Open AccessPower spectral analysis for optical trap stiffness calibration from high-speed camera position detection with limited bandwidth
Author(s) -
Astrid van der Horst,
Nancy R. Forde
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.007670
Subject(s) - optics , physics , calibration , nyquist frequency , photodiode , holography , bandwidth (computing) , optical power , position (finance) , noise (video) , laser , computer science , computer vision , image (mathematics) , telecommunications , finance , quantum mechanics , economics
The use of camera imaging enables trap calibration for multiple particles simultaneously. For stiff traps, however, blur from image integration time affects the detected particle positions significantly. In this paper we use power spectral analysis to calibrate stiff optical traps, taking the effects of blur, aliasing and position detection error into account, as put forward by Wong and Halvorsen [Opt. Express 14, 12517 (2006)]. We find agreement with simultaneously obtained photodiode data and the expected relation of corner frequency fc with laser power, up to fc = 3.6 kHz for a Nyquist frequency of 1.25 kHz. Spectral analysis enables easy identification of the contribution of noise. We demonstrate the utility of our approach with simultaneous calibration of multiple holographic optical traps.