关键词: 红外吸收/
超分辨成像/
衍射极限/
锁相放大器
English Abstract
A super-resolution infrared microscopy based on a doughnut pump beam
Liu Hong-Ji,Liu Shuang-Long,
Niu Han-Ben,
Chen Dan-Ni,
Liu Wei
1.College of Opto-Electronic Engineering, Shenzhen University, Shenzhen 518060, China
Fund Project:Project supported by the National Basic Research Program of China (Grant Nos. 2012CB825802, 2015CB352005), the National Natural Science Foundation of China (Grant Nos. 61335001, 61235012), the National Key Scientific Instrument and Equipment Development Project of China (Grant No. 2012YQ15009203), and the Science and Technology Planning of Shenzhen, China (Grant No. JCY20160308104404452).Received Date:07 July 2016
Accepted Date:01 September 2016
Published Online:05 December 2016
Abstract: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.
Keywords: infrared absorption/
super-resolution microscopy/
diffraction limit/
lock-in amplifier
