Phase-shift controlling of three solitons in dispersion-decreasing fibers

Nonlinear Dynamics - Phase-shift controlling can attenuate the interactions between solitons and gives practical advantage in optical communication systems. For the variable-coefficient nonlinear...     

Exact solitons,periodic peakons and compactons in an optical soliton model

Nonlinear Dynamics - To study the properties of one-dimensional spatial solitons in thermal nonlocal media, we investigate the dynamical behaviour and bifurcation of solutions of the planar systems...     

Interaction properties of double-hump solitons in the dispersion decreasing fiber

Nonlinear Dynamics - In this paper, the high-order coupled variable coefficient nonlinear Schrödinger equations is studied. The double-hump soliton solutions for the equations are obtained...     

Effective amplification of optical solitons in high power transmission systems

Nonlinear Dynamics - We study the effective amplification of optical solitons in high power transmission systems based on a nonlinear Schrödinger equation with variable coefficients. Three...     

光纤陀螺光路小型化技术

介绍了光纤陀螺基本工作原理，描述了光纤陀螺小型化的意义。分别论述了基于光学器件小型化、光学集成技术、三轴光学器件共用技术实现光纤陀螺光路小型化的技术途径及可能效果，指出了三轴共用探测器技术可能存在的问题。研究成果对促进光纤陀螺的应用、光纤陀螺的实用化具有重要意义。     

Stable transmission characteristics of double-hump solitons for the coupled Manakov equations in fiber lasers

Nonlinear Dynamics - The prime concern of this study is to simulate the joint effect for the presence of two fractional derivative parameters (memory indices) by providing a novel analytical...     

Bright optical spatial solitons in photorefractive waveguides having both the linear and quadratic electro-optic effect

Propagation characteristics of bright solitons are studied in a photorefractive waveguide having both the linear and quadratic electro-optic effect under the paraxial and Wentzel–Kramers–Brillouin–Jeffreys approximation. The planar waveguide structure enhances the self-focusing while reducing the minimum or threshold power required for self trapping. The waveguide structure embedded in the crystal can self trap a soliton of much lower power, which otherwise would not have formed without the presence of the waveguiding. As the waveguide parameter increases, minimum required power to self trap the beam decreases. Four distinct regions of power are identified and the dynamical evolution of the solitons in these power regions is demonstrated. In addition, the dynamical evolution of the solitons is demonstrated for different waveguide strength parameter. The existence of bistable states is also predicted.     

Measurement of residual internal stresses in optical fiber preforms

A non-destructive experimental procedure is presented which enables the determination of residual thermal stresses in optical fiber preforms. The procedure is based on integrated photoelasticity. We carry out the measurement of the optical retardation using the traditional Sénarmont compensation method combined with a fringe shifting technique. The radial distribution of the axial stress is reconstructed using Abel transform. We have investigated two different refractive-index profiles, adopted in the realization of monomode and multimode optical fibers. It was shown that in both cases the results obtained experimentally and those analytically predicted by the Timoshenko elastic model were in good agreement. To obtain accurate experimental results, it was necessary to apply a correction procedure to take into account the fact that the trafectories of the light rays inside the preforms are not straight lines.     

Solitary wave interactions and reshaping in coupled systems

The interaction of the components of composite solitary waves governed by nonlinear coupled equations is studied numerically. It is shown how predictions of the known exact traveling wave solutions may help in understanding and explaining the process of reshaping seen as head-on and take-over collisions of individual solitary waves. The most interesting results concern the switch in the sign or the periodic modulation of the amplitude of the solitary wave and the direction of its propagation due to collisions.     

Measurement of flame temperature by optical fiber thermometer

The characteristics of an optical fiber thermometer (OFT) having a black body cavity sensor, constructed with a thin platinum film sputtered on a sapphire rod tip, were examined and compared with those of bare or sheathed thermocouples. For time averaged temperature measurements by the OFT, the radiative heat loss is significant in the temperature range of flames. For fluctuating temperatures the OFT output has a slow response, due to its thermal inertia, which depends on the diameter of the sensor and flow conditions; in spite this the rapid response of the OFT is emphasized in the literature with the assumption of the ideal thermal behavior of the thin sputtered film ( 4 m) on a sapphire rod of 0.25 mm diameter. The fluctuation waveform predicted by the present numerical simulation agrees satisfactorily with the measured one, which proves that the major factor affecting the thermal inertia of an OFT sensor is the heat capacity of sapphire. A special compensation technique is needed to improve the response of the OFT.     

Nonlinear control for soliton interactions in optical fiber systems

Nonlinear Dynamics - The realization of soliton control and soliton quality balance is one of the key research contents of optical communications. In order to better reflect the nonlinear...     

光纤陀螺热致漂移误差的模糊补偿(英文)

针对光纤陀螺启动过程中的热致漂移误差问题,研究了一种模糊模型补偿方案。依据Shupe非互易性理论和Mohr加热模型试验的结论,以光纤环内侧温度和温度变化率为输入,以陀螺漂移为输出,建立了二输入一输出模糊模型。利用全温范围(-25℃～45℃)内光纤陀螺的恒温静态试验数据,基于自适应神经网络模糊推理系统的自学习功能,辨识出模糊规则库。通过实时施行模糊推理可实现光纤陀螺温度漂移的在线自动补偿。室温验证试验表明,陀螺的零偏稳定性由补偿前的0.037(°)/h提高到0.017(°)/h,陀螺启动时间由补偿前的30 min减少为2 min。     

Dynamics of optical solitons and nonautonomous complex wave solutions to the nonlinear Schrodinger equation with variable coefficients

Variable coefficients nonlinear evolution equations offer us with more real aspects in the inhomogeneities of media and nonuniformities of boundaries than their counter constant coefficients in some real-world problems. Under consideration is a nonlinear variable coefficients Schrödinger’s equation with spatio-temporal dispersion in the Kerr law media. We are aimed at constructing novel solutions to the equation under consideration. Bright and combined dark–bright optical solitons are successfully revealed with aid of the complex amplitude ansatz scheme. Using two test functions, two nonautonomous complex wave solutions in dark and bright optical solitons forms are successfully revealed. The effect of the variable coefficients on the reported results can be clearly seen on the 3-dimensional and contour graphs.

     

空心金属光纤导引原子和Monte-Carlo模拟

在空心金属光纤,首先计算了TE01模的电磁场分布和光强分布。其次以~(85)Rb原子为例,计算了TE01模和~(85)Rb原子相互作用的光学势。研究表明,TE01模在空心金属光纤中集中分布在空心区,沿光纤截面呈环状分布。最后采用Monte-Carlo方法,分别模拟了原子在直空心金属光纤和弯曲空心金属光纤中的直导引效率和弯曲导引效率,相比直导引方案,弯曲导引方案效率明显偏低。空心金属光纤原子导引不仅可用于原子干涉仪研究,采用环形空心金属光纤的原子导引还可用于角速度测量研究。     

Three-dimensional optical solitons formed by the balance between different-order nonlinearities and high-order dispersion/diffraction in parity-time symmetric potentials

Nonlinear Dynamics - Under parity-time symmetric potentials, different-order nonlinearities such as cubic, quintic and septimal nonlinearities, altogether with their combinations and second-order...     

Collisions,mutual losses and annihilation of pulses in a modular nonlinear medium

Nonlinear Dynamics - One of the most important sections of nonlinear wave theory is related to the collisions of single pulses. These often exhibit corpuscular properties. For example, it is well...