Complex light beams realized by phase modulation techniques represent a versatile tool in several fields of optics as the material structuring at small scales and the optical manipulation of micro-objects. Soft matter based micro-particles, with controlled supramolecular structure, studied by implementation of optical trapping, lead to new opto-mechanical properties.
Structured light fields for optical control and manipulation
Methods to generate structured light fields are studied: light patterns and complex vectorial beams are realized by using optical phase modulation by means of polarization holograms. Taking advantage of the diffraction properties, the high efficiency, and the intrinsic achromaticity of the polarization holograms, the method overcome the limitations related to stability and efficiency, making it attractive for applications. These light fields coupled with photosensitive soft materials are used to investigate manifold new optical effects: perform materials structuring; design defects architectures in materials; optical manipulation of micro-objetcs.
Keywords: Complex and vector beams; vectorial light patterns; optical tweezers
Ruiz, Instituto Nacional de Astrofísica, Óptica y Electrónica, Puebla, Messico
Yu. Reznikov Istituto di Fisica dell’Accademia Nazionale delle Scienze dell’Ucraina, Kiev, Ucraina
Chiral microdroplets/microparticles optofluidics
Optical studies of chiral microparticles combine soft matter science with both photonics and optical manipulation. The particles are made by liquid crystalline polymer and are realized by controlling both the internal structure and the surface features. They constitute spherical microresonators suitable for several applications in photonics such as lasing. These microparticles enable the implementation of new strategies for optical trapping. Investigations on their opto-mechanical properties have shown that several kinds of optical manipulation (trapping, rotation and orbiting motion) are realized by means of the spin angular momentum transfer from photons to micro-particles.
Keywords: Photopolymerization; optical polarized and confocal microscopies; optical manipulation by complex beams
Main collaborations:Volke-Sepulveda Institute of Physics, National Autonomous University of Mexico
O.M. Maragò, CNR-IPCF Messina