Elliptically polarized coherent anti-Stokes Raman scattering microscopy.
We report an approach to coherent anti-Stokes Raman scattering (CARS) microscopy that significantly suppresses the nonresonant background for high-contrast vibrational imaging. We employ an elliptically polarized pump field with an aspect ratio of 1:3 of the ellipse combined with a linearly polarized Stokes field for elliptically polarized CARS (EP-CARS) microscopy. The EP-CARS technique yields a 6-7-fold improvement in signal-to-background ratios compared with normal CARS, while providing an approximately 1.25-fold improvement in resonant CARS signal compared with normal polarization-sensitive CARS microscopy. We demonstrate this technique by imaging 1.5 microm polystyrene beads in water and lipid droplets in unstained fibroblast cells.
Lu
Fake
F
Bioimaging Laboratory, Department of Bioengineering, Faculty of Engineering, National University of Singapore, Singapore 117576.
Zheng
Wei
W
Huang
Zhiwei
Z
D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000379:methods*; D018613:Microscopy, Confocal / Q000295:instrumentation* / Q000379:methods; D008859:Microscopy, Polarization / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000295:instrumentation* / Q000379:methods