Open AccessLaser differential confocal ultra-large radius measurement for convex spherical surface
Author(s) -
Zhigang Li,
Lirong Qiu,
Weiqian Zhao,
Shuai Yang
Publication year - 2016
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.019746
Subject(s) - optics , radius , lens (geology) , physics , confocal , position (finance) , laser , computer science , computer security , finance , economics
A new laser differential confocal ultra-large radius measurement (LDCRM) method is proposed for high-precision measurement of ultra-large radii. Based on the property that the zero point of a differential confocal axial intensity curve precisely corresponds to the focus points of focusing beam, LDCRM measures the vertex positions of the test lens and the last optical surface of objective lens to obtain position difference L 1 , and then measures the vertex positions of the reflector and the last optical surface of objective lens to obtain the position difference L 2 , finally uses the measured L 1 and L 2 to calculate the radius of test lens. This method does not require the identification of confocal position. Preliminary experimental results and theoretical analyses indicate that the relative uncertainty is 0.03% for a convex spherical lens with a radius of approximately 20 m. LDCRM provides a novel approach for high-precision ultra-large radius measurement.