【作者】 谭勇；

【导师】 张喜和；

【作者基本信息】 长春理工大学 ， 光学， 2013， 博士

【摘要】 三阶非线性效应包括自相位调制、交叉相位调制、四波混频、受激拉曼散射和受激布里渊散射等,已经被广泛地研究和应用在高速、全光纤网络中。但是,实际应用的光纤总处于外界干扰或某种特定环境中,理想条件下的这些三阶非线性效应受到了挑战。本文针对外压力、熔接光纤和多种光纤差异,研究诱导三阶非线性现象。主要分为以下三部分：1.采用在光纤横截面上施加单向静压力和改变抽运光偏振条件的方法,对光纤中的受激拉曼散射、四波混频和连续谱等诱导非线性进行实验研究,获得了低压力下渐变多模光纤中Raman频移和FWHM减小,但是较高压力下Raman频移和FWHM反弹或增大；线偏振抽运光的频移对称,0～180°和180～360。相差的椭圆偏振抽运光的频移不对称,且后者的频移在三种压力下纠缠在一起的结果；观察到了不同压力下标准单模光纤中受激拉曼、四波混频和连续谱随着偏振条件相互竞争的现象。2.采用非零色散位移单模光纤和标准单模光纤熔接的方法,对两种光纤的熔接点影响非线性效应和光束模式进行了实验研究,获得了非零色散位移光纤中随着四波混频的出现并逐渐增强,受激拉曼散射光斑模式由LPol模转变为LP11模,光束经过非零色散位移光纤和标准单模光纤的熔接段后,光波模式演变为LP01模,四波混频光谱减弱并消失,非线性光谱以受激拉曼散射光谱为主的结果。3.利用飞秒脉冲激光在标准单模光纤和保偏单模光纤中传输,对强激光激励的非线性光谱进行了实验研究,获得了飞秒脉冲在标准单模光纤中传输,频率发生了红移和蓝移,主要是诱导拉曼效应引起的红移,飞秒脉冲在保偏光纤中传输时,也发生了红移和蓝移,但主要是因自相位调制引起的蓝移。本文的研究内容有助于开发新的光纤传感器、有助于光孤子通信的发展和应用。更多还原

【Abstract】 The third-order nonlinear effects, including self-phase modulation, cross-phase modulation, four-wave mixing, stimulated Raman scattering and stimulated Brillouin scattering, etc., have been extensively studied and applied in the high-speed, all-fiber network. However, the practical application of the total fiber in the outside interference or a certain environment, these third-order nonlinear effects under ideal conditions has been challenged.In this paper, for the external pressure, splice optical fiber, and a variety of optical fiber differences, the third-order nonlinear phenomena induced are researched. The following three parts are spread out:1.By changing low static pressure and pumping light polarization conditions in the optical fiber, nonlinear phenomena induced are studied in this paper, including the stimulated Raman scattering, four-wave mixing and continuous spectrum.First, changing the direction of linearly polarized pump light or the phase of elliptically polarized pump light and exerting the external pressure on the graded-index multimode fiber, the shift and full width at half maxium of stimulated Raman scattering spectra are researched, the probability of the anti-Stokes light is observed. In addition, under the same the pumping light conditions and external pressure conditions, stimulated Raman scattering, four-wave mixing and continuous spectrum phenomenon are studied in standard single-mode fiber.2. Two kind of fiber splice point is studied how to affect the non-linear effects and beam mode.With the emergence and increasment of four-wave mixing, stimulated Raman scattering spot mode changes from LP01mode to LP11mode in non-zero dispersion shifted fiber. After the beam passes through the splice segment of non-zero dispersion shifted fiber and standard single-mode fiber, LP11mode is evolved into the LP01mode again, the four-wave mixing weakens and disappears, the stimulated Raman scattering holds major intensity.3. The nonlinear spectroscopy is studied by femtosecond pulsed pump light in a standard single-mode fiber and a polarization maintaining single-mode fiber respevtively, because of several nonlinear effects above-mentioned, their transmission spectra are different.The frequency of femtosecond pulse occur the red shift and blue shift, mainly redshift in standard single-mode, but mainly blue shift in standard single-mode fiber.In this paper, these researches will contribute to the development of new fiber-optic sensor and the development and application of optical soliton communication.更多还原