Direct measurement of axial optical forces
Direct measurement of axial optical forces
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DOI：
10.1364/oe.23.006112
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发表时间：
2015-03-09
期刊：
影响因子：
3.8
通讯作者：
Ritsch-Marte, Monika
中科院分区：
文献类型：
--
作者：
Thalhammer, Gregor;Obmascher, Lisa;Ritsch-Marte, Monika
基于记录入射光和出射光之间的动量变化的光学力的直接测量对颗粒尺寸或形状或光束形状没有特定要求。因此，这种方法克服了基于位置测量的力测量的许多限制，这些限制需要频繁校准。在这项工作中，我们验证了在轴向方向上的单光束光镊设置的直接力测量的可实现的精度，基于数值模拟和实验研究的情况下，其中的真实力是已知的。我们发现，对于典型的实验情况下，可以实现一个良好的精度与误差小于1%的最大力，独立于颗粒的大小或折射率，只要在向后的方向散射的光的总量也被考虑在内，这是很容易实现的实验。由于直接力测量方法固有的颗粒形状独立性，这些发现支持它为任意形状的颗粒的3D力测量提供准确的结果。(C)2015美国光学学会
Direct measurement of optical forces based on recording the change of momentum between the in- and outgoing light does not have specific requirements on particle size or shape, or on beam shape. Thus this approach overcomes many of the limitations of force measurements based on position measurements, which require frequent calibration. In this work we validate the achievable accuracy for direct force measurements in the axial direction for a single beam optical tweezers setup, based on numerical simulations and experimental investigations of situations, where the true force is known. We find that for typical experimental situations a good accuracy with an error of less than 1% of the maximum force can be achieved, independent of particle size or refractive index, provided that the total amount of light scattered in the backward direction is also taken into account, which is easy to accomplish experimentally. Due to the inherent particle shape independence of the direct force measurement method, these findings support that it provides accurate results for 3D force measurements for particles of arbitrary shape. (C) 2015 Optical Society of America