Femtosecond pulse broadening in the focal region of a two-photon fluorescence microscope

: Hanninen P., Hell S.

: 1994

: Bioimaging

: 2

: 3

: 117

: 121

: 5

: 0966-9051

DOI: https://doi.org/10.1002/1361-6374(199409)2:3<117::AID-BIO1>3.0.CO;2-9

: http://api.elsevier.com/content/abstract/scopus_id:0028608767

We have determined the broadening of 130 fs and 80 fs pulses in the focus of a high numerical aperture microscope. The focal pulse length has been measured by cross-correlating two counter-propagating pulses at the focus of a 4Pi confocal microscope. This method allowed us to determine the pulse length directly in the sample. Focusing through refractive index interfaces leads to pulse broadening depending on the change in refractive index. Our results are relevant to the field of two-photon fluorescence microscopy and studies of nonlinear phenomena with high spatial resolution.