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Obesity Summit 2018 & Diabetes Conference 2018 & Laser Photonics Conference 2018 Biomedical Research | ISSN: 0976-1683| Volume 29
3rd INTERNATIONAL OBESITY SUMMIT AND EXPO
&
&
DIABETES, NUTRITION, METABOLISM & MEDICARE
2nd International Conference on
Joint Event on
OF EXCELLENCE
IN INTERNATIONAL
MEETINGS
YEARS
LASER, OPTICS AND PHOTONICS
World Conference on
Albrecht Lindinger, Biomed Res 2018, Volume 29 | DOI: 10.4066/biomedicalresearch-C7-018
TAILORED LASER PULSES FOR SELECTIVE
MULTIPHOTON EXCITATION AFTER
OPTICAL FIBERS
In recent years ultrashort laser pulses were increasingly used for multiphoton
excited imaging in biological samples. Fluorescent molecules were employed
to distinguish between tissue structures and a high contrast is favorable for
microscopic imaging. There to, laser pulse shaping provides a powerful tool by
tailoring the pulses such that two species may selectively be excited. In par-
ticular, shaping of laser pulses is applied to exploit intrapulse interference ef-
fects in multiphoton excited fluorescence. Furthermore, laser pulse shaping is
successfully used to control photo-induced molecular processes. Novel pulse
shaping schemes for simultaneous phase, amplitude, and polarization control
were designed recently, and a parametric sub pulse encoding was developed.
Thereby, physically intuitive parameters like chirps and polarization states can
be controlled. This yields new perspectives of utilizing all properties of the light
field in the pulse modulation.
This contribution reports pulse shaping methods for improved multiphoton
excited fluorescence contrast after transmitting a nanostructured kagome fi-
ber. The distortions due to the optical fiber properties are precompensated to
receive predefined shaped pulses at the distal end of the fiber. Special anti-
symmetric phase functions are employed for scans of the multiphoton exci-
tation fluorescence. Application of phase-shaped pulses for imaging contrast
enhancement is demonstrated for the auto fluorescing vitamins A and B2.
Moreover, particularly phase and polarization tailored pulses are generated to
optimally excite one dye in one polarization direction and simultaneously the
other dye in the other polarization direction, thereby utilizing the anisotropy of
the dye molecules. The presented method has a high potential for endoscopic
applications due to the unique kagome fiber properties for imaging of endog-
enous fluorophores.
Biography
Albrecht Lindinger has earned his PhD on helium
droplet spectroscopy in Gottingen in the group of
J-P Toennies and took his postdoc term in Berkeley
in the group of D Neumark. He received his habili-
tation in the field of coherent control at the Freie
Universität Berlin in the group of L Wöste and is
now a lecturer (PD) in the Institute of Experimental
Physics at the Freie Universität Berlin. He has pub-
lished 84 peer-reviewed papers in reputed journals.
His main scientific interests are laser optics, coher-
ent control, and biophotonics.
Albrecht Lindinger
Freie Universität Berlin, Germany