Development of real-time rotating waveplate Stokes polarimeter using multi-order retardation for ITER poloidal polarimeter

Abstract

Faraday rotation measurements on compact helical system by using a phase sensitive heterodyne polarimeter Rev. Sci. Instrum. 70, 730 (1999); 10.1063/1.1149314 This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitationnew. The rotating waveplate Stokes polarimeter was developed for ITER (International Thermonuclear Experimental Reactor) poloidal polarimeter. The generalized model of the rotating waveplate Stokes polarimeter and the algorithm suitable for real-time field-programmable gate array (FPGA) processing were proposed. Since the generalized model takes into account each component associated with the rotation of the waveplate, the Stokes parameters can be accurately measured even in unideal condition such as non-uniformity of the waveplate retardation. Experiments using a He-Ne laser showed that the maximum error and the precision of the Stokes parameter were 3.5% and 1.2%, respectively. The rotation speed of waveplate was 20 000 rpm and time resolution of measuring the Stokes parameter was 3.3 ms. Software emulation showed that the real-time measurement of the Stokes parameter with time resolution of less than 10 ms is possible by using several FPGA boards. Evaluation of measurement capability using a far-infrared laser which ITER poloidal polarimeter will use concluded that measurement error will be reduced by a factor of nine. C 2016 AIP Publishing LLC.[http://dx

High-frequency measurement of the interferometric phase, the Faraday rotation, and the Cotton-Mouton effect with a single detector in a far-infrared interferometer-polarimeter

“…To our knowledge, so far, a two-parameter polarization modulation with this frequency was never obtained in a interferometer-polarimeter operating at λ = 118.8 µm or at a longer wavelength. For example, in the poloidal polarimeter under development for ITER (POPOLA) a two-parameters polarization modulation by means of a mechanical method is employed (the rotating quarter wave polarimeter) but its frequency is limited to few kHz [28].…”

Simple Self-calibrating Polarimeter for Measuring the Stokes Parameters of Light

“…Light polarimetry [1] is extremely important in physics [1,2], plasma physics [3] and astronomy [4,5,6]. The application that triggered this study was the ACME (Advanced Cold Molecule Electron electric dipole moment experiment) collaboration's need to understand the systematic uncertainties in electron electric dipole measurements from polarization gradients imprinted on laser beam that pass through glass under mechanical or thermal strain [7,8].…”

Passive broadband full Stokes polarimeter using a Fresnel cone

“…Polarimeters identify the polarisation state of light and are an important tool in astronomy [1][2][3], material characterisation [4][5][6], remote sensing [7][8][9] and medicine [10][11][12]. Polarisation states describe two orthogonal complex field components and are commonly expressed as four real numbers in a Stokes vector [13].…”