Optical Analysis of an Optical Probe for Three-Dimensional Position Detection of Micro-Objects
SungHo Jang, Takemi Asai, Yuki Shimizu,
and Wei Gao
Nano-Metrology and Control Laboratory, Department of Nanomechanics, Tohoku University, 6-6-01 Aramaki, Aza Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
In this paper, the relationship between the photodetector outputs and the three-dimensional (3D) positioning of a micro-object in an optical probe is first analyzed based on geometric optics. In the optical model established for the analysis, a collimated laser beam is focused by an objective lens to generate a small beam spot at the focal position and a thin and rectangular micro-object is set close to the focal position. The influence of diffraction of the laser beam is investigated based on a model based on wave optics.
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