Asymmetric Trap: Correction Attempts and Existing Questions
Asymmetric Trap Strength: An Unsolved Mystery
If you have looked at both our Brownian motion data as well as our Stokes drag force data you will have noticed that the x and y trapping force and trap force constant are far from indentical. Consistant with previous groups, for the Brownian Motion calibrations, the x trap force constant is much larger than the y trap force constant. Conversely for the Stokes drag force calibrations, the y trapping force is actually stronger than the x trapping force. These asymmetries in trap strength have led us to beleive that at the focal point of the laser is elliptically shaped, with the long axis of the ellipse oriented along the y axis. This would allow for greater y direction oscillations in brownian motion, and allow for a larger trapping area for the Stokes measurements. The source of the elliptical beam spot was investigated. As a reference to future groups, the corrections there attempted were:
