共查询到18条相似文献,搜索用时 78 毫秒
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提出一种用光源调制和施加压力相结合进行保偏光纤拍长测量的方法,利用锁相放大提高测量信号的信噪比,故使测量装置既结构简单,易于操作,又能达到较高的测量分辨率和重复测量精度。测量结果表明,利用该测量方法进行测量的装置其拍长测量范围为0.1 ̄70mm,测量分辨率可达0.005mm,测量的重复精度达0.05mm。 相似文献
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针对提高光纤光栅折射率传感器抗干扰能力以及增加反射率的需求,本文提出了一种基于Fabry-Perot腔的保偏微结构光纤(PM-MOF)布拉格光栅折射率传感器.根据传榆矩阵法和有限元方法,分析了微结构光纤光栅F-P腔中被测物折射率与F-P腔反射谱中两个偏振模谐振波长差的关系,在此基础上讨论了中心孔直径、F-P腔长度等参数对传输特性的影响.研究结果表明,随着空气孔中填充物折射率的增加,保偏微结构光纤光栅F-P腔的两个偏振态的谐振波长差将逐渐减小;F-P腔的干涉作用使反射率较单个光栅有很大提高,便于长距离传输和实时解调;两个偏振模对外界干扰具有相似的响应,因此该传感器具有更强的抗干扰能力.本文研究结果为保偏微结构光纤光栅在折射率传感器及其生物传感器方面的应用提供了理论依据. 相似文献
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提出一种基于半导体激光调频外差干涉原理的保偏光纤双折射率的测量方法,即通过测量由保偏光纤构成的偏振干涉仪输出的外差信号的频率,求得保偏光纤的相对双折射率,此方法具有较高的分辨率和潜在的高精度,以及系统结构简单,无运动部件和非破坏测量等优点。 相似文献
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保偏光纤偏振轴方位图象特征分析 总被引:4,自引:0,他引:4
偏振轴方位的精密探测和对准是保偏光纤应用中的关键技术。文中提出了一种利用摄像显微镜观测熊猫光纤偏振轴方位的横向图象处理方法,并利用光线追迹方法对保偏光纤在横向准直均匀光束照明情况下偏振方位图象的构形机理及特征信息提取方法进行了分析和讨论。计算机仿真拟合结果和实验观测结果相吻合。 相似文献
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研制出一种智能化的光纤折射率分布测试仪,其测量精度达到10 - 4 ,空间分辨率达到1 微米。本文介绍了仪器的测量原理及其测试系统的设计。 相似文献
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Jennifer R. Verkouteren Eric B. Steel Eric S. Windsor John M. Phelps 《Journal of research of the National Institute of Standards and Technology》1992,97(6):693-705
Errors in the double variation teclinique of refractive index measurement are analyzed using a new approach. The ability to measure matching wavelength is characterized, along with the effect on the calculated refractive index. Refractive index accuracy and precision are very dependent on the specifics of each calibration set, particularly the difference in dispersion between the liquid and solid. Our best precision (±1 or 2×10−4) is attained only when the difference in dispersion between liquid and solid is small, and is dependent on an individual operator’s ability to perceive changes in relief. This precision is impossible to achieve for the other glass/liquid combinations, where we are limited by a precision of approximately 1 nm in the selection of matching wavelength. A bias in the measurement of matching wavelength exists that affects the accuracy of the calculated refractive indices. The magnitude of the bias appears to be controlled by the bandpass of the graded interference filter. The errors in refractive index using a graded interference filter with a bandpass of 30 nm FWHM (full width at half maximum intensity) are an order of magnitude larger than the errors using a filter with a bandpass of 15 nm FWHM. 相似文献
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Many workers have published various methods to measure refractive index of various liquids. Mostly, the measurement results are not traceable to SI units. A novel method is developed at CSIR-NPL, India (NPLI) to measure refractive of index of liquids using gauge blocks, metrological microscope and displacement laser interferometer. A vessel with flat bottom is chosen to hold the liquid under test. A pair of gauge blocks of different lengths is fixed in the vessel. The vessel is arranged under a vertically movable microscope. A calibrated displacement laser interferometer is attached to the microscope stage. The microscope is focused to the surface of gauge block before poring liquid. After poring liquid in the vessel, the microscope is moved vertically to regain the focussed image of surface of submerged gauge blocks. The measurement method is simulated mathematically. The refractive index of liquid medium is calculated using this mathematical model. Refractive index of water, isopropyl alcohol is measured. Various error contributing sources are identified. The measurement uncertainty is evaluated. 相似文献
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用甲基丙烯酸甲酯(MM A)作为基质,在离心设备上采用界面凝胶聚合技术成功地制备了中空的渐变折射率分布(G I)塑料光纤预制棒,避免了普通的界面凝胶聚合方法制备时容易出现气泡的现象,而且可以得到需要的折射率分布。将这样的空心预制棒在合适的条件下熔融拉丝,即可以得到连续、透明、实心的渐变分布折射率塑料光纤。 相似文献
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为了在光纤陀螺等关键器件中使用超细径保偏光纤取代常用的普通直径保偏光纤,需要对其偏振轴的确定方法进行改进和优化.首先,使用光线追迹法对图像侧面成像对轴法在几种条件下的理论图像进行计算机仿真,并对仿真结果较好的两种情形进行实验验证;然后,对实验数据曲线进行傅里叶展开以抑制随机干扰,将结果较好的三亮纹方法改进为三亮纹四点特征法,并对该方法进行实验验证;最后,测定使用三亮纹四点特征法得到的重复精度.实验结果表明,该方法大大提高了超细径保偏光纤偏振轴定轴过程中的抗干扰能力,重复精度达到1.6°,达到了普通直径保偏光纤的偏振轴定轴精度,满足实际应用要求. 相似文献
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