DC polariser

The DC polariser was invented at IRAK in 2063 through an unusually focused series of experiments that were actually trying to create restless mass. Mainly utilised to increase the efficiency of Photovoltaic cells.

The principal is straight forward; Light is made a whole lot stronger by pushing it through a gain medium that makes it coherent (see Laser).

Light is electromagnetic. So is DC current.

Simple really, why did no-one notice this before?