JPS6370693A - Optical matrix switch device - Google Patents

Abstract

PURPOSE:To greatly reduce crosstalk from other optical gratings to a path to a common outgoing-side optical fiber in an optional array by coupling only the outgoing line of an optical basic grating which is so selected as to form the path with the common outgoing-side optical fiber. CONSTITUTION:Optical basic gratings 20a - 20d and optical selectors 28a - 28d are as shown by solid lines when 0 is inputted from a decoder 32 or by dotted lines when 1 is inputted. Further, outgoing circuit numbers are so set for respective circuits a1, a2, a3 and a4 that an output is sent to b1 at the time 00, to b2 at the time of 01, to b3 at the time of 10, and to b4 at the time of 11; and the outgoing circuit numbers are extracted from the respective circuits and inputted to the decoder 32 to perform switching control over the respective optical basic grating optical selectors. The decoder 32 output signals of 1 and 0 to the respective optical basic gratings 28a - 28d and also outputs signals of 1 and 0 to the optical selectors 28a - 28d to set respective connection states, thereby connecting respective incoming circuits to desired outgoing circuits. Thus, the crosstalk from other optical basic gratings to the path is greatly reduced.

Description

[Detailed Description of the Invention] [Summary] Connecting the output lines of each basic optical grating in each column of a plurality of basic optical gratings arranged in a matrix to a common output optical fiber via an optical selector. This prevents crosstalk of light from unselected basic optical lattices.

[Industrial application field]

The present invention relates to an optical matrix switching device, and more particularly to an optical matrix switching device that improves the coupling of each column optical basic grating output line to a co-protruding photometric fiber.

[Conventional technology]

In a telephone exchange, any one of a number of incoming lines is connected to any one of a number of outgoing lines, and while the outgoing line is connected, the other Similarly, it is necessary to be able to selectively connect people and outgoing lines. Such an exchange function can be easily realized using a mechanical type such as a crossbar switch, or a digital type such as a highway switch using memory. For example, in a mechanical or electronic exchange using a crossbar switch, a large-scale switch matrix can be easily constructed from a small-scale switch matrix called a basic lattice. Figure 3 shows 2x2 basic grid 10
(The subscripts a, b, . . . are used to distinguish each other) are used to form a 4×4 switch matrix, and the circuit configuration is simple as shown in the figure. In this figure, a and ~a4 are four incoming lines, b and ~b4 are four outgoing lines, and the points are wired ORs, and the basic grid is one of the incoming lines to one of the outgoing lines, and the other incoming line at the same time. Since it can be connected to the other outgoing line, any one of a1 to a4 can be connected to any one of b1 to b4 at the same time (excluding double selection, of course).

Naturally, a switching function is necessary in optical communications, and in this case as well, any one of the many incoming optical fibers can be connected to any one of the many outgoing optical fibers, and it can be easily connected using a small-scale basic lattice. It has been desired to be able to construct a large-scale switch matrix (optical space switch), and the present applicant disclosed an optical matrix switch device having a switching function that can meet this demand in Japanese Patent Application No. 16833'9/1983.

This optical matrix switch device has a configuration as shown in FIG. The device consists of a plurality of input optical fibers (al) assigned to each row of an optical elementary grating array arranged in a matrix.

a2 or a3. a4) is divided by the number of columns by the optical distributor (22, 22b or 22o, 22a), and the corresponding optical basic grating (20=, 20b or 20°, 20d) to the incoming line, and for each column, each optical basic path/child of that column (20,,
20° or 20b.

20d) to an optical coupler (248, 24b or 24o)
, 24d) to a common output optical fiber (bl
, t)2 or b3+b4).

This configuration allows any input optical fiber to be connected to any common output optical fiber using fewer optical elementary gratings.

[Problem that the invention seeks to solve]

However, in this optical 7-trix switch device, the output lines of each basic optical grating for each column are coupled to the common output optical fiber via an optical coupler, so the output lines are connected to the common output optical fiber. The optical signal from the optical basic lattice forming the path is mixed with the optical signal from the other optical basic lattice in that column, causing crosstalk. That is, in general, a 2×2 optical basic lattice has two states, as shown in 20a: a solid line connecting al and t)2+a2, and a dotted line connecting a, b1+ a2 and b2. Since the optical signal of a3 is output to b2, the light distributed by optical splitter a or a2 is transmitted to optical coupler 24a.
This is because it is input to

Such crosstalk is undesirable in terms of exchange communication.

The present invention was created in view of such problems, and an object of the present invention is to provide an optical matrix switch device that can reduce crosstalk when coupling each optical basic grating output line to a common output optical fiber. purpose.

[Means for solving problems]

FIG. 1 shows a block diagram of the principle of the present invention. The present invention is the fourth
The optical coupler of the conventional optical matrix switch device shown in the figure is configured as an optical selector.

[For production]

Only the outgoing lines of the optical elementary gratings that are selected to form a path to that common outgoing optical fiber in any row of optical matrix switching devices are coupled to the co-extending photometric fiber. Therefore, crosstalk from other optical elementary gratings in the column to the path can be greatly reduced.

〔Example〕

FIG. 2 (al is an embodiment of the present invention, and shows an example in which a 4×4 switch matrix is constructed using four 2×2 basic optical lattices. a, ~a4 are input optical fibers, b, ~ b4 is an output optical fiber, 208 to 20d is an optical basic lattice, l is an optical fiber in the switch matrix, 22. to 22a is an optical splitter, 26 is an optical amplifier, 28 and 28a are two-man power 1-output optical selectors, 32 are decoders, and these optical selectors are switched to connect any incoming optical fiber to any outgoing optical fiber under the control of a switch control means that selectively controls each of the basic optical gratings. The optical basic lattice output light of the bus formed by the above-mentioned optical fiber can be switched and controlled so as to pass through to any of the output optical fibers.

Basic optical lattice 20a, 20b, 20c,
20d and optical selectors 28a, 28b, 28c, 2
8d is a solid line when "0" is input from the decoder 32, and is a solid line when "1" is input. Also, each line a1. a2+ "3+ For 24, b+ when 00, b2 when 01, b3゜1 when 10
The outgoing line number is set so that it is output to b4 when it is 1, and this outgoing line number is extracted from each line and input to the decoder 32 to control switching of each optical basic lattice optical selector. The decoder 32 includes optical basic gratings 20a, 20b, 20c, 20
01″ for d.

While outputting a signal of "0", the optical selector 28a,
'1'' for 28J 28c and 28d.

A signal of "0" is output to set each connection state and connect each incoming line to a desired outgoing line.

Figure 2(b) shows the outputs of the decoder outputs ■ to ■ when the outgoing line numbers of lines a and ~a4 are respectively assigned 00'', ``01'', ``10'', and ``11'' ( 0” or “1”).

Based on the input line number of each line, the decoder 32 assigns “0” or “1” to the signal lines
” is output.

Since the wiring shown in FIG. 2 (al) is the same as in FIG. 3, it is possible to perform the same exchange function as in FIG. 3.

In addition, each optical basic grating (20a, 20o or 20b) in each column
, 20d) is transmitted to the output optical fiber (b4.b2+b3) via the corresponding optical fiber β in the switch matrix, and the two-power one-output optical selector (288, 28b or 28°, 28d) of the row pair window. .b4), only the output light from the optical basic lattice selected to form the bus to the output optical fiber is selectively passed through the optical selector and sent to the optical selector. Even if the output light is input from another basic optical grating in the column, the propagation of the output light to the output optical fiber is significantly suppressed. Therefore, the crosstalk from the other optical elementary grids to the bus is very low.

〔Effect of the invention〕

As described above, according to the present invention, only the optical basic lattice output light selected to form the bus to the common output optical fiber is selectively passed through the co-protruding photometric fiber. Crosstalk to the bus can be reduced.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the principle configuration of the present invention, Figure 2 (al is a diagram showing an embodiment of the present invention, Figure 2 (b)
) is a diagram showing an example of decoding of a decoder, Figure 3 is a diagram showing an electric switch matrix configured using an electric switch type basic lattice, and Figure 4 is a diagram showing a conventional optical matrix switch device configured using an optical basic lattice. It is a diagram. In FIG. 1 and FIG. 2(a), 2Lt...20NN, 2011, 20b, 20°, 20d are optical basic lattices, 22r = 22N, 22-, 22b, 22c. 22d is a light distributor, 281...28Nl 28a, 28b, 28c. 28d is an optical selector, all...a N N + a 1...
a4 is an input optical fiber, and bl...bN are output optical fibers.

Claims (1)

[Claims] A plurality of basic optical lattices (20_1_1...20_N_N
) are arranged in a matrix in the row and column directions, and a plurality of input optical fibers (
a_i_1...a_i_N) as an optical distributor (22_i)
The lines are branched by the number of columns and connected to the corresponding optical basic grid input line of each column.
An optical matrix switching device characterized in that an output line of 0_N_j) can be connected to a column-corresponding common output optical fiber bj via an optical selector (28_j).