I started noticing a few weeks ago that when you enter a search, a link shows up with images related to the topic of your search. I was busy at the time and didn’t really stop to realize how significant this is. So today, it really took effect. In preparing to attempt to explain Polarization to a class of students, I happened to type in the fundamental way to look at polarization, the “Poincare Sphere”. Now typically I would have also gone to Google scholar at this point to see what original Poincare material is on-line, but, I am on vacation today (skiing in Powder Basin, Utah – very nice, 18” of new snow, sunny day, 30 degrees, are you jealous yet??). Anyway, below is the collection of images that appears in the 4th or so link. Is this great, or what?
I also learned a few things (I probably should have said relearned, but, I can’t remember). There are 8 descriptors for a polarized E&M field; average intensity, average phase (these two also applied to an unpolarized field) and diattenuation and retardance with each of the latter two have three characteristics; magnitude, orientation, and ellipticity. I always struggled with concept of more than 3-dimensions, but, here it is, an 8-dimensional space. I also picked up that these map to the 16 Mueller matrix values, with the added concept of depolarization. The depolarization created by a material occupy 9 of the Mueller spaces, the diattenuation and retardance get 6, and intensity gets the remaining slot.
While the preceding paragraph is courtesy of Jim McGuire, Ph.D., the Director of Optical Engineering at ORA, and someone with a Ph.D. in polarization, even more can be found by visiting ww.axometrics.com, a company formed by his advisor, Prof. Russell Chipman of the University of Arizona.
I’m sure I’ll come back to polarization, but, like I said, it is a vacation day (or evening at this point), so some other time.
