Abstract

The advantageous use of high speed cameras have been lately proposed for the direct characterization of optical tweezers in order to replace indirect measurements often performed by quadrant detectors, at the expense of a tradeoff between acquisition speed and resolution. In the proposed approach, subpixel motion data of the trapped particle is retrieved from a high speed low resolution video sequence. Due to the particular nature of the motion, we propose that the obtained motion information is not only useful for providing online characteristics of the optical trap force, but also for tackling the lack of resolution by means of applying superresolution algorithms on the low resolution image sequence. The results show that the proposed approach allows the characterization of the optical tweezers obtaining the real particle motion directly from the image domain, while still providing simultaneous high resolution imaging.

© 2009 Optical Society of America