Dynamic scan detection of focal spot on nonplanar surfaces: theoretical analysis and realization

Jianbo Luo; Yiyong Liang; Guoguang Yang

doi:10.1117/1.3597327

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1 July 2011 Dynamic scan detection of focal spot on nonplanar surfaces: theoretical analysis and realization

Jianbo Luo, Yiyong Liang, Guoguang Yang

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Optical Engineering, 50(7), 073601 (2011). https://doi.org/10.1117/1.3597327

Abstract

A new approach called dynamic-scan-detection is presented to detect the focal spot on nonplanar surfaces, which is a key technique for laser direct writing on nonplanar surfaces. From the depth response properties of a confocal system on a nonplanar surface, the approach scans the axial shift of intensity response peak by oscillating the modified pinhole in the axial direction, and demodulates the defocus by measuring the length of time between two peaks of measured intensity waveform in one period. Compared with conventional methods, this approach features easy implementation, wide depth measurement range without deterioration of the depth discrimination property, dynamically adjustable scan amplitude, and more importantly, suppression of common-mode noise or variable system factors.

©(2011) Society of Photo-Optical Instrumentation Engineers (SPIE)

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Jianbo Luo, Yiyong Liang, and Guoguang Yang "Dynamic scan detection of focal spot on nonplanar surfaces: theoretical analysis and realization," Optical Engineering 50(7), 073601 (1 July 2011). https://doi.org/10.1117/1.3597327

Published: 1 July 2011

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