The effect of integration time on fluctuation measurements: calibrating an optical trap in the presence of motion blur.

Citation:

Wong WP, Halvorsen K. The effect of integration time on fluctuation measurements: calibrating an optical trap in the presence of motion blur. . Opt Express 2006;14(25):12517-31.

Abstract:

Dynamical instrument limitations, such as finite detection bandwidth, do not simply add statistical errors to fluctuation measurements, but can create significant systematic biases that affect the measurement of steady-state properties. Such effects must be considered when calibrating ultra-sensitive force probes by analyzing the observed Brownian fluctuations. In this article, we present a novel method for extracting the true spring constant and diffusion coefficient of a harmonically confined Brownian particle that extends the standard equipartition and power spectrum techniques to account for video-image motion blur. These results are confirmed both numerically with a Brownian dynamics simulation, and experimentally with laser optical tweezers.