MEASUREMENT OF LONG FOCAL-LENGTH BASED ON STRIPE MATCHING

Jia Luo, Jian Bai,Yao Jiang, Fan He, Kaiwei Wang, Xiyun Hou, Changlun Hou

Abstract

A novel method for accurate long focal-length measurements, based on stripe matching, is proposed. This method consists of a laser source, two gratings and a detector. A divergent beam illuminating two parallel gratings produces moiré fringes on the second grating. Then, added a test lens in front of the first grating, a new moiré fringes is produced. The two moiré fringes are matched by moving the second grating and the corresponding focal-length can be easily obtained by the measurement of the distance between gratings. Experiment demonstrates the proposed method features high accuracy of 0.18% and stability of 0.0004%. Besides, this method tremendously reduces testing time.

Keywords: long focal-length, measurement, stripe matching, gratings, Moiré fringes
Download: IMEKO-TC14-2014-67.pdf
DOI: -
IMEKO TC: TC14 - Measurement of Geometrical Quantities

Event details

Event: TC14 LMPMI Symposium 2014
Technical Committee: TC14
Place: Tsukuba, JAPAN
Time: 3 September 2014 - 5 September 2014
Website: http://www.lmpmi2014.jp/

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