JPH0723928B2 - Optical wavelength selector - Google Patents

Description

TECHNICAL FIELD The present invention relates to an optical wavelength selector applied to an optical communication system using a plurality of lights.

"Prior Art and Its Problems" The optical multiplexer / demultiplexer 1 used in the wavelength division multiplexing optical communication system is
As shown in FIG. 10 which illustrates four wavelengths of λ _{1 to} λ ₄ , it has a two-terminal configuration including an input (output) force terminal 2 and an output (input) force terminal 3, and is represented as 1: n or n: 1. Generally, the input and output terminals are made to correspond.

In the above optical multiplexer / demultiplexer 1, there is no wavelength selection element having a three-terminal configuration, and therefore, for example, light of wavelengths λ ₁ , λ ₂ , λ ₃ is (λ ₁ , λ ₂ ), (λ ₂ , λ ₂ ), ( Switching selection is not possible as in λ ₁ , λ 3).

Wavelength multiplex bidirectional Y disclosed in JP-A-57-106249
The type optical transmission system is desirable in that such three wavelength switching selection can be performed.

However, in this known optical wavelength selecting means, in order to ensure a predetermined function, 6 optical directional couplers, 3 optical demultiplexers and 1 circulator are required.

When such a large number of parts are required, it is inevitable that the device configuration will be complicated, the size will be increased, and the cost will be increased. In particular, in view of the current situation that the size of optical communication devices is required to be small in optical access systems that are rapidly expanding, it is important to solve these problems at an early stage.

In view of these problems, the present invention aims to provide a three-wavelength optical switching selector that simplifies the configuration, reduces the size, and reduces the cost.

[Means for Solving the Problems] The present invention uses three input / output terminals for inputting / outputting lights having different wavelengths λ ₁ , λ ₂ , and λ ₃ , and transmitting and / or reflecting these lights. And three different wavelength selecting elements for selecting these different wavelengths λ ₁ , λ ₂ , λ _3.
Two wavelengths (λ ₁ , λ ₂ ), (λ ₂ ,
In order to selectively switch the light of λ ₃ ) and (λ ₁ , λ ₃ ), three pairs of terminals consisting of two input / output terminals correspond to each other through three wavelength selection elements among three input / output terminals. In the optical wavelength selector, each of the wavelength selection elements is composed of a wavelength selection transmission mirror having a bent shape along the length direction, and these wavelength selection elements are arranged in a triangular shape relative to each other, and the triangular shape The above-mentioned respective input / output terminals are arranged at the respective vertices of (1) to achieve the intended purpose.

Example An optical wavelength selector according to the present invention will be described below with reference to the drawings.

The optical wavelength selector 10 according to the present invention is provided with input / output terminals 11a, 11b, 11c as shown in FIG. ₁ , and for _three wavelengths λ ₁ , λ ₂ , λ _{3 which} are different from each other, (λ ₁ , λ ₂ ),
It has a switchable configuration such as (λ ₂ , λ ₃ ) and (λ ₁ , λ ₃ ).

As an example of the configuration, as shown in FIG. 2, three wavelength selection elements 12a, 12b, 12c, which are wavelength selection transmission mirrors, are used.
Are arranged relative to each other so as to form a triangle, and input / output terminals 11a and 1a made of optical fibers are respectively provided at the vertices of the triangle.
1b and 11c are arranged.

The wavelength selective transmission mirror used as the wavelength selection elements 12a, 12b, 12c is composed of a dielectric multilayer film filter and transmits a certain wavelength λ _A and reflects a different wavelength λ _B as shown in FIG. It has the function of

On the other hand, the input / output terminals 11a, 11b, 11c are arranged in the three-point arrangement as shown in FIG.

Therefore, λ ₁ is reflected as the wavelength selection element 12a,
If one that transmits λ ₂ is adopted, one that reflects λ ₂ as the wavelength selection element 12b and one that transmits λ ₃ is adopted, and one that reflects λ ₃ as the wavelength selection element 12c is adopted, (Λ ₁ , λ ₂ ), (λ ₂ ,
λ ₃ ) and (λ ₁ , λ ₃ ) can be switched and selected, and the optical wavelength selector 10 described in FIG. 1 can be obtained.

The wavelength selective transmission mirror for each wavelength selection element illustrated in FIG. 3 has two element parts 12 ₁ and 12 ₂ having a relative bending angle, which are integrated.
It is also possible that 12 ₁ and 12 ₂ are separate bodies.

In addition, a combination of a diffraction grating and a reflecting mirror may be considered as having a function equivalent to that of the wavelength selective transmission mirror, and these may be adopted as the wavelength selection elements 12a, 12b, 12c.

6 and 7 show wavelength switching selection patterns by the optical wavelength selector 10 of the present invention, and FIG. 8 shows wavelength switching selection patterns when an optical circulator is constructed by the optical wavelength selector 10 of the present invention.

FIG. 9 shows an example in which the optical wavelength selector 10 of the present invention is used to remotely switch branch routes according to the patterns illustrated in FIGS. 6 and 7.

In FIG. 9, an electric switch 21 and an electric / optical converter (E / O) 2
2. The optical coupler 23 connects the optical wavelength selector 10 via the optical fiber 25.
Similarly, the optical / electrical converter (O / E) 24 is connected to the optical wavelength selector 10 via the optical fiber 25, and the optical wavelength selectors 10 and 10 are also connected via the optical fiber 25. However, in this case, the electrical switch 21, the electrical / optical converter 22, the optical combiner
23 and the like are arranged far away from the optical wavelength selector 10 located at the branch point.

When the wavelengths λ ₁ , λ ₂ , and λ ₃ exist in the same wavelength band for the optical / electrical converter 24, one type of O / E may be used, for example, λ ₁ = 0.80 μm, λ ₂ = 0.85 μm, λ ₃
= 0.90 μm, all signals can be detected by using the Si detector.

When the wavelengths λ ₁ , λ ₂ and λ ₃ are in the 1.3 μm band, a Ge or InGaAs detector is used as the optical / electrical converter 24.

When lights of different wavelength bands such as λ1 = 0.85 μm and λ2 = 1.3 μm are mixed, it is necessary to detect lights having different wavelengths by different detectors corresponding to them.

[Advantages of the Invention] In the optical wavelength selector according to the present invention, each wavelength selection element formed of a predetermined wavelength selection transmission mirror is arranged in a triangular shape and is relatively disposed, and each input / output terminal is provided at each vertex of the triangle shape. The following effects are obtained as an optical wavelength selector capable of switching and selecting three wavelengths.

Since the main wavelength selection element (wavelength selection transmission mirror) is a small component, and more than three wavelength selection elements are sufficient, the optical wavelength selector can be miniaturized.

It is only necessary to combine three wavelength selection elements (wavelength selection transmission mirrors) in a triangular shape and arrange each input / output terminal at each apex of the triangular shape, which simplifies the assembly and simplifies the configuration. To do.

Since the number of main components such as three wavelength selection elements (wavelength selection transmission mirrors) and three input / output terminals is small, the cost of the optical wavelength selector can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory view of an optical wavelength selector of the present invention, FIG. 2 is a front view of an essential part of the optical wavelength selector, and FIG. 3 is a wavelength selection of the optical wavelength selector. FIG. 4 is a side view showing an example of the element, FIG. 4 is a perspective view of an input / output terminal of the optical wavelength selector, and FIG. 5 is an explanatory view showing a state of wavelength switching selection in the optical wavelength selector of the present invention.
FIG. 8 to FIG. 8 are explanatory views showing each wavelength switching selection pattern by the optical wavelength selector of the present invention, FIG. 9 is an explanatory view showing an example of use of the optical wavelength selector of the present invention, and FIG. It is explanatory drawing which shows a wave device. 10 …… Optical wavelength selector 11a ～ 11c …… Input / output terminals 12a ～ 12c …… Wavelength selector

Claims (4)

[Claims] 1. Input / output terminals for inputting / outputting lights of different wavelengths λ ₁ , λ ₂ , λ ₃ and three wavelength selection elements for selecting these lights by transmission and / or reflection. And these different wavelengths λ ₁ , λ ₂ , λ
To ₃ of each light, two wavelengths _{(λ 1, λ 2),} (λ 2,
In order to selectively switch the light of λ ₃ ) and (λ ₁ , λ ₃ ), three pairs of terminals consisting of two input / output terminals correspond to each other through three wavelength selection elements among three input / output terminals. In the optical wavelength selector, each of the wavelength selection elements is composed of a wavelength selection transmission mirror having a bent shape along the length direction, and these wavelength selection elements are arranged in a triangular shape relative to each other, and the triangular shape An optical wavelength selector characterized in that each of the input / output terminals is arranged at each vertex of. 2. The optical wavelength selector according to claim 1, wherein the wavelength selective transmission mirror comprises a dielectric multilayer film filter. 3. The optical wavelength selector according to claim 1, wherein the wavelength selective transmission mirror comprises a combination of a diffraction grating and a reflection mirror. 4. The optical wavelength selector according to claim 1, wherein the input / output terminals are optical fibers.