Title :
Photoexcitations in luminescent conjugated polymers
Author :
Dogariu, A. ; Vacar, D. ; Heeger, A.J.
Author_Institution :
Inst. for Polymers & Org. Solids, California Univ., Santa Barbara, CA, USA
Abstract :
Summary form only given. Using ultrafast time-delayed pump-probe measurements, we study the mechanisms leading to stimulated emission (SE) and photoinduced absorption (PA) in thin films and solutions of poly[2-methoxy-5-(2´-ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV). We monitor the change in the excited-state spectra by means of femtosecond time-resolved nonlinear spectroscopy in order to identify the SE and PA spectral regions and their time evolution. We also present femtosecond gain-narrowing measurements and the influence of the PA on the photoluminescence spectra. We demonstrate bimolecular interaction at high excitation densities and independence of the PA and SE dynamics on the pump wavelength.
Keywords :
conducting polymers; nonlinear optics; optical polymers; photoexcitation; photoluminescence; stimulated emission; superradiance; time resolved spectra; ASE; bimolecular interaction; excited-state spectra; femtosecond gain-narrowing measurements; femtosecond time-resolved nonlinear spectroscopy; high excitation densities; luminescent conjugated polymers; photoexcitations; photoinduced absorption; photoluminescence spectra; poly[2-methoxy-5-(2´-ethylhexyloxy)-1,4-phenylenevinylene]; polymer laser materials; solutions; stimulated emission; thin films; time evolution; ultrafast time-delayed pump-probe measurements; Distributed Bragg reflectors; Laser excitation; Laser stability; Laser theory; Mirrors; Optical films; Polymers; Surface emitting lasers; Temperature dependence; Vertical cavity surface emitting lasers;
Conference_Titel :
Lasers and Electro-Optics, 1998. CLEO 98. Technical Digest. Summaries of papers presented at the Conference on
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
1-55752-339-0
DOI :
10.1109/CLEO.1998.675789