Weekly Report

May 28, 2001

My first day on the AGEP summer research program. I just met the rest of my fellow researchers in my building and they are a merry bunch. This week I plan to get back into my interference and polarization research. I want to continue working on my original Mach-Zhender interferometer and use it as a basis for other projects.

June 4 , 2001

My laser wasn't working so I could not do any observations. Instead I'm reading on different journals anything related to my topic. I met one of the High School students doing research this summer, Jon Fuchs. He plans to study diffraction in general and also the inner-workings of the CCD camera that we have in the lab. I used this camera to get data last semester on the which-way project. However, a member of the faculty raised a question on something that was obvious and which I had overlooked. His comment was on how accurate is the representation of the data gathered on the picture versus the actual data. Which means in a few words, How accurate is my data!. I didn't know last semester that the CCD camera auto-adjusted to the local intensities in the field of view. This automatic procedure of the camera absolutely changed the foundation of my use of the CCD as a fast data gathering device. On the coming weeks we will study what is the optimum way to get data using the camera and how realistic is this graphical representation compared to the raw data we observe with our eyes. In conclusion, Jon and me plan to study the uses of the CCD camera as a tool in laser research.

June 11, 2001

I spoke with Prof. Metcalf last week. He proposed me a question regarding the behavior of the polarization of the light field across the interference pattern. In particular the region between the dark and bright fringes. One of his ideas was that around that area, the field behaves in a circular polarized mode. In a few lines of work, he showed me how complex the field and polarization of light changes for two particles linearly polarized as they approach head on. This probably will be the project on which I will present my final report at the end of the summer. Also, If I have enough time I plan to build a computer model of how the polarization behaves across the light field. At the lab, Dr. Noe tasked me on finding useful information regarding CCD technology. CCD cameras are used by both amateur and proffesional astronomers with incredible results. Dr. Noe thinks that we can achieve equal important results on our projects.

June 18, 2001

I just realized that looking for a CCD camera is bound to become a big project for itself. There are so many different sensor design. And they all present some attractive characteristic. The CCD sensors can be divided into 3 major groups, Full Frame Transfer, Inter-line Transfer and Frame Transfer. For instance, Inter-line Transfer provides the fastest integration time and presentation output of a picture, while Full Frame Transfer sensors provided the highest resolution. Also I found about a site in the internet called the CCD Camera Cookbook.

June 25, 2001

An interesting event was observed in my Mach-Zehnder interferometer. Some of the optics seem to be flipping the axis of polarization by 90 degrees. This causes vertically polarized light to be transformed into horizontally polarized light. I was witnessed to something like this last semester when I was working with Mirna, but in that time I though that the effect was only confined to the beam splitter. Now it seems that also the mirrors are doing this axis flipping. This seems to contradict some of my already understood ideas regarding the behavior of the polarization axis when interacting with my optics. There must be an underlying physical reason, because this chages do not change with time and they are always by a factor of 90 degrees.

July 4, 2001

During this week I went over my basics in Matrix analysis in Optics. Specially over the Jones Matrix and Vector. This little 2 by 2 matrix is powerful enough to describe the properties of a laser beam before and after going through a polarizer/retarder device. I wonder If there is some neat and short way how I can describe everything of what is going in my interferometer using this kind of matrix modeling?.

July 10, 2001

Last Friday the AGEP group went to Brookhaven National Labs. It was a fairly interesting field trip. We went to the Quantum Chromatography super-computer. It sounded impressive but it didn't look that mighty when in person. We were given a presentation of data analysis in 3 dimensions using polarizing glasses. It was a nice phenomenon, because for me it was a novel way to produce stereoscopic vision. Sadly we couldn't visit the gem and flower of B.N.L. Relativistic Heavy Ion Collider R.H.I.C. Tuesday Prof. Metcalf explained to me why I have polarization changes with the mirror and beam splitter. It has to do with solutions of the Maxwell equations for boundary conditions between dielectric and normal materials. Hopefully I will able to understand this fully within the next few months.

On the other hand, I'm still debating on which is the best option for our CCD camera, home made or one that is already assembled. A home made camera will cut our costs by over 50%. However, there is an huge amount of options for the individual components of the camera. Also, the integration of this components in a working device could prove tedious. In any case, the construction of the device would be an excellent exercise in electronics construction.

July 16, 2001

I received the CCD Cookbook. The book is has some interesting sections regarding the technology and operation of CCD chips. However, I was somehow dissapointed with the maximum resolution of the chips, 700x300 pixels. That is pretty mediocre resolution compared with the mid-range commercial digital cameras. Which rate at around 1024x768 pixels. I guess you should sacrifice resolution of the camera for linearity of the data recorded by the device. Within the CCD Cookbook, i saw some pictures taken with the camera. However, a few of these pictures showed blooming. That is charge spillage from the potential wells that are spilling into other wells. This forms white streaks within the image. The fact that this was shown on the book, makes me believe that the CCD design has no protection against this effect.

I think that the construction of the camera will have to wait until next semester. Some of the components for the camera seem to take more than a couple of weeks before arriving. I wonder if I could tinker a little bit with the design shown in the book. I would like to get a higher resolution CCD array. I may even be cheaper that the one in the book. Since the high-resolution chip may still being in production.

July 24, 2001

This week, I got involved in learning about Laser Cooling. Which is Proff. Metcalf specialty. I went to a couple of lectures together with my labmates, Ziggy and Doug. The topic seems really interesting. You can slow atoms down by shooting little bullets of electromagnetic energy. Sadly, I don't have the necessary advanced knowledge in physics to get a more intuitive feeling regarding to the material I'm listening.

July 30. 2001


Full Frame CCD Chip Layout



Inter-line transfer CCD sensor layout


August 3. 2001


The Summer Conference is over. It was of my best summers ever. I learned a lot from these 10 weeks. Not only about my project (CCD Cameras) but also about the work of the other undergrads working in the lab. I learned a little bit about Sonoluminescence, Holograms, Laser backscattering, Matrix analysis in optics, Laser Cooling, etc. More that academics I learned a lot just by taking with the other undergrads that were working here for the summer. Wherever you are, the best of lucks.!!


August 22, 2001


Regular classes are just a few days away. The weeks after the summer conference were somehow boring. Maybe a little too quiet and without excitement for my taste. Next semester is going to be heavy. I will be taking the core of my physics classes: Introduction to Solid State, Electromagnetic Theory, Mechanics and Quantum Physics. Doug Broege will probably be in a couple of them so we could help each other. Anyway, the course load will be on the heavy side, but I'm excited to take these classes.
On the other hand, I'm working on my plan to go abroad for the Spring 2002 semester. I have two options, Australian National University at Canberra or the Rheinische Friedrich Wilhelms Universitat at Bonn, Germany. They are all good Universities, but Im slighty leaning towards the Australian option.

Finally, after weeks of discussion and analysis, a CCD camera was ordered. The model chosen was the Electrim 1000N with a resolution of 652x494 pixels. Some of the features of this camera are its small R.M.S. Noise at 15 electrons/pixel , Pixel Size of 7.4x7.4 micrometers (Square Pixel), Spatial Resolution of 652(H)x494(V), Image Size of 4.84x3.67mm and a Pixel Well Capacity of 30.000 electrons. Due to problems in the relocation of the Electrim offices, the shipment of the camera will take a couple of weeks.

August 29, 2001


The new semester has started. And I finally have decided on my class schedule. These are the classes that I'm going to be taking: Elementary German, Origins of the American Society, Applied Real Analysis, Electromagnetic Theory, Analytical Mechanics, Quantum Physics and a Research class under the tutelage of Prof. Metcalf and Dr. Noe. I've attended to these classes for a week and they all seem interesting. Specially the Electromagnetic Theory class. The introduction to vector calculus was really cool and neat.


September 4, 2001


Second week of class. Sadly the Introduction to Solid State class was canceled. This may arise some problems for any classes next semester that use it as a pre-requisite. On the other hand, I have to start thinking on my presentation for the OSA meeting in a couple of months. For this, I have review my insights of the Mach-Zehnder Welcher Weg project and update it with any new material I get from my current classes. Finally, this semester I'm going to spending some time in Prof. Metcalf lab . One of my first tasks for the lab is to work with Xiyue Miao in installing Optical Fibers to move laser light around the different labs.