Presentation on theme: "Forecasting two-photon absorption based on one-photon properties Mikhail Drobizhev, Zhiyong Suo, Aleks Rebane E. Scott Tarter, Benjamin D. Reeves, Brenda."— Presentation transcript:
Forecasting two-photon absorption based on one-photon properties Mikhail Drobizhev, Zhiyong Suo, Aleks Rebane E. Scott Tarter, Benjamin D. Reeves, Brenda Spangler Fanqing Meng, Charles W. Spangler Craig J. Wilson, Harry L. Anderson Department of Physics, Montana State University, Bozeman, MT Sensopath Technologies, Inc., Bozeman, MT MPA Technologies, Inc., Bozeman, MT Department of Chemistry, University of Oxford, Mansfield, Oxford, UK Nikolay Makarov, Department of Physics, Montana State University
Motivation: Why to predict? Which one is better? Why? N NC N NC
Motivation: What can quantum chemistry do? 0, E 0, 0 1, E 1, 1 m, E m, m C. Katan, S. Tretiak, M.H.V. Werts, A.J. Bain, R.J. Marsh, N. Leonczek, N. Nicolaou, E. Badaeva, O. Mongin, M. Blanchard-Desce, “Two-photon transitions in quadrupolar and branched chromophores: experiment and theory”, J. Phys. Chem. B 2007, 111, 9468-9483
Experiments: Setup Jobin Yvon Triax 550 Wavelength control PC LabView LN CCD sample L1 M1 F1 300 600 1200 l /mm -1 Laser system Coherent VERDI 6 4W CW 532nm Coherent MIRA 900 0.5W 795nm 150fs Coherent LEGEND Regen. Amplifier 1.1W 1kHz 795nm 150fs TOPAS-C 0.3W 1kHz 125fs OSA FROG Corre- lator Pulse characterization Filter wheel CCD camera control and DAQ Digital Oscilloscope Ref. Channel DAQ GPIB USB Serial Intensity control Ref. detector sample Hamamatsu Streak Camera C5680 Perkin-Elmer Lambda900 Spectrophotometer Perkin-Elmer LS 50B Luminescence Spectrometer L2
Calculations: How to? 0 1 Second order perturbation theory: Local field factors: Lorentz Onsager Dipole moments: Linear absorption, fluorescence Solvatochromic shifts Molecule densityFluorescence anisotropy
Calculations: Results R2R2 For molecule density ( =1) For anisotropy 2 (a) 2 (b) 2 (a) 2 (b) fLfL 0.83.31.4 fOfO 0.61.80.80.9
Conclusions See poster for details We show that the perturbation theory applied for two-level system quantitatively predicts the 2PA cross sections in dipolar molecules, provided that the necessary molecular parameters such as transition- and permanent dipole moments are independently measured. In most cases, the discrepancy between theory and experiment was less than 20%, and always less than 50%. This is the first time that such direct quantitative correspondence is demonstrated for a wide range of dipolar molecules. The overall significance of this work demonstrates a practical way how a set of relatively straightforward linear spectroscopic measurements can be used to study and predict nonlinear 2PA properties. Acknowledgements The work was supported by AFOSR.