Patent ID: 6320995
Filing Date: 2001-11-20
Classification: G02B,H04Q

Abstract:
A multistage optical switch in which each stage includes a plurality of switching units having arrays of input ports and output ports, said input ports of each array and said output ports of each array having a ranking from lowest to highest, each switching unit including an arrangement of optical switching regions for selectively coupling said input ports to said output ports, said switching regions being arranged such that the number of switching regions an optical signal traverses within said each switching unit is dependent on said rankings of specific input and output ports through which said optical signal is propagated, where said number increases in correspondence with increases in said rankings of said specific input and output ports, said optical switch comprising:a first stage of said switching units; anda second stage of said switching units for which high ranking input ports of said switching units of said second stage are optically coupled to low ranking output ports of said switching units of said first stage, thereby achieving at least some equalization in sums of said numbers of said switching regions through which optical signals propagate when optical signals are input at said first stage and output at said second stage.