基于环形抽运光的红外超分辨显微成像方法  

A super-resolution infrared microscopy based on a doughnut pump beam

作　　者：刘鸿吉 刘双龙[1] 牛憨笨[1] 陈丹妮[1] 刘伟[1] 

机构地区：[1]深圳大学光电工程学院,光电子器件与系统(教育部/广东省)重点实验室,深圳518060

出　　处：《物理学报》2016年第23期85-89,共5页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2012CB825802,2015CB352005);国家自然科学基金(批准号:61335001,61235012);国家重大科学仪器设备开发专项(批准号:2012YQ15009203);深圳市科技计划(批准号:JCY20160308104404452)资助的课题~~

摘　　要：本文提出一种突破衍射极限的红外显微成像方法,该方法基于抽运-探测模式,采用了环形而非高斯型强度分布的抽运光,由于样品在环形光强度峰值附近区域达到吸收饱和,因此当高斯分布的探测光随后到达样品时,只有环形光的中心区域才能吸收探测光的能量,而且吸收区域随着环形光的强度增加而减小.这意味着,如果以被吸收的探测光能量作为该成像系统的信号,本文提出的方法可以使系统的分辨率超越衍射极限的限制.本文模拟了不同环形光能量下成像系统的空间分辨率,结果表明:当环形光能量为100 n J、探测光能量为0.1 n J时,该方法的理论分辨率在236 nm,比传统红外显微成像系统分辨率提高了约14倍.An approach to breaking through the diffraction limitation in infrared microscopies is put forward in this paper.In this method, instead of Gaussian pump beam, an intensive vortex beam is first focused on the sample, leading to the saturation absorption of peripheral molecules in the point spread function（PSF）. The vortex beam is followed by a Gaussian probe beam with the same wavelength. Because of the previous saturation absorption, the probe beam can only be absorbed by the molecules near the center, resulting in a shrunk PSF which means super-resolution. Furthermore,the PSF of a system based on this approach is numerically simulated. With a 100 nJ pulse energy vortex beam and a 0.1 nJ pulse energy probe beam, the theoretical resolution FWHM（full width at half maximum） is measured to be about 236 nm which is 14 times better than that of the traditional infrared microscopy.

关 键 词：红外吸收 超分辨成像 衍射极限 锁相放大器 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]