高灵敏低噪声光束偏转检测系统设计  

Design of a Low Noise Optical Beam Deflection Detection System with High Sensitivity

作　　者：曲章 武兴盛 魏久焱 马宗敏[1,2] Qu Zhang;Wu Xingsheng;Wei Jiuyan;Ma Zongmin(Science and Technology on Electronic Test and Measurement Laboratory;School of Instruments and Electronics, North University of China, Taiyuan 030051, China)

机构地区：[1]中北大学电子测试技术重点实验室,太原030051 [2]中北大学仪器与电子学院,太原030051

出　　处：《微纳电子技术》2018年第5期359-365,370,共8页Micronanoelectronic Technology

基　　金：国家自然科学基金面上项目(61274103);山西省自然科学基金资助项目(201701D121080);山西省自然科学基金(青年)资助项目(2014021023-2)

摘　　要：为了进一步提高自制超高真空室温非接触式原子力显微镜（NC-AFM）的检测灵敏度和获得材料表面更高分辨率的原子图像,在比较了原子力显微镜探针振动位移检测的三种方法的基础上,重点研究了光束偏转检测方法,理论上分析了这种方法的偏转检测灵敏度与噪声。设计了一个高灵敏度、低噪声的光束偏转检测系统,该系统的激光光斑能够高精度地聚焦在悬臂上,能容易、直观地对准激光光路,并高效地检测到悬臂的振动和探针的共振频率。通过实验,验证了准直激光的质量及光路的对准,并利用该系统在超高真空非接触式原子力显微系统中进行探针振动实验,得到了探针的共振频率为161.736 8 kHz,通过计算得到探针共振的品质因数为12 939,说明系统具有高灵敏度和低噪声的性能。有望在进一步提高原子力显微镜分辨率方面得到应用。To improve the detection sensitivity of the home-made non-contact atomic force microscopy（NC-AFM）under the ultra-high vacuum（UHV）at room temperature and to obtain the high resolution atomic image of the material surface,the method of the optical beam deflection detection was researched emphatically based on the comparison of three methods of the probe oscillation displacement detection with the AFM.And the detection sensitivity and noise of the method were analyzed theoretically.And then a low noise optical beam deflection detection system with high sensitivity was designed,ensuring that the laser spot of the system can be focused on the cantilever accurately,the laser path can be aligned easily and intuitively,and the oscillation of the cantilever and the resonant frequency of the probe can be detected efficiently.The quality of the collimation laser and the alignment of the laser path were demonstrated through the experiment,and then the probe oscillation experiment was carried out using the system in the UHV-NC-AFM.The results show that the resonant frequency of the probe is 161.736 8 kHz,and through calculation,the probe resonant quality factor is 12 939,verifying high sensitivity and low noise performance of the system.Further,it is expected to be applied to improve the resolution of the AFM.

关 键 词：光学测量 非接触式原子力显微镜(NC-AFM) 光束偏转检测 高灵敏度 低噪声 共振频率 

分 类 号：TH741[机械工程—光学工程]