JP4158895B2 - Functional optical fiber connector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a functional optical fiber connector having an optical adjustment function used for optical communication.
[0002]
[Prior art]
As shown in FIG. 5, an optical fiber connector 100 having a conventional optical characteristic adjuster includes a filter 55 having an absorption film having a thickness gradient in the longitudinal direction. By arranging the filter 55 in a direction perpendicular to the beam 50 and moving the filter 55 in a direction having a thickness gradient, the absorption rate of the light beam is changed. The single optical variable attenuator is used for each of a plurality of single mode optical fibers. A schematic diagram of this scheme is shown in FIG.
[0003]
In addition, optical components such as AWG (Array Waveguide Grating) as an element that adjusts the light beam of an arrayed optical fiber arranged in parallel are provided with a waveguide on a silicon substrate, and the optical characteristics are set on this waveguide. A lens waveguide to be modulated, a diffraction grating, and other optical components are integrated to synthesize or demultiplex light.
[0004]
[Patent Document 1]
Japanese Unexamined Patent Publication No. 2000-66062.
[Patent Document 2]
JP-A-11-72644.
[Patent Document 3]
JP-A-11-109161.
[0005]
[Problems to be solved by the invention]
When conventional array-type optical components are used at each wavelength of DWDM (Dense Wavelength Division Multiplexing) communication, which is expected to develop in the future, the number is expected to exceed 100. Thus, using many single optical components occupies a very large volume because the size of the single optical component is large. In AWG, optical components are integrated on one chip, but at present, the size is on the order of several cm.
[0006]
In addition, with an optical connector manufactured by paralleling a fiber guide on a chip manufactured by MEMS (Micro-electro mechanical System), it is very difficult to attach the optical fiber to the fiber guide, and the optical fiber taken out from the chip If the cable is not carefully routed, the optical fiber will be broken and a large additional loss will occur. Further, in this method, it is necessary to cover the fiber guide after the optical fiber is disposed, and the manufacturing process is complicated and the manufacturing equipment is large.
[0007]
The same applies to AWG, and it is very difficult to connect each waveguide to an optical fiber for connecting the light from the outside. Further, it is difficult to handle the optical fiber after connecting the optical fiber, as in the case of other optical components arranged in parallel or arrayed.
[0008]
[Means for Solving the Problems]
The inventor has intensively studied to solve the above-described conventional problems. As a result, as shown below, a functional optical fiber connector and an oblique emission functional optical fiber connector that solved problems that could not be solved by the prior art were discovered.
[0009]
In the functional optical fiber connector of the present invention, an optical fiber array in which a plurality of collimators in which an optical fiber and a lens are integrated is arranged to face each other, and an optical characteristic adjusting means is arranged between the opposed optical fiber arrays. These members are integrated in a predetermined position by guide pins. According to the present invention, it is possible to realize a small-sized functional optical fiber connector that can easily perform reliable alignment.
The basic aspect of the functional optical fiber connector of the present invention is:
(A)Single modeOptical fiberThe core at the tip of the 2 Graded index fiber with squared refractive index profile ( GI Fiber) and a collimator lensAn integrated optical fiber array on the output side having a collimator function;
(B)Single modeOptical fiberGraded index fiber with a core having a nearly square distribution of refractive index distribution at the tip of GI Fiber) and a collimator lensAn integrated optical fiber array on the light-receiving side having a collimator function;
(C) Inserted between the optical fiber array on the emission side and the optical fiber array on the light reception sideThe characteristics of propagating lightLight adjusting means for adjusting;
(D)Means for integrating the output side optical fiber array, the light receiving side optical fiber array, and the light adjusting means with a guide pin;
A functional optical fiber connector that receives the light beam emitted from the optical fiber array on the emission side by the optical fiber array on the light reception side,
The light beam emitted from the optical fiber array on the emission side is a parallel light beam having an angle of spread within ± 2 degrees, and the working distance of the collimator lens is doubled ± 1000 μm in order to reduce the additional loss due to axial misalignment in the optical axis direction. The light adjusting means having a thickness corresponding to the dimension is disposed between the incident side optical fiber array and the light receiving side optical fiber array. It is a functional optical fiber connector.
[0010]
Also, when the optical beam to be optically coupled is emitted obliquely from the optical fiber optical axis, it has the same mechanism as the functional optical fiber connector described above, and a plurality of optical fibers are arranged in parallel or in a matrix form The oblique emission type functional optical fiber connector in which the optical fiber assembly and the lens assembly in which a plurality of lenses are arranged in parallel or in a matrix form are aligned by a guide pin and integrated are found. The outer diameter of the lens mounted on this lens assembly is larger than the outer diameter of the optical fiber mounted on the optical fiber assembly. And the central axis of the lens are shifted. With this structure, even if the end surface of the lens is flat, the light beam is emitted obliquely with respect to the optical axis of the optical fiber.
[0011]
Here, on the surface opposite to the surface facing the optical fiber of the lens, a reflection plate is formed by vapor deposition of a metal reflective material or a dielectric multilayer film, so that the light beam is folded back by 180 degrees. It is possible to realize an oblique emission type functional optical fiber connector that functions as, for example.
[0012]
Furthermore, the above-mentioned optical fiber assembly and the lens assembly are arranged opposite to each other, that is, the oblique emission type in which the optical fiber assembly, the lens assembly, the lens assembly, and the optical fiber assembly are arranged in this order. A functional optical fiber connector can also be realized.
In this configuration, the light beam propagates obliquely with respect to the optical axis of the optical fiber from the lens of one lens assembly to the lens of the other lens assembly. Various types of filters such as a non-reflective coating and a reflective film can be formed on the lens surface, and application examples as various optical components such as an add drop filter are conceivable.
[0013]
This oblique emission type functional optical fiber connector basic mode includes at least one optical fiber assembly in which a plurality of optical fibers are arranged in parallel or in a matrix and an outer diameter larger than the outer diameter of the optical fiber. A plurality of lenses having at least one lens assembly arranged in parallel or in a matrix, and
An oblique emission type functional optical fiber connector, wherein the optical fiber assembly and the lens assembly are aligned and integrated by a guide pin.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Functional optical fiber connector of the present inventionIsA functional optical fiber connector comprising the following member for receiving a light beam incident from an output side optical fiber array by a light receiving side optical fiber array.
(A)Single modeOptical fiberThe core at the tip of the 2 Graded index fiber with squared refractive index profile ( GI Fiber) and a collimator lensAn integrated optical fiber array on the output side having a collimator function;
(B)Single modeOptical fiberThe core at the tip of the 2 Graded index fiber with squared refractive index profile ( GI Fiber) and a collimator lensAn integrated optical fiber array on the light-receiving side having a collimator function;
(C) Inserted between the optical fiber array on the emission side and the optical fiber array on the light reception sideThe characteristics of propagating lightLight adjustment means to adjust.
[0015]
Functional optical fiber connector of the present inventionIsAs means for integrating the optical fiber array and the light adjusting means,(D) Means for integrating the light emitting side optical fiber array, the light receiving side optical fiber array, and the light adjusting means with a guide pin is employed.
[0016]
Functional optical fiber connector of the present inventionIs collimatedA functional optical fiber connector comprising an optical fiber array in which a graded index fiber having a substantially square distribution refractive index distribution as a lens is fusion-bonded to a tip of a single mode fiber.
[0017]
Functional optical fiber connector of the present inventionIs, On the exit sideOptical fiber arrayIn order to reduce the additional loss due to the axial deviation in the optical axis direction, the light beam emitted from the beam is a parallel light beam with a spread angle within ± 2 degrees.·lensThe optical fiber on the light receiving side within ± 1000 μm of the working distance ofarrayA light adjusting means having a thickness corresponding to the dimension of the optical fiber on the incident side.arrayAnd optical fiber on the light receiving sidearrayIt is arranged between.
[0018]
The functional optical fiber connector of the present invention2The functional optical connector is characterized in that the light adjusting means is a light shielding plate whose position relative to the light beam can be adjusted by an actuator.
[0019]
The functional optical fiber connector of the present invention3The functional optical connector is characterized in that the light shielding plate is a plate-like metal silicon obtained by sputtering a metal thin film.
[0020]
The functional optical fiber connector of the present invention4The functional optical connector is characterized in that the light adjusting means is a liquid crystal plate capable of adjusting incident light.
[0021]
According to a fifth aspect of the functional optical fiber connector of the invention, the liquid crystal is STN or TFT.
[0022]
The functional optical fiber connector of the present invention6A functional optical connector is characterized in that the light adjusting means is a dielectric multilayer film.
[0023]
The oblique emission type functional optical fiber connector of the present inventionIsA plurality of optical fibers arranged in parallel or in a matrix, and a plurality of lenses having an outer diameter larger than the outer diameter of the optical fiber are arranged in parallel or in a matrix. An integrated at least one lens assembly;
The optical fiber assembly and the lens assembly are aligned by a guide pin and integrated.is doing.
[0024]
The oblique emission type functional optical fiber connector of the present inventionIsThe lens is a graded index fiber (GI fiber) whose core has a substantially square distribution of refractive index distribution.Yes.
[0025]
The oblique emission type functional optical fiber connector of the present inventionIsThe positions of the central axes of the optical fiber and the lens are different, and the optical fiber assembly and the lens assembly are integrated at a contact position..
[0026]
The oblique emission type functional optical fiber connector of the present inventionIsThe positions of the central axes of the optical fiber and the lens are different, and the optical fiber assembly and the lens assembly are integrated at a position spaced apart from each other..
[0027]
The oblique emission type functional optical fiber connector of the present inventionFirstThe aspect ofOne optical fiber assembly in which a plurality of optical fibers are arranged in parallel or in a matrix, and
A graded index fiber having an outer diameter larger than the outer diameter of the optical fiber and a core having a substantially square distribution refractive index distribution ( GI A plurality of lenses made of fiber) arranged in parallel or in a matrix and integrated into one lens assembly,
The optical fiber assembly and the lens assembly are oblique emission type functional optical fiber connectors integrated at a position where they are in contact with or spaced apart from each other,
The oblique emission type functional optical fiber connector comprising a reflective film made of a metal material or a dielectric multilayer film that reflects light on a surface opposite to the surface facing the optical fiber of the lens.It is.
[0028]
The oblique emission type functional optical fiber connector of the present inventionSecondIn this aspect, the end surface of the lens on the reflection film side is polished obliquely with respect to the lens optical axis, and the reflection film is set so that optical coupling loss occurs when the angle with respect to the lens optical axis is inoperative. Oblique emission type functional optical fiber connectorIs.
[0029]
The oblique emission type functional optical fiber connector of the present invention isA plurality of optical fibers arranged in parallel or in a matrix and integrated on the output side and the light reception sideTwo optical fiber concentrators;A plurality of lenses arranged in parallel or in a matrix and integrated on the output side and the light reception sideAnd the two lens aggregators, and are arranged in order of the emission side optical fiber aggregator, the emission side optical lens aggregator, the light reception side lens aggregator, and the light reception side optical fiber aggregator. It is characterized by that.
[0030]
The oblique emission type functional optical fiber connector of the present inventionIsThe exit side optical lens assembly and the light reception side lens assembly are integrated at a spaced position..
[0031]
The third aspect of the oblique emission type functional optical fiber connector of the present invention is:A plurality of optical fibers arranged in parallel or in a matrix and integrated on the output side and the light reception sideTwo optical fiber concentrators;A plurality of lenses arranged in parallel or in a matrix and integrated on the output side and the light reception sideAnd the two lens aggregators, and are arranged in order of the emission side optical fiber aggregator, the emission side optical lens aggregator, the light reception side lens aggregator, and the light reception side optical fiber aggregator. An oblique emission type functional optical fiber connector,
The oblique emission type functional optical fiber connector is characterized in that a dielectric multi-layer filter is inserted between the lenses facing the emission side optical lens assembly and the light reception side lens assembly without any gap.
[0032]
The oblique emission type functional optical fiber connector of the present inventionIsThe filter has different wavelength characteristics depending on the facing lens.It is characterized by.
[0033]
The oblique emission type functional optical fiber connector of the present inventionIsA filter that functions as a double-sided mirror is inserted between the lenses facing the emission side optical lens assembly and the light reception side lens assembly without any gap..
[0034]
The fourth aspect of the oblique emission type functional optical fiber connector of the present invention is:A plurality of optical fibers arranged in parallel or in a matrix and integrated on the output side and the light reception sideTwo optical fiber concentrators;A plurality of lenses arranged in parallel or in a matrix and integrated on the output side and the light reception sideTwo lens assemblies, and are arranged in order of the emission side optical fiber assembly, the emission side optical lens assembly, the light reception side lens assembly, and the light reception side optical fiber assembly. In addition, there is an oblique emission type functional optical fiber connector in which a filter that functions as a double-sided mirror is inserted between the lenses facing the emission side optical lens assembly and the light reception side lens assembly without any gap. And
The oblique emission type functional optical fiber connector is characterized in that the filter performing the function of the double-sided mirror is a filter whose position with respect to the light beam can be adjusted by an actuator.
[0035]
Hereinafter, the present invention will be described in detail with reference to the drawings. However, the following specific examples are not intended to limit the present invention, and also include a range that can be easily conceived by those skilled in the art from the specific examples disclosed below.
[0036]
In the present invention, as shown in FIG. 1, a multi-fiber connector (hereinafter referred to as MT connector) 10 that has been used conventionally and has a proven record in positioning accuracy and reliability is used. An optical fiber having a collimator function is integrated into the ferrules 3 and 4 by fusing and connecting an all-core type graded index fiber (hereinafter referred to as GI fiber) to a tip of the optical fibers 1 and 2 for a predetermined length. And accommodate. An optical fiber array on the output side is an optical fiber array in which the optical fiber 1 having a collimator function is accommodated in a ferrule 3, and an optical fiber array on the light receiving side is an optical fiber array in which the optical fiber 2 having a collimator function is accommodated in a ferrule 4. Although FIG. 1 shows an array in which optical fibers are arranged in a row, the present invention is not limited to this, and an array in which upper and lower rows are arranged is also possible.
[0037]
As the all-core type GI fiber, a GI fiber in which the core has a substantially square distribution refractive index distribution is desirable. The reason why the parallel rays are within a light beam spread angle of ± 2 degrees is to minimize loss of light intensity between collimators. Further, in order to reduce the loss due to the axial misalignment in the optical axis direction, the thickness of the light adjusting means (distance in the optical axis direction) should be less than twice the working distance of collimators (1/2 of the distance between the collimators facing each other) The reason for this is that the intensity loss of the light beam is minimized when it is twice or less.
[0038]
The MT connector is aligned with the guide pins 41 and 42 and the corresponding pin holes 31 and 32. This MT connector can be positioned in submicron units (± 0.1 μm or less), is low in cost, and has excellent productivity. Therefore, in the present invention, the guide pins 41 and 42 are passed through the guide holes 51 and 52 provided in the light adjusting means 5 so that the light adjusting means can be accurately aligned. In FIG. 1, the light beam is attenuated by the light shielding plate 60 as the light adjusting means. This conceptual diagram is shown in FIG. 1, and a detailed shape of the light shielding plate is shown in FIG.
[0039]
FIG. 2A shows the outline of the whole, and FIG. 2B shows the details. In this embodiment, a 4-core type MT connector is used, and a collimator is formed of an all-core GI fiber having the same outer diameter as the SM optical fiber at the tip of a general single mode fiber (hereinafter referred to as SM optical fiber). The lens function was provided by fusion splicing. The spot size of the lens is about 70 μm, and the working distance (1/2 of the distance between the collimators facing each other) is about 500 μm.
[0040]
The guide pin of one MT connector is inserted into the pin holes 61 and 62 of the light adjusting means, and is inserted into the opposing MT connector and fixed. The light adjusting means 6 is a light adjusting means having four light shielding plates 60 and a thickness of about 1 mm. After assembly, the whole was brought into close contact and sandwiched between clips (not shown). This assembly is equivalent to the assembly of a general MT connector, and the difference is that light adjusting means having a light shielding plate is arranged between the MT connectors.
[0041]
The thickness of the light adjusting means having four light shielding plates 60 is selected to be 1 mm because the working distance of the collimator is about 500 μm. This is because it is double, that is, about 1 mm. After the entire clip is sandwiched and integrated, it is housed in a housing, and a bonding pad (not shown) provided on the side of the light adjusting means having a light shielding plate and the housing electrode are bonded and sealed. .
[0042]
This electrode is connected to a voltage source for driving the light shielding plate with a voltage. Each light shielding plate 60 is connected to a spring 65, and this spring 65 is connected to an upper comb-shaped actuator 63 that moves up and down by electrostatic force. When the upper comb-shaped actuator 63 is drawn into or pulled out from the fixed lower comb-shaped actuator 64, the light shielding plate 60 moves up and down via the spring 65 to change the light beam 66.
[0043]
The above-described device can be manufactured by utilizing so-called MEMS technology and combining polysilicon lamination, sacrificial layer lamination, etching, and the like on a silicon substrate. It can also be produced by etching the silicon wafer and partially etching the insulating layer. Sputtering a thin film of metal such as gold or aluminum on the surface of the light shielding plate of the silicon substrate is desirable in that the light shielding property is enhanced.
[0044]
Using the array collimator used in the above embodiment, only the thickness in the optical axis direction of the light adjusting means having four light shielding plates was reduced to about 625 μm. In this case, since the theoretical facing distance of the array collimator is about 1 mm, the additional loss increases. However, in the design of this collimator, the light beam is almost a parallel light beam. The loss due to the axis misalignment is as small as about 0.2 dB even when the thickness is about ± 1000 μm.
[0045]
However, as described above, in the method of adjusting the intensity of the light beam by blocking light in the light blocking area, if the beam diameter is the same, if the distance from the light blocking plate position to the light receiving side collimator is reduced, the polarization dependence loss ( Since it has been confirmed that (PDL) can be reduced, about 625 μm was adopted to improve PDL at the expense of a loss of about 0.2 dB.
[0046]
Although the PDL is improved as the thickness of the light adjustment means is reduced, the loss of light intensity between collimators and the restrictions on the production of the light adjustment means having a light-shielding plate, for example, if the film is too thin, it is likely to be damaged at the production stage. Therefore, about 625 μm is considered optimal in the current technology.
[0047]
As a further embodiment, a liquid crystal film can be used as means for adjusting the light intensity using the parallel collimator. The liquid crystal films are partitioned one by one on the four light beam optical paths, and the light intensity of each light beam is adjusted by passing a current through each liquid crystal film. The thickness of the liquid crystal film is about 600 μm. This is because the liquid crystal film has a refractive index of 1 or more (air or more), and the theoretical distance between the collimators is about 1 mm. However, since the refractive index is high, the distance between the faces is reduced accordingly. In anticipation, the thickness can be reduced.
[0048]
For example, when the distance between the collimators facing is about 1 mm in the air, if the optical path is filled with a medium having a refractive index of 2.0, the distance between the theoretical facings is about 500 μm. FIG. 3 is a diagram of a chip of the liquid crystal film 74 inserted in the multi-core connector used in this embodiment. An electrical wiring 75 is connected to the liquid crystal layer, and the light intensity can be adjusted by changing the transmittance of the liquid crystal by controlling the voltage, for example.
[0049]
In addition, as the array collimator used in the above-described embodiment, a medium whose refractive index changes with the current value can be used as a condensing system having a spot size of about 20 μm and a theoretically facing distance of about 700 μm. The medium is a substance obtained by doping a glass material mainly made of silica with a semiconductor material such as GaAs or InP. LiTaO_Three, LiNbO_ThreeFurthermore, a double heterostructure medium such as GaInAsP / InP or GaAlAs / GaAs can also be used.
[0050]
The thickness in the optical axis direction of the means for adjusting the light intensity is about 500 μm. The light intensity adjusting means in this case substantially changes the optical path length by changing the refractive index, and makes the amount of axial deviation of the collimator variable. That is, changing the refractive index produces the same effect as changing the distance between the collimators facing each other, so that the light intensity can be adjusted by changing the refractive index.
[0051]
The collimator is a condensing system. In the case of the condensing system, the allowable axis deviation in the optical axis direction is smaller than that of the parallel system. This is because, in contrast to the loss, there is a large loss of about 20 dB in the condensing system, and a large change in light intensity is possible with a small change in refractive index.
[0052]
Further, a filter 84 using a dielectric multilayer film was inserted as an optical characteristic adjusting means between the arrayed parallel collimators. One dielectric multilayer film is provided on each of the four light beam paths, and each dielectric multilayer film transmits only light of a certain wavelength by changing its film structure. For example, SiO as a dielectric multilayer film₂, Ta₂O_FiveAre used by laminating, and the thickness is about 800 μm. This is because the dielectric multilayer film has a refractive index of 1 or more (air or more), so the distance between the theoretical facing of the collimator is about 1 mm. The thickness was reduced in consideration of that amount. FIG. 4 is a view of the light adjusting means in which the dielectric multilayer film inserted between the multi-fiber connectors used in this embodiment is arranged.
[0053]
Next, an embodiment of the oblique emission type functional optical fiber connector for emitting a light beam obliquely from the optical fiber optical axis will be described.
[0054]
One method can be realized by obliquely polishing the light beam emission end face of the GI fiber fused to the tip of the optical fiber. However, if a method of making the outer diameter of the lens larger than the outer diameter of the optical fiber as described below is adopted, a further great advantage can be obtained.
[0055]
The lens constitutes an independent lens aggregator without being fused to the optical fiber, and the outer diameter of the lens that emits light is larger than the outer diameter of the optical fiber. Have. The end face of the fiber is less likely to be chipped or cracked on the outer periphery of the fiber than when the end face is polished obliquely using a polishing jig or the like to produce a lens. There are advantages.
[0056]
In addition, since one light beam can be emitted from a plurality of optical fibers, the same function can be achieved with a smaller number of lenses than the number of optical fibers. Therefore, the mold of the lens assembly is simplified, and the risk of deformation due to temperature shrinkage during the molding of the lens assembly is reduced. Accordingly, the possibility of lens axis misalignment is reduced, and the selection of the material for the lens assembly can be made in a wide range because the risk of temperature shrinkage is reduced.
Furthermore, since the end surfaces of the lenses are not inclined, it is very easy to match the facing distances between the lenses or between the lens and the optical fiber.
[0057]
FIG. 5 is a schematic view showing a basic configuration of the oblique emission type functional optical fiber connector of the present invention.
An optical fiber tape 101 in which a plurality of optical fibers 102 are arranged in a matrix is connected to a ferrule 103 a having an MT connector structure to constitute an optical fiber collector 103. The optical fiber assembly 103 is provided with a guide pin hole 104 for alignment and integration.
[0058]
The lens assembly 105 is also manufactured using the MT connector technology. The mounted lens is an all-core GI fiber having an outer diameter of 375 μm. In a general MT connector, one end is polished and an optical fiber tape is projected from the opposite end. In this lens assembly 105, both ends of the GI fiber are polished to form a lens having flat end surfaces. . Further, one end face of this lens is coated with anti-reflection coating by dielectric multilayer film deposition after polishing.
[0059]
Here, the optical fiber assembly 103 and the lens assembly 105 are aligned and fixed by a guide pin, and an integrated oblique emission type functional optical fiber connector is manufactured. Although guide pins are not shown in the figure, they may be independent components, or guide pins may be attached to the optical fiber assembly 103 or the lens assembly 105 in place of the guide pin holes.
[0060]
FIG. 6 shows the positional relationship between the optical fiber 102 and the lens 106 when the optical fiber collector 103 and the lens collector 105 are aligned with the guide pins. 6A shows the optical fiber collector 103, FIG. 6B shows the lens collector 105, and FIG. 6C shows the positional relationship between the optical fiber 102 and the lens 106.
The outer diameter of the optical fiber 102 is 125 μm, and the outer diameter of the lens 106 is 375 μm. Further, the distance between the center of the optical axis of the optical fiber 102 and the center of the lens 106 is shifted by 125 μm. In this embodiment, the two optical fibers 102 are covered by one lens 106. Further, the optical fiber 102 and the lens 106 can be integrated at a contact position, or can be integrated at a predetermined interval.
[0061]
Next, FIG. 7 and FIG. 12 show an embodiment of the oblique emission type functional optical fiber connector using one optical fiber assembly and one lens assembly. Although the present embodiment shows an example in which the optical fiber collector 110 and the lens collector 111 are integrated in contact with each other, it is also possible to fix them at intervals.
[0062]
First, FIG. 7 will be described. This oblique emission type functional optical fiber connector includes a reflective film 115 on the end surface of the lens 114 opposite to the surface in contact with the optical fibers 112 and 113. It is conceivable that the reflective film 115 is provided by depositing a metal having a high reflectance such as gold on the end face of the lens 114 or by depositing a multi-derivative film layer.
[0063]
The light beam incident from the IN port and propagating through the optical fiber 112 enters the lens 114 whose center axis is deviated from the optical fiber 112, and then proceeds obliquely with respect to the optical axis of the optical fiber 112. When the light reaches the reflection film 115, the light is reflected and travels diagonally in the lens 114 in the opposite direction. Then, the light enters the optical fiber 113, travels through the optical fiber 113 with the direction changed by 180 degrees from the beginning, and reaches the OUT port. Therefore, the oblique emission type functional optical fiber connector of this embodiment can be used as an ultra-small 180-degree folded optical waveguide.
[0064]
Next, FIG. 12 will be described. This oblique emission type functional optical fiber connector is a modification of FIG. 7 and can be used as a variable attenuator. 12A is a perspective view of the lens assembly, FIG. 12B is a perspective view of the reflective film 115, and FIG. 12C is an assembly of FIGS. 12A and 12B. FIG.
[0065]
In the oblique emission type functional optical fiber connector of FIG. 12, the end surface 114a of the lens 114 on the reflection film 115 side is polished obliquely with respect to the lens optical axis, and the reflection surface of the reflection film 115 is in an inoperative state. The angle is adjusted to be parallel to the optical axis. The non-operating state is an initial state and indicates a state where the reflective film 115 is not operated.
[0066]
In the oblique emission type functional optical fiber connector shown in FIG. 12, the angle of the reflection film 115 with respect to the optical axis of the lens is controlled by the MEMS unit 130, and the optical coupling efficiency between the optical fiber 112 and the optical fiber 113 is made variable. It can be used as an attenuator. The MEMS unit 130 is formed with an insertion hole 132 for inserting a guide pin, and the guide pin is inserted into the insertion hole 132 so as to be coupled to the optical fiber collector 110 and the lens collector 111.
[0067]
The optical fiber 112 has an outer diameter of 125 μm, the lens 114 is a GI fiber having an outer diameter of 375 μm and a core diameter of 325 μm, and the lens length on the center line of the lens 114 is 1.26 mm. In this embodiment, the optical fiber assembly 110 has an 8-channel configuration in which 16 fibers are arranged in a horizontal row and the lens assembly 111 has 8 fibers in a horizontal row. In this configuration, two optical fibers 112 are covered with a lens 114 made of one GI fiber. Further, the optical fiber 112 and the lens 114 can be integrated at a contact position, or can be integrated at a predetermined interval.
[0068]
The end surface 114a of the lens 114 is polished at an angle of 1.3 ° with respect to the lens optical axis. The reflection film 115 is set at an angle such that the reflection surface thereof faces the end surface 114a substantially in parallel in the initial state. The end surface 114a of the lens 114 is polished by polishing the end surface of the lens assembly 111 at a predetermined angle with respect to the lens optical axis after the lens 114 is disposed and fixed on the lens assembly 111. Further, the end surface of the lens assembly 111 on the optical fiber assembly 110 side and the end surface of the optical fiber assembly 110 on the lens assembly 111 side are polished at an angle of 8 ° with respect to the optical axis. This is to obtain a sufficient return loss.
[0069]
A copper L-shaped electrode 140 corresponding to the lens 114 in a one-to-one correspondence is formed on the upper portion of the lens 114 of the lens collector 111 by insert molding. Note that an antireflection film is provided on an end surface of the lens 114 on the reflective film 115 side.
[0070]
A metal frame 142 having a shape surrounding the lens 114 and the electrode 140 is provided on the reflective film 115 side of the lens assembly 111. This is because, after the MEMS unit 130 is combined with a guide pin, the lens assembly 111 and the reflection film 115 are fixed with solder, so that the space in which the beam propagates has a hermetic structure from the external space. In order to obtain a hermetic structure, a glass plate 134 is attached to the end surface of the MEMS portion 130 opposite to the reflective film 115.
[0071]
The MEMS unit 130 uses a two-layer SOI wafer having an upper active layer thickness of 28 μm, an intermediate active layer thickness of 2 μm, a supporting substrate thickness of 300 μm, and an intermediate insulating layer thickness of 1 μm. In this SOI wafer, a window is formed in the upper active layer, and a reflective film 115 is formed in the intermediate active layer.
[0072]
The upper active layer functions as a spacer for creating a beam propagation space. The reflective film 115 is structured to be rotatable by etching a part of the support base corresponding to the reflective film 115 from the back surface of the support substrate to form a through hole. Note that the front and back surfaces of the reflective film 115 are coated with gold. The through hole formed in the portion of the support substrate corresponding to the reflective film 115 has a structure in which the glass substrate for anodic bonding is anodically bonded to the end surface opposite to the reflective film 115 of the MEMS portion 130 to be closed.
[0073]
In the oblique emission type functional optical fiber connector shown in FIG. 12 described above, first, a beam emitted from the lens assembly 111 is propagated through a 28 μm space existing between the lens assembly 111 and the reflective film 115. Subsequently, the light is reflected by the reflective film 115, propagates again through the 28 μm space, and returns to the lens 114, but is not optically coupled to the optical fiber 113 at the OUT port in the initial state. Further, as described above, the beam propagation space is separated from the external space, and is a hermetic sealed space.
[0074]
Next, a specific example of the oblique emission type functional optical fiber connector shown in FIG. 12 will be described. The beam emitted from the lens 114 made of the GI fiber of the lens assembly 111 is polished because the end surface 114a emitted from the lens assembly 111 is polished at an angle of 1.3 ° with respect to the optical axis of the lens 114. Radiated at an angle of about 0.58 ° in the angular direction. The beam emitted from the lens 114 subsequently propagates through a space of 28 μm and is reflected by the reflection film 115 adjusted to 1.88 ° (0.58 ° + 1.3 °). The beam reflected by the reflective film 115 again propagates through the 28 μm space and then enters the lens 114.
[0075]
In this embodiment, the beam spot size is about 100 μm, and when the reflective film 115 is adjusted to an angle of 1.88 °, the optical coupling loss is about 45 dB. That is, the optical power of 45 dB is attenuated in the initial state. This level is a value corresponding to the interruption of the optical signal.
[0076]
When a voltage is applied to the electrode of the lens assembly 111 from this initial state, the angle of the reflective film 115 is rotated according to the applied voltage, and the optical coupling efficiency increases. FIG. 13 shows the relationship between the applied voltage and the optical coupling efficiency (shown as Loss in FIG. 13) in this example. When the applied voltage is zero, the value of Loss is 45 dB, but when the applied voltage is gradually increased to 58 V, the value of Loss becomes 0 dB (optical coupling efficiency 100%). Note that at an applied voltage higher than that (58 V or higher in FIG. 13), the reflective film 115 is pulled-in and enters a cut-off state. That is, the optical coupling efficiency is 0%, and the loss value is 45 dB or more.
[0077]
This blocking state at a high applied voltage (in FIG. 13, a state of 58 V or more) can be used for blocking an optical signal in an emergency, for example. The cutoff state when the applied voltage is zero is 45 dB attenuation, and can be used when it is necessary to cut off a high-power optical signal or when it is desired to cut off more.
[0078]
As described above, the oblique emission type functional optical fiber connector shown in FIG. 12 has a configuration in which the optical coupling efficiency is low in the initial state, and the optical coupling efficiency is increased by adjusting the angle of the reflection film 115 from this state. . For this reason, when the power supplied to the MEMS unit 130 is cut off, the optical coupling efficiency in the initial state is the lowest, and propagation of the optical signal can be cut off. In particular, in the event of an emergency such as a power failure of the system, it is often necessary to cut off the propagation of the optical signal, so the oblique emission type functional optical fiber connector shown in FIG. 12 has an effective configuration.
[0079]
Next, FIGS. 8 and 9 show an oblique emission in which two optical fiber aggregators and two lens aggregators are integrated so that the pair of optical fiber aggregators and lens aggregators shown in FIG. An example of a type functional optical fiber connector is shown.
[0080]
In FIG. 8, the lens assembly 111 on the emission side and the lens assembly 117 on the light receiving side are arranged with a predetermined space therebetween. Usually, this interval is 100 μm or less. This interval can be realized by inserting a spacer or the like of a predetermined dimension into the guide pin.
In this embodiment, the optical fiber assembly and the lens assembly (member numbers 110 and 111, and 116 and 117) are arranged in contact with each other. However, they can be arranged at a predetermined interval. It is.
Each member is aligned and integrated in the order of the optical fiber assembly 110, the lens assembly 111, the lens assembly 117, and the optical fiber assembly 116 using a guide pin and a spacer as necessary.
[0081]
The light beam incident from the IN # 1 port and propagating through the optical fiber 112 travels through the lens 114 and the lens 120 obliquely from the optical axis of the optical fiber and enters the optical fiber 119. Then, it propagates through the optical fiber 119 and reaches the OUT # 1 port.
Similarly, the light beam incident from the IN # 2 port and propagating through the optical fiber 113 travels through the lens 114 and the lens 120 obliquely from the optical axis of the optical fiber and enters the optical fiber 118. Then, it propagates through the Hikari fiber 118 and reaches OUT port # 2.
[0082]
As described above, the oblique emission type functional optical fiber connector of this embodiment can serve as a multi-channel optical connector that transmits light from a predetermined optical fiber to a predetermined optical fiber.
[0083]
In the embodiment shown in FIG. 9, the lens assembly 111 on the emission side and the lens assembly 117 on the light receiving side are in contact with each other via the dielectric multilayer film 121. That is, there is no space between the two lens assemblies. The rest of the configuration is the same as that of the embodiment shown in FIG.
This dielectric multilayer film 121 has an optical characteristic of reflecting only light having a wavelength of λx and transmitting light of other wavelengths when a light beam multiplexed with n wavelengths from λ1 to λn is incident. Have.
[0084]
First, the embodiment of FIG. 9A will be described.
A light beam in which n wavelengths from λ1 to λn are multiplexed enters from the IN port, propagates through the optical fiber 112, and enters the lens 114. Since the central axes of the optical fiber 112 and the lens 114 are shifted, the incident light beam travels obliquely in the lens 114 with respect to the optical axis of the optical fiber 112 and reaches the dielectric multilayer film 121.
[0085]
The light beam having the light wavelength λx is reflected by the dielectric multilayer film 121, travels obliquely in the opposite direction in the lens 114, and reaches the optical fiber 113. Then, the direction is changed by 180 degrees from that when the light is incident on the optical fiber 112, and the light propagates through the optical fiber 113 and reaches the DROP port.
[0086]
In addition, light having a wavelength of λ1 to λn other than the wavelength λx passes through the dielectric multilayer film 121, proceeds obliquely through the lens 120, and enters the optical fiber 119. The light beam propagates in the optical fiber 119 in the same direction as the traveling direction in the optical fiber 112 and reaches the OUT port.
Therefore, in the embodiment of FIG. 9A, it is possible to fulfill the function of a multi-channel branching filter (drop filter).
[0087]
Next, the embodiment of FIG. 9B will be described.
Light having wavelengths from λ1 to λn excluding the wavelength λx enters from the IN port, propagates through the optical fiber 112, and reaches the lens 114. Since light having a wavelength other than the wavelength λx passes through the dielectric multilayer film 121, all light beams incident from the IN port travel obliquely through the lens 120 and enter the optical fiber 119. The light beam propagates in the optical fiber 119 in the same direction as the traveling direction in the fiber 112 and reaches the OUT port.
[0088]
On the other hand, the light beam having the wavelength λx incident from the ADD port travels through the optical fiber 118 in a direction 180 degrees opposite to the light beam having the wavelengths λ1 to λn excluding the wavelength λx. The light then enters the lens 120, travels obliquely through the lens 120, and reaches the dielectric multilayer film 121.
[0089]
Here, since the dielectric multilayer film has symmetrical optical characteristics, the light beam having the wavelength λx is reflected by the dielectric multilayer film 121, and the light beam travels obliquely in the opposite direction through the lens 120, and the optical fiber 119. Incident to Here, the light beam having the wavelength λx is combined with the light beams having the wavelengths λ1 to λn excluding the wavelength λx incident from the IN port, travels through the optical fiber 119, and reaches the OUT port.
[0090]
Therefore, in the embodiment of FIG. 9B, it is possible to fulfill the function of a multi-channel multiplexer (add filter).
As described above, the oblique emission type functional optical fiber connector shown in FIGS. 9A and 9B can supply a very small multi-channel multiplexer / demultiplexer (add / drop filter). It can be expected to play an important role in DWDM communication systems.
[0091]
Next, FIG. 10 shows an embodiment of a 24-channel multiplexer / demultiplexer using an oblique emission type functional optical fiber connector.
FIG. 10 (a) shows an optical fiber concentrator 103 in which 4 optical fibers x 12 optical fibers = 48 optical fibers 102 having a total outer diameter of 125 μm are arranged in a matrix on an MT connector at a pitch of 250 μm vertical by 500 μm horizontal. Show. FIG. 10B shows a lens assembly in which 2 cores × 12 horizontals = 24 total core GI fiber lenses 106 having an outer diameter of 375 μm are arranged in a matrix on the MT connector at a pitch of 500 μm vertical and 500 μm horizontal. A container 105 is shown.
[0092]
When a filter that reflects different wavelengths is formed on each lens 106 constituting the lens assembly 105 by dielectric multilayer deposition, a 24 channel multiplexer / demultiplexer is formed by one oblique emission type functional optical fiber connector. It is possible to fulfill the functions of
If the wavelength characteristics of the deposited filter are all reflected by λx, only light having a wavelength of λx is extracted or added from 24 wavelength-multiplexed optical fiber lines. The function of a single wavelength 24-channel multiplexer / demultiplexer can be achieved by a single oblique emission type functional optical fiber connector.
[0093]
Furthermore, when this filter portion is changed to a filter that functions as a double-sided mirror and can be inserted and removed by an actuator, the function of a 24-channel optical switch is achieved by a single oblique emission type functional optical fiber connector. It is possible.
Therefore, the oblique emission type functional optical fiber connector of the present invention can provide an optical communication component including a very compact DWDM communication.
[0094]
【The invention's effect】
The present invention provides a functional multi-fiber optical connector provided with an array of light adjusting means using a conventional multi-fiber connector. In the present invention, a functional connector reduced in size can be provided by applying the technology of the MT connector used conventionally.
In addition, the downsizing leads to problems in the assembly and manufacturing process, but the multi-fiber connector and the optical characteristic adjusting means using the MT connector guide pins can be collectively positioned, making the assembly easy and simple. A functional connector can be realized in the process.
[0095]
In addition, since the collimator is built in the ferrule of the MT connector, it is possible to align the distance between all the collimators at the same time, and adjust the distance between the facings according to the thickness of the optical connector adjusting means inserted between the connectors. In addition, it is easy to handle the optical fiber, and it is difficult to fix the fiber and it is inconvenient to handle. The problem of loss and fiber breakage was solved. That is, according to the present invention, arraying or paralleling the optical characteristic adjusters, miniaturization, ease of manufacture, and simplification of the process can be achieved at a time.
[0096]
Further, an oblique emission type in which an optical fiber assembly in which optical fibers are arranged in a matrix and a lens assembly in which lenses made of GI fibers having an outer diameter larger than the outer diameter of the optical fiber are combined in a matrix are combined. In the functional optical fiber connector, there is little risk of damage to the lens, and it becomes easy to match the distance between the opposing optical fiber collector and the lens collector. Also, since a plurality of optical fibers can be covered with a single lens, the number of lenses can be reduced, making it easy to create a frame for the lens assembly, and the scope for selecting a frame material is widened.
[0097]
Furthermore, by combining various types of filters with the oblique emission type functional optical fiber connector of the present invention, a very compact multi-channel optical component such as a 180-degree folded optical waveguide, multiplexer / demultiplexer, optical switch, etc. is provided. Therefore, application to a DWDM communication system or the like is expected.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a functional optical fiber connector in which a light shielding plate is incorporated as a light adjusting means between opposing MT connectors as one embodiment of the present invention.
FIG. 2 is a diagram showing an outline of a functional optical fiber connector in which a light shielding plate having a comb-shaped actuator is incorporated as a light adjusting means between opposing MT connectors as another embodiment of the present invention.
FIG. 3 is a diagram showing an outline of a functional optical fiber connector using liquid crystal as light adjusting means between opposing MT connectors as another embodiment of the present invention.
FIG. 4 is a diagram showing an outline of a functional optical fiber connector using a dielectric multilayer film as light adjusting means between opposing MT connectors as another embodiment of the present invention.
FIG. 5 is a schematic view showing a basic configuration of the oblique emission type functional optical fiber connector of the present invention.
FIG. 6 is a diagram showing a positional relationship between an optical fiber and a lens when the optical fiber collector and the lens collector are aligned with a guide pin.
FIG. 7 is a diagram showing an embodiment of an oblique emission type functional optical fiber connector using one optical fiber assembly and one lens assembly.
FIG. 8 shows a functional optical fiber connector of oblique emission type in which two optical fiber aggregators and two lens aggregators are arranged so that a pair of the optical fiber aggregator and the lens aggregator shown in FIG. The figure which shows an Example.
9 is a view showing an embodiment when a filter is inserted between the lens assembly and the lens assembly in the oblique emission type functional optical fiber connector in the case of FIG. 8;
FIG. 10 is a diagram showing an example of a 24-channel multiplexer / demultiplexer using an oblique emission type functional optical fiber connector;
FIG. 11 is a diagram showing a case where an absorption film filter is inserted between conventional single mode optical fibers to shield light.
FIG. 12 is a diagram showing an oblique emission type functional optical fiber connector using one optical fiber assembly and one lens assembly; FIG. 12A is a perspective view showing the lens assembly, and FIG. ) Is a perspective view showing the reflective film, and FIG. 12C is a schematic sectional view.
13 is a graph showing the relationship between applied voltage and optical coupling efficiency of the oblique emission type functional optical fiber connector shown in FIG.
[Explanation of symbols]
1, 2 Optical fiber
3,4 ferrule
31, 32 Pin hole of connector
41, 42 Connector guide pins
55 Filter with thickness gradient
51, 52 Guide holes for light adjusting means
6 Light adjustment means for light shielding plate using comb actuator
60 Shading plate
61, 62 pin holes
63, 64 Upper and lower comb actuators
65 Spring
66 Light Beam
7 Light adjustment means with liquid crystal
71, 72 pin holes
8. Light adjusting means provided with a dielectric multilayer film
81,82 pin holes
101 optical fiber tape
102 Optical fiber
103a Ferrule
103 Optical fiber collector
104,107 Guide pin hole
105 Lens assembly
106 lenses
110, 116 Optical fiber collector
111,117 Lens collector
112,113 Optical fiber
114,120 lens
114a end face
115 Reflective film
118,119 optical fiber
130 MEMS Department
132 Insertion hole
134 Glass plate
140 electrodes
142 frames

Claims (10)

(A) An exit side having a collimator function, in which a collimator lens made of a graded index fiber (GI fiber) having a substantially square distribution of refractive index distribution is integrated by fusion at the tip of a single mode optical fiber. An optical fiber array,
(B) A light receiving side having a collimator function in which a collimator lens made of a graded index fiber (GI fiber) having a substantially square distribution of refractive index distribution is integrated by fusion at the tip of a single mode optical fiber. An optical fiber array,
(C) a light adjusting unit that is inserted between the optical fiber array on the emission side and the optical fiber array on the light reception side, and adjusts the characteristics of the propagating light;
(D) comprising a means for integrating the light emitting side optical fiber array, the light receiving side optical fiber array, and the light adjusting means with a guide pin;
A functional optical fiber connector for receiving a light beam emitted from the optical fiber array on the emission side by the optical fiber array on the light reception side,
The light beam emitted from the optical fiber array on the emission side is a parallel light beam having a spread angle of ± 2 degrees or less, and the working distance of the collimator lens is doubled ± 1000 μm in order to reduce the additional loss due to the axial deviation in the optical axis direction. The light-adjusting means having a thickness corresponding to the size of the light-emitting side optical fiber array and the light-receiving side optical fiber array is provided between the light-receiving side optical fiber array and the light-receiving side optical fiber array. A functional optical fiber connector characterized by being disposed between. The functional optical connector according to claim 1, wherein the light adjusting unit is a light shielding plate whose position relative to the light beam can be adjusted by an actuator. 3. The functional optical connector according to claim 2, wherein the light shielding plate is a plate-like metal silicon obtained by sputtering a metal thin film. The functional optical connector according to claim 1, wherein the light adjusting unit is a liquid crystal plate capable of adjusting incident light. The functional optical connector according to claim 1, wherein the liquid crystal is STN or TFT. The functional optical connector according to claim 1, wherein the light adjusting unit is a dielectric multilayer film. One optical fiber assembly in which a plurality of optical fibers are arranged in parallel or in a matrix, and
A plurality of lenses made of graded index fibers (GI fibers) having an outer diameter larger than the outer diameter of the optical fiber and having a core having a substantially square distribution of refractive index distribution are arranged in parallel or in a matrix shape. A single lens assembly,
The optical fiber assembly and the lens assembly are oblique emission type functional optical fiber connectors integrated at a position where they are in contact with or spaced apart from each other,
The oblique emission type functional optical fiber connector comprising a reflective film made of a metal material or a dielectric multilayer film that reflects light on a surface opposite to the surface facing the optical fiber of the lens. The lens is characterized in that the end surface on the reflective film side is polished obliquely with respect to the lens optical axis, and the reflective film is set so that optical coupling loss occurs when the angle to the lens optical axis is inoperative The oblique emission type functional optical fiber connector according to claim 7. A plurality of optical fiber assemblies on the emission side and the light reception side, in which a plurality of optical fibers are arranged in parallel or in a matrix, and integrated ;
A plurality of lenses arranged in parallel or in a matrix and integrated on the output side and the light receiving side , the output side optical fiber assembly, the output side optical lens assembly, the light receiving An oblique emission type functional optical fiber connector arranged and integrated in the order of a side lens assembly and the light receiving side optical fiber assembly,
An oblique emission type functional optical fiber connector, wherein a dielectric multi-layer filter is inserted between the lenses facing the emission side optical lens assembly and the light reception side lens assembly without any gap. A plurality of optical fiber assemblies on the emission side and the light reception side, in which a plurality of optical fibers are arranged in parallel or in a matrix, and integrated ;
A plurality of lenses arranged in parallel or in a matrix and integrated on the output side and the light receiving side , the output side optical fiber assembly, the output side optical lens assembly, the light receiving A side lens assembly and the light receiving side optical fiber assembly are arranged and integrated in this order, and a function of a double-sided mirror is provided between the facing lens of the emission side optical lens assembly and the light receiving side lens assembly. An oblique emission type functional optical fiber connector in which a filter that fulfills
The oblique emission type functional optical fiber connector, wherein the filter performing the function of the double-sided mirror is a filter whose position relative to the light beam can be adjusted by an actuator.

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