We present a systematic comparison between coherent and spontaneous Raman scattering under conditions relevant for biological imaging. Using spectral domain imaging, we find that the signal levels for each method are comparable at the low excitation power and low concentrations appropriate for biological samples. For samples of polystyrene beads with a molecular concentration of 10 M, we determine the critical power at which the two methods give equal signal levels to be ~1.3 mW. The advantages offered by coherent Raman methods are mitigated by the low excitation power, low sample concentrations, and short interaction lengths involved with biological imaging. We present calculations to support our measurements.

Date Published: 26 February 2010
PDF: 7 pages
Proc. SPIE 7569, Multiphoton Microscopy in the Biomedical Sciences X, 75690O (26 February 2010); doi: 10.1117/12.842847

Published in SPIE Proceedings Vol. 7569:
Multiphoton Microscopy in the Biomedical Sciences X
Ammasi Periasamy; Peter T. C. So; Karsten König, Editor(s)