19 October 2016 Theoretical research and comparison of forces in optical tweezers based on ray optics method and T matrix method
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Proceedings Volume 10155, Optical Measurement Technology and Instrumentation; 101551F (2016) https://doi.org/10.1117/12.2246489
Event: International Symposium on Optoelectronic Technology and Application 2016, 2016, Beijing, China
Based on ray tracing method of ray optics (RO) theory and T-matrix method of electromagnetic scattering theory, we establish optical trap force model and calculate the optical trap force of trapped microspheres whose size is in the beam wavelength scale. Calculation results of axial and transverse trapping efficiency based on the two models agree qualitatively, but differ quantitatively. Then we introduce a trapping efficiency calculation deviation parameter to characterize the difference between these two methods, and analyze how the deviation parameter is influenced by trapped microsphere radius and trapping beam waist radius. Simulation result shows that best agreement between RO model and T matrix calculation method is met when a strongly focused laser beam traps a large microsphere in near the beam waist plane area. In such cases both ray optics approximation conditions and T matrix method approximate conditions are satisfied. Numerical results coincide well with theoretical expectations.
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Zhenggang Li, Huizhu Hu, ZhenHai Fu, Qi Zhu, Yu Shen, "Theoretical research and comparison of forces in optical tweezers based on ray optics method and T matrix method", Proc. SPIE 10155, Optical Measurement Technology and Instrumentation, 101551F (19 October 2016); doi: 10.1117/12.2246489; https://doi.org/10.1117/12.2246489


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