Title :
Various optical nonlinear processes in J-aggregates
Author_Institution :
Dept. of Phys., Tokyo Univ., Japan
fDate :
Aug. 30 1999-Sept. 3 1999
Abstract :
Molecular J-aggregates have attracted much attention because of ultrafast and large optical nonlinearity caused by excitonic resonance. Especially, porphyrin J-aggregates are materials of great interest since they are model substances for the light-harvesting mechanism in a system of antenna chlorophyll. In the present paper, we performed femtosecond pump-probe measurement of porphyrin J-aggregates and observed two new transitions from one-exciton to homo- and hetero-2-exciton states. Blue-shifted induced absorption was found around Q/sub x/-band due to the transition to homo-2-exciton states. J-aggregate size was estimated as N/spl ges/15 by using the energy shift from the monomer to the J-aggregates.
Keywords :
biexcitons; nonradiative transitions; optical saturable absorption; organic compounds; spectral line shift; time resolved spectra; visible spectra; J-aggregate size; bleaching; blue-shifted induced absorption; energy shift; exciton state transitions; excitonic resonance; femtosecond pump-probe measurement; hetero-2-exciton states; homo-2-exciton states; internal conversion; large optical nonlinearity; molecular J-aggregates; nonlinear optical processes; one-exciton states; population relaxation; porphyrin J-aggregates; ultrafast optical nonlinearity; Absorption; Aggregates; Delay; Nonlinear optics; Optical materials; Optical pumping; Physics; Resonance; Space vector pulse width modulation; Ultrafast optics;
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
DOI :
10.1109/CLEOPR.1999.814697
