Trapping nanoparticles with optical tweezers (Vol. 52, No. 1)

Optical tweezers are a rapidly growing technology, and have opened up a wide variety of research applications in recent years. The devices operate by trapping particles at the focal points of tightly focused laser beams, allowing researchers to manipulate the objects without any physical contact. So far, optical tweezers have been used to confine objects just micrometres across – yet there is now a growing desire to extend the technology to nanometre-scale particles. Janine Emile and Olivier Emile at the University of Rennes, France, demonstrate a novel tweezer design, which enabled them to trap fluorescent particles just 200 nanometres across for the first time.

O. Emile, J. Emile, Nanometre optical trap based on stimulated emission in evanescence of a totally reflected Arago spot, Eur. Phys. J. E 43, 68 (2020)
[Abstract]