Polarisation

Terminology

S and P polarisation

s=senkrecht (perpendicular, from the German) and p=parallel. The p vibrations have the E field parallel to the plane of incidence. This is the lines representing the E field are of finite length on the usual drawing of reflection from a plane. On reflection at Brewster's angle (57 degrees) from a piece of glass only s rays remain, all the p rays are coupled into the glass. Thus Polaroid sunglasses have their axes vertical.