Throughout this documentation you might see me say that the orientation of a beam is 45 degrees. There's a number of different ways to interpret this, so let's spell out exactly what I mean.

• The beam is traveling away from me.
• The +x-axis is pointed to the right, and corresponds to an angle of zero.
• All other angles are measured counter-clockwise from the +x-axis.

For example, if I say that a beam has an orientation of 90 degrees, that means that it is oriented along the +y-axis. In actuallity, the polarization of a beam is a line that extends out to infinity in both directions, so the polarization in the previous example would extend along both the +y- and -y-axes.

The handedness of a circularly polarized beam is defined using the right-hand rule. If the beam is traveling away from you, the polarization vector of a "right"-hand circularly polarized beam will rotate clockwise in the plane of the polarization.

The output of polsim will follow the conventions of Jones calculus with regards to relative phases. This means that the phase of the x-component will be factored out from both the x- and y-components, leaving the x-component as a real number, and potentially leaving the y-component with some phase relative to the x-component.

All beams start with an intensity of 1. If the output of your simulation shows intensity: 5.00000e-1, that means that the intensity of the beam at the end of the simulation is half of the original intensity.

The phases that you see at the end of a simulation are always in radians.