Direction of the electric field oscillation of a Laser beam.
In many, although not all, cases the output of a laser is polarized. This normally means a linear Polarization state, where the electric field oscillates in a certain direction perpendicular to the propagation direction of the laser beam. There are cases with Fiber lasers where an elliptical but also more or less stable polarization state is generated, which can be transformed into a linearly polarized beam by using an appropriate combination of waveplates. This is not possible, however, for broadband emission with wavelength-dependent polarization state.