<i>In Vivo</i> and <i>in Situ</i> Spectroscopic Imaging by a Handheld Stimulated Raman Scattering
Microscope
Chien-Sheng Liao
Pu Wang
Chih Yu Huang
Peng Lin
Gregory Eakins
R. Timothy Bentley
Rongguang Liang
Ji-Xin Cheng
10.1021/acsphotonics.7b01214.s002
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.
2017-12-27 00:00:00
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