Wave vector division multiplexing ("WVDM") is a method of free-space
multiplexing for optical communications. In WVDM, wave vectors of
individual laser beams are manipulated so that each individual laser beam
has a unique wave vector. These individual laser beams are multiplexed
into an aggregate beam, which is transmitted to a receiver. The receiver
separates the individual laser beams on the basis of their unique wave
vectors. One area where WVDM is useful is in quantum cryptography. WVDM
can also be combined with traditional wavelength division multiplexing
("WDM") to increase throughput even further.