Today I worked for a long time to try and get my AO devices to work. I am improving my prism coupling and alignment skills though I would say that I feel a little too much of my time is spent in those steps. I believe that my transducers for AO 4 are working but there is a lot of loss happening between the laser and the actual device. A couple of improvements that I would like to make on AO5 are put the transducers closer to the actual waveguides, make them shorter so there is less loss and risk of error. I hope to finish testing AO4 and fabricate a lot of AO5 tomorrow and Thursday. This design might require more polishing because the AO device needs to be close to the waveguides but also close to the edge so it can be correctly steered.

This last month I have been working on AO devices. I think that things are going well. I finally got a device with 100 um aperture to work and the network analyzer says that I should be able to get some good control of the movement. I have not succeeded in getting that movement. For the future, I think it could be very valuable to try different sizes both smaller and bigger.

I took my probe all the way through the fabrication process on Friday. This morning I worked on learning how to use the apparatus for testing. More specific details are found on the basic probe tests page.

On May 5, I spent the day making sure that my design was correct. We finished up the fabrication process and began testing. After looking through the lasers for a considerable amount of time and being unsuccessful in locating a waveguide, we decided to run a new sample with bigger waveguides and we would withold the final aluminum etching step until we were able to find them and measure their angles. This is done because once we have taken off the aluminum after proton exchange, it is extremely difficult to see the waveguides even under the microscope. So that is the next step in the process. However I ran the Heidelberg and was unsuccessful with test 2. For some reason, the Heidelberg printed the design incorrectly. The design was printed as if it had not been centered and so only 2 waveguides were present on the device and they did not run the full length of the device. There is a picture which shows this under the basic probe test 2 section. It is possible that I forgot to turn on the vacuum, not likely but possible.

I spent most of today working on refining my design. After finishing the proton exchange and annealing of my brain probe yesterday afternoon, I came in this morning and worked on the next steps in fabrication. I used aluminum etch to remove the rest of the aluminum. This made it difficult to see what was happening on my sample and determine top from bottom but I think I worked through it okay. I was trained on the metricon and being able to see the different modes that come in our power density. However I wasn't able to see them on my brain probe but instead was only able to see them on the dummy sample. I spend quite a bit of time polishing today, trying to get everything straight so that each side had a clear surface without any microscopic lines. The plates were a little difficult but using the polisher was straight forward and eventually the 1 um plate was able to get my sample as clean as they needed to be.

Basic Probe is my first project that I am in charge of. It is a simple brain probe that should steer light simply and is good practice at going through the whole process of fabrication.