I worked on my SURF progress report and abstract (due Friday, August 2). The most revised version is on the SVN.
Tara and I went down to the lab to set up and test the current driver. In order to do this, we are using a function generator as our power supply for the reverse bias on the laser diode at a frequency of 10e-6 sec (for now, sufficient for temporary testing). We were able to see an output beam, so the current driver works! We noticed that the beam diverges VERY quickly. We will need a collimating lens with a very small focal length as a result. We played around with some lenses sitting around the lab, but they had relatively large focal lengths (we are looking at ~2-4mm this is commonly used in the literature...).
Tara found some problems with my soldering so I fixed it. I learned how to use heat shrink to make sure the solder joints don't touch, and I will be careful to do this in the future. I may go and put heat shrink on the TEC solders in order to eliminate the possibility of a short circuit.
Tomorrow I will look at different lenses in the setup and see if I can find a small focal length lens to use. |