The effects of oxygen concentration and light intensity on the photostability of zwitterionic chromophores

Photostability measurements at different oxygen partial pressures and light intensities have been made on host-guest films containing amorphous polycarbonate and an organic chromophore with a high second order nonlinear optical figure of merit. We find that the photodegradation quantum efficiency dramatically increases with increasing oxygen partial pressure. At very low oxygen partial pressures (8×10−6 bar) the average number of photons required to photodegrade a chromophore is as high as 2×108 at 655 nm. The photodegradation quantum efficiency in air is observed to decrease with increasing optical intensity. We show that this is due to a reduced oxygen content in the film caused by chromophore photodegradation rather than ground state bleaching. There is an anomalous increase and then decrease in the photoluminescence intensity that cannot easily be explained.

[1]  Paresh Chandra Ray,et al.  Nonlinear optical properties of zwitterionic merocyanine aggregates: role of intermolecular interaction and solvent polarity. , 2005, The journal of physical chemistry. A.

[2]  G. Stegeman,et al.  Photodegradation of selected π-conjugated electro-optic chromophores , 2003 .

[3]  P. Günter,et al.  Photochemical stability of nonlinear optical chromophores in polymeric and crystalline materials. , 2008, The Journal of chemical physics.

[4]  Koen Clays,et al.  Strategies for optimising the second-order nonlinear optical response in zwitterionic merocyanine dyes , 2009 .

[5]  Larry R. Dalton,et al.  Photostability studies of π-conjugated chromophores with resonant and nonresonant light excitation for long-life polymeric telecommunication devices , 2007 .

[6]  Antao Chen,et al.  From molecules to opto-chips: organic electro-optic materials , 1999 .

[7]  Alan F. Benner,et al.  Exploitation of optical interconnects in future server architectures , 2005 .

[8]  Sankaran Thayumanavan,et al.  Photostability of electro-optic polymers possessing chromophores with efficient amino donors and cyano-containing acceptors , 2001 .

[9]  G. D. Boyd,et al.  OPTICALLY‐INDUCED REFRACTIVE INDEX INHOMOGENEITIES IN LiNbO3 AND LiTaO3 , 1966 .

[10]  C. Bosshard,et al.  Organic Nonlinear Optical Materials , 2001, CLEO/Europe Conference on Lasers and Electro-Optics.

[11]  S Thayumanavan,et al.  Systematic behavior of electro-optic chromophore photostability. , 2000, Optics letters.

[12]  Peter Günter,et al.  Generation of terahertz pulses through optical rectification in organic DAST crystals: theory and experiment , 2006 .

[13]  Larry R. Dalton,et al.  Polymer-based optical waveguides: Materials, processing, and devices , 2002 .

[14]  Yuxia Zhao,et al.  Synthesis and linear/nonlinear optical properties of a new class of ?RHS? NLO chromophoreElectronic supplementary information (ESI) available: synthesis and characterisation data. See http://www.rsc.org/suppdata/jm/b3/b315274j/ , 2004 .

[15]  J. B. Birks,et al.  Photophysics of aromatic molecules , 1970 .

[16]  Andrew J. Kay,et al.  The effects of molecular aggregation and isomerization on the fluorescence of “push-pull” hyperpolarizable chromophores , 2006 .

[17]  Jerry March,et al.  Advanced Organic Chemistry: Reactions, Mechanisms, and Structure , 1977 .

[18]  Tony C. Kowalczyk,et al.  Photodegradation of azobenzene nonlinear optical chromophores: the influence of structure and environment , 2000 .

[19]  J. Federici,et al.  THz imaging and sensing for security applications—explosives, weapons and drugs , 2005 .

[20]  Bojie Wang,et al.  Activation barriers for oxygen diffusion in polystyrene and polycarbonate glasses : effects of low molecular weight additives , 1994 .

[21]  Y. Ren,et al.  Waveguide photodegradation of nonlinear optical organic chromophores in polymeric films. , 2000, Applied optics.

[22]  Zhang,et al.  Low (Sub-1-volt) halfwave voltage polymeric electro-optic modulators achieved by controlling chromophore shape , 2000, Science.

[23]  John Crank,et al.  The Mathematics Of Diffusion , 1956 .

[24]  M. Kasha,et al.  The exciton model in molecular spectroscopy , 1965 .

[25]  D. Reinhoudt,et al.  Enhanced poling efficiency in highly thermal and photostable nonlinear optical chromophores , 2008 .

[26]  Larry R. Dalton,et al.  Modeling Photobleaching of Optical Chromophores: Light-Intensity Effects in Precise Trimming of Integrated Polymer Devices , 2008 .

[27]  A. Dubois,et al.  Photostability of dye molecules trapped in solid matrices. , 1996, Applied optics.

[28]  Larry R. Dalton,et al.  Nonlinear Optical Polymeric Materials: From Chromophore Design to Commercial Applications , 2002 .

[29]  Larry R. Dalton,et al.  Resonance enhanced THz generation in electro-optic polymers near the absorption maximum , 2004 .

[30]  G. Giusti,et al.  DABCO effect on the photodegradation of photochromic compounds in spiro[indoline-pyran] and spiro[indoline-oxazine] series , 1995 .

[31]  G I Stegeman,et al.  Effect of temperature and atmospheric environment on the photodegradation of some Disperse Red 1-type polymers. , 1999, Optics letters.