Sriramshankar R, Sri Muthu Mrinalini R, Jayanth G R
Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012, India.
Rev Sci Instrum. 2013 Oct;84(10):105001. doi: 10.1063/1.4824357.
Measurement of in-plane motion with high resolution and large bandwidth enables model-identification and real-time control of motion-stages. This paper presents an optical beam deflection based system for measurement of in-plane motion of both macro- and micro-scale motion stages. A curved reflector is integrated with the motion stage to achieve sensitivity to in-plane translational motion along two axes. Under optimal settings, the measurement system is shown to theoretically achieve sub-angstrom measurement resolution over a bandwidth in excess of 1 kHz and negligible cross-sensitivity to linear motion. Subsequently, the proposed technique is experimentally demonstrated by measuring the in-plane motion of a piezo flexure stage and a scanning probe microcantilever. For the former case, reflective spherical balls of different radii are employed to measure the in-plane motion and the measured sensitivities are shown to agree with theoretical values, on average, to within 8.3%. For the latter case, a prototype polydimethylsiloxane micro-reflector is integrated with the microcantilever. The measured in-plane motion of the microcantilever probe is used to identify nonlinearities and the transient dynamics of the piezo-stage upon which the probe is mounted. These are subsequently compensated by means of feedback control.
高分辨率和大带宽的面内运动测量能够实现运动平台的模型识别和实时控制。本文提出了一种基于光束偏转的系统，用于测量宏观和微观尺度运动平台的面内运动。一个曲面反射镜与运动平台集成在一起，以实现对沿两个轴的面内平移运动的灵敏度。在最佳设置下，测量系统理论上在超过1 kHz的带宽上实现亚埃级测量分辨率，并且对线运动的交叉灵敏度可忽略不计。随后，通过测量压电弯曲平台和扫描探针微悬臂梁的面内运动，对所提出的技术进行了实验验证。对于前一种情况，采用不同半径的反射球形球来测量面内运动，测量的灵敏度平均与理论值的偏差在8.3%以内。对于后一种情况，一个聚二甲基硅氧烷微反射镜原型与微悬臂梁集成在一起。微悬臂梁探针测量的面内运动用于识别安装探针的压电平台的非线性和瞬态动力学。随后通过反馈控制对这些进行补偿。
