Phys. 426 undergraduate Physics laboratory

Optical tweezers experiment

Optical tweezers at St. Andrews University:

Optical tweezers poster 1   Optical tweezers poster 2

Schematics of our experimental setup

These pictures show the optical tweezers at four stages:

(1) before the laser is applied, the microspheres distribute randomly, (2) a microsphere is being trapped by the optical tweezers, (3) the microsphere is trapped and (4) after several minutes, a large number of microspheres is grouped.

Click here to watch the optical tweezers demonstration movie(file size 6.7M, format .wmv).

References:

Stephen P. Smith, Sameer R. Bhalotra, Anne L. Brody, Benjamin L. Brown,
Edward K. Boyda, and Mara Prentiss, Inexpensive optical tweezers for undergraduate laboratories, Am. J. Phys., 67, 26-35 (1999).

Robert Pastel, Allan Struthers, Ryan Ringle, Jeremy Rogers, Charles Rohde, and Peter Geiser, Laser trapping of microscopic particles for undergraduate experiments, Am. J. Phys. 68, 993-1001 (2000).

D. N. Moothoo, J. Arlt, R. S. Conroy, F. Akerboom, A. Voit, and K. Dholakia, Beth’s experiment using optical tweezers, Am. J. Phys. 69 271-276 (2001).

John Bechhoefer and Scott Wilson, Faster, cheaper, safer optical tweezers for the undergraduate laboratory, Am. J. Phys., 70, 393-400 (2002).

Matthew J. Lang and Steven M. Block, Resource Letter: LBOT-1: Laser-based optical tweezers, Am. J. Phys. 71(3), 201-215 (2003).