User:Steven J. Koch/Notebook/Kochlab/2009/07/10/Summary of the day

Steve Koch 04:00, 11 July 2009 (EDT): I think I got good at doing the power spectrum. Except for the huge spike at 120-ish Hz, it can look pretty good at a beam power of 40 mW (39.95). To me, the data seem reasonably reliable and indicate a trap stiffness factor of about 0.25 pN / nm / W. This is for the (supposedly) 1 micron spheres. These have a pretty big range in the trap, say 500 microns. Currently I don't understand how to get the power meter to go higher than the strange number it maxxes out at now (698 or something? I wrote it down elsewhere), but let's assume we can fix that problem. I think it'd be safe to put 1.5 W into the objective. Thus, we could achieve a trap stiffness of about 0.4 pN / nm. That would be 40 pN over 100 nm and 80 pN over 200 nm. Thus, if we were able to use 1 micron beads conveniently (doubtful,though), I think we could do all that we wanted.

• My main worries at this point:
  • Will we be able to visualize the 0.5 micron beads w/ DIC? Maybe with a darkfield ring that we can pop on and off easily?
  • Do we have tetherable unzippable DNA? I could not find the DNA from Diego and I last year. I suppose it's still at Osley's?

Questions

• Andy Maloney 12:17, 11 July 2009 (EDT): What do you think the source of the noise is? If it mechanical, then I can fix it. If it is a problem with ghost images coming from the dichroic, I can fix that as well. Should I just go ahead and fix both of these issues? I will make a design to mount the dichroic in so you can see it.