High-order dispersion of ultrashort laser pulses (with ~100 nm bandwidth) is shown to account for significant reduction of two-photon excitation fluorescence and second harmonic generation signal produced at the focal plane of a laser-scanning two-photon microscope. The second- and third-order corrections recover 20-40% of the signal intensity expected for a transform-limited laser pulse, while the rest depends on the proper compensation of higher-order terms. It can be accomplished through the use of a pulse shaper by measuring and correcting all nonlinear spectral phase distortions.

Date Published: 13 February 2009
PDF: 6 pages
Proc. SPIE 7183, Multiphoton Microscopy in the Biomedical Sciences IX, 71830W (13 February 2009); doi: 10.1117/12.808429

Published in SPIE Proceedings Vol. 7183:
Multiphoton Microscopy in the Biomedical Sciences IX
Ammasi Periasamy; Peter T. C. So, Editor(s)