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Koide, Kaoru; Yamakawa, Minoru*
Chikyu O Nozoku Fuaibasukopu; Rikujo Kussaku Saiensu, Puran, p.75 - 79, 2005/12
no abstracts in English
Yamada, Hidetaka; Yokoyama, Keiichi; Teranishi, Yoshiaki*; Sugita, Akihiro; Shirai, Toshizo*; Aoyama, Makoto; Akahane, Yutaka; Inoue, Norihiro*; Ueda, Hideki*; Yamakawa, Koichi; et al.
Physical Review A, 72(6), p.063404_1 - 063404_5, 2005/12
Times Cited Count:6 Percentile:31.16(Optics)A demonstration of coherent quantum control for ultrafast precise selection of closely-lying states is reported. A phase-locked pair of femtosecond laser pulses is generated through a pulse shaper to excite the ground-state cesium atom to the Cs(7) and Cs(7) states by two-photon absorption. The excited state population is measured by detecting fluorescence from each spin-orbit state. By controlling the phase-difference of the pulse pair, an ultrafast precise selection is accomplished. The contrast ratio of the maximal to minimal selection ratio exceeds 10 with the delay less than 400 fs.
Yokoyama, Keiichi; Teranishi, Yoshiaki; Toya, Yukio; Shirai, Toshizo; Fukuda, Yuji; Aoyama, Makoto; Akahane, Yutaka; Inoue, Norihiro*; Ueda, Hideki; Yamakawa, Koichi; et al.
Journal of Chemical Physics, 120(20), p.9446 - 9449, 2004/05
Times Cited Count:6 Percentile:18.74(Chemistry, Physical)Optimal laser control for ultrafast selection of closely-lying excited states, whose energy separation is smaller than the laser bandwidth, is reported on the two-photon transition of atomic cesium; Cs(6S 7D, J = 5/2 and 3/2). Selective excitation was carried out by pulse shaping of ultrashort laser pulses which were adaptively modulated in a closed-loop learning system handling eight parameters representing the electric field. Two-color fluorescence from the respective excited states was monitored to measure the selectivity. The fitness used in the learning algorithm was evaluated from the ratio of the fluorescence yield. After fifty generations, a pair of nearly transform-limitted pulses were obtained as an optimal pulse shape, proving the effectiveness of "Ramsey fringes" mechanism. The contrast of the selection ratio was improved by 30 % from the simple "Ramsey fringes" experiment.
Yamakawa, Minoru;
Symposium on geo-pollution problem with special reference to hazard waste and excavated matters, 0 Pages, 1999/00
None
; ; ; Shimizu, Kazuhiko; Miyahara, Kaname; Yamakawa, Minoru
Waste Management 99 (WM99), 0 Pages, 1999/00
None
Umeki, Hiroyuki; ; ; Yamakawa, Minoru; Ishikawa, Hirohisa
Proceedings of 19th Annual Conference of the Canadian Nuclear Society, p.74 - 81, 1998/00
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Yamakawa, Minoru
Nihon Genshiryoku Gakkai-Shi, 35(11), p.978 - 984, 1993/00
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)None
Yoshida, Eiichi; Osawa, Hideaki; Yanagizawa, Koichi; Yamakawa, Minoru
Oyo Chishitsu, 30(3), p.131 - 142, 1989/00
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