A New Strategy of Spectrum and Polarization Measuring based on LCVR and AOTF
WANG Yao-li1, 2, 3, ZHANG Rui1, 2, 3, WANG Zhi-bin1, 2, 3, WEN Ting-dun1, 2, LI Ke-wu1, 2, 3
1. Key Laboratory of Instrumentation Science and Dynamic Measurement, North University of China, Taiyuan 030051, China 2. School of Information and Communication Engineering, North University of China, Taiyuan 030051, China 3. Engineering Technology Research Center of Shanxi Province for Opto-Electronic Information and Instrument, North University of China, Taiyuan 030051, China
Abstract：In view of the existing relatively cumbersome polarization measurement method of using liquid crystal phase variable retarder (LCVR) and acousto-optic tunable filter (AOTF), a new strategy of spectrum and polarization measurement is put forward. This method removed mechanical movement and reduced the amount of phase delay from four groups to two groups. This method realizes the spectrum and polarization measurements by measuring the plus and minus 1 level diffraction light of the system with two LCVR, one AOTF and two same version detectors. For the polarization measurement of a particular wavelength, the computer controlled LCVR driving voltage to achieve the required phase delay in accordance with the requirements of the wavelength, it also controlled the driving frequency to implement the required wavelength selection of AOTF. Because of the different driving frequencies of AOTF corresponding to the different wavelengths, so it can get the spectral information by scanning the whole frequency bands, In this paper detailed principles are deduced and the polarization model of AOTF is analyzed, it also deduced the measurement formula of I, Q, U in the corresponding Stokes parameter through the theoretical calculation Muller matrix of the LCVR and AOTF. Finally it analyzed and simulated the measurement error of the whole system which was caused by the tiny deviation of phase delay, the simulation results show that relative error <3% when the phase delay amount within the range of ±π/100. This experiment proved the feasibility and accuracy of the measurement system, the results show that the error of the measuring system overall <6%. This study provides a new method of polarization measurement which is simple, feasible and precise, it has important application value.
[1] CHEN You-hua, WANG Zhao-ba, WANG Zhi-bin, et al(陈友华，王召巴，王志斌，等). Acta Physica Sinica(物理学报), 2013, 62(6): 060702. [2] ZHU Bao-hui, ZHANG Chun-min, JIAN Xiao-hua, et al(祝宝辉, 张淳民, 简小华, 等). Acta Physica Sinica(物理学报), 2012, 61(9): 090701. [3] Frank C, Jong W, Klamer S. Opt. Eng., 2002, 41: 1021. [4] Hasekamp O P, Landgraf J. Appl. Opt.，2007，46：3332. [5] Ford K B, Michael R D. Opt. Express, 2001, 9: 444. [6] Kurosaki H. Adv. Space Res., 2007, 39: 185. [7] Jones H S, Iannarilli J F, Kehahian L P. Opt. Express, 2004, 12: 6559. [8] Scharmer G B, Narayan G, Hillberg T. Astrophys. J, 2008 689: 69. [9] WANG Zhi-bin, ZHANG Rui, ZHAO Dong-e, et al(王志斌，张 瑞，赵冬娥，等). Optics and Precision Engineering(光学精密工程), 2013, 21(4): 876. [10] ZHANG Rui，WANG Zhi-bin，ZHAO Dong-e，et al(张 瑞，王志斌，赵冬娥，等). Journal of Applied Optics(应用光学)，2013, 34(3): 479. [11] ZHAO Hai-li, WANG Xiao-man, JIANG Hui-lin, et al(赵海丽，王晓曼，姜会林，等). Chinese Journal of Scientific Instrument(仪器仪表学报)，2010, 31(2): 416. [12] WANG Qi-chao, SHI Jia-ming, ZHAO Da-peng, et al(王启超，时家明，赵大鹏，等). Opto-Electronic Engineering(光电工程)，2013, 40(1): 66.
