JPS60263596A - Light highway switch - Google Patents

Abstract

PURPOSE:To exchange information between plural time division multiple highways in the state of light signals by leading light signal on an input highway to optional output highway in following exchange action information that makes a gate type light switch an object. CONSTITUTION:Light signals from a time division multiplexed incoming highway are converted to wavelength corresponding to an outgoing highway by wavelength converting circuits T11, T12, united with light signals corresponding to each incoming highway by a light coupler C1, branched to each outgoing highway by a light branching device D1, and wavelength converted by wavelength converting circuits T21, T22. In such a case, if, for instance, a channel A and channel C are exchanged, signals of the channel A are converted from lambda0 to lambda2, and signals of the channel B are converted from lambda0 to lambda1. On the other hand, in the circuit T12, signals of the channel C are converted from lambda0 to lambda1, and signals of the channel D are converted from lambda0 to lambda2. After united by the coupler C1, branched by the branching device D1 to each wavelength, and wavelength converted from lambda1 to lambda0 in the circuit T21 and from lambda2 to lambda0 in the circuit T22.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an optical highway switch, which is a basic component of an optical exchange that exchanges information transmitted using light as a medium in the form of light.

(Prior technology) With the introduction of optical communication systems, information can be transmitted using optical signals on transmission lines, but before entering the exchange, it is converted into electrical signals, and the information is transmitted in the form of electrical signals by combining time switches, highway switches, etc. We are doing an exchange.

Therefore, there is a drawback that an optical-to-electrical converter is required at the connection point between the transmission line and the exchange.

In recent years, the development of optical functional devices has been vigorously pursued, and studies are underway toward the realization of an optical switch that directly exchanges optical signals.

Optical switches include mechanical switches that perform switching by mechanical operation, but there are limits to their use as replacement switches in terms of size and operating speed. On the other hand, optical switches using optical integrated circuit technology include optical switches using directionally coupled optical waveguides, but further development of optical integrated circuit technology is required to form large-scale switch matrices. It is.

(Purpose of the invention) The present invention eliminates these drawbacks on a large scale.

Optical high-speed technology that exchanges information as optical signals between multiple time-division multiplex highways without using optical switch matrices☆
It provides a stingray switch.

This will be explained in detail below using the drawings.

(Structure and operation of the invention) The present invention provides a plurality of optical time-division exchanges in which a plurality of pieces of information are time-division multiplexed and transmitted, in which input information is transmitted using a gate-type optical switch and an optical coupler. By multiplexing multiplexing information and controlling the phase during multiplexing, information can be exchanged between multiple highways.

Figure 1 shows the basic principle of the present invention, and shows an example where there are two input/output highways, and each highway has two channels of information multiplexed, each consisting of 3 bits. be. In the figure, I, , I2 are input highways, 08,02 are output highways, G, , G2 . G3
．． G4 is a gate type optical switch, C0&'ma optical coupler,
S is the optical splitter, Tachibana and Kame are the optical mono multivibrator C
C indicates a control section.

FIG. 2 is a timing chart of the above exchange operation,
The symbols a-h correspond to a-h in FIG.

Here, the operation of this circuit will be described as i&IM, taking as an example a case where channel A of input highway 1 and channel C of input highway 2 are exchanged in this circuit.

The gate type optical switches G, , G2 are operated ON-OFF at twice the input highway speed, and input information is sampled at high speed. However, in order to realize the exchange operation, the sampling phase is changed appropriately. In this example, channel B
Channel 1 is sampled in the first half of the evidence, and channels A and D are sampled in the second half. After these pieces of information are multiplexed by the optical coupler C1, the same information is sent to the gate type optical switch G3°G by the optical splitter S1. Gate type optical switch G3. G4 samples all the information on the output highway O1 in the first half phase of 1 bit, and samples the output highway 0□ in the second half phase of 1 bit. This makes it possible to exchange channels A and C. After that, input information is input by optical monomultivibrators M+ and K.

Convert to the same speed as

The operating clock of the gate type optical switch is supplied from the control unit CC, and all the switches operate synchronously.

Figure 3 shows an embodiment of the present invention, and as can be seen from the figure, the major feature of the switch circuit of the present invention is that it can easily be connected in multiple stages, reducing the number of ports for optical branching and couplers. Even if it is small, it is possible to configure a large-scale switch.

As gate type optical switches, laser diode switches, IX2 directional coupling type switches, etc. can be applied, and nS
Order switching speed can be expected.

On the other hand, an optical mono-multivibrator can be realized with a configuration using an optical bistable element (Bungshi to Electronic Communication, 1982-Rin 228).

In FIG. 3, as the degree of multiplicity increases, ultra-high speed optical switches are required. Figure 4 shows an embodiment of the present invention in which wavelength multiplexing is used to avoid this, and the time-division multiplexed optical signal from the input highway is converted by a wavelength conversion circuit to a wavelength corresponding to the output highway. The signal is combined with the optical signal for each highway at an optical coupler, split into each output highway at an optical demultiplexer, and wavelength-converted at a wavelength conversion circuit. In the figure, A1 to An are the multiplexing units described up to Figure 3;
B, ~Bn is the separation part, T11~T1n2T21~T2
n is a wavelength conversion circuit, C8 is an optical coupler, Dl is an optical demultiplexer,
λ. , λ1 to λn are wavelengths. The wavelength conversion circuit is a light-
This can be realized by a combination of an electric conversion element and an electric-optical conversion element. FIG. 5 shows the basic principle of an optical highway switch using wavelength multiplexing, and is an example in which two channels of information each consisting of 3 bits are time-division multiplexed and further wavelength-multiplexed. FIG. 6 is a diagram showing the wavelengths of each part in wavelength multiplexing, and the symbols azi are a to a in FIG.
Corresponds to 1.

Hereinafter, the case where channels A and C are exchanged in FIG. 6 will be explained as an example. In the wavelength conversion circuit T11, the signal of channel A is λ. From A2 to A2, the signal on channel B is converted from A1 to A1. On the other hand, at TI2, the channel C signal is λ. From A1 to A1, the signal on channel D is converted from A2 to A2.

After being combined by the optical coupler C1, the signals are separated into wavelengths by the optical demultiplexer D1, and then sent to the wavelength conversion circuit T2. In, A
1 to λ. λ from A2 at T22. The wavelength is converted to

(Effects of the Invention) As explained above, the present invention realizes switching operation by time-division multiplexing the input signal as an optical signal and controlling the phase during multiplexing, thereby easily achieving high-speed operation. A large-scale switch can be realized.

Further, the present invention can be similarly applied even when the input/output highway is not time-division multiplexed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention, FIG. 2 is a diagram showing an operation timing chart, FIGS. 3 and 4 are diagrams showing embodiments of the present invention, and FIG. A diagram showing the principle, and FIG. 6 is a diagram showing the operating wavelength. ■++ 'l+~In...Input highway 0, ,0
2. ~On ・Output highway G,, G2. ~Gn...
・Gate type optical switch SI+ ``'2+~Sn... Optical splitter C,, C2, ~Cn... Optical coupler M, , M2.~Mn-... Optical mono multivibrator CC... Control unit Dl...Demultiplexer AI r A2, ~An...Time division multiplexer BI+
"l+~Bn...Time division separation unit Tl21~T+ nv
'I'2+ + T221 to T2 n ... Wavelength conversion circuit λ. , λ1. ~λn... Wavelength patent applicant Nippon Telegraph and Telephone Corporation Patent application agent Megumi Yamamoto -

Claims (2)

[Claims] (1) Gating optical signals on multiple input highways;
A gate type optical switch provided for each input highway, an optical coupler that couples the output of each gate type optical switch,
A gate-type optical switch corresponding to the output highway is coupled to the output via an optical splitter, and an optical mono-multivibrator is coupled to the output of each gate-type optical switch to provide an optical output at a predetermined speed. and is configured to guide an optical signal on an input highway to an arbitrary output highway by controlling the gate type optical switch according to and independently of each other in accordance with the intended switching operation information. highway switch. (2) gating optical signals on multiple input highways;
A gate type optical switch is provided for each input highway, a wavelength conversion circuit receives the output optical signal, an optical coupler connects the output of each wavelength conversion circuit, and the output is connected via an optical demultiplexer. a wavelength conversion circuit, a gate type optical switch coupled to the output thereof and provided for output highway correspondence, and an optical mono-multivibrator coupled to each gate type optical switch to provide optical output at a predetermined speed; 1. An optical highway switch characterized in that the optical highway switch is configured to guide an optical signal on the input highway to an arbitrary output highway by controlling a wavelength conversion circuit and a gate type optical switch according to an intended switching operation.