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基于长周期光纤光栅马赫-曾德干涉仪的频分复用技术是实现光纤多参量传感的重要途径.研究了频分复用中复合条纹信号的傅里叶处理方法,分析了傅里叶频谱中和频与差频信号的幅值与单个干涉条纹信号的关系,提出了抑制和频与差频信号的有效方法,即改变光栅结构参量适当降低中心波长处的条纹对比度以提高频谱信号的信噪比,增加特征频谱滤波的有效性.结果表明:经过优化调整的傅里叶频谱信噪比可以提高至原来的2倍以上;对比频谱调整后恢复相位的余弦曲线与原条纹信号发现,频谱信噪比提高的同时保留了反映各单个原条纹特征的足够相位信息.该光谱优化方法可为基于光纤光栅马赫-曾德干涉仪和频分复用的光纤多参量传感技术提供理论与技术指导. 相似文献
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调相光栅的正交相干相位检测 总被引:1,自引:1,他引:0
本文提出了一种解调调相光栅相位的新方法.将一幅相位调制光栅图输入计算机,通过正交相干相位解调算法处理,能够高精度、快速地获得光栅的相位分布.本文详细论述了正交相干相位解调原理,并给出实验系统和处理结果,最后与其他类似的相位解调方法进行了比较. 相似文献
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基于空间部分相千光成像理论,分析了编码相位片形成的假彩色及振幅光栅和相位光栅对这种假彩色的调节作用,求得了精确解. 相似文献
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为了满足测量的高分辨率和灵敏度,基于光栅为关键元件的光学测量方法要求光栅有很高的频率。在已有的高折射率介质制栅方法的基础上提出了一种新的制作超高频全息光栅的方法,该方法制栅准确、简单、方便,其特点是所制光栅的频率与激光波长及介质的折射率无直接关系,而是等于制栅光路所得频率与两倍母栅频率之和。实验表明,利用该方法制得10000线/mm的光栅是完全可能的 相似文献
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The dual-frequency grating measurement theory is
proposed in order to carry out the measurement of a discontinuous
object. Firstly, the reason why frequency spectra are produced by
low frequency gratings and high frequency gratings in the field of
frequency is analysed, and the relationship between the wrapped-phase and
the unwrapping-phase is discussed. Secondly, a method to combine the
advantages of the two kinds of gratings is proposed: one stripe is
produced in the mutation part of the object measured by a suitable
low frequency grating designed by MATLAB, then the phase produced by
the low frequency grating need not be unfolded. The integer series of
stripes is produced by a high frequency grating designed by MATLAB
based on the frequency ratio of the two kinds of gratings and the
high frequency wrapped-phase, and the high frequency unwrapping-phase
is then obtained. In order to verify the correctness of the
theoretical analysis, a steep discontinuous object of 600×600
pixels and 10.00~mm in height is simulated and a discontinuous object
of ladder shape which is 32.00~mm in height is used in experiment.
Both the simulation and the experiment can restore the discontinuous
object height accurately by using the dual-frequency grating measurement theory. 相似文献
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级联光纤光栅的发展及应用 总被引:2,自引:1,他引:1
简要回顾了光纤光栅的发展、基本分类.在介绍光纤光栅基本特性及其在通信、传感中的应用的基础上,讨论了级联光纤光栅的结构、工作原理、分析方法、基本性质,以及它在传感和通信领域中的应用.展望了级联光纤光栅在传感、通信及其他领域的发展前景. 相似文献
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对利用零级抑制均匀相位掩模版结合同透镜制作啁啾光纤光栅的技术进行了详细的理论和实验研究。结果表明这种方法适合于制作啁啾参数较小的光纤光栅,当所制作的光栅啁啾参数较大时,将导致严重的光谱不对称性和包层模耦合。 相似文献
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A fiber laser sensor, which consists of two coupled cavities based on three fiber Bragg gratings (two of them acting as sensing elements) and is interrogated via the longitudinal mode beating frequency, is presented. The two resonant cavities have lengths of 4250 m and 4297 m, respectively. Their beating frequency is of the order of 24 kHz, and its shift as a function of the variation of the period of one (or both) of the sensing gratings, induced by strain or temperature changes, can be measured by a radio-frequency analyzer. The system is suitable for long-distance sensing with high spatial resolution and high sensitivity. 相似文献
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P. F. Romanenko N. V. Sopinskii I. Z. Indutnyi E. F. Venger G. B. Beketov 《Journal of Applied Spectroscopy》1999,66(4):664-668
We devised a method of producing blaze hologram diffraction gratings by transforming symmetric grooves of the original grating
into asymmetric ones using an additional oblique irradiation by monochromatic or polychromatic light and a repeated chemical
etching of the additionally irradiated grating. Photosensitive As2Se3 film layers are used as a photoconductive material for recording gratings. A numerical computer modeling of the formation
of asymmetric grooves is conducted. The calculated shape of the groove profile is in good agreement with experimental data.
The manifestation of asymmetry of the profile shape of the produced gratings in angular and spectral relations for their diffraction
efficiency is considered. It is shown that by varying the parameters of producing the original gratings and the conditions
of their additional treatment it is possible to obtain hologram gratings with the required profile shape and blaze angle.
To whom correspondence should be addressed.
Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, 45, Nauka Ave., Kiev, 252028, Ukraine. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 587–590, July–August, 1999. 相似文献
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非均匀光纤光栅响应特性的研究 总被引:12,自引:3,他引:9
光纤栅在未来光纤通信与光纤传感系统中将关键性作用。本文进行了不同线型光栅迹与喃啾 等波导结构参数下的非均匀光纤光栅响应特性的数值计算,并通过对光栅响应不对称性的研究讨论,提出了光栅响应对称性的两个一般条件。 相似文献