基于OAM光束的球形颗粒的手性信号增强机理  

Enhancement mechanism of chiral signal from spheres based on OAM beams

作　　者：孙阳 胡海峰 SUN Yang;HU Haifeng(School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学光电信息与计算机工程学院,上海200093

出　　处：《光学仪器》2023年第3期80-86,共7页Optical Instruments

基　　金：国家自然科学基金(62075132);上海市自然科学基金(22ZR1443100)。

摘　　要：为了分析球形颗粒的手性信号增强机理,基于T矩阵法对手性球形颗粒的Mie散射特性进行了研究,分析了基于入射光束轨道角动量(OAM)的调控和颗粒特性参数调控的手性信号增强机理。对紧聚焦线偏振光的波前进行调控,通过调控光束携带OAM的符号实现OAM二色性的测量,并研究OAM阶数与手性信号强度之间的关系。当光束携带OAM的阶数与小球的尺寸相匹配时得到较圆偏振光散射圆二色性信号22.8倍的提升。同时分析了小球特性参数(颗粒尺寸、手性参数)对OAM二色性信号的影响。In order to analyze the mechanism of chiral signal enhancement of spherical particles,the Mie scattering characteristics of spherical particles are studied based on the T-matrix method,and the mechanism of chiral signal enhancement is analyzed based on the regulation of incident beam with orbital angular momentum(OAM)and particle’s characteristic parameters.The wave front of tightly focused linearly polarized light is regulated,the dichroism of OAM is measured by regulating the sign of OAM carried by the beam,and the relationship between the order of OAM and the intensity of the chiral signal is studied.When the order of the OAM carried by the beam is matched with the size of the sphere,the scattering circular dichroism signal can be enhanced by 22.8 times compared to that of circularly polarized light.The influence of particle size and chiral parameters on OAM dichroism signal is also analyzed.

关 键 词：轨道角动量 MIE散射 T矩阵 手性测量 光场调控 

分 类 号：O434.14[机械工程—光学工程]