共查询到19条相似文献,搜索用时 203 毫秒
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近场扫描光学显微术中, 近场距离的检测和控制是需要解决的核心技术之一. 本文研究了基于DDS驱动的压电传感器, 在一个压电陶瓷片上, 电极被分成相同的两部分, 分别用于振动驱动和振幅检测. 近场扫描的光纤探针固定于此压电陶瓷片上. 振动驱动信号采用DDS, 在样品的远场时, 可以通过频率扫描得到误差在0.006 Hz以内的压电陶瓷片谐振频率驱动信号, 而当光纤探针处于样品的近场距离之内时, 压电陶瓷片的谐振频率偏离驱动信号频率, 振幅明显减小, 从而检测出近场距离. 高精度振动驱动源DDS和高灵敏度压电传感器的采用提高了检测灵敏度和工作稳定性. 相似文献
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《物理学报》2021,(15)
基于非对称光纤悬臂结构的Lissaj ous扫描光纤探头可实现低电压驱动下的大范围扫描成像.本文研究了全封装的小型化预标定Liss ajous扫描光纤探头.通过优化设计与数值仿真,选择了能实现高填充率Liss ajous扫描的正交谐振频率,确定了非对称光纤悬臂的结构参数.全封装探头在5 mm工作距离处的焦点直径为25 μm,视场大小达到1.5 mm × 1.5 mm,总刚性长度和外径分别为35 mm和3.5 mm.研究了全封装探头扫描轨迹的稳定性、可重复性与扫描成像的旋转稳定性.结合实验室搭建的50 kHz扫频光学相干层析(OCT)系统,对硬币和生物组织进行高质量成像,验证了用于内窥OCT成像的小型化预标定Liss ajous扫描光纤探头具有良好的成像性能. 相似文献
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分布反馈光纤激光器水听器设计与实验 总被引:2,自引:2,他引:0
为验证分布反馈光纤激光器水听器具有抗干扰强、动态范围大、灵敏度高等独特优点,进行了该水听器的系统设计,并给出分布反馈光纤激光器的输出特性曲线.采用非平衡M-Z光纤干涉仪进行分布反馈光纤激光器水听器的解调,结合工作点扫描和控制的测量方法,利用压电陶瓷相位调制器来进行相位补偿,使系统稳定工作在最灵敏处.采用制作的光纤干涉仪,搭建室内水听器模拟对比实验,通过扬声器产生1.34 KHz和7.24 KHz的高频周期激励信号,以及对水听器进行敲击激励,分析水听器的响应.进行了激光器水听器和压电水听器低频频响特性对比测试,实验得出光纤激光器水听器的光电探测输出信号的信噪比高,可以准确、可靠地反映原始声信号. 相似文献
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提出并实验验证了一种基于匹配光纤光栅法布里-珀罗干涉仪的应变传感器解调方法,该方法综合了光纤法布里-珀罗干涉技术和匹配光纤光栅滤波法的优点.通过半导体制冷片和压电陶瓷组成的闭环负反馈控制系统,精确调节匹配光栅法布里-珀罗干涉仪的温度和应变,有效解决了光栅法布里-珀罗干涉仪的失配问题,从而保证系统静态工作点处于最佳匹配位置,同时能够避免探头因环境温度波动导致的测量误差.实验结果表明,该系统能够响应50~800 Hz的输入信号,应变最小分辨力至少为0.4 nε/Hz1/2,解调灵敏度高,且不受环境温度波动的影响,因而在动态应变或振动测量中具有较高的实用性. 相似文献
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提出了一种基于光纤光栅法布里-珀罗(F-P)腔的低频振动传感方案并进行了理论分析和实验研究。采用单频激光器作为光源,光纤光栅F-P腔通过两点涂胶方式粘接在等强度悬臂梁上,待测振动信号通过支架和悬臂梁将振动作用传至光纤光栅F-P腔,引起腔长周期性变化,从而改变光纤光栅F-P腔的反射光谱特性,通过解调输出光信号的振荡频率和峰值,即可实现对振动信号频率和幅值的测量。利用压电陶瓷模拟的低频振动信号进行了实验验证,测量结果与理论分析相吻合。该传感器测量灵敏度高,特别适用于微弱振动信号的测量。 相似文献
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基于匹配光纤光栅法布里-珀罗干涉仪的应变解调方法 总被引:2,自引:1,他引:1
提出并实验验证了一种基于匹配光纤光栅法布里-珀罗干涉仪的应变传感器解调方法,该方法综合了光纤法布里-珀罗干涉技术和匹配光纤光栅滤波法的优点.通过半导体制冷片和压电陶瓷组成的闭环负反馈控制系统,精确调节匹配光栅法布里-珀罗干涉仪的温度和应变,有效解决了光栅法布里-珀罗干涉仪的失配问题,从而保证系统静态工作点处于最佳匹配位置,同时能够避免探头因环境温度波动导致的测量误差.实验结果表明,该系统能够响应50~800Hz的输入信号,应变最小分辨力至少为0.4nε/Hz1/2,解调灵敏度高,且不受环境温度波动的影响,因而在动态应变或振动测量中具有较高的实用性. 相似文献
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In this paper, we study the dynamic modes of a scanning near-field optical microscope (SNOM) which uses an optical fiber probe; and the sensitivity of flexural and axial vibration modes for the probe were derived and the closed-form expressions were obtained. According to the analysis, as expected each mode has a different sensitivity and the first mode is the most sensitive mode of flexural and axial vibration for the SNOM probe. The sensitivities of both flexural and axial modes are greater for a material surface that is compliant with the cantilever probe. As the contact stiffness increases, the high-order vibration modes are more sensitive than the lower-order modes. Furthermore, the axial contact stiffness has a significant effect on the sensitivity of the SNOM probe, and this should be noted when designing new cantilever probes. 相似文献
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We propose the two-dimensional scanning probe operating with a single actuator, which is thought useful as a sample probe for optical coherence tomography (OCT). The probe was designed to use a single-body lensed fiber cantilever loaded with an iron-bead and driven by a single-solenoid actuator. Elliptic spiral trace patterns were achieved using off-axis magnetic fields of the solenoid. A three-dimensional OCT image was obtained for a scanning area of 3.8 mm × 3.4 mm at an acquisition speed of 16.7 s/V. Up to 27 Hz B-scan rate, the proposed probe worked well, and 1000 A-scans were made per each B-scan. 相似文献
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As a component of near-field scanning optical microscope (NSOM), optical fiber probe is an important factor influncing the equipment resolution. Electroless nickel plating is introduced to metallize the optical fiber probe. The optical fibers are etched by 40% HF with Turner etching method. Through pretreatment, the optical fiber probe is coated with Ni-P film by electroless plating in a constant temperature water tank. Atomic absorption spectrometry (AAS), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometry (EDXS) are carried out to characterize the deposition on fiber probe. We have reproducibly fabricated two kinds of fiber probes with a Ni-P film: aperture probe and apertureless probe. In addition, reductive particle transportation on the surface of fiber probe is proposed to explain the cause of these probes. 相似文献
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一种探针-样品距离的切变力控制新方法 总被引:1,自引:1,他引:0
报道了近场扫描光学显微镜(Near-filed Scanning Optics Microscope NSOM)中一种基于切变力的探针 样品间距控制新方法.条形压电蜂鸣器片的上表面电极被沿着中心线分成两半,一半用于驱动,其上施加振荡源谐振频率进行激励,另一半上粘附光纤探针,并利用压电效应作为光纤探针的振幅传感器.当受振动激励的光纤探针由远处逐渐接近样品表面时,由于样品与探针之间的切变力阻尼作用使得探针的振幅减小,通过检测探针振幅的变化可以控制探针与样品的间距.我们建立了一套探针 样品间距探测控制系统并利用该系统获得了CD盘片表面8μm×8μm范围内的切变力形貌图. 相似文献
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为了提高纳米坐标测量机探针的测量精度,且能满足对复杂曲面或微结构进行精确测量的要求,提出了一种新颖的基于微探针系统的光纤布拉格光栅(FBG)探针。该探针具有较高灵敏度和可重复性。提出该新型FBG探针,即探针里有一个熔融的球形顶端,FBG作为应变传感器内置在测杆上。介绍了光纤探针的基本原理,并利用有限元软件ANSYS 11对探针的应变分布在轴向和横向载荷两种典型配置分别进行了仿真分析,结果表明仿真分析和理论计算相吻合。通过实验对光纤探针的灵敏度和分辨率分别进行测试。实验结果表明,在轴向载荷条件下,用位移分辨率为1.5 nm的压电换能器对探针进行性能测试,得到光纤探针的测量分辨率为60 nm。即光纤探针具有较高的灵敏度和分辨率,其性能满足实际测量需要。 相似文献
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For the evaluation of two-dimensional carrier profiles in semiconductor devices, we have developed a novel form of probe–sensor combined unit that uses an etched tungsten wire as a conductive probe, and commercially available quartz tuning fork as the force sensor. This unit has a self-sensing capability due to the piezoelectric effect of quartz tuning fork, thus obviating optical setup, and its conductivity is higher and more stable than that of conventional metal-coated Si cantilever. In addition, this probe–sensor combined unit is inexpensive and easy to use, when compared to the well-known optical methods of Si-based cantilever vibration detection system. Our scanning probe microscope using this probe–sensor combined unit is able to mapping the capacitive gradient signal (dC/dZ image) and internal damping of quartz tuning fork oscillation (dissipation image) while scanning the sample surface. In this letter, we show the results of visualization of the p–n junction locus of a Si metal–oxide–semiconductor field effect transistor in both dC/dZ and dissipation images. 相似文献