共查询到20条相似文献,搜索用时 31 毫秒
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In this work, we investigate the optical solitons to the non-linear Shrödinger’s equation with spatio-temporal dispersion. There are two types of non-linear media studied in this paper. They are Kerr law and parabolic law. By adopting a complex amplitude ansatz method composed of the addition of bright and dark optical solitons, we present the exact dark, bright and dark-bright or combined optical solitons to the model. Numerical results and discussions are also presented. 相似文献
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N. Iqbal 《Journal of Modern Optics》2013,60(17):1419-1426
The article focuses on an approach to overcome the dispersion present in optical communication systems. The group velocity dispersion (GVD) remains an important issue in this context. The approach presented in this paper is based on the use of chiral nihility mediums with different chirality parameters in dual-core planar optical waveguide. It is found that the two cores can be resonantly coupled in the guide, and also, the waveguide would yield high GVD by choosing suitable design parameters. For the analytical investigation, transfer matrix method is used and the dispersion relation is derived by implementing appropriate boundary conditions. Excitation of supermodes in the guide may be achieved through the coupling of two particular core modes, which would ultimately result in giant GVD. This essentially demonstrates that the structure may find applications in dispersion compensating systems. 相似文献
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综合介绍了近年国外关于低衰耗的色散补偿光纤,非零色散位移光纤,用于恶劣环境的碳涂覆和氮化硅涂覆光纤的研究;光纤带制造技术包括光纤带的结构、涂层、性能、生产工艺,大芯数光纤带状光缆包括层绞式松管、中心松管式、骨架式、干缆芯带状光缆的设计制造技术的最新进展。 相似文献
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Michelle Savescu A.H. Bhrawy A.A. Alshaery E.M. Hilal Kaisar R. Khan M.F. Mahmood 《Journal of Modern Optics》2013,60(5):441-458
This paper addresses solitons in nonlinear directional couplers in non-Kerr law media, with spatio-temporal dispersion. Both twin-core couplers as well as multiple-core couplers are studied. The nonlinearities studied are Kerr law, power law, parabolic law, dual-power law and log law. Bright, dark and singular soliton solutions of the governing equation are studied. 相似文献
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In this work, combined optical solitons are constructed in a weakly nonlocal nonlinear medium. The spatio-temporal dispersion (STD), parabolic law nonlinearity, detuning, nonlinear dispersion as well as inter-modal dispersion are taken into account. The integration tool that is applied is the complex envelope function ansatz. The influences of different parameters on dynamical behavior of combined optical solitons are discussed. The results are useful in describing the propagation of combined optical solitons with STD and parabolic law nonlinearity. 相似文献
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Waters KR Hughes MS Mobley J Miller JG 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2003,50(1):68-76
Differential forms of the Kramers-Kronig dispersion relations provide an alternative to the integral Kramers-Kronig dispersion relations for comparison with finite-bandwidth experimental data. The differential forms of the Kramers-Kronig relations are developed in the context of tempered distributions. Results are illustrated for media with attenuation obeying an arbitrary frequency power law (/spl alpha/(/spl omega/) = /spl alpha//sub 0/ + /spl alpha//sub 1/ |/spl omega/|/sup y/). Dispersion predictions using the differential dispersion relations are compared to the measured dispersion for a series of specimens (two polymers, an egg yolk, and two liquids) exhibiting attenuation obeying a frequency power law (1.00 /spl les/ y /spl les/ 1.99), with very good agreement found. For this form of ultrasonic attenuation, the differential Kramers-Kronig dispersion prediction is found to be identical to the (integral) Kramers-Kronig dispersion prediction. 相似文献
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Spatial diversity as an effective technique to mitigate the turbulence fading has been widely utilized in free space optical (FSO) communication systems. The received signals, however, will suffer from channel correlation due to insufficient spacing between component antennas. In this paper, the new expressions of the channel correlation coefficient and specifically its components (the large- and small-scale channel correlation coefficients) for a plane wave with aperture effects are derived for horizontal link in moderate-to-strong turbulence, using a non-Kolmogorov spectrum that has a generalized power law in the range of 3–4 instead of the fixed classical Kolmogorov power law of 11/3. And then the influence of power law variations on the channel correlation coefficient and its components are analysed. The numerical results indicated that various value of the power law lead to varying effects on the channel correlation coefficient and its components. This work will help with the further investigation on the fading correlation in spatial diversity systems. 相似文献
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Rafael G. González-Acuña Julio C. Gutiérrez-Vega Michelle C. Rocha 《Journal of Modern Optics》2020,67(13):1170-1175
An analytical closed-form equation to design a freeform element that replicates an axicon is presented. In this paper, we get the mentioned analytical closed-form equation step by step. The equation comes from applying both the Fermat principle and the Snell's law at the first refractive surface. This Freeform axicon with azimuthal variation can be applied to produce annular conical beams with the possibility to receive wavefronts not necessarily collimated. In the paper, we test the equation in several scenarios to test the design of the Freeform axicon and the results of the performance of the Freeform axicon were as expected. 相似文献
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利用后置补偿法对10-Gbit/s长距离波分复用光纤传输系统进行色散均衡 总被引:2,自引:0,他引:2
通过系统仿真,对以常规单模光纤和色散补偿光纤(SMF+DCF)组成的16×10-Gb/s WDM色散补偿系统进行了分析,调制器啁啾为0,激光器静态线宽为5MHz.结果表明:(1)对于数百公里的传输距离,以DCF进行在线补偿就可以使各个信息达到较好的色散补偿效果(16×10-Gb/s,400km,眼图代价差别小于0.5dB);(2)由于SPM在SMF光纤中对脉冲的压缩效应,每一信道应保持略微偏正的残留色散量;(3)对于上千公里的传输距离,仅以DCF进行在线补偿无法同时均衡所有信道的色散(16×10-Gb/s, 1200km,眼图代价差别大于0.85dB).为此,本文以SMF或DCF在系统接收端再次对各信道逐个进行色散补偿(后置色散补偿),达到了良好的效果(16×10-Gb/s, 1200km, 眼图代价差别小于0.3dB). 相似文献
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Summary This paper discusses the propagation of plane body waves through a second-gradient micropolar elastic continuum. In an accompanying paper, this macroscopic constitutive law has been derived from the micro-level particle characteristics, which are the inter-particle stiffness, the particle size and the package density. As a result of incorporating the micro-scale effects, the body waves propagate in a dispersive manner, where dispersion becomes more prominent when the wavelength of the generated body waves reaches the order of magnitude of the particle size. After successively deriving the equations of motion and the dispersion relations for plane body wave propagation, the compressional wave properties for the second-gradient micro-polar model are compared to those for the Born-Karman lattice structure. Furthermore, distinguished features of the second-gradient micro-polar model are exhibited by comparing the dispersion relations of the coupled propagation of the shear wave and the micro-rotational wave with those of more simple constitutive models. The paper ends with a parameter study, where the effect by the translational particle contact stiffness and the rotational particle contact stiffness is examined. 相似文献
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I. V. Bondarenko S. N. Balashov A. Cimmino P. Geltenbort A. I. Frank P. Hoghoj A. G. Klein S. V. Masalovich V. G. Nosov 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2000,440(3):591-596
A Gravity Spectrometer for ultra-cold neutrons (UCN) using neutron interference filters has been designed and tested. An energy resolution of the order of 6.5 neV was obtained which is good enough for performing a number of neutron-optical experiments proposed in an earlier paper. Experimental tests of the UCN dispersion law are currently in progress. 相似文献
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The virtually-imaged phased array (VIPA) is a side-entrance etalon with potential application as a high-resolution spectral disperser for wavelength division multiplexing. Here we present an approximate analytical spectral dispersion law for the VIPA, which we confirm experimentally. 相似文献
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Summary This contribution is one in a series of two papers. In the current paper a constitutive law is developed that includes the micro-structural effects by particle displacement as well as particle rotation. Both degrees of freedom can be related to corresponding macroscopic kinematic continuum variables, where the resulting gradients of displacement are selected up to the fourth-order and the gradients of rotation up to the third order. The elastic micro-structural properties for an individual particle are used to derive the macro-level behavior for a fabric of equal-sized spherical particles, leading to a second-gradient micro-polar formulation. In this model, all coefficients are expressed in terms of particle stiffness and particle structure. It is shown that the second-gradient micro-polar model can be reduced to simpler forms, such as the classic linear elastic model, the second-gradient model and the Cosserat model. In the accompanying paper these reduced forms are treated in more detail by analyzing the corresponding dispersion relations for plane body wave propagation. 相似文献
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In this paper, the wave propagation and transient response of an infinite functionally graded plate under a point impact load are presented. The effective material properties of functionally graded materials (FGMs) for the plate are assumed to vary continuously through the plate thickness and be distributed according to a volume fraction power law along the plate thickness. Based on the higher-order shear deformation theory and considering the effect of the rotary inertia, the governing equations of the wave propagation in the functionally graded plate are derived by using the Hamilton’s principle. The analytic dispersion relation of the functionally graded plate is obtained by means of integral transforms and a complete discussion of dispersion for the functionally graded plate is given. Then, using the dispersion relation and integral transforms, exact integral solutions for the functionally graded plate under a point impact load are obtained. The transient response curves of the functionally graded plates are plotted and the influence of volume fraction distributions on transient response of functionally graded plates is analyzed. Finally, the solutions of the higher-order shear deformation theory and the first-order shear deformation theory are studied. 相似文献
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法拉第激光器是一种利用法拉第反常色散原子滤光器作为选频元件的新型外腔半导体激光器,原理上法拉第激光的输出波长随着激光二极管驱动电流及工作温度的变化,始终与原子跃迁谱线相对应,可以将激光频率有效地锁定至原子跃迁谱线,实现窄线宽的激光输出信号,并且短期与长期频率稳定性均较好。本文详细介绍了自1845年法拉第旋光效应提出以来,法拉第反常色散原子滤光器的发展历程,法拉第激光器的工作机理、发展历程以及性能优越性,并结合国内外的研究进展,介绍了法拉第激光发展各个阶段的技术瓶颈及相应的解决办法,同时展望了法拉第激光器未来在量子领域特别是量子精密测量领域的重要价值。 相似文献