Experimental demonstration of tunable refractometer based on orbital angular momentum of longitudinally structured light
作者机构:Edward S.Rogers Sr.Department of Electrical and Computer EngineeringUniversity of TorontoTorontoON M5S 3G4Canada School of Electrical and Computer EngineeringUniversity of CampinasCampinas–SP 13083-852Brazil
出 版 物:《Light(Science & Applications)》 (光(科学与应用)(英文版))
年 卷 期:2018年第7卷第1期
页 面:669-680页
核心收录:
学科分类:0809[工学-电子科学与技术(可授工学、理学学位)] 08[工学]
基 金:the support from the Natural Sciences and Engineering Research Council in Canada,the Ontario Graduate Scholarship,FAPESP(Grant No.2015/26444-8) CNPq(Grant No.304718/2016-5)
摘 要:The index of refraction plays a decisive role in the design and classification of optical materials and devices;therefore,its proper and accurate determination is *** most refractive index(RI)sensing schemes,however,there is a trade-off between providing high-resolution measurements and covering a wide range of *** propose and experimentally demonstrate a novel mechanism for sensing the index of refraction of a medium by utilizing the orbital angular momentum(OAM)of structured *** a superposition of co-propagating monochromatic higher-order Bessel beams with equally spaced longitudinal wavenumbers,in a comb-like setting,we generate non-diffracting rotating light structures in which the orientation of the beam’s intensity profile is sensitive to the RI of the medium(here,a fluid).In principle,the sensitivity of this scheme can exceed~2700°/RI unit(RIU)with a resolution of~105 ***,we show how the unbounded degrees of freedom associated with OAM can be deployed to offer a wide dynamic range by generating structured light that evolves into different patterns based on the change in *** rotating light structures are generated by a programmable spatial light *** provides dynamic control over the sensitivity,which can be tuned to perform coarse or fine measurements of the RI in real ***,in turn,allows high sensitivity and resolution to be achieved simultaneously over a very wide dynamic range,which is a typical tradeoff in all RI sensing *** thus envision that this method will open new directions in refractometry and remote sensing.