Translator Disclaimer
Presentation
9 September 2019 Precise calibration of optical tweezers using the interference pattern in the backscattered signal and application to the microrheology of blood clots (Conference Presentation)
Author Affiliations +
Abstract
When trapping a dielectric bead with optical tweezers, light backscattered by the bead interferes in the back focal plane of the objective with light reflected by the microscope cover slip. This well contrasted interference pattern can be used to calibrate precisely the relative position of the bead with respect to the center of the trapping laser, as well as the stiffness of the trap. We compared four calibration methods previously implemented in forward detection, namely step response, Bayesian inference, power spectrum analysis and equipartition. We showed that they agree for different heights and trapping powers. Effect of acoustic noise on all methods was observed, and the step response method was shown to be the least sensitive. In addition to giving better access to the sample, this backscattered interference pattern provides precise location of the bead with respect to the laser, both laterally and axially, even when the bead is not trapped by the laser. We apply this to microrheology of blood clots, where the focused laser exerts a force on a bead confined by the fibrins of the clot but does not actually trap it .
Conference Presentation
© (2019) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Nathalie Westbrook, Flavie Gillant, Julien Moreau, Karen Perronet, Maximilian U. Richly, Antigoni Alexandrou, Laura Wolff, and Jean-Marc Allain "Precise calibration of optical tweezers using the interference pattern in the backscattered signal and application to the microrheology of blood clots (Conference Presentation)", Proc. SPIE 11083, Optical Trapping and Optical Micromanipulation XVI, 110830H (9 September 2019); https://doi.org/10.1117/12.2530645
PROCEEDINGS
PRESENTATION


SHARE
Advertisement
Advertisement
RELATED CONTENT

Optical tweezers escape forces
Proceedings of SPIE (September 16 2014)
Optical tweezers calibration with Bayesian inference
Proceedings of SPIE (September 16 2014)
Measurements of optical tweezers stiffness
Proceedings of SPIE (October 24 2001)
Optical stretching on chip with acoustophoretic prefocusing
Proceedings of SPIE (October 10 2012)
How the stiffness of the optical trap depends on the...
Proceedings of SPIE (October 11 2005)

Back to Top