JPH0229634A - Optical multi-wavelength converting circuit - Google Patents

Abstract

PURPOSE:To convert an input signal to an optical signal of one or more arbitrary wavelength by providing an optical modulator for modulating and emitting an output light beam of a wavelength selecting element made incident from a first input terminal, in accordance with a signal applied to a second input terminal. CONSTITUTION:A light beam to be modulated 110 to which wavelength is multiplexed by light beams of wavelengths lambda1-lambda4 are made incident on a wavelength selecting element 100. When a signal is applied to a control electrode 102, the wavelength selecting element 100 selects the light beams of wavelengths lambda1, lambda3 and lambda4 from the light beams to be modulated 110 consisting of wavelength lambda1-lambda4 and emits a light beam to be modulated 111 consisting of wavelengths lambda1, lambda3 and lambda4 to an optical modulator 101. The optical modulator 101 modulates the light beam to be modulated 111 inputted from the wavelength selecting element in accordance with the amplitude of an input signal 113 and outputs modulated light beams 114 consisting of wavelengths lambda1, lambda3 and lambda4. In such a way, the input signal 113 can be converted to optical signals of wavelengths lambda1, lambda3 and lambda4 among wavelength lambda1-lambda4.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical multi-wavelength conversion circuit used in wavelength-division optical exchangers and the like.

(Prior art) Optical fiber transmission systems that use optical fibers as transmission paths have advantages such as being able to transmit a large amount of information because the optical fiber has a wide band, and that the optical fiber is not subject to induced noise. , is expected to be widely used in the future.

The switch used with this optical fiber transmission system is preferably an optical switch that can exchange optical signals in the optical domain.
As such an optical switch, a wavelength division optical switch is known, which is described on page 3,100 of the Proceedings of the 1985 Electrical and Information Related Societies Federation Conference. Wavelength division optical switching equipment performs switching by setting communication channels between each wavelength of wavelength-multiplexed input and output optical signals and converting the wavelengths.
Therefore, a wavelength conversion switch that converts the wavelength of an optical signal is essential. One such wavelength conversion switch has a configuration shown in FIG.

The wavelength multiplexed optical signal including wavelengths λ, .
521, 522, and 523. The fixed wavelength selection element 520 fixedly selects the optical signal with the wavelength λ1 from the wavelength multiplexed optical signals of λ1 to λ4, and outputs the optical signal with the wavelength λ1 to the variable wavelength conversion element 530. Similarly, fixed wavelength selection elements 521, 522, 52
3 are respectively wavelengths λ2. λ1. The optical signal of λ4 is selected and the wavelength λ2. λ3
．． Each outputs an optical signal of λ.

The variable wavelength conversion elements 530, 531, 532, and 533 convert the wavelength of input light into an arbitrary wavelength. In the example of FIG. 5, the variable wavelength conversion element 530 changes from wavelength λ to wavelength λ
1, the variable wavelength conversion element 531 converts the wavelength λ2 to the wavelength λ4.
, the variable wavelength conversion element 532 converts the wavelength λ to the wavelength λ2, and the variable wavelength conversion element 533 converts the wavelength λ to the wavelength λ2.
Convert the wavelength to 1.

The merger 540 includes variable wavelength conversion elements 530 to 533.
The optical signal is guided to the optical waveguide 501, and the wavelength λ, ~λ4
Creates a wavelength-multiplexed optical signal.

In this way, a communication channel can be set between arbitrary wavelengths of the wavelength-multiplexed optical signal with wavelengths λ1 to λ4 on the optical waveguide 500 and the wavelength-multiplexed optical signal with wavelengths λ1 to λ4 on the optical waveguide 501.

(Problems to be Solved by the Invention) The variable wavelength conversion elements 530 to 533 of the conventional wavelength conversion switch shown in FIG.
Therefore, for example, the wavelength of an optical signal of wavelength λ1 on the optical waveguide 500 can be converted from λ2 to wavelength λ, λ1 . Simultaneously converting to λ sound and passing through the optical waveguide 5
It was not possible to make a branch connection to output to 01. As described above, there are problems that need to be solved with the conventional method.

An object of the present invention is to provide an optical multi-wavelength conversion circuit that can solve such problems and convert an input optical signal into an optical signal of one or more arbitrary wavelengths.

(Means for Solving the Problems) The optical multi-wavelength conversion circuit of the first invention of the present application selects light of one or more arbitrary wavelengths from input wavelength-multiplexed modulated light according to a control signal. It is composed of a wavelength selection element that emits light, and an optical modulator that modulates the output light of the wavelength selection element that is input from a first input end according to a signal applied to a second input end and outputs the modulated light. It is characterized by the presence of

Further, the optical multi-wavelength conversion circuit according to the second invention of the present application is an optical modulator that modulates the wavelength-multiplexed modulated light input from the first input terminal according to a signal applied to the second input terminal and outputs the modulated light. and a wavelength selection element that selects and outputs light of one or more arbitrary wavelengths from input light output from the optical modulator according to a control signal.

(Function) The optical multi-wavelength conversion circuit of the present invention simultaneously modulates light of one or more arbitrary wavelengths of wavelength-multiplexed light according to an input signal, so that the input signal can be converted into a multi-wavelength optical signal. Therefore, by using the optical multi-wavelength conversion circuit of the present invention, it is possible to configure an optical communication path that can be branched and connected.

(Example) Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the first invention of the present application.

The input signal is set to wavelength λ1. of wavelengths λ1 to λ4. λ1. λ
The case of converting into the optical signal No. 4 will be explained. In FIG. 1, modulated light 11G, which is wavelength-multiplexed with wavelengths λ1 to λ4, is incident on a wavelength selection element 10G. When a signal is applied to the control electrode 102, the wavelength selection element 100 selects wavelengths λ1 . λ
3. λ.

Select the light of wavelength λ1. λ3. A modulated light 111 having a wavelength of λ4 is emitted to the optical modulator 101. The optical modulator 101 modulates the modulated light 111 input from the wavelength selection element 100 according to the amplitude of the input signal 113 to obtain wavelengths λ1. λ3.
A modulated light 114 of λ4 is output. Therefore, in the embodiment of FIG. 1, the input signal 113 is transmitted to the wavelengths λ1... of the wavelengths λ1 to λ4. λ1. λ.

can be converted into optical signals. In this manner, the configuration shown in FIG. 1 allows an input signal to be converted into an optical signal of one or more arbitrary wavelengths.

FIG. 2 is a perspective view showing a specific example of the wavelength selection element 100 of the embodiment shown in FIG. The optical waveguides 204 and 205 are coupled to each other by propagating surface acoustic waves corresponding to each wavelength to the intersecting surface acoustic wave waveguides 203 via a separation layer 201 formed on the substrate 200. In region 202, the selection of the wavelength of light is performed.

The operation of the wavelength selection element 100 shown in FIG. 1 will be explained using FIG. 2. If the wavelength multiplexed light 110 with wavelengths λ1 to λ4 is input from the end face a of the optical waveguide 204 and the surface acoustic wave is not propagated to the surface acoustic wave waveguide 203 as a control signal, the optical waveguide 2
Wavelength λ from end face C of 04.

The wavelength multiplexed light of ~λ is output as is.

On the other hand, a surface acoustic wave is sent to the surface acoustic wave waveguide 2 as a control signal.
03 at the same time, light with a wavelength corresponding to the surface acoustic wave is selected from the wavelength multiplexed light 110 in the coupling region 202 and output from the end face of the optical waveguide 205. Second
In the example shown, the wavelength λ, ~λ.

From the wavelength multiplexed light 110 of wavelengths λ0, λ3. The light of wavelength λ4 is selected, and the end face has a wavelength of λ3. λ,.

A wavelength multiplexed light 111 consisting of λ is output.

Therefore, depending on whether or not the end face a of the optical waveguide 204 is used as the input end, the end face of the optical waveguide 205 is used as the output end, and the surface acoustic wave is used as a control signal, the surface acoustic wave is propagated to the surface acoustic wave waveguide 203. Light of one or more arbitrary wavelengths can be selected from the wavelength-multiplexed light incident on the end face a and emitted from the end face.

FIG. 3 is a diagram showing a specific example of the optical modulator 101 of the embodiment shown in FIG. In FIG. 3, a case will be explained in which the input signal 113 in FIG. 1 is an optical signal.

In FIG. 3(a), an input signal light 113 having a wavelength λ is converted into a single-carrier electrical signal 321 by an optical-to-electrical converter 310. The converter 300 has a wavelength λ1. λ1. Modulated light 111 consisting of λ4
are simultaneously modulated according to the amplitude of the electrical signal 321, so
Wavelength λ! , λ5. Modulated light 114 of λ4 can be extracted.

In FIG. 3(b), the input signal light 113 with the wavelength λ1 is incident on the end face 302 of the modulator 300 via the optical multiplexer 33G, and the input signal light 113 with the wavelength λ1. λ3. The modulated light 111 of λ4 is at the end face 301
is incident on the When the light intensity of the input signal light of wavelength λ1 incident from the end face 302 is at the lower level of the two values of high level and low level, the modulator 300 modulates the wavelength λ5, λ) incident from the end face 301. .

If the modulated light 111 with wavelength λ4 is not emitted from the end face 302 and the amount of input signal light is at a high level, the modulated light 111 with wavelength λ1. λ1
．． The modulated light 111 of λ is sent from the end face 302 to the optical combiner 33
0, the wavelength λ3 . λ1. λ,
modulated light 114 can be extracted.

Note that when the input signal 113 in FIG. 1 is an electrical signal,
In FIG. 3(a), the optical-to-electrical converter 310 may be removed and the input signal 113 may be directly applied to the converter 300.

FIG. 4 is a diagram showing an embodiment of the second invention of the present application,
Like numbers in FIG. 1 represent identical components in FIG. In FIG. 4, modulated light 110 having wavelengths λ, ˜λ4 is incident on optical modulator 101. In FIG.

The optical modulator 101 modulates the modulated light 110 according to the amplitude of the input signal 113, and outputs the modulated light 400 with wavelengths λ, to λ4 to the wavelength selection element 100. The wavelength selection element 100 receives modulated light 40 of wavelengths λ1 to λ4 emitted from the optical modulator 101.
Depending on the signal applied to control $t4i102 from 0,
In this example, the wavelength λ1. λ, select the light of λ4, and set the wavelength λ
1λ1. A modulated light 401 consisting of λ4 is output. Therefore, in the configuration of FIG. 4 as well, the input signal 113 is set to wavelength λ1 . λ1. It can be converted into a λ4 optical signal. In this way, also according to the embodiment of the second invention of the present application shown in FIG. 4, it is possible to simultaneously modulate light of a plurality of arbitrary wavelengths with an input signal. Also in FIG. 4, the input signal 113 may be either an electrical signal or an optical signal as in FIG. 1.

(Effects of the Invention) As described above, according to the present invention, an input signal can be converted into an optical signal having one or more arbitrary wavelengths.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the first invention of the present application, and FIG. 2 shows a wavelength selection element 100 in the embodiment of FIG.
3 is a block diagram showing a specific example of the optical modulator 101 in the embodiment of FIG. 1, FIG. 4 is a block diagram showing an embodiment of the second invention of the present application, FIG. 5 is a block diagram showing an example of a conventional wavelength conversion switch. In the figure, 100 is a wavelength selection element, 101 is an optical modulator, 102 is a control electrode, 110 and 111 are modulated lights, and 1
14, 400, 401 are modulated lights, 300 is a modulator,
310 is a photo-electrode converter, 330 and 540 are optical combiners, 510 is an optical splitter, 520 to 523 are fixed wavelength selection elements, and 530 to 533 are variable wavelength conversion elements, respectively.

Claims (1)

[Claims] 1. A wavelength selection element that selects and outputs light of one or more arbitrary wavelengths from input wavelength-multiplexed modulated light according to a control signal; and an optical modulator that modulates the output light of the wavelength selection element according to a signal applied to a second input terminal and outputs the modulated light. 2. An optical modulator that modulates wavelength-multiplexed modulated light input from a first input terminal according to a signal applied to a second input terminal and outputs the modulated light, and output light of the optical modulator that is input. 1. An optical multi-wavelength conversion circuit comprising a wavelength selection element that selects and emits light of one or more arbitrary wavelengths according to a control signal.