US 6,285,809 B1 · Wraparound optical switch matrix

Abstract

An optical switch matrix connects N input waveguides to M output waveguides via M rows of switch sets. Each row of switch sets includes a first switch set that has one input port and two output ports, N−2 intermediate switch sets that have two input ports and two output ports, and a last switch set that has two input ports and one or two output ports. One output port of each first or intermediate switch set is optically coupled to an input port of a succeeding switch set in the same row, and the other output port is optically coupled to an input port of a respective switch set in a cyclically succeeding row, by intermediate waveguides that do not cross each other. The only exceptions are the intermediate waveguides that connect the last row to the first row. These intermediate waveguides may cross other waveguides. Preferably, however, no intermediate waveguides cross each other: the intermediate waveguides that connect the last row to the first row either cross the input waveguides or cross the output waveguides or cross no waveguides. Preferably, each switch set includes a 1×2 switch and a 2×1 combiner coupled optically to each other and to the input and output ports of the switch set. Optionally, in an N×N optical switch matrix, yet another switch set with two input ports and one output port is appended to each of L<N−1 of the rows, starting from the next to last row and working upwards. The first L switch sets of the last row are optically coupled to respective appended switch sets instead of to respective switch sets of the first row.

Claims30

Dependent claims

An optical switch matrix comprising:

(a) N input waveguides, N being an integer greater than 2;
(b) M output waveguides, M being an integer greater than 2;
and
(c) K rows of switch sets, where K is a larger of M and N, including:
(i) a first said switch set having at least one input port and two output ports,
(ii) a last said switch set having two input ports and at least one output port, and
(iii) L−2 intermediate said switch sets, where L is a lesser of M and N, each said intermediate switch set having two input ports and two output ports;
wherein one of said at least one input ports of each of N of said first switch sets is optically coupled to a respective said input waveguide;
wherein one of said at least one output ports of each of M of said last switch sets is optically coupled to a respective said output waveguide;
wherein, for each said row, for each said switch set other than said last switch set, a first said output port of said each switch set is optically coupled via a first respective intermediate waveguide to a respective said input port of a succeeding said switch set, and a second said output port is optically coupled via a second respective intermediate waveguide to a respective said input port of a respective switch set of a cyclically succeeding said row;
and
wherein, for each said row other than a last said row:
for each said switch set other than said last switch set, said first and second intermediate waveguides avoid each other.

10 more elements

An optical switch matrix comprising:

(a) N input waveguides, N being an integer greater than 2;
(b) N output waveguides;
and
(c) N rows of switch sets, all N said rows including:
(i) a first said switch set having one input port and two output ports, said input port of said first switch set being optically coupled to a respective said input waveguide,
(ii) a penultimate said switch set having two input ports and one output port, said output port of said penultimate switch set of a last said row being optically coupled to a respective said output waveguide, and
(iii) N−2 intermediate said switch sets, each said intermediate switch set having at least one input port and two output ports, said intermediate switch sets and said penultimate switch set of each of a last N−1 said rows each having two said input ports, each of a last L of a first N−1 said rows, where L is an integer less than N−1, further including:
(iv) a last switch set having two input ports and one output port, said output port of said last switch set being optically coupled to a respective said output waveguide, a first said input port of said last switch set being optically coupled to said output port of said penultimate switch set of said each row;
wherein said output ports of said penultimate switch sets of a first N-L−1 of said rows are optically coupled to respective said output waveguides;
wherein, for each said row, for each said switch set selected from the group consisting of said first switch set of said each row and said N−2 intermediate switch sets of said each row, a first said output port of said each switch set is optically coupled via a first respective intermediate waveguide to a respective said input port of a succeeding said switch set;
wherein, for each of said first N−1 rows, for each said switch set selected from the group consisting of said first switch set of said each row and said N−2 intermediate switch sets of said each row, a second said output port of said each switch set is optically coupled via a second respective intermediate waveguide to a respective said input port of a respective switch of a succeeding row;
and
wherein, in said last row, for each of a first L said switch sets, a second said output port of said each switch set is optically coupled to a second said input port of a respective said last switch set.

10 more elements

Dependencies are inferred from the claim text.

Wraparound optical switch matrix

Life of this patent

Wraparound optical switch matrix

Life of this patent

Abstract

Claims30