Thickness dependant effective radius of an optical trapping toward water-air interface

Abstract

This study aimed to determine the effect of sample thickness on optical trapping towards water-air interface. 3 μm polystyrene bead was diluted in deionised water and transferred to special test cell design to form 18, 70 and 141 μm. Bead was trapped by 975 nm laser from 20 to 220 kW/cm2 from the bottom glass-water interface towards water-air interface. The result showed that the bead is more confined with smaller effective radius in higher water thickness.