Structured light to miniaturize optical micromanipulation

Optical trapping is the science of holding and immobilizing particles and cells, for further manipulation and spectroscopic studies. Enhancing the application of optical trapping is limited by size and flexibility of this tool, mostly limited to high numerical aperture objectives. In this work, we show the potential of using structured light to further enhance the capabilities of optical fibres as optical tweezers, to be used for applications in which space and throughput are of importance. Using femtosecond two photon direct laser writing, we produce accurately designed micro-optic probes at the tip of optical fibres to enhance the light field for trapping single particles as well as single live cells. Enhanced trapping efficiency, ease of transporting trapped particle, and potential of performing wide spectrum spectroscopy on the trapped entity are the advantages of the present approach.