Related Experiment Video
Updated: Aug 8, 2026

Differential Imaging of Biological Structures with Doubly-resonant Coherent Anti-stokes Raman Scattering (CARS)
Published on: October 17, 2010
High-sensitivity vibrational imaging with frequency modulation coherent anti-Stokes Raman scattering (FM CARS)
Feruz Ganikhanov1, Conor L Evans, Brian G Saar
1Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
Abstract:
We demonstrate a new approach to coherent anti-Stokes Raman scattering (CARS) microscopy that significantly increases the detection sensitivity. CARS signals are generated by collinearly overlapped, tightly focused, and raster scanned pump and Stokes laser beams, whose difference frequency is rapidly modulated. The resulting amplitude modulation of the CARS signal is detected through a lock-in amplifier. This scheme efficiently suppresses the nonresonant background and allows for the detection of far fewer vibrational oscillators than possible through existing CARS microscopy methods.
Related Concept Videos
Super-resolution Fluorescence Microscopy
Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
Atomic Force Microscopy
The AFM Probe
The probe is regarded as the heart of any AFM setup and comprises the...
