User:Andy Maloney/Notebook/Lab Notebook of Andy Maloney/2009/03/20/Optical tweezers

Condenser

So I got the part from John today. It is the dovetail flange that was designed to accommodate Thorlabs' ø2" lens tubes. Here are some shots of it.

I was also able to assemble the QPD housing. Complete with room for optics and removable ND filter holders.

One issue is that the condenser doesn't actually make it to the sample plane. This is an extremely easy fix since I had John make the "SM2" threads from Thorlabs'. Thanks Thorlabs for providing the thread dimensions! All we have to do is order a longer ø2" lens tube which has already been done. I love engineering things that work.

Diode laser

It turns out that I can connect some back plane pins to get monitoring of temperature, current, and possibly power from the laser system. This is beyond cool because Larry can program a DAQ in LabVIEW to monitor everything.

I've already tried this and it works for temperature monitoring. One issue I think I may have is grounding. Typically a BNC connector will ground to the chassis but, I grounded my trial to one of the GND pins on the ITC133. I think I should probably ground to the board, but I'll have to make sure the BNC panel mounts do not ground to the chassis. This may prove to be irritating if I can't find isolated BNC panel mounts.

Yeah! I did find Isolated mounts!