Optical trapping is an established field for movement of micron-size objects and cells. However, trapping of metal nanoparticles, nanowires, nanorods and molecules has received little attention. Nanoparticles are more challenging to optically trap and they offer ample new phenomena to explore, for example the plasmon resonance. Resonance and size effects have an impact upon trapping forces that causes nanopartiele trapping to differ from micromanipulation of larger micron-sized objects. There are numerous theoretical approaches to calculate optical forces exerted on trapped nanoparticles. Their combination and comparison gives the reader deeper understanding of the physical processes in an optical trap. A close look into the key experiments to date demonstrates the feasibility of trapping and provides a grasp of the enormous possibilities that remain to be explored. When constructing a single-beam optical trap, particular emphasis has to be placed on the choice of imaging for the trapping and confinement of nanoparticles.
Bibliographical noteFunding Information:
The authors thank Woei Ming Lee for the power spectrum in Fig. 13. KD is a Royal Society Wolfson Research Merit Award Holder. MD acknowledges the financial support of the Stiftung der Deutschen Wirtschaft, sdw (Foundation of German Business) and SPIE. The authors thank the UK Engineering and Physical Sciences Research Council for funding.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics