Optics and Precision Engineering, Volume. 21, Issue 2, 281(2013)
Design of laser parallel confocal measurement system with single source and dual beam paths
To avoid the Talbot effect that is a multiple imaging in the traditional laser parallel confocal measurement, this paper introduces a Digital Micromirror Device(DMD) into the laser parallel confocal measurement to recognize the in-focus image. By taking the DMD as an optical splitting system, it is verified to be a flexible array source, and can not bring Talbot effect into the measurement system. However, the DMD is not an effectual splitting source as it can not converge the split ray effectively. Based on the characteristics of DMD, a laser parallel confocal measurement system with a single source and dual beam paths is constructed by combining a DMD and a Microlens Array(MLA). In this system, the position of in-focus image can be distinguished with the beam path of DMD and the high precision measurement can be completed with the beam path of MLA. The theoretical analysis and the experiment results indicate that the difference between the positions of in-focus images under two kinds of optical detection paths is about 2 μm. Moreover,the influence of Talbot effect on the laser parallel confocal measurement becomes weaker, and the parallel confocal measurement with high precision is achieved.
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YU Qing, YU Xiao-fen, CUI Chang-cai. Design of laser parallel confocal measurement system with single source and dual beam paths[J]. Optics and Precision Engineering, 2013, 21(2): 281
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Received: Sep. 11, 2012
Accepted: --
Published Online: Feb. 26, 2013
The Author Email: Qing YU (jorson.y@163.com)