US 5,953,141 A · Dynamic optical add-drop multiplexers and wavelength-routing networks with improved survivability and minimized spectral filtering

Abstract

A method and apparatus for constructing an optical wavelength-routing network in which each network node is a dynamic add-drop multiplexer (OADM) with minimized spectral filtering effect on pass-through channels and survivability upon power failure. By using cascaded tunable reflection filters as the building blocks, strictly add-drop non-blocking OADMs for single input/output fibers, double input/output fibers, and 3 input/output fibers can be constructed for application to unidirectional and bidirectional ring networks and mesh networks of arbitrary degree. Methods and apparatus for minimizing various types of out-of-band and in-band crosstalk occurring within the dynamic OADMs are also described.

A F.times.F N-channel dynamic optical add/drop multiplexer (OADM) where F>=3, the OADM having F OADM input fibers and F OADM output fibers, comprising:

F 1.times.2 drop-control tunable spectral switches (TSS);
F drop fibers;
F add fibers;
a first 1.times.2 drop-control 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 drop-control 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;
a third 1.times.2 drop-control TSS having an input connected to a third OADM input, and a first output of the second 1.times.2 TSS connected to a third drop fiber;
F 2.times.1 add-control TSSs;
a first 2.times.1 add-control TSS having a first input connected to a second output of the first 1.times.2 drop-control 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 drop-control TSS connected to a first OADM output;
a second 2.times.1 add-control TSS having a first input connected to a second output of the second 1.times.2 drop-control 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 second OADM output;
a third 2.times.1 add-control TSS having a first input connected to a second output of the third 1.times.2 drop-control TSS;
a second input of the second 2.times.1 TSS connected to a third add fiber;
and an output of the second 2.times.1 TSS connected to a third OADM output;
and
at least three F.times.F tunable spectral switches (TSS) having F inputs and F outputs, where F>=3, selected from the group consisting of:
(a) a first F.times.F TSS interposed between one of:
(i) the two 1.times.2 drop-control TSSs and the OADM input fibers, and (ii) the first outputs of the 1.times.2 drop-control TSSs and the drop fibers;
a second F.times.F TSS interposed between one of:
(i) the two 2.times.1 add-control TSSs and the OADM output fibers, and (ii) the second inputs of the 2.times.1 add-control TSSs and the add fibers;
a third F.times.F TSS interposed between the 1.times.2 drop-control TSSs and the 2.times.1 add-control TSSs;
(b) a first F.times.F TSS interposed between the two 1.times.2 drop-control TSSs and the OADM input fibers;
a second F.times.F TSS interposed between the first outputs of the 1.times.2 drop-control TSSs and the drop fibers;
a third F.times.F TSS interposed between one of:
(i) the two 2.times.1 add-control TSSs and the OADM output fibers, and (ii) the second inputs of the 2.times.1 add-control TSSs and the add fibers;
and
(c) a first F.times.F TSS interposed between one of:
(i) the two 1.times.2 drop-control TSSs and the OADM input fibers, and (ii) the first outputs of the 1.times.2 drop-control TSSs and the drop fibers;
a second F.times.F TSS interposed between the two 2.times.1 add-control TSSs and the OADM output fibers;
and a third F.times.F TSS interposed between the second inputs of the 2.times.1 add-control TSSs and the add fibers.

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Dynamic optical add-drop multiplexers and wavelength-routing networks with improved survivability and minimized spectral filtering

Life of this patent

Dynamic optical add-drop multiplexers and wavelength-routing networks with improved survivability and minimized spectral filtering

Life of this patent

Abstract

Claims8