[19a-PA2-1~13] 3.1 Basic optics and frontier of optics

▲ [19a-PA2-6] Laser trapping-induced periodical structure of polystyrene particles and its transformation at solution/glass interface

Ching-Hsiang Tseng¹, 〇(M1)Abdullah Kamit¹, Tetsuhiro Kudo¹, Hiroshi Masuhara^1,2 (1.Dept. of Appl. Chem., National Chiao Tung Univ., Taiwan, 2.Center for Emergent Functional Matter Science, National Chiao Tung Univ. Taiwan)

Keywords:laser trapping, polystyrene particles, light propogation

A single assembly much larger than the irradiated area is prepared. With time, structural transformation occurred from the outer to the central parts, and four-horn formation dynamics was directly observed with linearly polarized laser. Laser polarization dependence is demonstrated and the assembly formed by a circularly polarized laser. After laser irradiation, we switched off the laser for 10 sec and switched on again, which provides orientational/diffusional relaxation and reassembling keeping the high local concentration. Thus, structural control of the assembly from hexagonal to tetragonal was demonstrated together with the four horn formation. The hexagonal and tetragonal structures without horn and with 4 or 6 horns, respectively, are well interpreted in terms of propagation of the trapping laser through the assembled particles. Also we will demonstrate high potential of dual objective lens microscope in elucidating laser trapping dynamics.