Spectral behavior of second harmonic signals from organic and non-organic materials in multiphoton microscopy.
Multimodal nonlinear microscopy allows imaging of highly ordered biological tissue due to spectral separation of nonlinear signals. This requires certain knowledge about the spectral distribution of the different nonlinear signals. In contrast to several publications we demonstrate a factor of [Formula: see text] relating the full width at half maximum of a gaussian laser pulse spectrum to the corresponding second harmonic pulse spectrum in the spatial domain by using a simple theoretical model. Experiments on monopotassium phosphate crystals (KDP-crystals) and on porcine corneal tissue support our theoretical predictions. Furthermore, no differences in spectral width were found for epi- and trans-detection of the second harmonic signal. Overall, these results may help to build an optimized multiphoton setup for spectral separation of nonlinear signals.
Institute of Applied Optics, Friedrich-Schiller-University Jena , Froebelstieg 1, 07743 Jena, Germany.
Tobias
T
Ehmke
Institute of Applied Optics, Friedrich-Schiller-University Jena , Froebelstieg 1, 07743 Jena, Germany.
Andreas
A
Knebl
Stephan
S
Reiss
Institut fuer Refraktive und Ophthalmo-Chirurgie (IROC) , Stockerstrasse 37, 8002 Zuerich, Switzerland.
Isaak R
IR
Fischinger
Institut fuer Refraktive und Ophthalmo-Chirurgie (IROC) , Stockerstrasse 37, 8002 Zuerich, Switzerland.
Theo G
TG
Seiler
Department of Ophthalmology, University of Rostock , 18057 Rostock, Germany.
Oliver
O
Stachs
Institute of Quantum Optics, University of Hanover , 30167 Hanover, Germany.
Alexander
A
Heisterkamp