User:Andy Maloney/Notebook/Lab Notebook of Andy Maloney/2009/07/31/Noisy tweezers

Noise

Anthony and I tried to work on ways to dampen the noise we are getting with the optical tweezers. We found the following:

• When you turn on and off the fume hood exhaust, spikes show up in the piezo and QPD. While this may not be a big deal, it does indicate that there are possible electrical issues. I really have no clue as to how to fix this. Maybe making a better power supply for the QPD with a power supply and a box. It might get rid of any ground looping from the power supplies.
• We thought about putting rubber spacers between the stages on the microscope to dampen vibrations.
• One thing we did notice is that the QPD housing is pretty robust however, the piezo is really sensitive to vertical movements.

There is more to come. I did find that butyl rubber is better at damping.