Spinning nanorods - active optical manipulation of semiconductor   nanorods using polarised light
  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. 
C. Robin Head, Elena Kammann, Marco Zanella, Liberato Manna and Pavlos   G. Lagoudakis
physics.bio-ph physics.optics