Optical data transfer by switching waves in bistable interferometers with a specified optical thickness distribution

The evolution of switching wave fronts in thin-layer bistable Fabry-Perot interferometers with a specified topology of the transverse distribution of the optical thickness of an intermediate layer is studied. The conditions of passage of switching waves through the boundary between regions with different thicknesses and of tunneling of waves through a barrier of a variable thickness and width formed by two such boundaries are determined by numerical modeling. The possibilities of the formation of planar waveguide channels, regions of retardation and acceleration of the motion of switching waves, and points of the splitting and joining of their fronts are demonstrated, as well as the possibility of creating planar structures on this basis that can perform optical logic operations.     

Bistable switching using an optical Tamm cavity with a Kerr medium

All-optical bistable switching is proposed to realize by using an optical Tamm cavity in which a Kerr medium is sandwiched between a metal layer and a Bragg mirror. Results show that the excitation of clockwise and counterclockwise bistable switching under the control of external optical injection is due to the presence of optical Tamm states. In addition, the bistable characteristics of optical Tamm cavities are found to be sensitive to the polarization of external optical injection.     

Optical switching of semiconductor laser amplifiers

The underlying physics of optical switching in bistable diode-laser amplifiers is reviewed. The importance of minimizing the switching energy of optical bistable devices is emphasized. It is shown that conventional diode-laser amplifiers are switched with only thousands of photons in less than a nanosecond. Recent developments in single quantumwell lasers allow switching with total energy (including electronic) less than a picojoule.     

On the integrability aspects of nonparaxial nonlinear Schrödinger equation and the dynamics of solitary waves

The integrability nature of a nonparaxial nonlinear Schrödinger (NNLS) equation, describing the propagation of ultra-broad nonparaxial beams in a planar optical waveguide, is studied by employing the Painlevé singularity structure analysis. Our study shows that the NNLS equation fails to satisfy the Painlevé test. Nevertheless, we construct one bright solitary wave solution for the NNLS equation by using the Hirota's direct method. Also, we numerically demonstrate the stable propagation of the obtained bright solitary waves even in the presence of an external perturbation in a form of white noise. We then numerically investigate the coherent interaction dynamics of two and three bright solitary waves. Our study reveals interesting energy switching among the colliding solitary waves due to the nonparaxiality.     

高阶非线性薛定谔方程的一个新型孤波解

给出了高阶非线性薛定谔方程的一个新型孤波解, 该解描述了满足一定参数条件时光纤中超短光脉冲的传输, 解的表达式可以表示为亮孤子和暗孤子和的形式. 同时利用分步傅里叶方法在一定微扰条件下对脉冲传输进行了数值模拟.     

Polarization Switching Bistability and Dynamics in Vertical-Cavity Surface-Emitting Laser under Orthogonal Optical Injection

Bistability as well as dynamics associated to polarization switching in a vertical-cavity surface-emitting laser (VCSEL) submitted to orthogonal optical injection from an external master laser are investigated. Intensity-polarization switching bistability is studied by increasing and decreasing the intensity of the injected beam and for a fixed frequency detuning, i.e. the frequency offset between master and the free running VCSEL. Depending on the frequency detuning, bistable switching is experimentally found to occur with or without injection locking of the fundamental mode to the master laser frequency. For large positive detuning, injection locking of the first-order transverse mode with a strong depression of the fundamental mode has been observed. The case of frequency – polarization switching bistability, i.e. when the frequency detuning is first decreased and then increased for a fixed injected power, has also been theoretically analyzed. Qualitative comparison with previous experimental work is presented for the dependence of the width of the bistable switching region on the injection strength level. Finally we show an experimental result of complicated dynamics including period doubling route to chaos that accompany polarization switching and which motivates future theoretical investigations.     

Switching dynamics of optical bistable devices

The switching dynamics of optical bistable devices is studied and some recent results are reviewed.     

Numerical studies of the switching of a bistable optical memory

The switching of a bistable optical memory in presence of external noise is discussed.     

Transients in all-optical bistability using transverse optical pumping: Observation of critical slowing down

We report on the transient response of an all-optical bistable device to step-inputs of light. The nonlinear mechanism used for bistable switching relies on transverse optical pumping within the Zeeman sublevels of the sodium ground state. Our measurements demonstrate the crucial role of critical slowing down for switching time. We also find that time-dependent diffusion processes can strongly affect the dynamics of this bistable device. Numerical calculations are shown to yield results in satisfactory agreement with experimental data.     

内含等离子体的Fabry-Perot干涉仪的光学开关和双稳现象

本文理论研究了内含等离子体的Fabry-Perot干涉仪的光学开关和双稳现象。在均匀平面波的近似下得到了表述透射光强是入射激光强度的多值函数。并且给出了双稳态工作方式的临界失谐和开关强度的一般公式。最后还给出了数值实例。 关键词：     

新型驱动原理及低电压反射式双稳胆甾型液晶显示器的实验实现

通过对液晶材料参量、液晶盒结构的优化,本文研制了一种低电压驱动反射式双稳胆甾型液晶显示器.在此基础上提出了一种新型驱动方法,通过首先将液晶显示器所有像素从平面态刷新到焦锥态,可用普通的被动式矩阵驱动器件实现1ms快速驱动,新的驱动方法不存在光学延迟.     

Propagation of a solitary fission wave

Reaction-diffusion phenomena are encountered in an astonishing array of natural systems. Under the right conditions, self stabilizing reaction waves can arise that will propagate at constant velocity. Numerical studies have shown that fission waves of this type are also possible and that they exhibit soliton like properties. Here, we derive the conditions required for a solitary fission wave to propagate at constant velocity. The results place strict conditions on the shapes of the flux, diffusive, and reactive profiles that would be required for such a phenomenon to persist, and this condition would apply to other reaction diffusion phenomena as well. Numerical simulations are used to confirm the results and show that solitary fission waves fall into a bistable class of reaction diffusion phenomena.     

Ultra-Low Threshold Optical Bistability and Multi-Stability in Dielecrtric Slab Doped with Semiconductor Quantum Well

A scheme for switching of the optical bistability (OB) and multi-stability (OM) in a dielectric slab doped with a three-level ladder-configuration n-doped semiconductor quantum well is simulated. It is shown that the bistable behavior of the system in dielectric slab can be controlled via amplitude or relative phase of applied fields. This optical system may provide some new possibilities for test the switching process.     

Modeling of optical devices for the design of multistage interconnection network systems

Guidelines of the modeling of an all-optical architecture is presented. This basic architecture is universal and flexible. It can be used as the switching building block for a number of interconnection networks. The power analysis of an all optical buffering architecture [1] that can be interfaced with such an element is discussed. The modeling analysis is given in terms of the switch model, the multistage model and the power analysis of the optical buffer. The architecture uses bistable optical devices such as Fabry-Perot etalons, SEED and S-SEED. A number of important issues remain to be addressed, such as the use of different nonlinear optical devices, synchronization, and simulation.     

Controllable optical bistability and multistability in asymmetric double quantum wells via spontaneously generated coherence

We investigate the nonlinear optical phenomena of the optical bistability and multistability via spontaneously generated coherence in an asymmetric double quantum well structure coupled by a weak probe field and a controlling field. It is shown that the threshold and hysteresis cycle of the optical bistability can be conveniently controlled only by adjusting the intensity of the SGC or the controlling field. Moreover, switching between optical bistability and multistability can be achieved. These studies may have practical significance for the preparation of optical bistable switching device.     

Manipulating a micro-cantilever between its optomechanical bistable states in a lever-based Fabry-Pérot cavity

In this paper, we demonstrate experimentally switching a cantilever between its optomechanical bistable states in a low finesse optical cavity. Our experiment shows that the deformation of cantilever can be manipulated by tuning the cavity resonance. When the laser power increases across the threshold value of 110 ?W, optomechanical bistability is induced by strong static photothermal backaction at room temperature. Numerical calculation revealed that the bistable effect originates from the multi-well potential created via the optomechanical interaction. Switching of the cantilever between the bistable states was achieved by tuning the cavity to the corresponding boundaries of the bistable region, where the barrier between the bistable states vanishes.     

Incoherent switching between multistable cavity solitons in a semiconductor optical resonator

We demonstrate numerically a two-dimensional threefold storage scheme based on different types of solitary waves in the transmitted field of a semiconductor planar resonator. Switching between among different solitary waves can be achieved by use of a weak incoherent switching beam.     

Competition between modulational instability and switching in optical bistability

We study theoretically and experimentally the switching dynamics of a nonlinear optical bistable system that exhibits modulational instability in the vicinity of its lower limit point. We show that modulational instability induces premature upswitching and, in this way, truncates the bistable cycle. The role of the modulation instability is identified experimentally through the observation of the transient pattern formation that precedes upswitching. Our experiment illustrates the importance of cooperative behavior in practical distributed bistable systems.     

Scaling properties of switching pulses

We investigate analytically the switching process of a bistable system which is described near each limit point by a single ordinary nonlinear differential equation. For a holding beam near the limit point and a rectangular switching pulse, we prove that the requirement of switching imposes a constraint on the pulse area. This results hold for bistability in general and is applied to purely dispersive optical bistability.