Phase retardation measurement and fast axis calibration system for wave plate

Wang Jinwei; Li Kewu; Jing Ning; Luo Xinwei; Wang Zhibin

doi:10.3788/IRLA201948.0217002

In order to efficiently and accurately measure the phase retardation of wave plate and the azimuth angle of fast axis at the same time, to realize the integration and automation of measuring system, a wave plate measuring system based on the combination of the photo-elastic modulation and the digital phase-locked technology was designed. The detecting laser was modulated by the photo-elastic modulator. By means of digital phase-locked technologies based on FPGA, the first harmonic term and the second harmonic term of the modulated signals were extracted. The phase retardation and the azimuth angle of fast axis of wave plate were demodulated by optimized algorithm. The stepper motor drives the wave plate to rotate to make the fast axis of wave plate reach the zero position. And the phase retardation was displayed by LCD. The experimental system was set up to measure the quarter-wave plate. The experimental results show that the measuring accuracy of azimuth angle of fast axis of quarter-wave plate is better than 0.31 and the measuring accuracy and repeatability of phase retardation of quarter wave plate are better than 99.47% and 0.14, respectively. The driving signal of the photo-elastic modulator and stepper motor and the processing of the data were controlled by FPGA. The measuring system realized optical, mechanical and electronic integration and the automation of the measuring process.

Phase retardation measurement and fast axis calibration system for wave plate

1. School of Information and Communication Engineering,North University of China,Taiyuan 030051,China;

2. Engineering and Technology Research Center of Shanxi Provincial for Optical-electric Information and Instrument,North University of China,Taiyuan 030051,China;

3. Key Lab of Instrument Science & Dynamic Measurement,Ministry of Education,North University of China,Taiyuan 030051,China

Received Date: 2018-09-05

Rev Recd Date: 2018-10-15

Publish Date: 2019-02-25

Key words:

Abstract: In order to efficiently and accurately measure the phase retardation of wave plate and the azimuth angle of fast axis at the same time, to realize the integration and automation of measuring system, a wave plate measuring system based on the combination of the photo-elastic modulation and the digital phase-locked technology was designed. The detecting laser was modulated by the photo-elastic modulator. By means of digital phase-locked technologies based on FPGA, the first harmonic term and the second harmonic term of the modulated signals were extracted. The phase retardation and the azimuth angle of fast axis of wave plate were demodulated by optimized algorithm. The stepper motor drives the wave plate to rotate to make the fast axis of wave plate reach the zero position. And the phase retardation was displayed by LCD. The experimental system was set up to measure the quarter-wave plate. The experimental results show that the measuring accuracy of azimuth angle of fast axis of quarter-wave plate is better than 0.31 and the measuring accuracy and repeatability of phase retardation of quarter wave plate are better than 99.47% and 0.14, respectively. The driving signal of the photo-elastic modulator and stepper motor and the processing of the data were controlled by FPGA. The measuring system realized optical, mechanical and electronic integration and the automation of the measuring process.

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Reference (9)

[1]	Xue Qingwen, Li Guohua. Half-shade method for measuring the phase retardation of quarter-wave plate[J]. Journal of OptoelectronicsLaser, 1998, 9(2):150-151. (in Chinese)
[2]	Xiao Haosu, Zhang Yunqiang. Precision analysis of polarization interference method for measuring stress birefringence of crystal[J]. Infrared and Laser Engineering, 2011, 40(2):273-275. (in Chinese)
[3]	Tan Qiao, Xu Qifeng. New method for retardance measurement of a quarter-wave plate[J]. Infrared and Laser Engineering, 2016, 45(7):0717002. (in Chinese)
[4]	Ren Hongliang, Wang Jiuyang. Measuring phase retardation and fast axis azimuth of a wave plate using michelson interferometer[J]. Chinese Journal of Lasers, 2008, 35(2):250-252. (in Chinese)
[5]	Hu jianming, Wang Xiangzhao. Measure phase retardation of wave plate based on photoelastic modulation[J]. Acta Optica Sinica, 2006, 26(11):02532239. (in Chinese)
[6]	Zeng Aijun, Li Fanyue. Simultaneous measurement of retardance and fast axis angle of a quarter-wave plate using one photo-elastic modulator[J]. Applied Optics, 2011, 50(22):4347-4352.
[7]	Li Kewu, Wang Zhibin. High sensitive measurement of optical rotation based on photo-elastic modu-lation[J]. Acta Phys Sinica, 2015, 64(18):184206. (in Chinese)
[8]	Li Kewu, Wang Liming. Measurement of residual birefringence combined photo-elastic modulation with electro-optic modulation[J]. Chinese Journal of Lasers, 2016, 43(5):0508003. (in Chinese)
[9]	Wang Shuang, Wang Zhibin. Realizing the measure-ment of the crystal electro-optic coefficient by photo-elastic modulation with digital phase locking[J]. Acta Photonica Sinica, 2017, 46(10):1012001. (in Chinese)

Phase retardation measurement and fast axis calibration system for wave plate

doi: 10.3788/IRLA201948.0217002

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