Abstract
Transition dynamics from optical saturable absorption (SA) to reverse saturable absorption (RSA) in multi-walled carbon nanotube (MWCNT)-doped fast sol-gel hybrid organic/inorganic glasses was studied by optical transmission of 532 nm laser pulses. Exposure to 6 ns long, temporally isolated single pulses of energies between and exhibited SA. Exposure to 1.5 ns long, 11 kHz repetitive pulses of energies between and exhibited a gradual development of RSA at a rate that increases with the pulse energy. SA results were analyzed by the slow saturable absorber theory, yielding a ground-state absorption cross section for a density of states. The first excited state absorption cross section was for a much higher, , density of states. The SA/RSA transition temporal evolution effects were modeled by a five-level energy scheme. The numerical simulation yielded light-intensity dependent parameters: ground-state densities decreasing from to ; ground-state absorption cross sections increasing from to ; and excited state absorption cross sections increasing from to . The occurrence of such huge state densities is consistent with observation by others on the formation of ionized carbon-black particles as plasma states under illumination.
© 2015 Optical Society of America
Full Article | PDF ArticleMore Like This
Mariana Pokrass, Zeev Burshtein, Raz Gvishi, and Menachem Nathan
Opt. Mater. Express 2(6) 825-838 (2012)
Xiao-Liang Zhang, Zhi-Bo Liu, Xin Zhao, Xiao-Qing Yan, Xiao-Chun Li, and Jian-Guo Tian
Opt. Express 21(21) 25277-25284 (2013)
Chunfei Li, Lei Zhang, Ruibo Wang, Yinling Song, and Yuxiao Wang
J. Opt. Soc. Am. B 11(8) 1356-1360 (1994)