JPS5866488A - Light wavelength multiplex switch - Google Patents

Abstract

PURPOSE:To obtain a light wavelength multiplex switch, by exchanging the wavelength of the light which carries the information of multiplexed wavelength. CONSTITUTION:The wavelength multiplex optical signals are transmitted to an incoming optical highway 1 and separated spatially with each wavelength through a multiplex separating circuit 3. The separated beams are fed to light wavelength converting circuits 5-1-5-m. A converting wavelength indicating register 6-1 inserts one of light wavelength converting elements 9-1-9-m on the basis of the indication information given from an exchange control part 12. The elements 9-1-9-m convert the wavelength of the light which carries input signals. These beams are synthesized through a multiplexing circuit 8 and delivered to an outgoing optical highway 2. The input and the output can be turned into a piece of optical fiber respectively for such light wavelength multiplex switch. This can save the number of optical fiber links.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an optical wavelength multiplexing switch, and more specifically,
The present invention relates to an optical wavelength multiplexing switch for changing the wavelength of light carrying wavelength-multiplexed information.

The practical application of optical communication systems is approaching, but the two major cores of Confucianism are transmission technology and switching technology. Since the technology has just arrived, there are still few proposals regarding the technology for specific switch configurations.This is because the development of optical switch elements, which are the basic elements that make up optical switches, and other optical circuit elements has not progressed.

However, recently, 1x chicken, 2x2, 4x4
The results of the development of several optical switch circuits, albeit of a small size, have been announced, and it has become possible to obtain optical switch circuits that can be used in optical switching equipment.

The current application area of optical switching equipment is limited to image exchange that handles broadband image information. Moreover, since the switching speed of the elements is not fast enough, a space division switching method is being considered.

However, as a matter of course, the space division method requires more switching points than the time division method or frequency (or wavelength) multiplexing method, and also requires a large number of optical fiber links connecting the switching points. Economicization is difficult.

In order to make optical switching more economical, C2 is expected to be based on a time division system or a wavelength multiplex system.

In the wavelength division multiplexing optical switching system, which exchanges wavelength-multiplexed information transmitted using light as a medium to its respective destination route, an optical wavelength division multiplexing switch is required as the basic element of the exchange. Become. This optical wavelength multiplexing switch switches the wavelengths of light carrying wavelength-multiplexed information, that is, wavelengths λ3... The light of λ, ~λ is the signal S1. When carrying S and -S1, for example, the wavelength of the light carrying the signal is switched, such as signal S1 to light of wavelength λ1, signal core to light of wavelength λt, etc.

An object of the present invention is to provide an optical wavelength multiplexing switch with a novel configuration that has the above-mentioned function, thereby making it possible to implement an optical wavelength multiplexing exchange system.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an example of an optical wavelength multiplexing switch embodying the present invention. In the figure, 1 is a light input highway, 2 is a light output highway, 3 is a demultiplexing circuit composed of, for example, an optical demultiplexer, 5-1 to 5-wn are optical wavelength conversion circuits,
8 is a multiplexing circuit composed of, for example, an optical multiplexer; 4-1.
4-2~4-Peng is intermediate light input link, 7-1.7-2~7
- Book is Nakaidemitsu link, 6-1. ~(5-w is a conversion wavelength instruction register, 12 is an exchange control unit. In the figure, 2
It is assumed that light passes through the path shown by parallel solid lines, and electrical control signals pass through the path shown by a single solid line.

When the light enters, A1 has a wavelength of λ modulated by signal S1, and signal S! The wavelength λ modulated by ! etc., respectively, the signal S1. Wavelength λ8 modulated by S, ~SvL
．． A wavelength-multiplexed optical signal composed of multiplexed lights of λ, .

The above wavelength-multiplexed optical signal input to the demultiplexing circuit 3 is
In the multiplexing/demultiplexing circuit 3, wavelengths are separated ζ spatially. That is, the lights with wavelengths λ, λ and λ are separated and output from the intermediate input links 4-1, 4-2, and 4-mζ, respectively, and are outputted to the corresponding optical wavelength conversion circuits 5-1*.
5-2 to 5-wgI=input.

The optical input conversion circuits 5-1 to 5-wn are provided in numbers corresponding to the number of wavelengths of light contained in the input signal.Since their configurations and functions are all the same, the optical wavelength conversion circuits 5-1 to 5-wn 1 will be explained in detail.

In the optical wavelength conversion circuit 5-1, 10 is a 1× folding optical switch circuit, and there are branch points 10-2-1, 10- on the door side that can be switched to one common optical path 10-1. 2-
2.~10-2-Rin are arranged in series, and a control voltage is applied to an external control electrode provided at the branch point to deflect the traveling direction of the light and switch the light, creating a common light path 10- The light incident on the conversion element 9-1. ~9-Pathway C to the horse: Exit.

Reference numeral 11 denotes an sxj optical switch circuit, which is similar to the 1xm optical switch circuit 10, but the traveling direction of light is opposite, and the conversion elements 9-1. ~9-ys, the light incident from the light path enters the common path 11-1 at the point of incidence 11-2-
1, 11-2-2 to 11-2-external, when a control voltage is present on the control electrode, light can enter the common path 11-1 from the point of incidence.

The conversion wavelength instruction register 6-1 stores instruction information sent from the exchange control unit 12, and based on the instruction information, sends a voltage to one of the control lines to control the optical switch circuits 10 and 11. Input and output of the conversion elements 9-1° to 9-wn = Apply control voltages to the control electrodes of the corresponding branch points and input points, and from this ζ;, the intermediate input link 4-1 and the intermediate output link 7-1 An optical wavelength conversion element (one of 9-1 to 9-@) specified by the exchange control unit 12 is inserted between the two.

The optical wavelength conversion elements 9-1 to 9-9 function to convert the wavelength of the light carrying the input signal S1, and when the light modulated with the wavelength λ1 of the signal S1 is input, the optical wavelength conversion elements 9-1 modulates the signal S1 with a wavelength λ□ (in this case, there is no conversion), and the optical wavelength conversion element 9-2 modulates the input light with the wavelength λ■. Moreover, the optical wavelength conversion element 9-w5. li also converts the input light into light obtained by modulating the signal S1 with the wavelength λ. That is, the conversion elements 9-1, 9-2 to 9-1 change the wavelength of the light carrying the signal to λ1. Convert to λ, ~λゎ.

Therefore, the light input from the intermediate light input link 4-1 is input to the light wavelength conversion element specified by the conversion wavelength designation register 6-1, undergoes the above conversion, and is sent to the intermediate light output link 7-1.
(::Output.

The light separated by the multiplexing/demultiplexing circuit 6 is subjected to the above conversion by the optical wavelength conversion circuits 5-1 to 5-5, respectively, and then sent to the multiplexing circuit 8.
are combined and output to Iway 2 to Idemitsu.

It is possible to configure it by an optical demodulator that obtains the signal S, and an optical modulator that modulates the signal S into light of an exchanged wavelength.

However, it goes without saying that the optical wavelength conversion element is not limited to the above-mentioned configuration (:) and may have another configuration that has the desired effect.

FIG. 2 ($1) One application example of the optical multiplex switch shown in FIG. 2 is that it can be used as a telephone exchange. It is not limited to application.

Figure 2 1=O, T,, T- is a telephone, LC! , L
Crn is a subscriber circuit, DD is an optical separation/demodulation circuit, Mu
is a light modulation/multiplexing circuit, and IHW is a light input equalizer (first
1), SW indicates the optical wavelength multiplexing switch shown in FIG. 1, and OHW indicates the Idemitsu equiway (corresponds to 2 in FIG. 1). Note that two parallel solid lines indicate a path of light, and one solid line indicates a path of an electrical signal.

It is assumed that the telephones tlkT*- to T-book C2 are respectively allocated with light having wavelengths λ1 to λ. The speech signal S sent from the telephone T1 passes through the 2-wire 4-wire coupler of the subscriber circuit LC, reaches the optical modulation/multiplexing circuit MMi, and is modulated by the telephone Tll - the light of the assigned wavelength λ1; , the call signals from other telephones are multiplexed with modulated light of different wavelengths, and sent to the input beam IHW.

The optical wavelength multiplexing switch y-8W is carried by the wavelength λ8, and the exchange control unit (set from 2) outputs the signal Si input from the input Equation IHW to the output Equation OHW on the light of the wavelength λ list. It is assumed that the light with the wavelength λ passes through the OHW to Idemitsu and reaches the optical separation/demodulation circuit DDt: along with light of other wavelengths, where the light is separated by wavelength. Each is demodulated and sent as a call signal to the telephone corresponding to the assigned wavelength.In other words, the light with wavelength λ is separated and demodulated to become the call signal S!, and the light with wavelength λ is sent to the telephone set corresponding to the assigned wavelength Tm's subscriber circuit LC, is transmitted twice, and the subscriber circuit L
Via the 2-wire 4-wire coupler in Cm.

The telephone reaches Tm. Similarly, the call signal S□ sent from telephone T is set so that it reaches telephone T, and from this C;, telephone T1. T can make a call.

Although one embodiment and one application example C= of the present invention have been described above, the present invention is not limited to the above embodiment, and various modifications can be made within its technical scope. For example, the optical wavelength conversion circuit 5-1, etc. (: The output optical switch circuit 11 used can be replaced with an optical multiplexing circuit, and in this case,
It is no longer necessary to control this optical multiplexing circuit with a conversion instruction register. The optical wavelength multiplexing switch according to the present invention has a second
Although it is also possible to configure an exchange by using one optical wavelength multiplexing switch C2 as shown in Figure (4: Optical wavelength multiplexing switch C2), a plurality of optical wavelength multiplexing switches according to the present invention can be connected to other optical circuits such as optical switch circuits, optical By combining it with a demultiplexing circuit, an optical multiplexing circuit, etc., it is also possible to apply it to the communication path of a large-scale optical wavelength division multiplexing switch.

Since the present invention is configured as described above, it is possible to obtain an optical wavelength multiplexing switch that performs the switching of the information by exchanging the wavelengths of the light that carries the wavelength-multiplexed information (secondarily). Moreover, since the optical wavelength division multiplexing switch according to the present invention 1 uses one multiplexed optical fiber as input and output, it is possible to use one optical fiber for each input and output, which saves on optical fiber links. In addition, the optical wavelength division multiplexing switch of the present invention, which can be configured with only 1x optical switch circuits and 1x optical switch circuits, has a better cross point than creating a large mxs optical switch grid using known optical switch circuits. This is advantageous in terms of the number of transmission characteristics and transmission characteristics.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of an example of application of the optical wavelength multiplexing switch according to the present invention. 1...Iremitsu Highway, 2...Iway to Idemitsu, 3
... demultiplexing circuit, 4-1.4-2. ~4-W&...
- Intermediate light input link, 5-1. ~5-s... Optical wavelength conversion circuit, 6-1. ~6-groove...conversion wavelength instruction register, 7-1.7-2~7-channel...intermediate Idemitsu link, 8.
...Multiplex circuit, 9-1. 〜9-屡... Optical wavelength conversion element. 10, 11... Optical switch circuit, 12... Details of replacement fee, patent applicant Fujitsu Limited agent, patent attorney Gobe Tamamushi (6 others) Figure 1

Claims (1)

[Claims] A multiplexing/demultiplexing circuit that spatially separates the wavelength-multiplexed optical signal input from the optical highway into wavelength-based light constituting the signal, and a demultiplexing circuit that spatially separates the wavelength-multiplexed optical signal input from the optical highway; an optical wavelength conversion circuit that converts the wavelength of each optical signal that has been transferred and separated; and a conversion instruction register that is provided in each of the optical wavelength conversion circuits and sets the wavelength to be converted under the control of an exchange control section. , and a multiplexing circuit that multiplexes the optical outputs of the respective optical wavelength conversion circuits and sends them to the Idemitsu Highway.