Numerical and Experimental Investigation on the Optical Manipulation from an Axicon Lensed Fiber

Here we numerically and experimentally studied the optical trapping on a microsphere from an axicon lensed fiber (ALF). The optical force from the fiber with different tapered lengths and by incident light at different wavelengths is calculated. Numerically, the microsphere can be trapped by the fiber with tapered outline y = +/-vertical bar x vertical bar/0.5 and y = +/-vertical bar x vertical bar at a short incident wavelength of 900 nm. While for the fiber with tapered outline y = +/- vertical bar x vertical bar/2, the microsphere can be trapped by the light with longer wavelength of 1100 nm, 1300 nm, or 1500 nm. The optical trapping to a polystyrene microsphere is experimentally demonstrated in a microfluidic channel and the corresponding optical force is derived according to the fluid flow speed. This study can provide a guidance for future tapered fibre design for optical trapping to microspheres.

Automated summary

This study numerically and experimentally investigated optical trapping on a microsphere using an axicon lensed fiber (ALF). The results show that the microsphere can be effectively trapped by fibers with different tapered lengths and incident light at different wavelengths. Experimental demonstration of optical trapping on polystyrene microspheres in a microfluidic channel was also conducted, and the corresponding optical forces were derived based on fluid flow speed. This study provides guidance for future design of tapered fibers for optical trapping of microspheres.