共查询到18条相似文献,搜索用时 46 毫秒
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为了精确地测量旋光效应中偏振光的旋光角度及其分布,提出了基于偏振分束成像的旋光角度场测量新方法。分析和推理论证了旋光角度场测量理论基础,设计构建了光电检测验证系统,即根据偏振光分束原理,借助于高清晰度CCD采集图像,由计算机对图像进行中值滤波和基于奇异值的匹配处理,再采用“差除和”信号处理以消除光源波动的影响,得到检测结果。实验结果表明,与传统的测量方法相比,该方法不受光源波动的影响,能精确、快速地检测旋光角度二维分布场,并具有很好的线性,数据的均方差仅为传统测量方法的40%。 相似文献
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光谱调制偏振测量技术是一种新型的偏振调制技术,通过由消色差/4波片、多级相位延迟器和偏振器组成的调制模块,能够把入射光的偏振信息调制到光波的光谱维上,得到线偏振度和线偏振角呈规律变化的正弦曲线。设计解调算法对偏振调制后的光谱进行解调,可以得到目标不同波长处的线偏振度、线偏振角、光谱及辐射信息。文中阐述了光谱调制偏振测量技术的基本原理,给出具体实现方案。设计解调算法,搭建实验平台并进行实验验证。实验结果表明该技术的正确性及实际应用的可行性。相对于传统的偏振调制方案,该方案无运动、电控部件,具有体积小、重量轻的优点,一次测量即可得到目标的偏振信息,而不是测得Stokes矢量后再经进一步计算。本研究为新型空间偏振探测遥感器的开发提供一种新的技术途径。 相似文献
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反射光偏振特性分析与物体形状的测量 总被引:2,自引:0,他引:2
基于反射光偏振特性,提出了利用图像处理技术测量透明物体三维形状的理论和方法.分析了物体表面反射光的偏振特性,表明自然光在经透明物体表面反射后,反射率随光的振动方向不同而不同,即反射光表现出部分偏振光的特性.研究了强度反射率与入射角以及光强与偏振片方向之间的函数关系,得到了光强大小与入射面方向的关系;根据偏振度概念并结合菲涅耳公式和折射定律,建立了偏振度和入射角之间的表达式,可求得物体表面法线方向,进而得到透明物体的形状.研制了光学实验平台,获得了物体反射光的偏振图像,经过图像处理,获得了被测物体的三维形状.实验结果表明,这种方法对透明物体形状测量是有效和实用的. 相似文献
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提出了一种基于可调偏振度源的偏振定标方法,利用方法完成了基于偏振光谱强度调制(PSIM)技术偏振光谱仪的线偏振光偏振度测量结果定标校正。以可调偏振度源输出的不同偏振度的线偏振光作为待测光源,用PSIM偏振光谱仪测量待测光源输出得到原始数据。将原始数据解析处理得到的偏振度谱与待测光源输出的理论偏振度谱进行线性拟合,得到校正系数。利用该校正系数对PSIM偏振光谱仪的测量处理结果进行定标校正。结果表明:在有效测量波段内(500~650nm),定标校正后PSIM偏振光谱仪的线偏振度测量解析精度明显提高,与待测光源输出的标准偏振度值间的最大误差由0.017减小到约为0.003,基于可调偏振度源的偏振定标校正方法具有可行性。 相似文献
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《光学技术》2013,(5):477-480
提出了一种基于双CCD的滚转角测量方法。测量系统包括两部分:移动部分由通过连接杆连接的两个CCD组成,连接杆固接在被测物上;固定部分包括光源、光开关和两个光学准直器,可以得到两路分别以一定角度相交入射到两个CCD上的准直光束。被测物发生滚转变化时,两CCD也同步变化,通过投射在其上的两个光斑位置变化,可求解出滚转角变化。MATLAB仿真证明被测物的各平动变化对滚转角测量无影响,在200″范围内的俯仰和偏摆变化,引起的滚转角测量误差不超过1″。搭建了滚转角测量实验系统,并与HP5529A双频激光干涉仪测量结果进行比对。测量结果表明,在1000″的测量范围内,系统滚转角测量偏差最大不超过1.5″。 相似文献
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External-cavity birefringence feedback effects of microchip Nd:YAG laser and its application in angle measurement 下载免费PDF全文
External-cavity birefringence feedback effects of the microchip Nd:YAG
laser are presented. When a birefringence element is placed in the
external feedback cavity of the laser, two orthogonally polarized
laser beams with a phase difference are output. The phase difference
is twice as large as the phase retardation in the external cavity
along the two orthogonal directions. The variable extra-cavity
birefringence, caused by rotation of the external-cavity
birefringence element, results in tunable phase difference between
the two orthogonally polarized beams. This means that the roll angle
information has been translated to phase difference of two output
laser beams. A theoretical analysis based on the Fabry--Perot cavity
equivalent model and refractive index ellipsoid is presented, which
is in good agreement with the experimental results. This phenomenon
has potential applications for roll angle measurement. 相似文献
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提出将正交互耦1550 nm垂直腔面发射激光器(1550 nm-VCSEL)在优化条件下输出的多路平均功率可比拟、延时特征(TDS)得到有效抑制的混沌信号作为混沌熵源,经8位模数转换器(ADC)量化和最低有效位(m-LSB)后续处理获取多路物理随机数的方案,并研究了系统参量对最终获取的比特序列随机性的影响.首先,基于VCSEL的自旋反转模型分析耦合强度和频率失谐对两个正交互耦合1550 nm-VCSEL输出动力学的影响,初步确定利用该系统产生四路平均功率可比拟、TDS得到抑制的混沌信号所需的耦合强度和频率失谐优化范围;在此基础上,选择一个耦合强度值,利用处于优化范围内的不同频率失谐下获取的四路混沌信号作为熵源,经8位ADC量化和m-LSB后续处理得到最终的比特序列;最后,采用NIST Special Publication800-22统计测试套件对获取的最终比特序列的随机性能进行测试,确定了同时获取四路高质量随机数所需的参数范围. 相似文献
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We presented a novel orthogonally linearly polarized Nd:YVO4 laser. Two pieces of a-cut grown-together composite YVO4/Nd:YVO4 crystals were placed in the resonant cavity with the c-axis of the two crystals orthogonally. The polarization and power performance of the orthogonally polarized laser were investigated. A 26.2-W orthogonally linearly polarized laser was obtained. The power ratio between the two orthogonally polarized lasers was varied with the pump power caused by the polarized mode coupling. The longitudinal modes competition and the corresponding variable optical beats were also observed from the orthogonally polarized laser. We also adjusted the crystals with their c-axis parallele to each other, and a 40.7-W linearly polarized TEM00 laser was obtained, and the beam quality factors were M2x=1.37 and M2y=1.25. 相似文献
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Controlling the contributions to high-order harmonic generation from different nuclei of N_2 with an orthogonally polarized two-color laser field 下载免费PDF全文
The generation of high-order harmonic and the attosecond pulse of the N2 molecule with an orthogonally polarized two-color laser field are investigated by the strong-field Lewenstein model.We show that the control of contributions to high-order harmonic generation(HHG) from different nuclei is realized by properly selecting the relative phase.When the relative phase is chosen to be φ= 0.4π,the contribution to HHG from one nucleus is much more than that from another.Interference between two nuclei can be suppressed greatly; a supercontinuum spectrum of HHG appears from 40 e V to125 e V.The underlying physical mechanism is well explained by the time–frequency analysis and the semi-classical threestep model with a finite initial transverse velocity.By superposing several orders of harmonics,an isolated attosecond pulse with a duration of 80 as can be generated. 相似文献
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<正>We presented a novel orthogonally linearly polarized Nd:YVO4 laser.Two pieces of a-cut grown-together composite YVO4/Nd:YVO4 crystals were placed in the resonant cavity with the c-axis of the two crystals orthogonally.The polarization and power performance of the orthogonally polarized laser were investigated.A 26.2-W orthogonally linearly polarized laser was obtained.The power ratio between the two orthogonally polarized lasers was varied with the pump power caused by the polarized mode coupling.The longitudinal modes competition and the corresponding variable optical beats were also observed from the orthogonally polarized laser.We also adjusted the crystals with their c-axis parallele to each other,and a 40.7-W linearly polarized TEMoo laser was obtained,and the beam quality factors were Mx2=1.37 and My2 =1.25. 相似文献
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Intensity modulation characters of orthogonally polarized HeNe lasers with different optical feedback level 下载免费PDF全文
This paper demonstrates the intensity modulation characters of orthogonally polarized HeNe lasers with different optical feedback level generated by the variable reflectivity of external reflector. The modulation depths of the orthogonally polarized frequencies are increased when the optical feedback level becomes strong. It also observes that the modulation amplitudes are different for different external cavity length. Based on the vectorial extension of Lamb's semi-classical theory, it finds that the calculations are consistent with the experimental results. 相似文献