File talk:Fresnel rhomb.svg
I submit: Because the amplitudes of the s and p components are conserved, the three traces (rectangles/ellipses) should all have the same overall width and height. Hence, because the slope (azimuth) of the first trace is less than 45 degrees, the third trace should be an ellipse, less high than it is wide (but with its axes horizontal and vertical). Only if the slope of the first trace is 45 degrees should the third trace be a circle.
IMHO, Gavin R Putland (talk) 07:38, 4 October 2017 (UTC).
P.S. It may be me, but: in the second and third graphs, I don't see what purpose is served by the blue sloping line, or the blue-gray angle at the lower left, or the black chord. The blue line may be the minor axis in the second graph, but it won't be in the third.
— Gavin R Putland (talk) 10:18, 4 October 2017 (UTC).
P.P.S. A new file with the suggested modifications has been uploaded at File:Fresnel rhomb linear to elliptical.svg.
