Abstract
An optically trapped birefringent microparticle is rotated by a circularly polarized beam in a confined gaseous medium. By recording the terminal rotation velocity and the change in polarization of the incident trapping beam, we determine the viscosity by probing a picoliter volume of air, carbon dioxide, and argon in the vicinity of the microparticle. We also characterize the optical force acting on a trapped particle in air using the generalized Lorenz-Mie theory taking into account the aberrations present. This opens up a new potential application of optical tweezers for the accurate measurement of gas viscosity in confined geometries.
Original language | English |
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Pages (from-to) | 8855-8858 |
Number of pages | 4 |
Journal | Analytical Chemistry |
Volume | 83 |
Issue number | 23 |
DOIs | |
Publication status | Published - 2011 Dec 1 |
All Science Journal Classification (ASJC) codes
- Analytical Chemistry