Spinning nanorods - active optical manipulation of semiconductor nanorods using polarised light

TL;DR

This paper demonstrates how a single-beam optical trap can manipulate and control the orientation of semiconductor nanorods in solution using polarized light, with analysis confirming near single-particle precision.

Contribution

It introduces a method for three-dimensional manipulation and orientation control of semiconductor nanorods using polarized light in an optical trap.

Findings

Successful 3D manipulation of nanorods

Control over nanorod orientation via electric field polarization

Correlation between polarisation, trap stiffness, and emitted light intensity

Abstract

In this Letter we show how a single beam optical trap offers the means for three-dimensional manipulation of semiconductor nanorods in solution. Furthermore rotation of the direction of the electric field provides control over the orientation of the nanorods, which is shown by polarisation analysis of two photon induced fluorescence. Statistics over tens of trapped agglomerates reveal a correlation between the measured degree of polarisation, the trap stiffness and the intensity of the emitted light, confirming that we are approaching the single particle limit.