Transverse Wave Trains and Plane Polarization

Generation of a transverse, plane polarized wave train in a Slinky™ is demonstrated.

Discussion

When the demonstrator moves one end of the Slinky™ from side to side, a sequence of transverse pulses moving on alternate sides of the Slinky™ (a wave train or wave) is generated. As this transverse wave moves along the Slinky™ lying on a table, the displacement of the coils is perpendicular to the direction in which the wave is traveling and is confined to the plane of the table top. Such a transverse wave is said to be plane polarized. Ripples on a pond or in a ripple tank are also examples of plane polarized waves.

In the illustration below, arrows are used to represent the direction of the displacements of two groups of plane wave trains that are propagating toward the viewer. The displacement directions of the unpolarized group of wave trains are random; for the polarized group of wave trains, they are parallel.