Elementary photonic switching modules in three divisions

In three-divisional photonic switching networks, data is interchanged among channels that are formed in space, time, and wavelength. This paper presents several techniques for designing the architectures of small photonic switching modules that switch in three divisions. In one technique, Marcus´ (1970) classical transformation from a space-only Clos network to a time-space-time architecture is generalized to the wavelength division and extended to three divisions. In another technique, Hunter´s (see IEEE J. Lightwave Technol., vol.11, no.3, p.495-511, 1993) space-time transformation is also generalized and extended to three divisions. It is illustrated on several classical network architectures, including the most elementary case of a three-division photonic switching module based on the Benes (1965) architecture: an eight-by-eight network in which each side has two fibers and each fiber has two wavelengths and two timeslots