Gas detection using absorption properties of liquid crystals

作     者：Wolowelsky, K. Gil, A. Elkabets, M. Rotschild, C. 

作者机构：Technion Israel Inst Technol Fac Mech Engn Haifa Israel CI Syst Ltd Migdal Haemeq Israel 

出 版 物：《OPTICS EXPRESS》 (光学快报)

年 卷 期：2017年第25卷第26期

页      面：32532-32538页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：Israel Innovation Authority 

主　　题：Fourier transform infrared spectroscopy Image processing algorithms Multispectral imaging Optical properties Refractive index Wire grid polarizers 

摘      要：Optical gas imaging is critical for many applications, but its use is currently limited by complexity and cost. Here we experimentally demonstrate a low cost solution based on an alternating bispectral IR filter. This filter is based on liquid crystal having absorption lines, which overlap those of hydrocarbon gases, and depend on the orientation of the liquid crystal molecules. An alternating voltage modulates the orientation and thus the transmittance in the absorption bands, giving rise to different on-to-off intensity ratios for gases, and any clutter emission. Our demonstration of refrigerant gas R134a detection shows a high gas to clutter contrast and opens the way for using this method in many low cost applications. (C) 2017 Optical Society of America under the terms of the OSA Open Access Publishing Agreement