Laser manipulation of a smectic liquid-crystal droplet
CREST-JST & Research Institute for Electronic Science, Hokkaido University, N21-W10, CRIS Bldg., 001-0021, Kita-ku, Sapporo, Japan
Accepted: 8 August 2006
Published online: 5 September 2006
The laser trapping of a smectic-A liquid-crystal micro-droplet was spatially traced during its transient into the trapped position. The lateral and angular orientation of the droplet were determined and followed in time during the axial descent of the micro-droplet into the stationary trapped position using the analysis of polarization changes of the light passed through the droplet with temporal resolution of a video refresh rate of 30 ms. The spatial resolution of 0.1-1μm has been achieved for typical laser trapping powers of 2-600 mW. The axial profile of a laser trapping force (an ellipticity of the focal spot) has been determined. The laser trapping mechanism of smectic micro-droplets is discussed in terms of minimization of a light-droplet interaction.
PACS: 87.80.Cc Optical trapping – / 42.70.-a Optical materials – / 42.70.Df Liquid crystals – / 61.30.-v Structure of solids and liquids; crystallography: Liquid crystals –
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2006