Levitational photonics

Dynamics of microscopic particles in various optical light fields
Modelling of optical tweezers

LF1At the heart of optical trapping there is the interplay between the so-called gradient and scattering forces. In the most popular single beam gradient trap, termed “optical tweezers,” these two forces are in equilibrium enabling stable optical trapping of micro- and nano-objects. We employ the state-of-the art techniques to study the dynamics of microscopic objects in carefully designed optical light fields, e.g. we have demonstrated counterintuitive transport of micro particles against photon flow in so cold Tractor beam and its utilization for passive sorting of micro objects according their size. Recently, we studied behavior of particles in highly non-linear cubic potential and transport in rocking ratchet system.

LF2We are using several theoretical approaches to model interaction of light with a particle(s) in optical traps. We use in house developed codes for the Rayleigh approximation, Generalized Lorenz-Mie scattering based on approaches of Barton as well as the T-Matrix method, Coupled Dipoles Method and commercially available Finite Elements Method (Comsol Multiphysics). We focus mainly on the interaction of a non-spherical particle or large ensemble of particles in structured or interference light fields. Furthermore, we analyse both the thermal effects connected to trapping as well as stochastic behaviour of particle ensembles.

Recent research highlights

  • Tractor beam in the micro world. We have demonstrated counterintuitive transport of micro particles against photon flow and its utilization for passive sorting of micro objects according their size. Read the article in Nature Photonics
  • Dynamics of micro particle in highly non-linear cubic potential. Read the article in Scientific Reports
  • Optical ratchets. A fully reconfigurable two-dimensional rocking ratchet system was employed to omnidirectional transport of micro particles. Read the article in Physical Review Letters

 

Recent research highlights

  • Optical printing. Optical printing is a powerful all-optical method that allows the incorporation of colloidal nanoparticles (NPs) onto substrates with nanometric precision. Read the article in ACS Nano
  • Optical binding of nanowires. Using a novel numerical model we uncover rich behaviour of optically bound dielectric nanowires. Read the article in Nano Letters
  • Morphology of plasmonic nanoparticle dictates optical forces. We demonstrate confinement of large gold nanoparticles in an optical trap based on very low numerical aperture optics. Read the article in Scientific Reports

 
Optically assembled soft matter
Optical levitation in vacuum

LF3 We study the optically mediated interaction between assembled microscopic objects - optical binding - that gives a rise to attractive and repulsive forces and dramatically influence the way such objects assemble and self-organize. This offers routes for colloidal self-assembly, crystallization, and organization of templates for biological and colloidal sciences. We focus not only on opto-mechanical aspects of optical mater but also on its photonic properties.

 

Recent research highlights

  • Gripped by light: Optical binding. The topic of optical binding was reviewed in Review of Modern Physics
  • Optical binding of microobjects. We created extended longitudinally optically bound chains of microparticles of various shapes with the use of counter-propagating light fields. Read our articles in Physical Review Letters, Physical review A
  • Particle transport in tractor beam enhanced by the optical binding. Here we demonstrate that motion of two optically bound objects in a tractor beam strongly depends on theirs mutual distance and spatial orientation. Read article in Light: Science & Applications

LF4 A optically trapped nano-particle in ultra high vacuum, has very weak physical contact to the environment, which makes it a promising system for quantum experiments even at room temperatures.  We focus not only on optical cooling of nanoparticles using feedback scheme but also on light-matter interaction in under-damped regime, e.g., demonstration of spin-orbiting phenomena or optical binding.



Recent research highlights

Orbital Motion From Optical Spin: The Extraordinary Momentum Of Circularly Polarized Light Beams.  preprint on arXiv

 

We are co-operating with:

  • Group of Prof. Alper Kiraz, Department of Physics, Koc University, Istanbul, Turkey
  • Photon Systems Instruments, s.r.c.
  • Group of Prof. Daniel Ou-Yang, Lehigh University, Bethlehem, USA
  • Group of Prof. Karen Volke Sepulveda, Instituto de Fisica Universidad Nacional Autonoma de Mexico
  • Meopta-optika, s.r.o.
  • Group of Prof. K. Dholakia at the University of St. Andrews, Scotland
  • Group of Prof. A. Sasso - Universita di Napoli Frederico II, Italy
  • Group of Prof. Z. Bouchal - Palacky University in Olomouc, Czech republic
  • Group of Prof. E.-L. Florin - Texas University, Austin, TE, USA
  • Groups of Prof. G. Badenes and Prof. R. Quidant at Institute of Photonic Sciences, Barcelona, Spain
  • Prof. Ormos's group in Szeged, Hungary
  • Groups of Prof. M. Liska, Prof. T. Sikola and Prof. R. Chmelik - Institute of Physical Engineering, Brno University of Technology
  • Group of Prof. S. Kozubek - Institute of Biophysics ASCR v.v.i., Brno
  • Group of Prof. M. Kozubek - Faculty of Informatics, Masaryk University in Brno
  • Center for Bionanoscience Research
  • Onofrio Marago and Maria Gracia Donato,  CNR-IPCF, Messina, Italy
  • Philip H. Jones Department of Physics and Astronomy, University College London, London WC1E 6BT, UK 
  • Simon Hanna H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK
  • Group of Fernando Stefani; Centro de Investigaciones en Bionanociencias