Abstract: 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.

Abstract: Apparatus for and methods of random number generation are disclosed, wherein a detector receives a group of n light pulses having single-photon intensity levels. Each of the n light pulses has a probability of less than one to produce a successful detection event at its time of arrival at the detector, and the detector is adapted to detect only one of the n pulses in the group. This single detection per group is thus a discrete random event that occurs only during one of n fixed time slots. The random event occurring during one of n timeslots is converted into a corresponding random integer from 1 to n. A series of such random numbers is generated by using a plurality of groups of n light pulses.

Abstract: In an apparatus and methods of random number generation, a detector (60) receives a plurality of groups of n light pulses (50), which an attenuator (40) typically dims to single-photon intensity levels. Each of the n light pulses has a probability less than one to produce a successful detection event at its time of arrival at the detector, but the detector detects only one of the n pulses per group. This single detection per group is thus a discrete random event. This detection even can occur only during one of n fixed timeslots during which a pulse may arrive at the detector. The method of the invention converts the random event at one of n timeslots into a random integer from 1 to n. The expected arrival time of the first pulse of the group becomes a timing reference with which to start a timer (90) and define the define the timeslots electronically.