共查询到17条相似文献,搜索用时 406 毫秒
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《原子与分子物理学报》2015,(5)
在准连续情况下,通过求解低双折射光纤中含有拉曼效应的右旋与左旋圆偏振光所满足的耦合非线性薛定谔方程,得到了归一化功率以及相位差的解析解.利用解析解,推导出了椭圆率和方位角的表达式,研究了拉曼效应和传输距离对偏振态演化的影响,并用相平面法对椭圆率和方位角随着输入功率的变化进行了直观描述.结果表明:低双折射光纤在传输的过程中,拉曼效应和传输距离都是影响其偏振态稳定性的因素,均改变了椭圆率和方位角的演变周期以及振荡幅度. 相似文献
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在准连续情况下, 通过求解低双折射光纤中含有拉曼效应的右旋与左旋圆偏振光所满足的耦合非线性薛定谔方程,着重研究了低输入功率和高输入功率情形在加入拉曼效应前后, 有效偏振拍长和输入功率的变化关系. 结果表明: 无论入射光的偏振是沿着慢轴或沿着快轴, 拉曼效应均改变了入射光偏振态演变的周期, 同时改变了入射光的传输距离. 相似文献
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在准连续情况下,通过求解低双折射光纤中含有拉曼效应的右旋与左旋圆偏振光所满足的耦合非线性薛定谔方程,着重研究了低输入功率和高输入功率情形在加入拉曼效应前后,有效偏振拍长和输入功率的变化关系.结果表明:无论入射光的偏振是沿着慢轴或沿着快轴,拉曼效应均改变了入射光偏振态演变的周期,同时改变了入射光的传输距离. 相似文献
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通过高双折射光纤中非线性耦合模传输方程,首先,利用斯托克斯参量,用庞加莱球研究分析了耦合模传输的稳定性及偏振态的演变,结果表明高双折射光纤中耦合模的传输不产生分歧现象,传输具有稳定性;其次,描述了拉曼效应对各种状态下偏振态演变规律的影响,给出了斯托克斯参量S1,S2与S3的解析解及拉曼效应对偏振态的演变周期的影响. 相似文献
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基于Sagnac原理的单轴分布式光纤传感系统偏振态分析 总被引:1,自引:8,他引:1
针对Sagnac干涉型单轴分布式光纤传感器中使用单模光纤作为传感器件时,由于传输光偏振态在双折射影响下所带来的干涉信号“偏振诱导衰落”问题,运用琼斯矩阵分析法,建立了该型传感器系统在传感光纤双折射和外部事件共同作用下,传输光的偏振态对系统功率传输系数影响的数学模型;仿真分析了在传感光纤线性双折射和圆双折射共同作用下,传输光的偏振态对系统功率传输系数的影响;提出了使用法拉第旋转镜提高系统抗偏振能力的改进方法.仿真结果表明,该方法能很好地消除光纤线性双折射和圆双折射. 相似文献
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Numerical solutions are obtained of the full self-consistent system of equations for the counter, rotating polarization components of the field of a short optical pulse propagating in a nonlinear birefringent fiber and in the ensemble of the energy-level degenerate doped resonance atoms implanted in the fiber material. In every cross section of the fiber, the ellipticity of the polarized wave experiences a complex evolution in time accompanied by rapid changes of the azimuthal angle due to the interplay of the dispersion and the Kerr nonlinear self-and cross-phase modulation. The reciprocal effect of the impurities on the traveling pulse causes oscillations of the pulse envelope that can completely distort the shape of the input signal, while the resonance absorption can drive the birefringence process from the nonlinear regime back to the linear one. 相似文献
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采用延迟器与旋光器的串联模型, 研究磁场中双折射光纤的偏振传输特性, 将它们的琼斯矩阵按照两种不同的顺序级联相乘, 导出了两种等效模型中等效相位延迟量、等效快轴方向和等效旋光角的解析表达式。研究发现, 当光纤同时具有线双折射和圆双折射时, 单位长度的等效相位延迟量并不等于其固有的线双折射, 等效旋光角也不等于其法拉第旋转角, 它们同时都与光纤的固有线双折射和磁场引起的圆双折射相关联。且在不同级联顺序的两种等效模型中, 等效相位延迟器的快轴方向都不与光纤的双折射主轴重合, 而是分别向两个相反的方向偏移一定的角度, 偏移角为等效旋光角的一半。 相似文献
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By considering the cross phase modulation (XPM) between the two orthogonal poparization components,the nonlinear birefringence and nonlinear polarization evolution (NPE) in highly-nonlinear fiber (HNLF),as well as the unequal evolutions of the state of polarization (SOP) between the clockwise (CW) and counter-clockwise (CCW) waves in a nonlinear amplifying loop mirror (NALM) are analyzed. It is pointed out that the traditional cosine expression is no longer valid for the power transmission of NALM due to uncompleted interference under the high power condition. The analytical expression considering NPE effect is derived, and the experimental result is presented. 相似文献
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The polarization transform errors of two-waveplate polarization state transformers (TWPST), which consist of quarter-waveplate (QWP) and half-waveplate (HWP), are discussed in detail. The error model of the TWPST based on a new and simple two dimensions geometry method instead of traditional Poincaré sphere method or Jones matrix method are proposed. We did the numerical calculations based on the error model of the TWPST. The results show that the output polarization state errors of the TWPST are chiefly sensitive to the azimuth angle errors of the QWP, and that there exist a pair of optimal error azimuth angles of QWP and HWP, which can minimize the azimuth angle error of the output polarization state of TWPST, and that the ellipticity error of output polarization state of TWPST is dependent only on the azimuth angle errors of QWP. The TWPST have enough accuracy to evaluate the polarization related effects (PRE) in the optical communication systems. 相似文献
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Polarization decorrelation in single-mode fibers with randomly varying elliptical birefringence is studied. It is found that the effects of ellipticity on the polarization decorrelation length depend on the relative sizes of the beat length and the autocorrelation length of the birefringence fluctuations in the fiber. However, the evolution of the differential group delay remains unaffected by ellipticity. 相似文献
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A linear transformation of orthogonal polarization modes in coiled optical spun-fibers with strong unperturbed linear birefringence, which causes the emergence of the dependences of the integrated elliptical birefringence and the ellipticity and azimuth of the major axis of the ellipse, as well as the polarization state of radiation (PSR), on the length of optical fiber has been considered. Optical spun-fibers are subjected to a strong mechanical twisting, which is frozen into the structure of the optical fiber upon cooling, in the process of being drawn out from the workpiece. Since the values of the local polarization parameters of coiled spunwaveguides vary according to a rather complex law, the calculations were carried out by numerical modeling of the parameters of the Jones matrices. Since the rotation speed of the axes of the birefringence is constant on a relatively short segment of a coiled optical spun-fiber in the accompanying torsion (helical) coordinate system, the so-called “Ginzburg helical polarization modes” (GHPMs)—two mutually orthogonal ellipses with the opposite directions of traversal, the axis of which rotate relative to the fixed coordinate system uniformly and unidirectionally—are approximately the local normal polarization modes of such optical fiber. It has been shown that, despite the fact that the unperturbed linear birefringence of the spun-fibers significantly exceeds the linear birefringence, which is caused by the winding on a coil, the integral birefringence of an extended segment of such a fiber coincides in order of magnitude with the linear birefringence, which is caused by the winding on the coil, and the integral polarization modes tend asymptotically to circular ones. It has been also shown that the values of the circular birefringence of twisted single-mode fibers, which were calculated in a nonrotating and torsion helical coordinate systems, differ significantly. It has been shown that the polarization phenomena occur in the process of linear transformation of local polarization modes, which lead to small quasi-harmonic oscillations of the birefringence integral parameters of the optical spun-fibers, which depend on their length, and the period of these oscillations is approximately equal to half of the effective period of polarization beating. 相似文献