Background free CARS imaging by phase sensitive heterodyne CARS.
In this article we show that heterodyne CARS, based on a controlled and stable phase-preserving chain, can be used to measure amplitude and phase information of molecular vibration modes. The technique is validated by a comparison of the imaginary part of the heterodyne CARS spectrum to the spontaneous Raman spectrum of polyethylene. The detection of the phase allows for rejection of the non-resonant background from the data. The resulting improvement of the signal to noise ratio is shown by measurements on a sample containing lipid.
Jurna
M
M
Optical Sciences group, MESA+ Institute for Nanotechnology, Faculty of Science and Technology (TNW), University of Twente, The Netherlands. m.jurna@tnw.utwente.nl
Korterik
J P
JP
Otto
C
C
Herek
J L
JL
Offerhaus
H L
HL
D000465:Algorithms; D004867:Equipment Design; D007368:Interferometry / Q000295:instrumentation / Q000379:methods; D008055:Lipids / Q000737:chemistry*; D015233:Models, Statistical; D055095:Optics and Photonics; D012542:Scattering, Radiation; D013059:Spectrum Analysis, Raman / Q000295:instrumentation* / Q000379:methods*
D008055:Lipids