This talk reviews our recent work on optical trapping and propulsion of microparticles in hollow-core photonic crystal fibre (HC-PCF). HC-PCF uniquely allows low-loss propagation of light in a microscale hollow channel. The optical forces provided by the waveguide modes can be used to launch and propel microparticles and cells in liquid-filled HC-PCF. The particle dynamics are monitored using an in-fibre non-imaging Doppler velocimetry technique, offering a unique way to study viscous forces in microfluidic channels. We recently extended this work to particle propulsion in air-filled HC-PCF. These experiments have led to the discovery of a novel optothermal trapping mechanism, which has potential applications in lab-on-a-chip devices. In the last part of my talk, I will show that a coherent superposition of co-propagating spatial modes can create a mode-based ‘optical conveyor belt’ that combines long-range transport with a positional accuracy of about 1 μm. Finally, I will demonstrate a new type of "flying particle" sensor which maps the electric field strength along a HC-PCF by measuring the transverse displacement of an optically propelled charged microparticle. This unique sensor allows electric field mapping over long distances and is suitable for otherwise inaccessible or harsh environments.

报告人简介：Tijmen Euser received his MSc (2002) at the University of Twente in the Netherlands, working on a novel laser interference lithography process and growth of colloidal photonic crystals. In 2007 he completed his PhD research on "Ultrafast optical switching of photonic crystals” in the group of Prof. Willem Vos, both at the MESA+ Institute for Nanotechnology at the University of Twente and the FOM Institute for Atomic and Molecular Physics (AMOLF) in the Netherlands. Since 2007, he is a team leader and postdoctoral fellow in the Photonic Crystal Fibre (PCF) Science Division, headed by Prof. Philip Russell, at the Max Planck Institute for the Science of Light in Erlangen, Germany. His team has developed a range of novel applications of photonic crystal fibre, including: particle guidance in liquid-filled and air-filled PCF, photochemistry experiments on sub-µl volumes, and excitation of higher-order fibre modes using spatial light modulation techniques.