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Two-photon absorption of organic molecules: fundamentals and applications. N.S. Makarov, Prof. A. Rebane Department of Physics, Montana State University, Bozeman.
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Two-photon absorption of organic molecules: fundamentals and applications N.S. Makarov, Prof. A. Rebane Department of Physics, Montana State University, Bozeman • Development of a systematic approach for quantitative description of the 2PA cross section in low-lying transitions of dipolar molecules, where the lowest energy transition is simultaneously allowed for one-photon absorption and 2PA. The 2PA cross section is proportional to the square of the transition dipole moment, square of the difference in permanent dipole moments, and is inverse proportional to the absorption linewidth. • Establishment of a set of reliable 2PA standards with spectra covering a broad range of wavelengths, 550-1600 nm, measured with high fidelity and high wavelength resolution. • Applications of organic molecules in 3D optical memory and fluorescent microscopy.
Two-photon absorption standards in the 550-1600 nm excitation range: correction curve for accurate cross section calibration Absolute 2PA cross section: Relative 2PA spectrum: Correction curve:
Two-photon absorption standards in the 550-1600 nm excitation range: some spectra
Quantitative description of two-photon absorption in dipolar molecules with two-level model: Spectra1
Quantitative description of two-photon absorption in dipolar molecules with two-level model: Spectra2
Quantitative description of two-photon absorption in dipolar molecules with two-level model: Molecular parameters
Quantitative description of two-photon absorption in dipolar molecules with two-level model
Applications of two-photon absorption in organic molecules: 3D memory. Basics
3D memory: molecular switching Frequency, cm-1 16500 16000 15500 15000 14500 14000 13500 13000 12500 O O O Qx(T1) O N N N N N N H 0 0.8 N N N H H N H N N 60 s N N N N O O 480 s 2580 s 0.6 Qy(T1) T1 T2 Qx,y (T2) Optical density 0.4 nL 0.2 0 600 625 650 675 700 725 750 775 800 Wavelength, nm
3D memory: simulations Pc3Nc at T = 77 K
3D memory: molecules Bu Bu Bu Bu t t t t 2 2 2 1 1 1 3 3 3 O O O O O O O O O O O O N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N H H H N N N H H H N N N N N N H H H N N N H H H H H H H N N N N N N N N H H H H Bu Bu Bu Bu t t t t N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N O O O H H H O O O O O O O O O Bu Bu Bu Bu t t t t O O O O O O 5 5 5 O O O 6 6 6 4 4 4 O O O O O O N N N N N N N N N N N N O O O N N N N N N N N N N N N N N N H H H N N N N N N H H H H H H N N N N N N H H H H H H N N N N N N H H H O O O N N N N N N N N N N N N N N N N N N N N N N N N O O O N N N O O O O O O O O O O O O O O O O O O O O O
3D memory: measured molecular parameters • The change of substituents from butyl groups at -positions to alkoxy groups at -positions (molecule 1 vs. 2) increases 2PA cross-sections by a factor of nearly 2. This also results in the red shift of entire 1PA spectrum by 30 nm (500 cm-1). The 2PA spectrum also experiences the red shift. This shows that addition of oxygen atoms increases -conjugation. • Addition of extra CHO group (molecule 1 vs. 6) results in a slight decrease of 2PA cross-section as compared to better purified compound 1 and in slight increase of the cross-sections compared to 1a and 1b. The 1PA spectrum practically does not change. • Substituting an external benzene ring with another alkoxy group (molecule 4 vs. 6) produces a nearly symmetrical molecule. This shifts both Qx and Qy peaks closer to each other so that they overlap. A similar shift appears in 2PA spectrum. The value of 2PA cross-section reduces by a factor of nearly 2, which is probably because of reduce of the difference in dipole moments in more symmetrical molecule. • Addition of extra hydrogen atoms (molecule 3 vs. 4) reduces degree of symmetry. This slightly increases the 2PA cross-section for molecule 3. However, its cross-section is smaller than for molecules 1 and 6. The reason is more symmetry and thus less difference in dipole moments in the molecule 3 • Change of substituent from molecule 3 to 5 makes the molecule less symmetrical, and thus increase 2PA cross-section. However, molecule 6, and especially 1 have the highest 2PA cross-sections among all studied samples.
3D memory: Efficiency comparison *For molecules 3 and 5 absorption spectra of tautomer forms significantly overlaps that makes them not practical as photochromes for 3D optical memory
Applications of two-photon absorption in organic molecules: imaging. Sensing local environment: pH-sensitivity
Imaging: Fluorescing proteins DsRed- Discosoma sp. coral, (Indo-Pacific area) GFP- Aequorea victoria, (Pacific Northwest) Katushka- Entacmaea quadricolor, (Moscow pet shop…)
Fluorescing proteins: mutations in the chromophore and surrounding
Conclusions • 2PA of 15 commercially available dyes in 550–1600 nm • 10% estimated accuracy of 2PA cross sections • Values are in good agreement with literature data (fluorescence technique) • Data can be used as reference for determining absolute 2PA cross sections and spectra • 2PA cross section in dipolar molecules is evaluated: (a) by direct measurement and (b) by using perturbation theory formula • For at least half of the systems studied, the discrepancy between (a) and (b) is less than 20%, and for all molecules less than 50% • This is the first time that such direct quantitative correspondence is demonstrated for a wide range of molecules • Storage materials need to have high molecular 2PA cross section, 2>103-104 GM • Two-photon sensitivity and the possibility of photochemical transformation are important • Choice of frequency and combination of 1PA and 2PA properties allow minimizing the negative impact of near resonance hot band absorption • Standard laser dye can be used to determine polarity of the local environment via 1PA or 2PA excitation • The same dye is sensitive to pH level • Resonance enhancement of 2PA cross section in proteins is observed • A wider series of the proteins is measured, and the structure-to property relations to be determined allowing for smart mutations of the protein • Spectroscopic properties of a set of proteins are measured
Publications (2005 – now) • Drobizhev M., Makarov N.S., Stepanenko Y., Rebane A., “Near-infrared two photon absorption in phtalocyanines: Enhancement of lowest gerade-gerade transition by symmetrical electron-accepting substitution”, J. Chem. Phys., vol. 124, 2006, 224701. • Makarov N.S., Rebane A., Drobizhev M., Wolleb H., Spahni H., “Optimizing two-photon absorption for volumetric optical data storage”, J. Opt. Soc. Am. B, vol. 24, № 8, 2007, pp. 1874-1885. • Rogers J.E., Slagle J.E., Krein D.M., Burke A.R., Hall B.C., Fratini A., McLean D.G., Fleitz P.A., Cooper T.M., Drobizhev M., Makarov N.S., Rebane A., Kim K.-Y., Farley R., Schanze K.S., “Platinum acetylide two-photon chromophores”, Inorganic Chem., vol. 46, 2007, pp. 6483-6494. • Drobizhev M., Makarov N.S., Rebane A., Wolleb H., Spahni H., “Very efficient two-photon induced photo-tautomerization in non-symmetrical phthalocyanines”, J. Luminescence, vol. 128, 2008, 217-222. • Drobizhev M, Makarov N.S., Rebane A, de la Torre G., Torres T., “Strong two-photon absorption in push-pull phthalocyanines: role of resonance enhancement and permanent dipole moment change upon excitation”, J. Phys. Chem., vol. 112, 2008, 848-859. • Drobizhev M., Makarov N.S., Hughes T., Rebane A., “Resonance Enhancement of Two-Photon Absorption in Fluorescent Proteins”, J. Phys. Chem., vol. 111, 2007, 14051-14054. • Makarov N.S., Drobizhev M, Rebane A, “Two-photon absorption standards in the 550-1600 nm excitation wavelength range”, Opt. Expr., vol. 16, 2008, 4029-4047. • Makarov N.S., Rebane A., Drobizhev M., Peone D., Wolleb H., Spahni H., “Experimental characterization of two-photon materials for fast rewritable optical data storage”, Proc. SPIE, vol. 6330, 2006, p. 63300K. • Drobizhev M., Makarov N.S., Rebane A., Wolleb H., Spahni H., “Phthalocyanine molecules with extremely strong two-photon absorption for 3D rewritable optical information storage”, Proc. SPIE, vol. 6308, 2006, p. 630803. • Makarov N.S., Rebane A., Drobizhev M., Wolleb H., Spahni H., “Resonance enhancement of two-photon cross section for optical storage in the presence of hot band absorption”, Proc. SPIE, vol. 6470, 2007, p. 64700R. • Rebane A., Makarov N.S., Drobizhev M., Spangler C.W., Gong A., Meng. F., “Broad bandwidth near-IR two-photon absorption in conjugated porphyrins core dendrimers”, Proc. SPIE, vol. 6653, 2007, p. 665307. • Makarov N.S., Drobizhev M., Rebane A., “Two-photon absorption standards in the 550-1600 nm excitation range: establishing a correction curve for accurate cross section calibration”, Proc. SPIE, vol. 6891, 2008. • Rebane A., Drobizhev M., Makarov N.S., “Ultrafast coherent transients and time-space holography in inhomogeneously broadened two-photon absorbing medium”, Proc. SPIE, vol. 6903, 2008. Acknowledgement This work is supported by AFOSR, CBIN, MBRCT
Presentations (2005 – now) • Makarov N.S., Rebane A.K., Drobizhev M., “Optimization of femtosecond two-photon storage by spectral pulse shaping”, Optics and Photonics 2005. • Makarov N.S., Rebane A.K., Drobizhev M., “Optimization of chromophores for two-photon optical volumetric storage”, Polymer chemistry and polymer matrix composites (air force office of scientific research) 2005. • Makarov N.S., Rebane A.K., Drobizhev M., “Optimization of fast rewritable optical storage in near-resonant conditions”, Optical science and laser technology conference 2005. • Drobizhev M., Makarov N.S., Rebane A., Makarova E.A., Luk’yanets E.A., “Two-photon absorption in tetraazachlorin and its benzoand 2,3-naphtho-fused derivatives: effective symmetry of -conjugation pathway”, fourth International Conference on Porphyrins and Phtalocyanines 2006. • Rebane A., Drobizhev M., Makarov N.S., de la Torre G., Torres T., “Modulation of two-photon absorption of asymmetricallysubstituted phthalocyanines by the position of inner protons (tautomerization) and structure of linking group”, fourth International Conference on Porphyrins and Phtalocyanines 2006. • Rebane A., Drobizhev M., Makarov N.S., Koszarna B., Gryko D.T., “The effect of electron withdrawing substituents on two-photon absorption properties of A3-corolles”, fourth International Conference on Porphyrins and Phtalocyanines 2006. • Drobizhev M., Makarov N.S., Rebane A., Wolleb H., Spahni H., “Very efficient two-photon induced photo-tautomerization in non-symmetrical phtalocyanines”, 9th Conference on Hole Burning, Single Molecule and Related Spectroscopies: Science and Applications 2006. • Drobizhev M., Makarov N.S., Rebane A., Wolleb H., Spahni H., “Phtalocyanine molecules with very strong two-photon absorption for 3D rewritable optical information storage”, Optics&Photonics 2006. • Makarov N.S., Drobizhev M., Rebane A., Wolleb H., Spahni H., Peone D., “Experimental characterization of two-photon materials for fast rewritable optical data storage”, Optics&Photonics 2006. • Drobizhev M., Makarov N.S., Rebane A., Stepanenko Y., Makarova E.A., Lukyanets E., de la Torre G., Torres T., “Two-photon absorption spectroscopy of phtalocyanines and related compounds”, Optics&Photonics 2006. • Makarov N.S., Drobizhev M., Rebane A., Wolleb H., Spahni H., Peone D., “Materials for 3D optical storage: two-photon access vs. one-photon background”, OpTeC 2006. • Makarov N.S., Drobizhev M., Rebane A., Wolleb H., Spahni H., “Experimental characterization of two-photon materials for fast rewritable optical data storage”, OpTeC 2006. • Makarov N.S., Rebane A., Drobizhev M., Wolleb H., Spahni H., “Optimizing two-photon optical storage in the presence of hot band absorption”, Photonics West 2007. • Makarov N.S., Rebane A., Drobizhev M., Wolleb H., Spahni H., “Resonance enhancement of two-photon cross section for optical storage in the presence of hot band absorption”, Photonics West 2007. • Drobizhev M., Makarov N.S., Rebane A., Hughes T.E., “Observation of new strong high-frequency feature in two-photon absorption spectrum of GFP and its description within three-level model with resonance enhancement”, Annual Meeting of Biophysical Society 2007. • Makarov N.S., Rebane A., Drobizhev M., Suo Z., Spangler C.W., Spangler B.D., Meng F., Anderson H.L., Wilson C.J., “Quantitative description two-photon absorption in dipolar molecules with two-level model”, Optics&Photonics 2007. • Drobizhev M., Makarov N.S., Rebane A., Hughes T.E., “Observation of new strong high-frequency feature in two-photon absorption spectrum of GFP and its description with three-level model with resonance enhancement”, Optics&Photonics 2007. • Drobizhev M., Makarov N.S., Rebane A., de la Torre G., Torres T., Wolleb H., Spahni H., “Two-photon and excited-state absorption in asymmetric phthalocyanines, push-pull phthalocyanines, and phthalocyanines: electron-acceptor diads”, Optics&Photonics 2007. • Rebane A., Drobizhev M., Makarov N.S., Spangler C.W., Gong A., Meng. F., “Broad bandwidth near-IR two-photon absorption in conjugated porphyrins core dendrimers”, Optics&Photonics 2007. • Makarov N.S., Rebane A., Drobizhev M., Suo Z., Spangler C.W., Spangler B.D., Meng F., Anderson H.L., Wilson C.J., “Forecasting two-photon absorption based on one-photon properties”, OpTeC 2007. • Makarov N.S., Rebane A., Drobizhev M., Suo Z., Spangler C.W., Spangler B.D., Meng F., Anderson H.L., Wilson C.J., “Quantitative description two-photon absorption in dipolar molecules with two-level model”, OpTeC 2007. • Drobizhev M., Makarov N.S., Rebane A., Hughes T.E., “Observation of new strong high-frequency feature in two-photon absorption spectrum of GFP and its description with three-level model with resonance enhancement”, OpTeC 2007. • Drobizhev M., Makarov N.S., Rebane A., “Two-photon absorption spectroscopy of phthalocyanines”, OpTeC 2007. • Drobizhev M., Makarov N.S., Rebane A., Hughes T.E. “Strong resonance enhancement of two-photon absorption in fluorescent proteins”, Photonics West 2008. • Makarov N.S., Drobizhev M., Rebane A., “Two-photon absorption standards in the 550-1600 nm excitation range: establishing a correction curve for accurate cross section calibration”, Photonics West 2008. • Rebane A., Drobizhev M., Makarov N.S., “Ultrafast coherent transients and time-space holography in inhomogeneously broadened two-photon absorbing medium”, Photonics West 2008.
Grants and awards • Soros student 2000, 2001, 2002, 2003 • CRDF travel grant 2001 • Russian Federation’s President grant 2001 • Diploma of Ministry of Education RF for the best scientific student work in natural, technical and humanitarian sciences 2001 • RFBR travel grants 2002 • Grant of Saint-Petersburg administration for students, aspirants and young specialists-2002 • Medal of Russian Academy of Science for the best student work in general physics and astronomy 2002 • SPIE Scholarship grant 2003 • Diploma for best university graduating student 2003 • Dynasty foundation grant 2003 • Medal of Ministry of Education RF for the best scientific student work in natural, technical and humanitarian sciences 2003 • Grant of Saint-Petersburg administration for students, aspirants and young specialists 2004 • Soros aspirant 2004 • SPIE Scholarship grant 2006 • BACUS Photomask Scholarship 2007 • SPIE D.J. Lovell Scholarship 2008 Thanks to Prof. Aleksander Rebane, Dr. Mikhail Drobizhev, Dr. Yuryi Stepanenko, Desire Peone, Daniel Koepke, Erich Beuerman, David Call-Segarra, and all our collaborators.