Translator Disclaimer
Paper
6 August 2014 Estimation of trapping position in three-dimensional off-axis trapping with optical vortices
Author Affiliations +
Proceedings Volume 9232, International Conference on Optical Particle Characterization (OPC 2014); 92320W (2014) https://doi.org/10.1117/12.2065644
Event: International Conference on Optical Particle Characterization (OPC 2014), 2014, Tokyo, Japan
Abstract
Dynamics of micrometer-sized dielectric objects can be controlled by optical tweezers with scanning light, however, the trapped objects fail to track the scan when drag exceeds the trapping by too quick movement. On the other hand, optical vortices (OVs), which have a property of carrying angular momenta, can directly control torque on objects rather than their position. Laguerre-Gaussian (LG) beams are the most familiar examples of OV and have been studied extensively so far. Revolution of the objects trapped by the LG beams provides typical models of nonequilibrium statistical system, but stable mid-water trapping by the LG beams becomes essential to evaluate physical properties of the system without extrinsic hydrodynamic effects,. Nevertheless, off-axis revolutions of small objects trapped in mid-water by the LG beams have not yet been established with secure evidences. Here we report stable off-axis trapping of dielectric spheres in mid-water using high-quality LG beams generated by a holographic complex-amplitude modulation method. Direct evidence of the three-dimensional off-axis LG trapping was established via estimating the trapping position by measuring the change of revolution radii upon pressing the spheres onto glass walls. Resultantly, the axial trapping position was determined as about half the wavelength behind the beam waist position. This result provides a direct scientific evidence for possibility of off-axis three-dimensional trapping with a single LG beam, moreover, suggests applications as powerful tools for studying energy-conversion mechanisms and nonequilibrium nature in biological molecules under torque.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Taro Ando, Tomoko Otsu, Yu Takiguchi, Yoshiyuki Ohtake, Haruyoshi Toyoda, and Hiroyasu Itoh "Estimation of trapping position in three-dimensional off-axis trapping with optical vortices", Proc. SPIE 9232, International Conference on Optical Particle Characterization (OPC 2014), 92320W (6 August 2014); https://doi.org/10.1117/12.2065644
PROCEEDINGS
6 PAGES


SHARE
Advertisement
Advertisement
Back to Top