Back-Focal-Plane Interferometry for 3D Position Tracking in Optical Tweezers

Author

Liu, Hongjun ; Hu, Huizhu ; Tie, Minqiang ; Zhang, Wei ; Shen, Yu

Author_Institution

Dept. of Opt. Eng., Zhejiang Univ., Hangzhou, China

fYear

2012

fDate

21-23 May 2012

Firstpage

1

Lastpage

4

Abstract

A far-field interferometry is presented to track the 3D positions of an optically trapped particle. This method can resolve the displacement within nanometers by measuring the intensity shift in the back-focal-plane of the lens which is introduced by the interference between the outgoing laser beam and scattered light from the trapped particle. Factors that affect its characteristics are elaborately analyzed using approximate formula and FDTD stimulation. Also, we propose a valid method to minimize the thermal noise that introduced by Brownian motion of the trapped particle.

Keywords

Brownian motion; distance measurement; finite difference time-domain analysis; focal planes; laser beam applications; light interferometry; light scattering; optical tracking; radiation pressure; thermal noise; 3D position tracking; Brownian motion; FDTD stimulation; approximate formula; back-focal-plane interferometry; distance measurement; far-field interferometry; intensity shift measurement; interference; light scattering; nanometers; optical trapped particle; optical tweezers; outgoing laser beam; thermal noise; Biomedical optical imaging; Charge carrier processes; Optical imaging; Optical interferometry; Optical scattering; Optical sensors; Time domain analysis;

fLanguage

English

Publisher

ieee

Conference_Titel

Photonics and Optoelectronics (SOPO), 2012 Symposium on

Conference_Location

Shanghai

ISSN

2156-8464

Print_ISBN

978-1-4577-0909-8

Type

conf

DOI

10.1109/SOPO.2012.6270909

Filename

6270909