1 Engineering Research Center of Optical Instrument and System, Ministry of Education, Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 JunGong Road, Shanghai 200093, China
An optical rotationmeasuringsystem using optical null methods is set up. The system is based on a step-motor rotating stage structure and a modulated laser, which both are controlled by digital signal processor. By introducing a curve-fitting method, the optical rotation angle is obtained from the step difference between the crossed positions in light signal curves with or without sample. The principle of this method is studied, and the system performance is investigated experimentally. We achieved an accuracy of the order of 10−3 degree in at least ±45° range, which is an improvement compared with the resolution of 0.01° for step-motor rotation stage.
Received 27 March 2013Accepted 26 April 2013Published online 13 May 2013
This work is supported by the National Basic Research Program of China (Grant No. 2011CB707500), the Innovation Fund Project for Graduate Student of Shanghai (Grant No. JWCXSL1202), and partly supported by the Shanghai Leading Academic Discipline Project (Project No. S30502).
Article outline: I. INTRODUCTION AND COMMON METHOD II. PRINCIPLE III. EXPERIMENTAL RESULTS IV. CONCLUSION
2.P. S. Huang, C. Chou, H. M. Tsai, H. T. Wu, and W. C. Kuo, “Optical rotation detection in a chiral scattering medium with an amplitude sensitive balanced detection polarimeter,” in 2005 Quantum Electronics and Laser Science Conference (QELS), IEEE Cat. No. 05CH37696, 2005.
3.A. Potts, W. Zhang, and D. M. Bagnall, “A new polarimeter based on optical non-reciprocity in gratings with two-dimensional chirality,” Appl. Phys. B: Lasers Opt.99, 679–693 (2010).
9.T. Akiyama, S. Tsuji-Iio, R. Shimada, K. Nakayama, S. Okajima, M. Takahashi, K. Terai, K. Tanaka, T. Tokuzawa, and K. Kawahata, “CO2 laser polarimeter for electron density profile measurement on the large helical device,” Rev. Sci. Instrum.74, 2695–2703 (2003).
12.G. N. Vishnyakov, G. G. Levin, and A. G. Lomakin, “Measuring the phase difference when there is linear birefringence in a differential phase polarimeter with a rotating analyzer,” J. Opt. Technol.78, 618–622 (2011).
14.A. Arnaud, F. Silveira, E. M. Frins, A. Dubra, C. D. Perciante, and J. A. Ferrari, “Precision synchronous polarimeter with linear response for the measurement of small rotation angles,” Appl. Opt.39, 2601–2604 (2000).