10.1021/acsphotonics.7b01214.s002
Chien-Sheng Liao
Chien-Sheng
Liao
Pu Wang
Pu
Wang
Chih Yu Huang
Chih Yu
Huang
Peng Lin
Peng
Lin
Gregory Eakins
Gregory
Eakins
R. Timothy Bentley
R. Timothy
Bentley
Rongguang Liang
Rongguang
Liang
Ji-Xin Cheng
Ji-Xin
Cheng
<i>In Vivo</i> and <i>in Situ</i> Spectroscopic Imaging by a Handheld Stimulated Raman Scattering
Microscope
American Chemical Society
2017
fiber-delivered
ultrafast pulses propagating
ambient-light chemical mapping
sample
SRS microscope
tissue
application
Situ Spectroscopic Imaging
lab-built objective lens
Raman signal
background
Handheld Stimulated Raman Scattering Microscope Spectroscopic
SRS imaging system
2017-12-27 00:00:00
Media
https://acs.figshare.com/articles/media/_i_In_Vivo_i_and_i_in_Situ_i_Spectroscopic_Imaging_by_a_Handheld_Stimulated_Raman_Scattering_Microscope/5783076
Spectroscopic
stimulated Raman scattering (SRS) microscopy is a label-free technique
that generates chemical maps of live cells or tissues. A handheld
SRS imaging system using an optical fiber for laser delivery will
further enable <i>in situ</i> and <i>in vivo</i> compositional analysis for applications such as medical diagnosis
and surgical guidance. In fiber-delivered SRS, the interaction of
two ultrashort pulses in the confined mode area creates a significant
background that overwhelms the stimulated Raman signal from a sample.
Here, we report the first background-free fiber-delivered handheld
SRS microscope for <i>in situ</i> chemical imaging. By temporally
separating the two ultrafast pulses propagating in the fiber and then
overlapping them on a sample through a highly dispersive material,
we detected a stimulated Raman signal that is 200 times weaker than
the background induced by the fiber. Broad applications of the handheld
SRS microscope were demonstrated through <i>in situ</i> ambient-light
chemical mapping of pesticide on a spinach leaf, cancerous tissue
versus healthy brain tissue in a canine model, and cosmetic distribution
on live human skin. A lab-built objective lens further reduced the
size of the pen-shaped microscope to about one centimeter in diameter.