DocumentCode :
348449
Title :
Picosecond Z-scan and optical Kerr gate in metalloporphyrin derivatives: origin of the nonlinearity and its use as an optical probe to determine pK
Author :
Bezerra, A.G., Jr. ; Borissevitch, I.E. ; De Araujo, R.E. ; Gomes, A.S.L. ; De Araujo, C.B.
Author_Institution :
Dept. de Fisica, Centro Federal de Educacao Tecnol. do Parana, Curitiba, Brazil
Volume :
2
fYear :
1999
fDate :
Aug. 30 1999-Sept. 3 1999
Firstpage :
569
Abstract :
In the present work, we report on Z-scan measurements of the nonlinear refractive index, of two water soluble porphyrins (PPh): a negatively charged meso-tetrakis(p-sulfonatophenyl)porphyrin and a positively charged meso-tetrakis(4-N-methylpyridiniumyl)porphyrin in their free-base forms and their Fe(III) and Mn(III) complexes, and the dependence of these characteristics on pH. Nonlinear absorption coefficients, proportional to the imaginary part of the nonlinear susceptibility, have also been measured. The data, together with time resolved measurements in the picosecond regime, led to the understanding of the origin of optical nonlinearities in the central atom out-of-plane porphyrin complexes. Furthermore, using the Z-scan technique, we were able to devise a method to determine pK points for these materials, as the pH was varied. The determination of pK is usually performed with linear optical absorption or EPR techniques.
Keywords :
infrared spectra; iron compounds; manganese compounds; optical Kerr effect; organic compounds; pH; paramagnetic resonance; time resolved spectra; ultraviolet spectra; visible spectra; EPR; Fe(III) complexes; Mn(III) complexes; free-base forms; linear optical absorption; meso-tetrakis(4-N-methylpyridiniumyl)porphyrin; meso-tetrakis(p-sulfonatophenyl)porphyrin; metalloporphyrin derivatives; nonlinear absorption coefficients; nonlinear refractive index; nonlinear susceptibility; nonlinearity; optical Kerr gate; optical probe; pK; picosecond Z-scan; time resolved measurements; Absorption; Atom optics; Atomic measurements; Current measurement; Nonlinear optics; Optical refraction; Optical variables control; Refractive index; Time measurement; Water;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Lasers and Electro-Optics, 1999. CLEO/Pacific Rim '99. The Pacific Rim Conference on
Conference_Location :
Seoul, South Korea
Print_ISBN :
0-7803-5661-6
Type :
conf
DOI :
10.1109/CLEOPR.1999.811574
Filename :
811574
Link To Document :
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