Browsing by Author "Ishihara, Hajime"

Now showing 1 - 2 of 2

Optical Manipulation by Nonlinear Response of Nanoparticles
(2017-01-01)
Ishihara, Hajime
;
Nakai, Tatsuya
;
Hoshina, Masayuki
;
Kudo, Tetsuhiro
;
應用化學系
We investigate the optical manipulation of nanoparticles with the resonant nonlinear optical response. Efficient trapping of nanoparticles observed in experiments under the resonance condition is elucidated by considering optical nonlinearity. Also, we propose the flexible optical manipulations of nanoparticles that have gain by optical pumping. The pulling force and the rotational switching are demonstrated, where the stimulated emission from nanoparticles with inverted population is considered. These results show that utilizing nonlinear optical effect will greatly enhance the degrees of freedom to manipulate nanoparticles.
Resonance optical trapping of individual dyedoped polystyrene particles with blue- and red-detuned lasers
(2017-03-06)
Kudo, Tetsuhiro
;
Ishihara, Hajime
;
Masuhara, Hiroshi
;
應用化學系
;
Department of Applied Chemistry
We demonstrate resonance optical trapping of individual dye-doped polystyrene particles with blue- and red-detuned lasers whose energy are higher and lower compared to electronic transition of the dye molecules, respectively. Through the measurement on how long individual particles are trapped at the focus, we here show that immobilization time of dye-doped particles becomes longer than that of bare ones. We directly confirm that the immobilization time of dye-doped particles trapped by the blue-detuned laser becomes longer than that by the red-detuned one. These findings are well interpreted by our previous theoretical proposal based on nonlinear optical response under intense laser field. It is discussed that the present result is an important step toward efficient and selective manipulation of molecules, quantum dots, nanoparticles, and various nanomaterials based on their quantum mechanical properties. (C) 2017 Optical Society of America