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为测量振动环境下层间结构内部微小间隙的相对变化,设计了一种用于狭小空间内的平直光栅传感器。根据指定应用条件研究设计光栅传感基片的封装方案及其主要技术指标,并制作出平直光栅传感器。该传感器测量范围0.5 mm~0.8 mm,标定指标良好。通过试验应用证明,采用光栅传感器可实现振动环境下微小间隙的直接测量,且不用破坏原结构,与传统方法相比,数据真实可信,满足测量精确度μm量级要求。 相似文献
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一种增敏型光纤光栅应变传感器的开发及应用 总被引:7,自引:2,他引:5
提出了一种基于两端夹持封装技术的光纤光栅应变传感器.该传感器具有应变放大机制,测量精度超过了裸光纤光栅,而且通过改变封装工艺参数可以调节应变传递率.这种传感器既可以埋入结构中也可以通过辅助构件构成夹持式传感器.利用万能试验机对该传感器进行了应变性能标定实验,研究了不同基体材料上传感器的应变灵敏特件,并与理论分析结果作了对比.这种光纤光栅应变传感器在高层大厦模型地震试验中进行了检测.试验结果表明,基于两端夹持封装技术光纤光栅传感器具有良好的灵敏度、低噪、牢固可靠以及测量长期稳定性好的优点,是动载环境下工作的结构长期安全监测的理想器件. 相似文献
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面向生物医学智能装备和软体机器人等领域柔性机构以及高端装备和重大基础设施复杂结构的曲率测量需求,提出一种高适应性柔性曲率传感器。通过将光纤布拉格光栅封装在硅胶基体中,并将硅胶基体与聚氯乙烯薄片贴合,形成基于光纤布拉格光栅的柔性硅胶曲率传感器。采用光纤传感解调系统和标准曲率标定块,实验测得光纤光栅传感器反射谱特征及其随标定块曲率变化规律,分析了光栅波长位移与曲率变化的关系以及传感器灵敏度与嵌入硅胶基体深度的关系。实验结果表明:硅胶-聚氯乙烯基体的曲率传感器可以实现曲率变化实时测量,最高灵敏度可达0.329 2 nm/m-1。随着光纤光栅嵌入深度的增加,传感器灵敏度在0.2~0.35 nm/m-1范围内逐渐增大。在多次重复测量中传感器具有较好的一致性,可用于柔性机构和复杂结构的曲率测量。 相似文献
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研发高精度、高灵敏度、大量程的传感器对于边坡、隧道、桥梁等工程结构的健康监测具有重要意义。该文基于杠杆原理,将弱光栅粘贴于基片上,并串联弹簧,形成上部传感单元,通过多种结构形式的比选,发现X型带上外拐加直立段为最优主体结构。基于上述传感结构,设计了一种构造简单、传力稳定,且具有大量程、高精度、高灵敏度的新型弱光栅位移传感器。从理论上推导了测量位移与弱光栅中心波长变化值的关系,并进行了标定试验和模型试验。结果分析表明,基于该结构的位移传感器可实现的测量范围为0~160 mm,灵敏度为24.4 pm/mm,且位移放大倍数可依据需要调整,由此展示了该传感器在结构大变形监测中的良好性能和广阔应用前景。 相似文献
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为了解决卫星星敏感器光学镜头结构在轨温度监测问题,提出一种弧形基底封装的光纤光栅温度传感器。分析了星敏镜头结构特征与光纤光栅温度传感原理,采用飞秒激光刻写的光纤光栅作为敏感元件,设计了可贴合于星敏镜头结构特征的弧形封装基底,完成了光纤光栅温度传感器封装,并对传感器进行了拉伸测试、温度标定及温度重复性测试,并已应用于实际工程中。结果表明:弧形封装结构形式的光纤光栅温度传感器线性度可达0.998,温度灵敏度达到8.54 pm/℃,同一温度下中心波长变化量在2 pm以内,且受弧形基底封装结构变形产生的应变影响小。卫星在轨温度监测,光纤光栅传感与电子式传感相差±3 ℃。可以实现星敏镜头结构的温度测量功能,在星敏感器结构在轨温度测温中具有应用前景。 相似文献
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随着纳米技术的广泛应用以及人们对纳米位移测量认识的不断深化,光栅位移测量技术正在受到广泛的关注。在研究反射式光栅位移测量原理的基础上,设计并实现了一种小型化纳米级单光栅位移测量系统,对系统总体设计、光路布局以及软件算法进行了阐述,最后,利用电容位移传感器ASP-10-ILA等辅助仪器进行了对比实验。实验结果表明:在两路信号不完全正交的情况下系统也能实现准确测量,且理论上系统的位移测量分辨率达到1 nm;在电容位移传感器的量程范围内进行小位移对比试验,系统测量均值与参考值最大偏差118 nm,且与拟合直线偏差均小于100 nm;当光栅发生10 mm以上的较大位移时,测量结果与均值的偏差均小于5 ppm。 相似文献
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为了解决光纤光栅(Fiber Bragg Grating, FBG)位移传感器易受温度、振动等外界因素影响而导致测量重复性差的问题,本文利用磁铁非接触的力传递特性,以光纤光栅为核心元件,工字型梁、永磁体等为辅助元件研究了一种无接触的FBG位移自校准装置。利用移动端磁铁与位置标定端磁铁位置重合时,工字型梁所受磁力最大,进行位置信息的自校准,进而提高FBG位移传感器的测量重复性和测量精度。通过将自校准装置安装在卷尺结构的位移传感器上,对其传感特性展开实验研究,结果表明:在0~360 mm的测量范围内,校准前平均均方根误差为5.838 mm,校准后平均均方根误差为0.953 mm。本文采用自校准装置在很大程度上提高了FBG位移传感器的测量重复性,为位移传感器的环境适应性优化提供了一种新方法。 相似文献
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《Quantum Electronics, IEEE Journal of》2009,45(8):954-961
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The advantages and flexibilities of using a grating to assist in the process of all-optical codirectional switching are investigated theoretically. It is found that the phase-matching condition which is required for complete switching is power dependent. In this respect, all-optical switching can be sensitive to a small change in input power level. In addition, this power-induced resonant tuning makes the grating structure automatically tuned, in the sense that complete switching becomes insensitive to manufacturing tolerances. The grating frequency is viewed as a “free design parameter,” which is selected to yield a desired device response. By chirping and/or scaling the grating frequency, the grating coupler can be designed to exhibit complete switching in the presence of material absorption and saturation 相似文献
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Johansson F.S. Lagerholm L.R. Kildal P.-S. 《Antennas and Propagation, IEEE Transactions on》1992,40(3):331-334
A frequency-scanned reflection grating (blazed grating) with polarizer properties is investigated. The grating structure considered consists of a periodic array of double-dipole elements etched on a dielectric substrate and placed over a ground plane. The two dipoles within a periodic cell are displaced and tilted from each other. Numerical results are presented showing that this grating structure can be designed to have the property of efficiently converting the power of an incident linear polarized wave into a circular polarized diffracted wave. A design is also outlined where the grating acts as a twist reflector, converting an incident linear polarized transverse electric wave into a first-order diffracted transverse magnetic wave. The theoretical analysis is based on Floquet's theorem and the method of moments. Experimental results verifying the numerical results are also presented 相似文献
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Jaejoong Kwon Byoungho Lee 《Photonics Technology Letters, IEEE》2003,15(11):1564-1566
A new method for tuning the dispersion profile of a fiber grating is described. The method involves compressing the fiber grating attached to a structure in which the cross-sectional area varies with its position. Because the cross-sectional area defines the compression rate, the local Bragg reflection wavelength that determines the dispersion profile varies along the position. A structure in which the cross-sectional area can be simply altered by inserting-extracting a part of structure was designed. Therefore, the dispersion order of the fiber grating attached to the structure can be selected. Using the method, a linearly-quadratically chirped fiber grating was made and various group delay slopes depending on the applied stress were obtained. 相似文献
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为获得高性能的偏振分束光栅,设计了一种亚波长夹层式金属光栅结构,通过严格耦合波分析和遗传算法优化出最佳光栅结构。所设计的光栅在波长为800 nm时,0级衍射级次上TM偏振波的透射率和TE偏振波的反射率分别为98%和96.5%。在波长747 nm 854 nm,以及入射角-27 27范围内,光栅的透射和反射消光比都大于20 dB,达到了高衍射效率、高消光比、宽带宽及大角度的要求,数值分析表明该光栅对周期、槽深、覆盖层厚度具有优良的工艺容差。该光栅结构简单,性能稳定,对入射光损耗低,偏振分束效果明显,在光学偏振器件、激光器系统、偏振成像等领域具有广泛的应用前景。 相似文献
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Over the past years, a number of groups have developed phase gratings as local oscillator beam multiplexers for array receivers in the submillimeter wavelength domain. The most popular type of grating is the Dammann (1977) grating, a simple and versatile binary phase grating. We introduce a new type of grating, the Fourier grating, which, in contrast to the binary structure of Dammann gratings, uses a smooth grating structure. Due to the lack of sharp edges these gratings can be manufactured with high precision as reflection gratings even for two-dimensional (2-D) dispersion. Fourier gratings are designed using a simple optimization procedure that only involves a small number of parameters. Their diffraction efficiency is very high. We have produced a number of gratings and tested them at a frequency of 490 GHz, verifying the theoretical results 相似文献
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Design and analysis of spectral beam combining system for fiber lasers based on a concave grating 下载免费PDF全文
A novel fiber laser spectral beam combining scheme based on a concave grating is presented.The principle of the presented system is analyzed,and a concave grating with blazed structure for spectral beam combining is designed.The combining potential of the system is analyzed,and the results show that 39 Yb-doped fiber laser can be spectrally beam combined via the designed system.By using scalar diffraction theory,the combining effect of the system is analyzed.The results show that the diffraction efficiency of the designed concave grating is higher than 72% over the whole gain bandwidth,and the combining efficiency is 73.4%.With output power of 1 kW for individual fiber laser,combined power of 28.6 kW can be achieved. 相似文献
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论文基于严格耦合波理论(Rigorous Coupled-Wave Analysis,RCWA),并采用遗传算法进行优化,设计并制作了一种具有高衍射效率的亚波长结构Dammann 光栅。光栅的分束比为111,最小特征尺寸为0.95 m,衍射效率设计值达到95%,优于传统Dammann 光栅约15%,且均匀性设计值小于2%。论文采用电子束光刻直写技术和反应离子刻蚀技术在石英基底上制作出亚波长结构图形。实验结果表明,电子束扫描曝光可以获得纳米级的图形分辨率。对石英基底的反应离子刻蚀中,射频功率、工作气压及气体流量均对刻蚀速率和栅线的表面形貌产生不同程度的影响,论文主要针对该问题进行了讨论。同时,论文也对电子束光刻直写过程中产生的线宽误差因素进行了分析。 相似文献
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V. I. Zubkov V. I. Shcheglov 《Journal of Communications Technology and Electronics》2006,51(3):311-315
The dispersion relation for magnetostatic surface waves in a ferrite/dielectric/metal-strip-grating structure is obtained. It is shown that dispersion of magnetostatic surface waves must be qualitatively the same as in a ferrite/dielectric/metal structure, while the slope of the dispersion curve in the region of backward magnetostatic waves existing in a ferrite/dielectric/grating structure (and in a ferrite/grating structure in particular) is considerably higher than the slope of this curve corresponding to a ferrite/dielectric/metal structure. It is found that this phenomenon can be explained by the dependence of the grating’s shielding capability on the wave number of magnetostatic surface waves. A grating shielding parameter is introduced and dependences of this parameter on the wave number that can be used to explain the phenomena observed in the experiment are determined. 相似文献