Simple system for measuring optical rotation of glucose solution using liquid-crystal grating. (28th October 2015)

• Record Type: Journal Article
• Authors: Honma, Michinori; Uchida, Etsuo; Saito, Hiroo; Harada, Takeshi; Muto, Seiei; Nose, Toshiaki
• Is Part Of: Japanese journal of applied physics. Volume 54:Number 12(2015:Dec.)
• Publication Date: 2015-10-28
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.54.122601
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We demonstrate an optical system for measuring the concentrations of optically active media using liquid-crystal polarization gratings (LCPGs). The optical rotation angle is determined by measuring the intensities of two diffracted light beams from an LCPG combined with a quarter-wave plate (QWP). The intensity ratio is used to evaluate the optical rotation angle, minimizing the dependence on changes in light source intensity and wavelength and reducing the influence of temperature-drift-induced LC birefringence shifts. We demonstrate the system by measuring the concentration of a glucose–water solution. The measurement error caused by the slight wavelength dependence of the QWP's retardation is assessed numerically.