JPH0445804B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a system that is used for bidirectional transmission by propagating light of different wavelengths on one optical transmission line.
The present invention relates to an optical multiplexing/demultiplexing module incorporating a light emitting element and a light receiving element.

[Conventional technology]

Figure 2 is a configuration diagram showing a conventional optical multiplexing/demultiplexing module presented at the 1982 Institute of Electronics and Communication Engineers General Conference (2682), in which 1 is a light emitting element that emits light of wavelength λ ₁ , and 2 is a 4 is the wavelength λ ₁ emitted from the light-receiving element, 3 optical fiber terminals, and the light-emitting element 1.
a collimating lens that converts the light into a parallel beam of light, 5
6 is a condensing lens for condensing light onto a light receiving element;
inputs the light of wavelength λ ₁ converted into a parallel beam by the collimating lens 4 into the optical fiber terminal 3, and
A common port lens for converting the light of wavelength λ ₂ emitted from the optical fiber terminal 3 into a parallel beam; 7 is a parallel beam of wavelength λ ₁ converted by the collimating lens 4; 8 is a parallel beam of light converted by the common port lens 6; wavelength λ ₂
9a is a multilayer dielectric filter that transmits light with a wavelength λ ₂ and reflects light with a wavelength λ ₁ ; 10 is a glass plate on which the multilayer dielectric filter 9a is formed; It is installed at an angle of 45° with respect to the optical path connecting the light receiving element 2 and the light receiving element 2. Further, the collimating lens 4 and the light emitting element 1 are installed so that the optical axes of the collimating lens 4 and the light emitting element 1 are perpendicular to the optical path connecting the optical fiber terminal 3 and the light receiving element 2 described above. .

Next, the operation will be explained. Light with a wavelength λ ₁ emitted from the light emitting element 1 is converted into a parallel beam 7 by the collimating lens 4, and enters the multilayer dielectric filter 9a formed on the surface of the glass plate 10 at an incident angle of 45 degrees. Here, since the multilayer dielectric filter 9a reflects the light with the wavelength λ ₁ , the parallel light beam 7 with the wavelength λ ₁
is reflected perpendicularly and incident on the common port lens 6, by which it is coupled to the optical fiber terminal 3. On the other hand, the light of wavelength λ ₂ emitted from the optical fiber terminal 3 is converted into a parallel beam 8 by the traffic port lens 6, and then passed through the multilayer dielectric filter 9.
incident on a. Here, the multilayer dielectric filter 9
Since a transmits light of wavelength λ ₂ , the parallel light beam 8 of wavelength λ ₂ travels straight and enters the condenser lens 5 , and is coupled to the light receiving element 2 by the condenser lens 5 . Light emitting element 1
As described above, the coupling between the optical fiber terminal 3 and the optical fiber terminal 3 and the coupling between the optical fiber terminal 3 and the light receiving element 2 are performed through two lenses in between. Therefore, in order to efficiently couple the light emitting element 1 and the optical fiber terminal 3, the light emitting element 1, collimating lens 4, common port lens 6, and optical fiber terminal 3 must be aligned and fixed together. Must be. Similarly, in order to efficiently couple the optical fiber terminal 3 and the light receiving element 2, each part of the optical fiber terminal 3, common port lens 6, condensing lens, and light receiving element 2 must be aligned and fixed. . Further, in the above configuration, a multilayer dielectric filter 9a for separating wavelengths of light is formed on the surface of the glass plate 10, and is installed tilted in the optical path. This glass plate 1
If the installation angle of 0 deviates from the installation value, the angle of the reflected light will deviate and the optical path will deviate. Therefore, it is necessary to set this glass plate 10 with high precision.

[Problem that the invention seeks to solve]

Since the conventional optical multiplexing/demultiplexing module is constructed as described above, it has the drawback that there are many axial alignment adjustment points and assembly is difficult. Furthermore, since the coupling system is sensitive to the inclination of the glass plate on which the multilayer dielectric filter is formed, it has the disadvantage of being susceptible to temperature fluctuations, vibrations, shocks, etc. Furthermore, in conventional optical wavelength multiplexing composite modules, the above configuration was housed in one metal case, so when the light emitting element was electrically driven and modulated with an electrical signal, this electrical signal was transmitted through the metal case. It has the disadvantage that it couples to the electrical terminal of the light receiving element, resulting in noise.

This invention was made to solve the above-mentioned problems. It reduces the number of adjustment points for axis alignment, has excellent environmental resistance against temperature fluctuations, vibrations, shocks, etc., and has excellent resistance to electrical interference. The objective is to obtain an optical multiplexing/demultiplexing module that does not require any optical multiplexing/demultiplexing.

[Means for solving problems]

The optical multiplexing/demultiplexing module according to the present invention includes a light emitting element collimator that integrates a light emitting element and a collimating lens, a common port lens, and a condensing lens that are inserted and fixed into a through hole drilled in the side surface of a metal case, and a multilayer A pentaprism with a film dielectric filter formed thereon is fixed in a metal case, and a light receiving element is fixed with an ultraviolet curing resin via a glass ring.

[Effect]

The optical multiplexing/demultiplexing module of this invention mechanically fits and fixes the light emitting element collimator, the common port lens, and the condensing lens into the through hole drilled in the side surface of the metal ace. A fiber terminal part, a light receiving element part,
When manufacturing a light emitting element collimator, only three locations are required: the light emitting element collimator lens part. Further, by forming and using a penta-prism multilayer dielectric filter, angular deviation of reflected light due to installation error of the penta-prism will not occur. Furthermore, by fixing the light receiving element with an ultraviolet curable resin via a glass ring, electrical insulation is maintained and the wraparound of electrical signals from the light emitting element is eliminated.

〔Example〕

FIG. 1 is a sectional view from above showing an embodiment of the present invention. In FIG. 1, numerals 1 to 8 are the same as the conventional device described above. 9b is a multilayer dielectric filter that transmits light of wavelength λ ₁ and reflects light of wavelength λ ₂ . 11 is a pentaprism, and a multilayer dielectric filter 9b and a mirror 12 are formed on the side surface. 13 is a light emitting element collimator;
A light emitting element 1 and a collimator lens 4 are connected, and a parallel light beam 7 is emitted from the end face. 14 is a metal case, and a light emitting element collimator 1 is mounted on the side wall.
Through-holes for inserting and fixing the light-emitting element collimator 13, condensing lens 5, and common port lens 6 are drilled with precision, and the light-emitting element collimator 13, condensing lens 5, and common port lens 6 are inserted and fixed, respectively. There is. Further, it is housed in a case 14 of the pentaprism 11. A spacer prism 15 is inserted into a gap between the end face of the light emitting element collimator 13 and the pentalism 11. Reference numeral 16 denotes a glass ring, which is attached so as to be flush with the end surface of the condenser lens 5. 17 is an ultraviolet curing resin, and a condensing lens 5 and a glass ring 16
The material is filled between the end face of the light receiving element 2 and the light receiving element 2, and is cured by ultraviolet irradiation. 18 is an optical fiber terminal 3
and the metal case 14, and are connected to the optical fiber terminal 3 and the case 14, respectively.

Next, the operation will be explained with reference to FIG. Parallel light beam 7 with wavelength λ ₁ emitted from light emitting element collimator 13
passes through the spacer prism 15 and enters the multilayer dielectric filter 9b. Here, since the multilayer dielectric filter 9b transmits light with the wavelength λ ₁ , the light with the wavelength λ ₁
The parallel light beam 7 passes through the pentagonal prism 11 and enters the common port lens 6, and is coupled to the optical fiber terminal 3 by the common port lens 6. On the other hand, the light of wavelength λ ₂ emitted from the optical fiber terminal is converted into a parallel beam 8 by a common port lens 6, transmitted through a pentaprism 11, and then passed through a multilayer dielectric filter 9.
incident on b. Here, the multilayer dielectric filter 9b
reflects the light of wavelength λ ₂ , so the parallel light beam 8 of wavelength λ ₂ enters the mirror 12 formed on the other side of the pentaprism 11 , where it is further reflected and enters the condenser lens 5 . The parallel beam of wavelength λ ₂ incident on the condenser lens 5 is transmitted to the light receiving element 2 by the condenser lens 5.
is combined with As described above, the multilayer dielectric filter 9b is formed on the side surface of the pentaprism 11, and the light component reflected here is further reflected by a mirror formed on another side surface of the pentaprism 11. In other words, the light of wavelength λ ₂ that is incident on the pentaprism 11 is reflected twice within the pentaprism 11 and then exits from the pentaprism 11.
Due to the principle of a single mirror, even if the pentaprism 11 is installed at an angle with respect to the optical path, the angle of the light emitted from the pentaprism 11 with respect to the light incident on the pentaprism 11 does not change. Therefore, the pentaprism 11 has a multilayer interference filter 9b formed on its side surface.
The installation accuracy is not too loose. Also, as mentioned above,
A light emitting element collimator 13 is mounted on the side wall of the metal case 4.
Since the through holes for inserting and fixing the condenser lens 5 and the common port lens 6 are pre-drilled with high precision, the light emitting element collimator 13, the condenser lens 5, and the common port lens 6 are simply inserted into the through holes. Assembly is completed just by fixing it. Therefore, the only parts that require alignment and fixing work are the three optical fiber terminals and the two light receiving elements.
Furthermore, the light-emitting element collimator 13 must be assembled in advance by aligning and fixing the light-emitting element 1 and the collimating lens 4, but this work can be mass-produced separately at another location, so the light-emitting element collimator 13 can be assembled in one piece. It can be treated as a component. Therefore, this configuration, which uses the light emitting element collimator 13 and allows assembly to be completed simply by inserting it into the case, is a highly productive configuration.

Further, as mentioned above, the light receiving element 2 is fixed using the glass ring 16 and the condensing lens 5 using ultraviolet curing resin.
This is done between the end face of the Therefore, since the light receiving element 2 is fixed to the metal case via the glass which is an insulator, it is possible to prevent electrical signals from the light emitting element from going around. Here, the reason why the light emitting element is brought into contact with the metal case 14 is to allow the heat generated by the driving of the light emitting element to escape through the metal case 14, which is advantageous in order to prevent deterioration of the light emitting element. The glass ring 16 is also necessary to guide ultraviolet rays to the adhesive layer 17.

〔Effect of the invention〕

As described above, according to the present invention, the common port lens, condensing lens, and light emitting element collimator are simply inserted and fixed into the through hole drilled in the side wall of the metal case, which has the effect of facilitating assembly. . In addition, since a pentaprism is used, the setting accuracy of the multilayer interference filter is loose, making it easy to assemble, and since some fluctuations are allowed, it has excellent environmental resistance against temperature fluctuations, vibrations, shocks, etc. It has the effect of being Furthermore, since the light-receiving element is fixed to the metal case via the glass ring, there is an effect that no noise is generated due to the interference of electricity.

[Brief explanation of drawings]

FIG. 1 is a sectional top view showing an optical multiplexing/demultiplexing module according to an embodiment of the present invention, and FIG. 2 is a configuration diagram showing a conventional optical multiplexing/demultiplexing module. In the figure, 1 is a light emitting element, 2 is a light receiving element, and 3 is a light emitting element.
is an optical fiber terminal, 4 is a collimating lens, 5 is a condenser lens, 6 is a common port lens, 7 is a wavelength λ ₁
8 is a parallel light beam of wavelength λ ₂ , 9a, 9b
is a multilayer dielectric filter, 10 is a glass plate, 11
12 is a pentaprism, 12 is a mirror, 13 is an element collimator, 14 is a metal case, 15 is a spacer prism, 16 is a glass ring, 17 is an ultraviolet curing resin adhesive layer, and 18 is a joint. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In an optical multiplexing/demultiplexing module that integrates a light emitting element, a light receiving element, and an optical wavelength multiplexing/demultiplexing section, a light emitting element collimator that integrates a light emitting element and a collimating lens for collimating the emitted light of this light emitting element, and a light receiving element. , a condensing lens for coupling light to this light receiving element, an optical fiber terminal, a common port lens for concentrating light on this optical fiber terminal and collimating the light emitted from this optical fiber, and a common port lens for collimating light emitted from this optical fiber, A pentaprism block equipped with a filter for demultiplexing and multiplexing according to wavelength, and a metal case having through holes in the side wall for inserting and fixing the light emitting element collimator, the condensing lens, and the common port lens, respectively. The pentaprism block is housed and installed in this metal case, the light emitting element collimator, the condensing lens, and the common port lens are respectively inserted and fixed into the through hole, and the optical fiber terminal is connected to the light emitting element. After coupling light to the element, it is connected to the metal case, and the light receiving element is coupled to the optical fiber terminal using ultraviolet curing resin through a ring-shaped glass ring with flat ends on both ends, and then connected to the metal case. An optical multiplexing/demultiplexing module that is fixed to a case.