JPS63299537A - Optical signal changeover switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an optical signal changeover switch for switching high speed broadband information signals.

BACKGROUND OF THE INVENTION Hitherto, no switches for high-speed, wide-band, high-speed optical signals have been put to practical use, and there are only two-circuit switches on a laboratory scale. Furthermore, it is difficult for switches using electronic circuits to operate on the G)lx order, and therefore the advantages of optical high-speed broadband digital signals are not fully utilized.

Problems to be Solved by the Invention Conventionally, mechanical or electronic switches have been used to switch information signals. Mechanical switches had problems in terms of response speed. Further, electronic switches are mainly used in a frequency band of several 100 MHz due to the stray capacitance of electronic circuits, and therefore have slow transmission speeds and are difficult to withstand electrical surges. - Although switches using a force tip have many advantages such as a wide frequency band and good noise resistance, they have drawbacks in terms of the configuration of the changeover switch section and the processing of high-speed optical signals. It was not yet practical.

The present invention provides a high-speed wideband optical signal changeover switch that can switch such high-speed wideband information signals without losing high-speed performance. , Means for Solving the Problems The present invention takes advantage of the high-speed, wide-band characteristics of optical signals, includes a plurality of identification pulses used for switch operation in a digital pulse train serving as a signal, and distinguishes between the shapes of the plurality of pulses. ,
When the detection form of the detection circuit that detects the identification pulse matches, a switch operation is performed, and a signal consisting of a digital pulse train including the identification pulse is distributed to the signal discrimination circuit.

An identification pulse is provided at an arbitrary time position (predetermined in advance) in the action light digital pulse train, and an electric switch driving circuit is separately provided with a detector for detecting this identification pulse, and the identification pulse is When the form of the digital pulse and the form of the detector match, the electrical switch drive circuit drives the optical switch, the corresponding optical switch circuit becomes "open," and the digital pulse train passes through this switch. It is configured to function as a high-speed broadband optical signal changeover switch.

Example An embodiment of the present invention will be described below.

FIG. 1 shows an example of an optical information digital pulse train.

In the figure, a indicates an identification pulse signal, which in this example is composed of a 2-bit pulse signal. Further, b indicates a pulse train of an information pulse signal, which in this example is composed of an 8-bit pulse signal. Further, in this example, the signal is expressed in a commonly used RZ signal format.

FIG. 2 shows the configuration of a switch according to an embodiment of the present invention, and it is now assumed that the optical information digital pulse train shown in FIG. 1 is input to the switch shown in FIG. 2 from the leftmost person. The optical pulse signal is divided into two parts by a splitter 1, and one part is converted into a pulse train based on a stain signal by a detection circuit 2 having an optical-to-electrical conversion function. The detection circuit 2 also includes a switch drive circuit for an optical switch. The electric pulse signal at this time has exactly the same signal form as that in FIG. Detection circuit 2
has a discrimination pulse detector, the detection circuit 2 identifies the discrimination pulse signal shown in FIG. The optical switch circuit 3 is operated so as to guide the signal to the branch to be distributed, and the optical electrical conversion circuit 4 to
7 and converts it into an electrical signal. This electrical signal is guided to one of buffer amplifiers 8-11. This identification was performed using a logic gate element or the like. The signal accumulated in the buffer 1 amplifier is passed through signal discriminators 12 to 15.
The signal enters one of them, is discriminated, and is output as an output to one of output terminals 16 to 19.

FIG. 3 shows an example of the configuration of the optical switch circuit 3 shown in FIG. 2. In FIG. The switch circuit comprises an optical waveguide 21 in which Ti or the like is diffused at high temperature on a substrate 2o made of a material such as ll1N'b03, and electrodes 22 to 2 are provided at the branch points of the optical waveguide 21 to face each other. between electrodes (e.g. 2
By applying an electric field between 2 and 23), the path of light can be polarized. Now, the light that has entered the switch circuit 3 from the leftmost optical fiber 28 is transmitted to the electrode 22.2.
Pass through 3 spaces. At this time, the switch drive circuit in the detection circuit 2 in FIG. 2 applies an applied voltage between the electrodes 22 and 23 in the direction determined by the discrimination pulse B in FIG. 1.

Depending on the applied voltage, the propagation path of the light that has passed between the electrodes 22 and 23 is changed, and the same thing is done between the electrodes 24 and 25 or between the electrodes 26 and 27, and the optical fibers 29 to 32 are
Output light can be obtained from either of the two.

The optical signal changeover switch with this configuration can be used in low-speed signal processing circuits, which conventionally could not process optical digital pulse signals that are input continuously at high speed without sacrificing high-speed performance. It also has great advantages, such as high-speed processing by adding a latch function to the buffer amplifier.

Note that when the switch operation of the optical switch circuit 3 is slow,
It is also possible to provide an air gap between portions a and b of the pulse train in FIG.

This high-speed switching mechanism can be applied to bus cables within computers or between computers, and can also be used as a high-speed parallel processing bus cable. That is, it has a switch function capable of high-speed real-time processing.

In addition, although the identification pulses in FIG. 1 are 2 pulses in the example, 1 pulse or 3 or more pulses may be used, but as a result of experiments, high-speed response is good and stable operation of the circuit is improved when 2 pulses or more are used. Obtained. Although the identification pulse may be placed at an appropriate position in the pulse train, it is necessary to adjust the timing with the detection circuit 2 or the timing of switching the next pulse train after the pulse train containing the identification pulse.

Effects of the Invention As described above, the present invention is extremely effective in processing high-speed optical information signals, and is of industrial value.

[Brief explanation of drawings]

Fig. 1 is a waveform diagram showing an example of a pulse train of a high-speed optical information signal, Fig. 2 is a block diagram showing an optical signal changeover switch according to an embodiment of the present invention, and Fig. 3 shows an embodiment of an optical switch circuit. FIG. 2...detection circuit, 3...optical switch circuit, a...identification pulse signal, b...information pulse signal.

Claims (1)

[Claims] A signal that includes at least two identification pulse signals in the pulse train of the digital optical reception signal, has a plurality of output circuits that generate response outputs according to the identification pulses, and that is determined separately from the output form of the output. The optical signal changeover switch is configured to detect a switch changeover signal included in the digital optical reception signal when the format matches the received digital optical reception signal, and use the switch changeover signal to change over an optical switch circuit comprising an optical waveguide on the receiving side.