Patent ID: 6208443
Filing Date: 2001-03-27
Classification: G02B,H04J,H04Q

Abstract:
A 2.times.2 dynamic optical add/drop multiplexer (OADM) having two OADM input fibers and two OADM output fibers, comprising:two 1.times.2 tunable spectral switches (TSS); two drop fibers; two add fibers;a first 1.times.2 TSS having an input connected to a first OADM input, and a first output of the first 1.times.2 TSS connected to a first drop fiber;a second 1.times.2 TSS having an input connected to a second OADM input, and a first output of the second 1.times.2 TSS connected to a second drop fiber;two 2.times.1 TSSs;a first 2.times.1 TSS having a first input connected to a second output of the first 1.times.2 TSS; a second input of the first 2.times.1 TSS connected to a first add fiber; and an output of the first 2.times.1 TSS connected to a second OADM output;a second 2.times.1 TSS having a first input connected to a second output of the second 1.times.2 TSS; a second input of the second 2.times.1 TSS connected to a second add fiber; and an output of the second 2.times.1 TSS connected to a first OADM output; andat least three 2.times.2 tunable spectral switches (TSS) selected from the group consisting of:(a) a first 2.times.2 TSS interposed between one of: (i) the two 1.times.2 TSSs and the OADM input fibers, and (ii) the first outputs of the 1.times.2 TSSs and the drop fibers; a second 2.times.2 TSS interposed between one of: (i) the two 2.times.1 TSSs and the OADM output fibers, and (ii) the second inputs of the 2.times.1 TSSs and the add fibers; a third 2.times.2 TSS interposed between the 1.times.2 TSSs and the 2.times.1 TSSs;(b) a first 2.times.2 TSS interposed between the two 1.times.2 TSSs and the OADM input fibers; a second 2.times.2 TSS interposed between the first outputs of the 1.times.2 TSSs and the drop fibers; a third 2.times.2 TSS interposed between one of: (i) the two 2.times.1 TSSs and the OADM output fibers, and (ii) the second inputs of the 2.times.1 TSSs and the add fibers; and(c) a first 2.times.2 TSS interposed between one of: (i) the two 1.times.2 TSSs and the OADM input fibers, and (ii) the first outputs of the 1.times.2 TSSs and the drop fibers; a second 2.times.2 TSS interposed between the two 2.times.2 TSSs and the OADM output fibers; and a third 2.times.2 TSS interposed between the second inputs of the 2.times.1 TSSs and the add fibers.