Paper published in Optics Letters

Our paper 'Optical trapping of single walled carbon nanotubes with cylindrical vector beams has been published as M. G. Donato et al, Opt. Lett. 37 3381-3383 (2012).  

From the abstract: We use laser beams with radial and azimuthal polarization to optically trap carbon nanotubes. We measure force constants and trap parameters as a function of power showing improved axial trapping efficiency with respect to linearly polarized beams. The analysis of the thermal fluctuations highlights a significant change in the optical trapping potential when using cylindrical vector beams. This enables the use of polarization states to shape optical traps according to the particle geometry, as well as paving the way to nanoprobe-based photonic force microscopy with increased performance compared to a standard linearly polarized configuration.

This paper has also been selected for inclusion in the Virtual Journal of Biomedical Optics 7 (2012)

Royal Society Summer Exhibition

This week we have been at the Royal Society Summer Exhibition 2012 with a display titled POP! The sound of bubbles.  Opposite you can see members of the team explaining the science of bubbles to guests at the soiree on Thu 05 Jul.

The exhibition and our display also featured on the BBC news, and in BBC R4's Material World programme on 05 July. The podcast of this show will be available to download for the next few weeks. 

Royal Society Summer Exhibition 2012

The UCL/NPL microbubble trapping project will have a stand at the Royal Society Summer Exhibition 2012, called 'Pop! The sound of bubbles'.  This stand will be run by many of the scientists involved in the project including Gianluca Memoli, Eleanor Stride, Caroline Harfield & Louise Wright.  The exhibition runs from 03-08 July 2012 at the Royal Society.
Our display will feature the science of microbubble trapping as well as many other everyday applications of microbubble technology (including some that might surprise you!).
You can follow the sound of bubbles blog for the latest updates on our project, or the Summer Science 2012 twitter @summerscience for more about the exhibition.

Visit by Onofrio Marago

Onofrio Marago from the NanoSoft Lab, IPCF-CNR (Messina) is visiting our group at UCL from 26-31 January.  Our groups have a long-running collaboration, and exchange visits are funded by the Royal Society as part of our International Joint Project on Photonic Force Microscopy.

Visit by Onofrio Marago and Maria Grazia Donato

This week (21-26 November) Onofrio Marago and Maria Grazia Donato from the NanoSoft Lab, IPCF-CNR (Messina) are visiting our group at UCL.  Our groups have a long-running collaboration, and exchange visits are funded by the Royal Society as part of our International Joint Project on Photonic Force Microscopy.

Visit to NanoSoft Lab, IPCF-CNR (Messina)

Phil is spending the week of 07-11 November visiting Onofrio Marago and colleagues at the NanoSoft Lab, IPCF-CNR (Messina).  Our groups have a long-running collaboration, and exchange visits are funded by the Royal Society as part of our International Joint Project on Photonic Force Microscopy.

Visit by Onofrio Marago

Onofrio Marago (NanoSoft Lab, IPCF-CNR, Messina) is visiting the group this week, 7-11 March 2011.

Onofrio has a long-running collaboration with the UCL Optical Tweezers Group and exchange visits between UCL and NanoSoft Lab are presently funded by our Royal Society International Joint Project.

Left: Onofrio adjusting the evanescent-wave optical binding experiment.

Visit to NanoSoft Lab, IPCF-CNR (Messina)

This week Susan and Marios are visiting the NanoSoft Lab at IPCF-CNR (Messina) where they are working with Dr Onofrio Marago.  This visit is part of our long-running collaboration with Dr Marago, and is funded by the Royal Society via an International Joint Project.

SPIE Conference Proceedings

Conference proceedings 'Plasmon-enhanced optical trapping of metal nanoparticles: force calculations and light-driven rotations of nanoaggregates' published as O. M. Maragò et al Proc. SPIE Vol. 7762, 77622Z (2010). 

Abstract:  We investigate experimentally and theoretically plasmon-enhanced optical trapping of metal nanoparticles. We calculate the optical forces on gold and silver nanospheres through a procedure based on the Maxwell stress tensor in the transition T-matrix formalism. We compare our calculations with experimental results finding excellent agreement. We also demonstrate how light-driven rotations can be generated and detected in non-symmetric nanorods aggregates. Analyzing the motion correlations of the trapped nanostructures, we measure with high accuracy both the optical trapping parameters, and the rotation frequency induced by the radiation pressure.

The paper included some work done with our Royal Society IJP was presented at  the conference Optical Trapping and Optical Micromanipulation VII by Onofrio Maragò.

Visit by Onofrio Marago

Onofrio Marago (NanoSoft Lab, IPCF-CNR, Messina) is visiting the group this week.  Onofrio has a long-running collaboration with the Optical Tweezers Group and exchange visits between UCL and NanoSoft Lab are presently funded by our Royal Society International Joint Project.

Visit to NanoSoft Lab, IPCF-CNR (Messina)

Phil spent the week of 13-18 September visiting Onofrio Marago and colleagues at the NanoSoft Lab, IPCF-CNR (Messina).  The visit was part of our International Joint Project on Photonic Force Microscopy funded by the Royal Society.  Among the highlights of the week was a half-day meeting on graphene with talks by Onofrio, Giuseppe Angilella (Catania) and Prof Norman March (former holder of the Coulson Chair in Theoretical Chemisty, Oxford).

Visit by Maria Grazia Donato

Maria Grazia Donato of the Istituto Processi Chimico-Fisici (IPCF-CNR) in Messina is be visiting the group this week.  Maria studied at the University of Messina, and recently joined the CNR where she works on Raman and photoluminescence spectroscopy of both amorphous and crystalline material, and steady-state and time-resolved fluorescence anisotropy of molecular aggregates.  She will be contributing to the work of our Royal Society International Joint Project with Dr Onofrio Marago.