What am I doing at BU?
This week I started my summer at BU as part of the RET (Research Experience for Teachers) program. This program gives ten high school and middle school teachers the opportunity to work full time for six weeks of the summer in a lab in the Photonics Center at BU. We are teamed in pairs, typically a veteran high school teacher with a new teacher or a middle school teacher. I am teamed up with Michelle McMillan who teaches 6th grade science in NH. She is originally from New Mexico. She studied Physics and Astronomy in Arizona and then did a City Year in NH and liked it enough to stay in NH and to keep teaching. She went to UNH for her master's in teaching and just finished her first year with her own class.
Michelle and I are assigned to work with Dr. Bifano, a mechanical engineering professor and the director of the Photonics Center. Dr. Bifano's research is in the field of adaptive optics. He and his team have developed deformable mirrors, which are small mirrors whose surface can be computer controlled. The mirror that we are working with has 144 actuators (12 by 12). These mirrors have enabled the field of adaptive optics to improve images of the retina, for example. The problem with imaging the back of the eye is that wavefront of the light gets distorted as it travels through the eye itself. The idea of adaptive optics is to measure that distortion and then deform a mirror with a shape that will make the wavefront smooth after it reflects off of the deformed mirror. When the smooth wavefront reaches a camera then it will create a much improved image.
Being on a College Campus Again
I visited a lot of college campuses these past few years with my two oldest as they decided where they wanted to go to college. It made me wish I was the one going back to school. So, it is fun to be able to back at college even if just for a summer. I have been really impressed with the facilities at BU and with the people I have met. We heard presentations from some undergraduates who are also doing research projects. They got into these projects mostly by asking their professors if they could participate in research. It made me want to be sure to tell my students to not just take classes when they get to college but to be sure to pursue these other opportunities. To be honest I'm also having fun riding the train and being in Boston everyday. I'm sure the commute would be tiresome after a while but it's fun for the summer.
Our Tasks This Summer
Michelle and I have several things we are working on this summer. For one we are setting up an adaptive optics controller on a work bench that could be used as a demo to explain what adaptive optics is. First we are just getting it to work and then we are going to see what we can demonstrate with it. This demo could be used in Dr. Bifano's class that he teaches in the honors program. It is really helping us understand what adaptive optics is ourselves. We are also possibly working on using a wavefront sensor to measure aberrations in imaging the backside of a computer chip. I'm not quite sure what that all entails yet. Finally, Dr. Bifano has a bunch of neat labs/demos that he did with his photonics class last year that he would like refined. We are going to see if we can improve on some of them.
We are working on the 7th floor of the beautiful new Photonics building that is right on the Mass pike. The view from the meeting area just outside our lab is incredible as we have nearly floor to ceiling windows that stretch 24 feet wide. Pictures do not do it justice. The lab itself has a couple of smaller rooms in which three graduate students have offices and then a big common lab area. We have our own workspace in the common lab area. The graduate students, Chris and Hari, have been extremely kind and helpful to us. The third student is in China getting married this summer.
Our Progress This Week
I thought the first week would have been spent doing a lot of reading and trying to figure out what we are going to do. Instead, Dr. Bifano spent a lot of time getting us up to speed and had a place ready for us to work so we were able to jump right in. On our first day we recreated one of his lab demos which was to build a light bulb with some tungsten, argon, a coffee pot and a car battery charger. We got it to light, though we had some smoke. The good news is it was not enough smoke to set off the smoke alarm. That could have been an embarrassing first day.
In the afternoon of the first day we set up the lasers, mirrors and lenses on the lab table for our adaptive optics system. We learned about how to align the laser with the mirrors and lenses and also how to magnify images with two lens pairs (called "telescopes," but not the telescopes you would use to look at the moon). The next day Dr. Bifano taught us about how adaptive optics works and helped us get all of the software running in our lab. The controller runs on Matlab which fortunately Michelle and I have used before.
Thursday Dr. Bifano was on vacation and we were on our own to see if we could get some improvements made to the software. When we first started it took a few attempts just to get everything set to run correctly, but then we figured out how to write the software to auto-adjust the exposure on the wavefront sensor. Now we can manually turn the neutral density filter and the software will automatically pick the right exposure value to use so the image isn't saturated. It was very exciting and we were pretty proud. We also figured out how to improve the slope display so the scaling is good and how to mask out the actuators that are outside of our field of view. It was an amazing first morning on our own.
Then in the afternoon we started to figure out how to align the pupil with the center of the deformable mirror. It seemed like every time we thought we were onto something then we'd run it and get something other than we expected. Sometimes it was because we had accidentally had the mirror "poked" when we set the reference (or some similar problem). Also I personally kept getting confused between the wavefront sensor's image and the colormapped slope image and then x and y are reversed on some things but not others. We could tell from our work that we needed to physically adjust the camera's position and Friday Chris helped us find a stand for it with knobs for fine adjustments. We spend the rest of Friday working out all of the details on the aligning software and I think we have it understood and working for the most part. We still want to find a way to figure out the radius automatically. Finally we just printed out all of our code and decided to take a fresh look next week.
It has been such a great experience already. I felt like I learned a lot this week and I really enjoy working with everyone in our lab. It has been especially great being teamed with Michelle. I think tackling these tasks could have been overwhelming on my own, but it's really fun getting to figure out things together.