JPH10308961A - Integrated optical switch array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the control configuration of an integrated optical switch array. SOLUTION: Switch elements Ax ,y are arranged in matrix electrically and the switch elements Axy on a row X are connected to one control line Lx of a control line group N at a terminal, and the switch elements Ax ,y on a column Y are connected to one control line Ly of a control line group M at a terminal, an electronic control circuit 30 has a clock oscillator 31 and a controller 32 connecting to the clock oscillator 31 and an external terminal and then a control pulse is applied to the switch elements Ax ,y in the time division multiplex system in a form of a voltage pulse or a current pulse.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated optical switch element having two terminals, each of which can be controlled independently of each other, and one connected to each of the optical switch elements.
The present invention relates to an integrated optical switch array including an electric control line having two external terminals and an electric control circuit connected to the external terminals.

[0002]

2. Description of the Related Art A switch array of this type is disclosed, for example, in the printed matter "22nd European Conference on Optical Communications ECOC '.
96 (22nd European Conference on Optical Communica
Discussion ECOC'96) ". 2.2. This known switch array is an 8 × 8 switch array having eight input optical waveguides and eight output optical waveguides. This known switch array comprises 128 switch elements, two of each being electrically connected in parallel with one another to form a switch element which can be controlled independently of one another. The total number of switch elements is therefore 64. Each switch element is connected to two control lines, and each control line has one external terminal. Thus, this known switch array has 128 control lines and the same number of external terminals.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an integrated optical switch array which requires a relatively simple control structure.

[0004]

According to the present invention, there is provided an integrated optical switch array of the type described above, in which the switch elements are arranged electrically in a matrix, each having a row of switch elements. Is each one
One terminal is connected to one control line of one group of control lines at one terminal, and each one row of switch elements is connected at one other terminal thereof to one control line of the other group of control lines. The control circuit has a clock generator and a control device connected to the clock generator and external terminals, whereby control pulses are applied to the switch elements in the form of voltage pulses or current pulses in a time-division multiplexed manner. It is solved by doing.

The advantages of the switch array according to the invention are:
A control line of about 2Z ^1/2 and about 2
That is, only the external terminal of Z ^1/2 is required. The switch array according to the invention therefore requires only 16 control lines and 16 external terminals in 64 switch elements which can be controlled independently of one another. This advantageously simplifies the electrical connection and reduces the number of control drives.

Since this switch element is controlled by a time division multiplex system, it is considered to be advantageous when the switch element is a digital optical switch. In the time-division multiplexing method, the switching elements are not supplied with voltage or current continuously in time, and voltage pulses or current pulses are applied at regular time intervals. The switching times to be accurately set for talk suppression are obtained only on a temporal average. Digital optical switches are particularly suitable for time division multiplex operation. This is because the digital operation characteristic of this switch enables a large suppression of crosstalk even when the switching point is not set accurately.

A particularly simple switching element is realized when the switching element is a thermo-optical switch or a carrier injection type switch.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a switch array according to the present invention.

The figure shows switch elements A _{x, y} (x = 1... N, y =
1. . . M). In practice, the individual switch elements are arranged spatially opposite one another, depending on the respective application of the switch array, and are therefore often arranged in a non-matrix fashion. Each switch element A _{x, y} of each one row X is connected at one terminal thereof to one control line L _{x of} one group N of control lines. Further, each switch element A in one column Y
_{x, y} are respectively connected to one control line L _y of the other group M of the control line at the one other terminal, respectively. Control line L _x of both Group N and M, L _y each via one of the external terminals are connected to a control circuit 30 having a clock generator 31 and a controller 32.
The clock generator 31 is connected to the input terminal E321 of the control device 32, and the other input terminal E322 of the control device 32 is connected to the controller 35 for setting the optical switching state of the integrated optical switch array. . This controller 3
5 determines which switching elements are to be actuated in each case in order to form a given optical transmission path, as described in the literature mentioned at the outset. The control device 32 comprises an EPROM module 40, which has one input terminal E401 and an input terminal E3 of the control device 32.
21 and thus to the output of a clock generator 31. The other input terminal E4 of the EPROM module 40
02 is connected to another input E322 of the control device 32 and thus to the controller 35. The output side of the EPROM module 40 is connected to an amplifier V _x, which is connected to each one of the external terminals of one control line L _x Group N control lines. Auxiliary device 6 in control device 32
0 is one input terminal E321 of the control device 32 at its input side.
It is connected to the. The output side of the auxiliary device 60 switches S _y is connected, the switch S _y is connected to the external terminals of the control line L _y other group M of each control line.

In order to achieve a constant switching state of the switch array according to the invention, the individual switch elements A _{x, y} are controlled by the control device 32, the clock generator 31 and the control device 35 for a short period of time, ie in a time-division manner. It is controlled in a multiplex manner, whereby the switching elements A _{x, y} are supplied with current or voltage pulses for this purpose. Such a pulse operation is particularly suitable for a slow-acting switch element such as a thermo-optical switch element whose switching time is in the millisecond range. The switch array according to the invention, however, can also be used for other switching principles that are relatively slow, such as, for example, carrier-injected switches with a long carrier life. Switch element A _{x, y}
Can be a digital optical switch. This is because the switch is not particularly sensitive to changes in control power or control current due to its stepwise switching characteristics.

When operating this switch array, it must be ensured that the individual switch elements A _{x, y} are controlled by control pulses of a sufficiently high repetition frequency. This is ensured when the switching time of each switching element A _{x, y} is clearly greater than the total time required for all the switching elements A _{x, y} provided in the switch array to operate. In this case, an almost constant switching state occurs in each switching element A _{x, y} on a time average. The height of the control pulse, which can be applied in the form of a voltage pulse or a current pulse, can be adjusted by changing the pulse height or pulse width, or alternatively by changing their combination.

In order to minimize the time between two control pulses at each switch element A _{x, y} , the control of the switch elements A _{x, y} is performed not on an individual basis but on a column basis. For this, a constant potential by one control line L _y switches S _y of the other group M of the control line, for example, is connected to the ground potential, while the remaining control line L _y of the other group M control lines It is connected to a non-potential for the same time. The switching elements A _{x, y in} column Y can then operate with the amplifier V _x . The control patterns of the individual columns Y corresponding to the desired switching state of the switch array are stored in the EPROM module 40. This control pattern is called when the memory address belonging to it is applied to the EPROM module 40 by the clock generator 31 and the controller 35. In this case, the memory address results from the combination of the number of the column Y to be controlled and the desired switching state of the switch array. The switching state of the switch array is then determined by the controller 35 from the EPR
Transmitted to OM module 40, numbers of each column Y is the auxiliary device connects the switch S _y on the output side 60
Is determined by a clock generator 35 which simultaneously controls

The control of the other columns takes place in the same way. Control is then repeated starting from the first row.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a switch array according to the present invention.

[Explanation of symbols]

30 electrical control circuit 31 clock generator 32 the control device 35 the controller 40 EPROM module 60 assist device A _{x, y} switching elements L _x belonging to the control line group N belonging to the control line L _y control line groups M control lines S _y switches V _x amplifier

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Karsten Kostulzewa, Germany 12045 Berlin Waixelplatz 2 (72) Inventor, Getz Huisyuwesk, Germany 10551 Berlin

Claims (4)

[Claims] 1. An integrated optical switch element having two terminals, each of which can be controlled independently of each other, an electric control line connected to the optical switch element and having one external terminal, respectively, and these external terminals. and a connecting electrical control circuit, switching elements (a _{x, y)} are arranged in the form of electrically matrix, the switching elements (a _{x, y)} of each one row (X) are each 1 One control line (L _x ) of one group (N) of control lines with one terminal
And the switching elements (A _{x, y} ) of each one column (Y) are each connected to one control line (L _y ) of the other group (M) of control lines at one other terminal thereof.
And an electric control circuit (30) having a clock oscillator (31) and a control device (32) connected to the clock oscillator (31) and the external terminal. _{x, y} ), wherein a control pulse is applied in the form of a voltage pulse or a current pulse in a time division multiplex manner. 2. The switch array according to claim 1 _{, wherein the} switch element (A _{x, y} ) is a digital optical switch. 3. The switch array according to claim 1 _{, wherein the} switch element (A _{x, y} ) is a thermo-optical switch. 4. The switch array according to claim 1 _{, wherein the} switch element (A _{x, y} ) is a carrier injection type switch.