I have been working on a new “easyAlign” cartridge. After we finished the paper, we began to work on getting an operational full-color monitor. I spent a good amount of time working on aligning a new red cartridge that will have a brighter output than the old using the mirror cartridge to have the long focal length. In the process, I discovered some important things. First, it was a big pain. Next, it's best to start gluing things down from the laser forward. This allows you to maintain some adjustability as you proceed down the line. The most important decision I reached is that we cannot hope to replicate the test stand results in the current cartridge design. The alignment process is too hard due to the instability of the cartridge. Any adjustment in X or Z causes a massive shift in the final location of the dot, and complete realignment is necessary after each change. As such, it is virtually impossible to fine-tune anything as the slightest change can completely ruin the alignment.
In order to simplify the alignment process and create better results I have developed a new “EasyAlign” cartridge. The idea is to use the test stand as a tool to align the cartridge, then glue everything in place. I designed a new test stand stage to which we can bolt the rotational stage of the cartridge, which now has a large, flat plate on the bottom. The frame of the cartridge is mounted directly on top of the rotational stage by pegs that allow the test stage to move freely. The laser no longer is attached to x and z stages, but is fixed. All movement will happen at the rotational stage. Once it's aligned, we will glue it together and we'll be done.
I have been working on a few different things since last time. I have been working with Mark testing the different lenses to see if we can find an optimum focal length. In general, it appears that longer focal lengths are better. We also found that by placing the sample closer to the lens than the focal length(ie: for a 130mm lens we put the sample at 110mm) we were able to get significantly brighter and larger dots. We believe this is because we are able to utilize more of the grating, since the power coming out is basically related to a combination of input brightness, grating efficiency, and the area of the grating being used. I have also been modeling many of the electronic parts in solidWorks so that we can make a full model of the monitor for use in our paper. Today I worked on a flowchart for the paper as well.
Justin and Scott have been teaching me how to align cartridges. I have learned to recognize the characteristic streak and other signs in order to correctly orient the sample with respect to the laser. I have taken on the task of testing and determining which of the lenses is best for the cartridge. I think it would be beneficial for me to learn to align the cartridge within the monitor in order to understand the different elements involved.
I've been working to finish the RF chains in order to achieve full color on the monitor. I took apart the chain that wasn't working and starting testing it as I put it together piece by piece. As I put it together, it slowly dropped farther below the expected level. It appeared that the gva 84 and the filter segments were most to blame. I have also decided to work on creating a larger monitor display. Dr. Smalley suggested using galvos for horizontal scanning and either a polygon mirror or the new sample's range for vertical scanning.
I worked on fixing up the power supply today and as a monitor group we put together the abstract for our paper. We basically will write about the monitor and how it is assembled and why it's the best. I have recently been working on the power supply for the old senior project monitor. I have been cleaning up problems and making it look nice. There were a few places that had bad solder joints and needed to be redone. Now it is all fixed and I have just been fixing little things here and there. I flipped it over so it will fit into the chassis better.
I have decided to find applications for the holomonitor and write a paper about it. I want to think of relevant uses for the monitor, ideally ones that can't easily be solved in another way. My current thought is to use a holomonitor to make an ATM more secure. Ideally, a kinect could track the head position of the user and only project the image to that point. This way, the only angle from which someone could see the image is from the head position of the user. We could also create a holographic ten key for the user to enter their password on. Since only they can see it, it would be very hard for someone to steal their PIN.
Today I worked on a project for the IMMERSE group to fix the alumni profiles on their website. I was able to find LinkedIn profiles for about half of the alums. I have also learned basic HTML over the past few days in order to be able to fix the alumni webpage.
I've been trying to think of how to solve the polygon mirror motor lock problem. I've basically thought that the best way would be to get above the locking point and then lower it in to lock it, but then if it comes out just start the process over. It's not a very refined method but I figure that if it can work, we can slowly close how high we ramp it up until it's small. Drew said that it's hard to get it to lock from below, so I think always locking from above will work better. I'm going to look into how to make a state machine on the Arduino code to do this.