caa a22 4500 445306041 CHVBK 20180317142613.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s10762-010-9677-1 doi (NATIONALLICENCE)springer-10.1007/s10762-010-9677-1 Observation of Amplified Stimulated Terahertz Emission from Optically Pumped Heteroepitaxial Graphene-on-Silicon Materials [Elektronische Daten] [Hiromi Karasawa, Tsuneyoshi Komori, Takayuki Watanabe, Akira Satou, Hirokazu Fukidome, Maki Suemitsu, Victor Ryzhii, Taiichi Otsuji] We experimentally observed the fast relaxation and relatively slow recombination dynamics of photogenerated electrons/holes in a heteroepitaxial graphene-on-Si material under pumping with a 1550-nm, 80-fs pulsed fiber laser and probing with the corresponding terahertz beam generated by and synchronized with the pumping laser. The time-resolved electric-nearfield intensity originating from the coherent terahertz photon emission is electrooptically sampled in total-reflection geometry. The Fourier spectrum fairly agrees the product of the negative dynamic conductivity and the expected THz photon spectrum reflecting the pumping photon spectrum. This phenomenon is interpreted as an amplified stimulated terahertz emission. Springer Science+Business Media, LLC, 2010 Graphene nationallicence Terahertz nationallicence Negative-dynamic conductivity nationallicence Population inversion nationallicence Stimulated emission nationallicence GOS nationallicence Coherent nationallicence Karasawa Hiromi Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut Komori Tsuneyoshi Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut Watanabe Takayuki Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut Satou Akira Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut Fukidome Hirokazu Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut Suemitsu Maki Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut Ryzhii Victor Depertment of Computer Science and Engineering, University of Aizu, 965-8580, Aizu-Wakamatsu, Japan aut Otsuji Taiichi Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut Journal of Infrared, Millimeter, and Terahertz Waves Springer US; http://www.springer-ny.com 32/5(2011-05-01), 655-665 1866-6892 32:5<655 2011 32 10762 https://doi.org/10.1007/s10762-010-9677-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10762-010-9677-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Karasawa Hiromi Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut NATIONALLICENCE 700 1- Komori Tsuneyoshi Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut NATIONALLICENCE 700 1- Watanabe Takayuki Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut NATIONALLICENCE 700 1- Satou Akira Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut NATIONALLICENCE 700 1- Fukidome Hirokazu Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut NATIONALLICENCE 700 1- Suemitsu Maki Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut NATIONALLICENCE 700 1- Ryzhii Victor Depertment of Computer Science and Engineering, University of Aizu, 965-8580, Aizu-Wakamatsu, Japan aut NATIONALLICENCE 700 1- Otsuji Taiichi Research Institute of Electrical Communication, Tohoku University, 2-1-1 katahira, Aoba-ku, 980-8577, Sendai, Miyagi, Japan aut NATIONALLICENCE 773 0- Journal of Infrared, Millimeter, and Terahertz Waves Springer US; http://www.springer-ny.com 32/5(2011-05-01), 655-665 1866-6892 32:5<655 2011 32 10762 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer