Diagram of initial board drawing:
...
Meghan's amended drawing (with a few less background images, and my best attempt at explaining how the system works from current knowledge):
The reference and return photodiodes will convert the light signals they receive into current; from that current, we need information about what wavelengths of light were received. From searching basic information about photodiodes, they have a response parameter (speed/time) determined by the materials out of which they are made, which affects sensitivity in different wavelength regions. For example, PIN photodiodes are faster than P-N photodiodes.
This example PIN photodiode seems to be sensitive to IR and visible light, and has a parameter
$ \frac{1}{2}$
After speaking to Dr. Morin about the structure of Physics 90r, it seems that at the beginning, there is some form that the student fills out indicating they have spoken to their advisor about expectations, and at the conclusion of the semester Dr. Morin reaches out to that person for a grade. So, the agreement is entirely between the student and the PIparameter \lambda_0 which seems to indicate the wavelength range in which the photodiode operates well.
Chris' comments Oct 24: Woo Hoo! Well done! As I look at this we can just use the beamsplitter to capture the outgoing light onto a photodiode at the top. We like (and have on hand) Hamamatsu 2281 photodiodes. They mount well in standard 1-inch mounting hardware.
Meghan response: Just to make sure I understand, the beam splitter would be placed where I have the two optical fibers magically breaking apart from one another (in the labeled place in below diagram)?
Hamamatsu 2881 photodiodes [datasheet] are silicon-based and have a relatively large photosensitive area (100 mm^2); the spectral response works great with our desired wavelength range (~450-750nm), as expected!
Tasks (10/24):
- Begin thinking about lock-in design
- We want to deconstruct the signal received at the return photodiode with respect to the signal at the reference photodiode
- Review lock-in notes
Background material/readingLook at some Hubble diagrams, supernova classificationBackground reading from email!
- Figure out how to LaTeX in Wiki/set up package to do so!
- GPT said use LaTeX syntax enclosed in '<math>' tags to TeX – workspace settings did not allow this
- Looking through more wiki documentation it seems Confluence is in this workspace
- GPT says: Confluence, a popular wiki software, supports LaTeX through the MathJax plugin. You can enable MathJax in Confluence to render LaTeX equations.
- apparently, if MathJax is enabled in Confluence, things should show up as TeX if you put them in dollar signs; however, I tested this below and it did not work.
- How to enable MathJax plugin without Confluence login?
Come up with a project name acronym (MOAT = Monitor Of Atmospheric Transmission currently)word possbilities: retroreflector, aerosol, detector, multicolor, automated, lockin, collimated, etc.
Update from Meeting (10/27):
Before spring semester begins:
- Conceptually flush out what we are trying to accomplish
- Do back of the envelope calculations and figure out what we expect numbers wise
- Get all part numbers for setup, and order all materials
Update 11/29:
Have completed readings, have a few questions. Writing Physics 95 final paper on this project, which should help me better absorb the background material!
Update 1/26:
Have switched projects to MOSS (next-generation of dome seeing measurement).