optical bistability is found to be favored as the difference between the dipole moments grows. When the excited electronic system is coupled to a vibrational normal mode of the nuclei, the susceptibility becomes three-valued and consequently a different type of optical bistability appears, which can coexists with the previous one.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Possibility of intrinsic optical (far-IR) bistability in an asymmetric double quantum well

A new type of optical bistability in a double quantum well is predicted. This is a pure intrinsic bistability which is not accompanied by any dc current in an external circuit and requires no source of electric energy. The effect is based on counterfield electron transfer and is driven and controlled by far-IR radiation resonant to an intersubband transition. Bistable switching and hysteresis can be monitored either electrically or optically. Theory shows the effect to be readily observable.

Phonon effects on optical bistability in a two-photon resonant absorber

Single beam two-photon optical bistability in a Fabry-Perot cavity is analyzed taking into account phonon effects. The Maxwell-Bloch equations of the system are further coupled by a term that is dependent on the electron-phonon interaction. It is shown that such an interaction can lead to a new type of optical bistability which competes with the ordinary absorptive one.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Effect of Optical Feedback on Self‐Induced Change of Light Polarization in Cubic Crystals with Directions Instable for Polarization

AbstractPolarization optical bistability (POB) in crystals with FA‐centers mounted into a Fabry‐Perrot cavity is analysed. This type of optical bistability is caused by amplification of fluctuations of light polarization in crystals under consideration and has no threshold on radiation intensity. The range of parameters is found for impure crystals and cavity under POB conditions.

Optical bistability in II–VI compounds

This paper reviews the different types of optical bistability in II–VI semiconductor compounds with particular emphasis on experimental results obtained in CdHgTe, CdTe and ZnSe. Results of optical bistability in an entirely molecular beam deposited ZnSe filter are presented for the first time.

Dynamics of various types of optical bistability and recent results on a CdS-SEED

We summarize photo-electronic and photothermal optical bistability observed in CdS. Then we present new results obtained wiht a CdS-SEED and briefly discuss their possible applications.

Dichroic optical bistability in a nonlinear Fabry–Perot interferometer

It is shown that a new type of optical bistability may occur in a Fabry–Perot resonator containing a nongyrotropic cubic crystal. This instability is due to an anisotropy of the nonlinear resonance absorption in the crystal. The explicit conditions for the establishment of dichroic optical bistability are determined for cases of two-photon absorption and resonance absorption by reorientable impurity centers.

Three types of electronic optical bistabilities in CdS

The authors investigate optical bistability in CdS, induced by photo-electronic non-linearities. Varying the photon energy and the temperature of the sample they find three different types of optical bistability. The switching times are always around 1 ns or below, notably 300 ps for dispersive optical bistability. Optical bistability by bleaching of absorption at room temperature shows a contrast ratio of about 50 between the two stable branches. The dependence on various parameters, including the microscopic foundations, is discussed experimentally as well as theoretically.

Optical bistability in semiconductors induced by thermal effects

We investigate thermally induced optical bistability (OB) in semiconductors using a cw-Argon-ion-laser beam pulsed by an electro-optic modulator. We obtain different types of OB due to absorptive and refractive changes with switching times in the order of ms. The different processes are modeled using a simple rate equation for the lattice temperature. Good agreement between theoretical predictions and the measurements are clearly to be seen.

Soliton in a ring cavity

The behaviour of short pulses in a ring-like optical cavity with external pumping and an internal absorptive nonlinear cell is investigated in the mean field approximation. The boundary conditions are approximated by perturbation of the evolution equations. A new type of optical bistability, the bistable dependence of the amplitude of the soliton upon the amplitude of the pumping field due to nonlinear perturbation is described.

Optical Nonlinearities and Instabilities in Semiconductors

The main mechanisms for the observed large optical nonlinearities in semiconductors are briefly discussed and illustrated for the example of the exciton ionization by plasma screening. These nonlinearities cause various types of optical bistability, either of intrinsic nature or evoked by an additional resonator feedback. Under certain operation conditions also higher instabilities such as oscillations and chaos can be obtained. As an example, the self-pulsing of an induced absorber in a ring cavity is treated. The resulting locked oscillations are shown to follow a Farey-tree scenarium.

Demonstration of optical bistability with intensity-coupled high gain lasers

Competition between external beam amplification and normal laser action is shown to result in a new type of optical bistability in high gain lasers. With one dye laser in a delayed self-extinction configuration, periodic pulsations are observed, showing the alternation of two quasi-stable states. With a twin dye laser configuration, only one laser at a time could be above threshold due to their mutual coupling. Switching with subnanosecond rise time has been obtained in a purely optical way.

Optical bistability with symmetry breaking

It is shown that a simple system without a cavity exhibits optical bistability with no hysteresis but with symmetry-breaking or pitchfork bifurcation. The optical system is composed of a cell containing atoms with spin in the ground state, a $\frac{\ensuremath{\lambda}}{8}$ plate and a mirror, and an incident light beam linearly polarized and nearly resonant with the atomic absorption line. The system has a positive-feedback loop for the rotation of polarization through competitive optical pumping by ${\ensuremath{\sigma}}_{\ifmmode\pm\else\textpm\fi{}}$ circularly polarized components. When the intensity of the incident light exceeds a critical value, symmetry breaking occurs and its polarization is subject to rotation in the clockwise or anticlockwise sense. Correspondingly, atomic spin polarization is produced spontaneously in a direction parallel or antiparallel to the incident beam. This new type of optical bistability is found to be explained well in context with the cusp catastrophe, as well as the ordinary one with hysteresis. It is also found that, in the presence of a transverse magnetic field, self-sustained spin precession occurs, which results in the steady-state modulation of the light polarization at about the Larmor frequency. Experimental evidence of the symmetry breaking and pitchfork bifurcation is obtained by using sodium vapor.

Resonatorless Optical Bistability Based on Increasing Nonlinear Absorption

AbstractA new type of optical bistability is presented. Instead of a resonator the intrinsic feedback between the optical excitation of carriers and their recombination is used. Optical bistability appears, if the absorption coefficient increases with growing carrier density. Both propagation effects and carrier diffusion are considered. Analytical model calculations are carried out for an abrupt behaviour of the absorption coefficient. The results explain the hysteresis in the transmittivity of CdS, recently observed.