JP3590222B2 - WDM transmission module - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical wavelength division multiplexing transmission module used on various optical communication networks, and more particularly to an optical wavelength division multiplexing transmission module having a wavelength multiplexing / demultiplexing function and / or an optical branching / coupling function.
[0002]
[Prior art]
In recent years, plans to introduce optical transmission technology toward multimedia in public communication networks have been promoted.In order to provide broadband services such as video in addition to the conventional narrowband services centered on voice. Therefore, bidirectional optical transmission using wavelength multiplexing has become indispensable. To achieve this, it is necessary to develop a module that has the function of splitting and combining optical signals and the function of separating and multiplexing optical signals of different wavelengths. Is the key. FIG. 3 shows an example of an optical wavelength division multiplexing transmission module having a conventional wavelength multiplexing / demultiplexing function and an optical branching / coupling function. The optical circuit includes a directional coupler 6 and a Y-branch 7 and is formed on an optical waveguide substrate 8. A first port 11, a second port 12, a third port 13, and a fourth port 14 are provided on the front and rear end surfaces of the optical waveguide substrate 8, which are respectively an input / output optical fiber 1, an output optical fiber 2, and a light emitting element. 3. Connect to light receiving element 4. When the multiplexed input optical signals having the wavelengths λ1 and λ2 enter from the first port 11, the wavelengths are separated by the directional coupler 6, and the light having the wavelength λ1 exits from the second port 12 as it is. The light having the wavelength λ2 is distributed by the Y-branch 7, and the light emitted from the fourth port 14 is received by the light receiving element 4. On the other hand, the light of wavelength λ2 incident from the light emitting element 3 via the third port 13 exits from the first port 11 as it is.
[0003]
[Problems to be solved by the invention]
According to the conventional optical wavelength division multiplexing transmission module described above, separation of multiplexed input signals of wavelengths λ1 and λ2 and bidirectional transmission of signal of wavelength λ2 are possible. At the time of connection with the optical waveguide substrate, it is necessary to perform alignment of the optical axis and the like individually and with high accuracy, and therefore, there is a problem that the mounting cost is easily increased. SUMMARY OF THE INVENTION The object of the present invention has been made in view of the above-mentioned problems in the conventional optical wavelength division multiplexing transmission module, and is easy to mount even in an optical wavelength division multiplexing transmission module comprising complex and multiplexed components. It is an object of the present invention to provide an optical wavelength division multiplexing transmission module capable of realizing cost reduction.
[0004]
[Means for Solving the Problems]
In view of the above problems, the present invention provides a wavelength filter having a function of selectively reflecting and transmitting light in an arbitrary wavelength region, an optical waveguide, and an optical fiber array block in which optical fibers are aligned and fixed in parallel. In the optical wavelength division multiplexing transmission module configured, light incident from at least one of the optical fibers between the optical fiber array block and the optical waveguide is reflected by the wavelength filter, and the reflected light is reflected by the other one. One lens for coupling to the optical fiber, an anti-reflection coating film provided only on the input / output optical fiber side, and an optical waveguide for transmitting light transmitted through the wavelength filter are formed. It is a feature.
In addition, a wavelength filter having a function of selectively reflecting and transmitting light in an arbitrary wavelength range, an optical waveguide, and an optical wavelength multiplex transmission comprising an optical fiber array block in which optical fibers are aligned and fixed in parallel. In the module, a wavelength filter arranged at an angle adjusted so that light incident from at least one of the optical fibers is coupled to another optical fiber, and a non-reflection coating film provided only on the input / output optical fiber side. And an optical waveguide for transmitting light transmitted through the wavelength filter.
Further, the wavelength filter is fixed to an end face of the optical waveguide.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a first embodiment of the optical wavelength division multiplexing transmission module according to the present invention. An optical waveguide 16 is formed on the optical waveguide substrate 8 from a fifth port 15 formed on an end face connected to the wavelength filter 5, and is connected to the light emitting element 3 and the light receiving element 4 via the Y-branch 7, respectively. A three port 13 and a fourth port 14 are formed. The wavelength filter 5 is fixed to the end face of the optical waveguide substrate 8 using an adhesive or the like, and has a filtering characteristic of reflecting light of wavelength λ1 and transmitting light of wavelength λ2. The input / output optical fiber 1 and the output optical fiber 2 are aligned and fixed using an optical fiber array block 10, and an end face of the input / output optical fiber 1 is coated with a non-reflection coating for preventing end reflection of an input signal. A film 17 is formed.
A lens 9 is provided between the optical fiber array block 10 and the optical waveguide substrate 8, and the multiplexed input signals of the wavelengths λ1 and λ2 incident from the input / output optical fiber 1 are applied to the surface of the wavelength filter 5 by the lens 9. The light having the wavelength λ1 collected on the upper side is reflected by the wavelength filter 5, and is coupled to the output optical fiber 2 via the lens 9 again. On the other hand, the light having the wavelength λ2 passes through the wavelength filter 5, enters from the fifth port 15, and propagates through the optical waveguide 16. The light having the wavelength λ2 is further distributed to the Y branch 7, and the light emitted through the fourth port 14 is received by the light receiving element 4. On the other hand, the light of wavelength λ2 incident from the light emitting element 3 via the third port 13 propagates through the optical waveguide 16 and exits from the fifth port 15 and is coupled to the input / output optical fiber 1 via the lens 9. .
In the present embodiment, the use of the optical fiber array block 10 eliminates the need to individually perform alignment of the optical axis and the like when connecting the input / output optical fiber 1 and the output optical fiber 2 to the optical waveguide substrate 8, and the lens 9 can be combined at once. Further, in the above embodiment, the wavelength filter 5 is fixed to the end face of the optical waveguide substrate 8, so that it is not necessary to perform the positioning of the wavelength filter 5 with high accuracy.
FIG. 2 shows a second embodiment of the optical wavelength division multiplexing transmission module according to the present invention. The wavelength filter 5 is fixed to the end face of the optical waveguide substrate 8, and its angle is adjusted so that the light having the wavelength λ1 which is incident from the input / output optical fiber 1 and reflected by the wavelength filter 5 is coupled to the output optical fiber 2. . On the other hand, the light of the wavelength λ2 transmitted through the wavelength filter 5 enters from the fifth port 15 and propagates through the optical waveguide 16.
[0008]
According to this embodiment, the input / output optical fiber 1 and the output optical fiber 2 can be directly coupled to the optical waveguide substrate 8, and the design, adjustment, and mounting of an optical system using a lens or the like can be omitted. Alternatively, simplification can be achieved.
[0009]
【The invention's effect】
As described above, according to the present invention, when connecting the input / output optical fiber and the output optical fiber to the optical waveguide substrate, it is not necessary to individually and precisely perform alignment of the optical axis and the like, and by using the optical fiber array block, , Lenses and the like can be connected collectively. Further, by fixing the wavelength filter to the end face of the optical waveguide, it is possible to eliminate the necessity of performing highly accurate positioning and angle fixing of the wavelength filter. Therefore, an optical wavelength multiplex transmission module that can be mass-produced and reduced in cost can be realized.
[Brief description of the drawings]
FIG. 1 is a plan view showing a first embodiment according to the present invention.
FIG. 2 is a plan view showing a second embodiment according to the present invention.
FIG. 3 is a plan view showing an example of a conventional optical wavelength division multiplexing transmission module.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Input / output optical fiber 2 ... Output optical fiber 3 ... Light emitting element 4 ... Light receiving element 5 ... Wavelength filter 6 ... Directional coupler 7 ... Y branch 8 ... Optical waveguide board 9 ... Lens 10 ... Optical fiber array block 11 first port 12 second port 13 third port 14 fourth port 15 fifth port 16 optical waveguide 17 anti-reflection coating film

Claims (3)

In an optical wavelength multiplexing transmission module comprising a wavelength filter having a function of selectively reflecting and transmitting light in an arbitrary wavelength region, an optical waveguide, and an optical fiber array block in which optical fibers are aligned and fixed in parallel . , one of the lenses for the light incident from at least one of the optical fiber between the optical fiber array block and the optical waveguide is reflected by the wavelength filter, thereby coupling the reflected light to the other of said optical fiber And a non-reflection coating film provided only on the input / output optical fiber side and an optical waveguide for transmitting light transmitted through the wavelength filter. In an optical wavelength multiplexing transmission module comprising a wavelength filter having a function of selectively reflecting and transmitting light in an arbitrary wavelength region, an optical waveguide, and an optical fiber array block in which optical fibers are aligned and fixed in parallel . A wavelength filter arranged at an angle adjusted so that light incident from at least one of the optical fibers is coupled to another optical fiber, and an anti-reflection coating film provided only on the input / output optical fiber side ; An optical wavelength division multiplexing transmission module, comprising: an optical waveguide for transmitting light transmitted through a wavelength filter. 3. The optical wavelength multiplex transmission module according to claim 1, wherein the wavelength filter is fixed to an end face of the optical waveguide.

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