Performance of a rotating aperture for spinning and orienting objects in optical tweezers.

The spinning of asymmetric objects trapped within optical tweezers that have a rotating rectangular aperture inserted into the trapping laser beam is characterized. The measured maximum rotation rates of various asymmetric micron-sized objects are in agreement with a linear dependence on laser power. Maximum rotation rates of up to 0.2 Hz per mW of laser power suggest that rotation rates in the region of 10-20 Hz should be readily achievable in commercially available tweezers that have been modified by the inclusion of a rotating rectangular aperture. In addition, the possibility to alter the orientation of the aperture allows convenient control over the orientation of tweezed objects. [ABSTRACT FROM AUTHOR]