JP2008046333A - Optical transmission/reception module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical transmission/reception module in which a flexible belt-shaped polymer optical waveguide film which follows the deformation such as bending and torsion, and the transmission and reception of an optical signal are performed via an optical waveguide formed in the film even in a deformed state. <P>SOLUTION: In the bi-directional optical transmission/reception module 10, the end parts of the polymer optical waveguide film 11 are mounted on a submount 24 having a reflection face 24c on an optical transmission/reception part 20 side and a submount 25 having a reflection face 25c on an optical transmission/reception part 21 side, respectively, a back face light emission type light emitting element 22 is arranged so that the light emitted from the back face light emission type light emitting element 22 is made incident to a transmission optical waveguide via the reflection faces 24c and 25c, and a back face light reception type light reception element 23 is arranged so that the light from the reception optical waveguide is received via the reflection faces 24c and 25c. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical transmission / reception module, and more particularly to an optical transmission / reception module that transmits and receives an optical signal via an optical waveguide formed on a polymer optical waveguide film.

As an example of a conventional method for producing a polymer optical waveguide, for example, (1) a method in which a film is impregnated with a monomer, a core portion is selectively exposed, and a film is laminated by changing a refractive index (selective polymerization method) ,
(2) A method of forming a clad portion using reactive ion etching after applying a core layer and a clad layer (RIE method),
(3) A method of exposing and developing an ultraviolet curable resin obtained by adding a photosensitive material in a polymer material by photolithography (direct exposure method),
(4) Method using injection molding,
(5) Various methods such as a method of changing the refractive index of the core part by exposing the core part after applying the core layer and the clad layer (photo bleaching method) have been proposed.

  However, the selective polymerization method (1) has a problem in film lamination. The RIE method (2) and the direct exposure method (3) are expensive because they use a photolithography method. The injection molding method (4) has a problem in the accuracy of the obtained core diameter. The photo bleaching method (5) has a problem that the difference in refractive index between the core layer and the clad layer cannot be sufficiently obtained.

  Practical production methods include the RIE method (2) and the direct exposure method (3), but there is a problem in production cost as described above. In any of the production methods (1) to (5), it is practically unsuitable for forming a polymer optical waveguide on a flexible plastic substrate having a large area.

  On the other hand, as an example of a method for producing a polymer optical waveguide that is completely different from the conventional production method, there is a method for producing a polymer optical waveguide using a mold called, for example, a micromold method (for example, Patent Documents 1 to 3). reference.). According to the polymer optical waveguide manufacturing methods described in Patent Documents 1 to 3, it is possible to mass-produce optical waveguides very simply and at low cost. Moreover, although it is a simple manufacturing method, an optical waveguide with small optical waveguide loss can be produced stably. Furthermore, it is possible to produce an optical waveguide on a flexible plastic substrate that has been difficult to produce in the past. In addition, the manufacturing method of the polymer optical waveguide described in the said patent documents 1-3 is what the present applicant etc. proposed previously.

  By the way, recently, in IC technology and LSI technology, in order to improve the operation speed and the degree of integration, instead of performing high-density electrical wiring, optical wiring is performed between equipment devices, between boards in equipment equipment, and in chips. Is attracting attention. In particular, various elements for optical wiring using a surface emitting laser and a photodiode as a surface light receiving element, which are advantageous for power saving and surface array, have been proposed.

  As an example of such an element, for example, a polymer optical waveguide having a core and a clad surrounding the core is provided with a light emitting element and a light receiving element in the core / cladding direction, and light from the light emitting element is incident on the core. An optical element having an incident side mirror and an output side mirror for emitting light from the core to the light receiving element, and corresponding to an optical path from the light emitting element to the incident side mirror and from the output side mirror to the light receiving element Have proposed an optical element in which a cladding layer is formed and the light from the light emitting element and the light from the output side mirror are converged (see, for example, Patent Document 4).

  In addition, in an optical element in which light from a light emitting element is incident on a core end face of a polymer optical waveguide having a core and a clad surrounding the core, the light incident end face of the core is formed to be convex toward the light emitting element. An optical element in which light from the light emitting element is converged to suppress waveguide loss has been proposed (see, for example, Patent Document 5).

Further, there has been proposed an optoelectronic integrated circuit in which a polymer optical waveguide circuit is directly assembled on an optoelectronic circuit board in which electronic elements and optical elements are integrated (see, for example, Patent Document 6).
JP 2004-29507 A JP 2004-86144 A JP 2004-109927 A JP 2000-39530 A JP 2000-39531 A JP 2000-235127 A

  However, in all the optical wiring methods proposed so far, the optical waveguide is fixed on the substrate together with the light emitting / receiving element and the mirror, and the degree of freedom of wiring is small compared with the electric wiring by the wire, and the hinge part. As an optical wiring, there is a problem that it is difficult to apply to mobile devices such as mobile phones and thin personal computers that are often folded.

  On the other hand, optical fiber tapes made by collecting several strands of resin-coated optical fibers into tapes are used for optical wiring, but optical fibers are made of quartz glass and are not easily bent. There was a problem of being small.

  The present invention uses a flexible belt-shaped polymer optical waveguide film that can follow deformation such as bending and twisting, and transmits and receives optical signals through the optical waveguide formed in the film even in a deformed state. An object of the present invention is to provide an optical transmission / reception module.

[1] The present invention relates to a polymer optical waveguide film in which an optical waveguide is formed, a first submount having a first reflecting surface for converting an optical path of incident light, a back-emitting light emitting element, And placing one end of the polymer optical waveguide film on the first submount, and the light emitted from the light-emitting element is converted in the optical path by the first reflecting surface. An optical transmitter having a configuration in which the light emitting element is disposed so as to be coupled to an incident end face of an optical waveguide, a second submount having a second reflecting surface for converting an optical path of incident light, and a rear light receiving type And the other end of the polymer optical waveguide film is placed on the second submount, and light emitted from the exit end face of the optical waveguide is reflected on the second reflecting surface. The light path is converted by and received by the light receiving element. Wherein in the optical transceiver module, characterized by comprising a light receiving portion of the configuration of arranging the light-receiving element so.

[2] Furthermore, the present invention relates to a polymer optical waveguide film in which a transmission optical waveguide and a reception optical waveguide are formed, and optical signals are transmitted and received bidirectionally via the transmission optical waveguide and the reception optical waveguide. Each of the pair of light transmitting / receiving units on both sides includes a rear light emitting element and a rear light receiving element, and a sub surface having a reflecting surface for converting an optical path of incident light. And an end of the polymer optical waveguide film is mounted on the submount, and light emitted from the light emitting element is converted in an optical path by the reflecting surface and incident on the transmitting optical waveguide. The light receiving element is disposed so as to be coupled to an end face, and the light receiving element is received by the light receiving element after the light path emitted from the emitting end face of the receiving optical waveguide is converted by the reflecting surface. Place In the optical transceiver module according to claim Rukoto.

[3] In the invention described in [1] or [2] above, the polymer optical waveguide film has a thickness of 50 μm to 200 μm.

[4] In the invention according to any one of [1] to [3], the film surface of the polymer optical waveguide film is bonded to the main surface of the submount.

[5] In the invention according to any one of [1] to [4], the core portion of the optical waveguide is duplicated using a silicone resin mold.

[6] In the invention according to any one of [1] to [5], the core portion of the optical waveguide is manufactured by cutting with a dicing saw.

[7] The invention according to any one of [1] to [6], wherein the submount is made of metal, and a cutting surface formed on the submount by dicing is used as the reflection surface. It is said.

[8] In the invention described in [1] or [2] above, the submount is made of silicone, and metal is deposited on a cutting surface formed on the submount by dicing to form the reflective surface. It is a feature.

[9] In the invention described in [1] or [2] above, the submount is made of quartz glass, and a metal is vapor-deposited on a cut surface formed in the submount by dicing to form the reflective surface. It is characterized by.

[10] In the invention described in [1] or [2] above, the metal is one or more metals selected from the group consisting of gold, silver, nickel, copper, cobalt, aluminum, and titanium, or the metal It is characterized by being an alloy.

[11] In the invention described in [1] or [2] above, the light emitting element and the light receiving element are fixed on the submount with the same resin as a resin constituting a core portion of the optical waveguide. It is characterized by that.

  According to the present invention, since a flexible belt-shaped polymer optical waveguide film that can follow deformation such as bending and twisting is used, the optical waveguide formed on the film can be used even when the film is deformed. The optical signal can be transmitted and received through the network. At the same time, a reflecting surface is directly formed on the submount, and mounting is performed with a simple configuration in which the backside light emitting element, the backside light receiving element, and the polymer optical waveguide film are optically coupled through the reflecting surface. As a result, it is possible to reduce the number of parts and the work man-hours and production costs.

  Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

[First Embodiment]
(Configuration of optical transceiver module)
FIG. 1 is a perspective view schematically showing a configuration example of a bidirectional optical transceiver module according to the first embodiment of the present invention. In the first embodiment, a bidirectional optical transceiver module will be described as an example. However, the present invention is not limited to this, and for example, optical transmission provided with a backside light emitting element. Of course, it can be used for a one-way optical transmission / reception module that performs one-way optical communication between the optical receiver and the light receiving unit including the rear light-receiving type light receiving element.

  In the same figure, the code | symbol 10 has shown the external appearance structure of the bidirectional | two-way optical transmission / reception module which concerns on typical 1st Embodiment. As shown in FIG. 1, the basic configuration of the bidirectional optical transceiver module 10 includes a belt-shaped polymer optical waveguide film 11, a transmission optical waveguide formed in the polymer optical waveguide film 11, and a receiver. The first and second optical transmission / reception units 20 and 21 transmit and receive optical signals bidirectionally via the optical waveguide. Each of these optical transceivers 20 and 21 includes a surface emitting semiconductor laser diode (LD) 22 that is a back light emitting type light emitting element, a photodiode (PD) 23 that is a back light receiving type light receiving element, and a first light emitting element. Alternatively, the second submounts 24 and 25 are provided, and both ends of the polymer optical waveguide film 11 are held on the submounts 24 and 25, respectively. A microlens is provided on each of the optical transmission surface of the LD 22 and the optical reception surface of the PD 23. FIG. 2B shows a microlens 22 a provided on the optical transmission surface of the LD 22.

(Polymer optical waveguide film)
As shown in FIG. 1, the polymer optical waveguide film 11 is made of a transparent resin film material having a flexible bending radius of 3 mm or less, and has a followability to deformation such as bending and twisting. . With this configuration, even when the polymer optical waveguide film 11 is deformed, the optical signal transmitted from the LD 22 of the first optical transmission / reception unit 20 is guided through the optical waveguide of the polymer optical waveguide film 11, so that the second Can be received by the PD 23 of the optical transceiver 21.

  The polymer optical waveguide film 11 is preferably set to a thickness of 50 μm to 300 μm, and more preferably 70 μm to 200 μm, in order to improve followability to deformation. For the same reason, the width of the film is preferably set in the range of 0.5 mm to 10 mm, and more preferably in the range of 1 mm to 5 mm.

  As shown in FIG. 2 (b), the polymer optical waveguide film 11 is composed of a mouth-shaped core portion 12 extending in the film length direction and a clad portion 13 surrounding the core portion 12. . The polymer optical waveguide film 11 has the same structure on both sides in the film length direction. In the polymer optical waveguide film 11, a plurality of core portions 12 are arranged in parallel in the film width direction, and a plurality of optical waveguides 14 are formed in the film. Although this invention is not specifically limited, In this Embodiment, the two optical waveguides 14 are formed in the film corresponding to LD22 and PD23. An end surface perpendicular to the optical axis of the optical waveguide 14 is formed at the end of the polymer optical waveguide film 11.

(Optical transceiver with submount)
FIG. 2 schematically illustrates a configuration example of an optical transmission / reception unit including a submount. Fig.2 (a) is a top view of an optical transmission / reception part, FIG.2 (b) is the II-II sectional view taken on the line of Fig.2 (a). As shown in FIG. 1, the first and second optical transmission / reception units 20 and 21 have the same structure on both sides except for the installation positions of the LD 22 and the PD 23. For this reason, in this Embodiment, only the 1st optical transmission / reception part 20 of one side is demonstrated.

  As shown in FIG. 2, the submount 24 of the first optical transmission / reception unit 20 is configured by a substrate made of a substantially rectangular parallelepiped. The basic structure of the submount 24 is that a film mounting surface 24a on which the end of the polymer optical waveguide film 11 is mounted, an electrode forming surface 24b on which an electrode film is formed, and a 45-degree mirror that performs optical path conversion. Surface 24c. The film mounting surface 24a has a concave shape formed lower than the electrode forming surface 24b by the thickness of the polymer optical waveguide film 11, for example, by cutting the substrate of the submount 24 from the surface. The mirror surface 24c is composed of a vertical surface extending linearly so as to traverse the concave portion forming the film mounting surface 24a, and an inclined surface inclined downward at an angle of 45 degrees with respect to the main surface of the submount 24. It has a wedge shape.

  The 45-degree mirror surface 24c functions as an optical path conversion surface that converts the optical path of incident light. Light incident on the mirror surface 24c at an angle of 45 degrees has its optical path bent at 90 degrees on the mirror surface 24c. As the mirror surface 24c, the substrate of the submount 24 can be cut at an angle of 45 degrees to form a cut surface, and a metal film having a high reflectance can be formed on the cut surface. When the submount 24 is manufactured using a silicon (Si) crystal substrate or a metal substrate, the cutting surface can be used as a mirror surface as it is.

  As the submount 24, a crystal substrate such as Si, a glass substrate such as quartz glass, gold (Au), silver (Ag), nickel (Ni), copper (Cu), cobalt (Co), aluminum (Al), titanium The film mounting surface 24a and the mirror surface 24c of the submount 24 can be formed on a metal substrate such as (Ti) or an alloy thereof. The mirror surface 24c is produced by, for example, forming a step between the film mounting surface 24a and the electrode forming surface 24b by etching, and then cutting the mirror surface 24c with a predetermined thickness using an angled blade. Can be formed.

  As a method for producing the film mounting surface 24a of the submount 24, for example, reactive ion etching (RIE) with high formation accuracy is preferably used. As a method for producing a cutting surface to be the mirror surface 24c, for example, dicing having an angled blade is preferably used. In particular, in the case of a crystal substrate such as Si, dicing along the crystal plane is preferable. Although the mounting positional accuracy depends on the manufacturing accuracy of the submount 24, it is possible to obtain sufficient manufacturing accuracy by dicing, and the LD 22, the PD 23, and the polymer optical waveguide film 11 can be mounted easily. it can. Further, for example, vapor deposition or sputtering is preferably used for forming the metal film on the cut surface of the submount 24.

  On the electrode forming surface 24b of the submount 24, an electrode film for performing electrical wiring to the LD 22 and the PD 23 can be formed. The electrode film of the submount 24 may be formed, for example, by depositing a metal film such as gold (Au) or aluminum (Al) on the surface of the submount 24 and then patterning the metal film by a photolithography technique. it can. By forming an electrode film on the submount 24, when the bidirectional optical transceiver module 10 is stored in a package, electrical wiring to the light receiving element and the light emitting element is facilitated.

  The submount 24 can be constituted by a metal substrate made of a substantially rectangular parallelepiped in which metal layers are uniformly formed by electroforming, for example. As an example of the manufacturing method, for example, an electro fine forming method which is a kind of ultraprecision etching method can be cited. According to this configuration, it is not necessary to attach a metal heat sink to the lower surface of the member on which the LD 22 is mounted, and heat generated from the LD 22 can be efficiently released to the outside. For this reason, power consumption can be suppressed and light emission with high luminance is possible.

  Next, with reference to FIG. 3, the mounting of the optical transmission / reception unit will be described. FIG. 3 is a plan view schematically showing one implementation example of the optical transmission / reception unit including the submount. Even in this illustrated example, the first and second optical transmission / reception units 20 and 21 have the same structure on both sides except for the installation position of the light receiving element and the light emitting element as shown in FIG. Only the first optical transceiver 20 will be described. In FIG. 3, the same member names and symbols are assigned to substantially the same members as those in the above embodiment. Therefore, the detailed description regarding these members is omitted.

  When the bidirectional optical transceiver module 10 is mounted, as shown in FIG. 3, the rear light emitting LD 22, the rear light receiving PD 23, and the polymer optical waveguide film 11 are held on the submount 24 of the optical transceiver 20. Is done. By holding the end portion of the polymer optical waveguide film 11 with the film mounting surface 24a of the submount 24, the flexible polymer optical waveguide film 11 can be stably held.

  The backside light emitting LD 22 and the backside light receiving PD 23 have their respective light transmitting surfaces and light receiving surfaces facing directly above the 45 ° mirror surface 24c, and the upper end surface of the polymer optical waveguide film 11 and the submount 24. It is closely attached to the top. The light emitted from the optical transmission surface of the LD 22 is reflected by the mirror surface 24 c and enters the end surface (incident end surface) of the core portion 12 of the transmission optical waveguide 14 of the polymer optical waveguide film 11. The light guided in the core portion 12 can be easily assembled by aligning and mounting so that the light is reflected by the mirror surface 24c and received by the light receiving surface of the PD 23.

  Further, in the bidirectional optical transceiver module 10, as shown in FIG. 3, the submount 24 is fixed on the film placement surface 24a of the substrate 30 made of ceramic. Although the present invention is not particularly limited, the upper surface of the ceramic substrate 30 is, for example, plated with gold having good thermal conductivity. The ceramic substrate 30 has two electrode pads 31 wired to the cathode and anode electrodes formed on the back surface of the LD 22, and a photodiode for electrical connection to the cathode and anode electrodes formed on the back surface of the PD 23. An amplifier 32 and three electrode pads 33 electrically connected to the amplifier 32 are mounted. In the illustrated example, the submount 24 does not require patterning.

  When the submount 24 is made of metal, the optical transmitter / receiver 20 and the ceramic substrate 30 are mounted in a non-contact state, so that the heat generated in the LD 22 does not propagate to the ceramic substrate 30 side. As a result, the influence on the ceramic substrate 30 can be minimized, and heat can be stably radiated by the submount 24. In addition, heat generated during operation of the amplifier 32 can be enhanced by the cooperation of the submount 24 and the ceramic substrate 30. Therefore, the noise characteristics and reliability of the bidirectional optical transceiver module 10 can be improved.

(Operation of bidirectional optical transceiver module)
In the bidirectional optical transceiver module 10 configured as described above, the first optical transceiver 20 provided at one end of the polymer optical waveguide film 11 is provided at the other end of the polymer optical waveguide film 11. When an optical signal is transmitted to the second optical transceiver 21, the light emitted from the optical transmission surface of the rear light emitting LD 22 held on the submount 24 of the first optical transceiver 20 is a 45-degree mirror surface. Incident light is incident directly above (incident end face) 24c. The light is reflected by the 45-degree mirror surface 24c, undergoes an optical path change of 90 degrees, and is guided in the core portion 12 of the transmission optical waveguide 14. The light is converted into a vertical waveguide direction at a 45-degree mirror surface (outgoing end face) 24c on the second optical transmission / reception unit 21 side, and is received by the rear light receiving type held by the submount 25 of the second optical transmission / reception unit 21. The light is received by the light receiving surface of the PD 23.

  When the first optical transmitter / receiver 20 receives the optical signal transmitted from the second optical transmitter / receiver 21, the light emitted from the optical transmission surface of the back-emitting LD 22 in the second optical transmitter / receiver 21 is received. , 45 degrees from the mirror surface (incident end face) 24c. The light is reflected by the 45-degree mirror surface 24c, undergoes an optical path change of 90 degrees, and is guided in the core portion 12 of the receiving optical waveguide 14. The light is converted into a vertical propagation direction on the 45-degree mirror surface (outgoing end face) 24c on the first optical transmitter / receiver 20 side, and is received by the light receiving surface of the back-side light receiving type PD 23.

  In the optical transmission / reception module 10 according to the present embodiment, as described above, bidirectional optical communication is performed between the pair of optical transmission / reception units 20 and 21, but a flexible belt-like polymer optical waveguide film 11 is provided. Has followability to deformation such as bending and twisting, so that optical signals can be transmitted and received through the optical waveguide 14 formed in the polymer optical waveguide film 11 even when the film is deformed. Can do. Therefore, it can be effectively used for optical wiring of mobile devices such as mobile phones and thin personal computers that are often folded.

  In the optical transceiver module 10 according to the present embodiment configured as described above, the submount 24 that is processed into a predetermined shape and formed with the mirror surface 24c is used, so the following (1) to ( As shown in 4), the polymer optical waveguide film 11, the backside light emitting LD 22, and the backside light receiving PD23 can be easily mounted.

(1) A film mounting surface 24a on which the end of the polymer optical waveguide film 11 is mounted is formed on the submount 24, and the end of the polymer optical waveguide film 11 is held by the film mounting surface 24a. Therefore, the flexible polymer optical waveguide film 11 can be stably held on the submount 24.

(2) The polymer optical waveguide film 11 is placed on the submount 24, a mirror surface 24c is formed on the same submount 24, and the backside light emitting LD 22 and the backside light receiving PD23 are connected via the mirror surface 24c. Since the mounting is performed by a simple method of optically coupling the polymer optical waveguide film 11, the number of parts can be reduced.

(3) When the mirror surface 24c is formed on the submount 24, it is possible to obtain sufficient accuracy with a dicing saw, and mounting becomes easier.

(4) Since alignment can be performed by controlling the thickness of the polymer optical waveguide film 11, mounting without a microlens is possible.

  Next, an example of a method for manufacturing the submount 24 will be described.

  The submount 24 having the above configuration can be efficiently manufactured as follows. FIG. 4A to FIG. 4F are conceptual diagrams showing steps for manufacturing a submount. In the following manufacturing examples, a method for manufacturing three submounts will be described, but the present invention is not limited to this.

(Preparation of master)
As shown in FIGS. 4 (a) and 4 (b), the master 40 is formed on the silicone wafer by reactive ion etching (RIE) on the film mounting surface except for the portion that becomes the electrode forming surface forming convex portion 40b. Three film mounting surface forming recesses 40a corresponding to the form are produced. Next, using a dicing having an angled blade, three mirror surface forming recesses 40c corresponding to the shape of the mirror surface are cut across the film mounting surface forming recesses 40a on the silicone wafer. Thereby, the master 40 made of silicone can be produced.

(Production of mold)
As shown in FIG. 4 (c), the mold 41 is formed by applying or casting a curable resin for forming a mold on the concavo-convex forming surface of the master 40 produced according to a standard method, and placing the film on the submount. A curable resin layer having the forming convex portion 41a, the electrode forming surface forming concave portion 41b, and the mirror surface forming convex portion 41c is formed. Next, a drying process is performed to cure the curable resin layer. The cured curable resin layer is peeled from the master 40. Thereby, the casting_mold | template 41 which consists of a curable resin layer is producible.

(Production of submount)
In producing the curable resin substrate 42 to be the submount, as shown in FIG. 4D, an ultraviolet curable resin or thermosetting material for forming the submount is formed on the concavo-convex forming surface of the produced mold 41 according to a conventional method. The resin is molded by coating or casting. Next, the ultraviolet curable resin layer or the thermosetting resin layer is cured by heat or light. Thereby, the curable resin board | substrate 42 which has the film mounting surface 24a, the electrode formation surface 24b, and the mirror surface 24c is producible.

  Next, as shown in FIG. 4E, a metal film 24d is deposited on the three mirror surfaces 24c of the produced curable resin substrate. In depositing the metal film 24d on the mirror surface 24c, for example, a metal mask having a through hole corresponding to the mirror surface 24c can be used. A metal film 24d can be deposited from the metal mask side toward the mirror surface 24c via the vapor deposition source in a state where the through hole of the metal mask is aligned with the mirror surface 24c. Next, as shown in FIG. 4F, the curable resin substrate 42 is cut at a right angle by a dicer or the like to form three independent submounts 24.

[Second Embodiment]
(Submount production method)
FIG. 5A to FIG. 5E are conceptual diagrams showing other processes for manufacturing the submount according to the second embodiment.

  A significant difference from the manufacturing method of the submount 24 shown in FIG. 4 is that the film mounting surface 24a, the electrode forming surface 24b, and the mirror surface 24c of the submount 24 are formed by molding using a stamper. In the illustrated example, as shown in FIGS. 5A and 5B, three film mounting surface forming convex portions 41a, three electrode forming surfaces, and three mirror surfaces are formed by RIE. After forming the mold 41 having the forming recesses 41b and 41c, as shown in FIG. 5C, the concavo-convex pattern of the manufactured mold 41 can be used as a stamper. After the film mounting surface 24a, the electrode forming surface 24b and the mirror surface 24c having substantially the same shape as the concavo-convex pattern of the mold 41 are formed on the surface of the quartz glass substrate 43 to be the submount, as shown in FIG. By vapor-depositing the metal film 24d on the mirror surface 24c and cutting the quartz glass substrate, as shown in FIG. 5E, three independent quartz glass submounts 24 can be produced.

  Next, an example of a method for producing a polymer optical waveguide film will be described.

(Production method of polymer optical waveguide film)
The polymer optical waveguide film 11 can be efficiently produced by the following steps (1) to (6).
(1) A mold formed from a cured layer of a mold-forming curable resin, provided with a concave portion corresponding to the core convex portion of the optical waveguide, and two or more through holes communicating with one end and the other end of the concave portion, respectively. Step of preparing (2) Step of bringing a flexible film substrate for clad having good adhesion to the mold into contact with the mold (3) Recess of the mold in which the flexible film substrate for clad is stuck Filling a through hole at one end of the core with a curable resin for core formation, and vacuum suction from the through hole at the other end of the concave portion of the mold to fill the concave portion of the mold with the core forming curable resin (4) Step of curing the filled core-forming curable resin and peeling the mold from the clad flexible film substrate (5) Step of forming a clad layer on the clad flexible film substrate with the core formed (6) Polymer optical waveguide fiber by dicing Forming an end face of Lum

  Each of these steps (1) to (6) is effective by a manufacturing method substantially the same as the manufacturing technique of the polymer optical waveguide and the like described in Patent Documents 1 to 3 previously proposed by the present applicants. Can get to.

  Optical elements manufactured from polymer optical waveguides can be used for optical wiring in various levels. The material of the flexible film base material for the clad considers optical properties such as refractive index and light transmittance, mechanical strength, heat resistance, adhesion to the mold, and flexibility depending on the use of the optical element. Is selected. Examples of the film include an alicyclic acrylic resin film, an alicyclic olefin resin film, a cellulose triacetate film, an epoxy resin film, and a fluorine-containing resin film. In order to secure a difference in refractive index from the core, the refractive index of the film substrate is preferably smaller than 1.55, preferably smaller than 1.53. Further, the thickness of the film substrate is appropriately selected in consideration of flexibility, rigidity, ease of handling, and the like, and generally about 0.02 mm to 0.1 mm is preferable.

  As the core-forming curable resin, resins such as radiation curable, electron beam curable, and thermosetting can be used. Of these, ultraviolet curable resins and thermosetting resins are preferred. As the ultraviolet curable resin or thermosetting resin for forming the core, for example, an ultraviolet curable or thermosetting monomer, an oligomer, or a mixture of a monomer and an oligomer is preferably used. Moreover, as an ultraviolet curable resin, an epoxy type, a polyimide type, and acrylic type ultraviolet curable resin are used preferably, for example.

  The refractive index of the cured product of the core-forming curable resin needs to be larger than the film base material to be the clad, and the difference in refractive index between the clad and the core is 0.01 or more, preferably 0.03 or more. is there.

  As the curable resin for cladding, for example, an ultraviolet curable resin or a thermosetting resin is preferably used, and an ultraviolet curable or thermosetting monomer, an oligomer, or a mixture of a monomer and an oligomer is used. In addition, it is preferable from the viewpoint of light confinement that the refractive index of the clad be the same as that of the film substrate.

  According to the method for producing a polymer optical waveguide film, the production process is greatly simplified, and the polymer optical waveguide film can be easily produced. Therefore, it becomes possible to produce a polymer optical waveguide film at a very low cost as compared with the conventional method for producing a polymer optical waveguide film. Furthermore, although it is a simple method, the waveguide loss of the obtained polymer optical waveguide film is reduced, is highly accurate, and can be freely loaded into various devices.

  Hereinafter, examples will be described in detail as more specific embodiments of the present invention.

(Production of polymer optical waveguide film)
A thick film resist (SU-8, manufactured by Micro Chemical Co., Ltd.) is applied to a Si substrate by spin coating, then pre-baked at 80 ° C., exposed through a photomask, developed, and formed into a square cross section. Convex portions (width: 50 μm, height: 50 μm, length: 80 mm) were formed. The interval between the protrusions was 250 μm. Next, this was post-baked at 120 ° C. to prepare a master for preparing a polymer optical waveguide.

  Next, after applying a mold release agent to this master, a thermosetting liquid dimethylsiloxane rubber (manufactured by Dow Corning Asia Co., Ltd .: SYLGARD 184, viscosity of 5000 mPa.s) and a mixture of the curing agent are poured, and 120 ° C. After being cured by heating for 30 minutes, it was peeled off to produce a mold having a concave portion corresponding to a convex portion having a rectangular cross section (mold thickness: 5 mm).

  Further, a mold was produced by punching through-holes having a tapered cross-sectional shape in the thickness direction in a mold having a circular planar shape so as to communicate with the recess at one end and the other end of the recess.

This mold and a clad film substrate (Arton film, manufactured by JSR Corporation, refractive index 1.510) having a film thickness of 50 μm, which is slightly larger than the mold, were brought into close contact with each other. Next, the viscosity is 500 mPa.s in the entrance side through hole of the mold. When a few drops of the ultraviolet curable resin of s were dropped and sucked under reduced pressure from the discharge side (vacuum suction side) through-hole, the ultraviolet curable resin was filled in the recess in 10 minutes. Next, 50 mW / cm ² of UV light was irradiated from the upper part of the mold for 5 minutes to be cured by ultraviolet rays. When the mold was peeled off from the Arton film, a core having the same shape as the master disc protrusion was formed on the Arton film.

Next, an ultraviolet curable resin having a refractive index after curing of 1.510, which is the same as that of the ARTON film, is applied to the core forming surface of the ARTON film, and then a 50 μm clad film base material is laminated to obtain a 50 mW / cm ² By irradiating with UV light for 5 minutes and curing with ultraviolet light, the two films were bonded to form a belt-shaped polymer optical waveguide film having a width of 1.5 mm and a film thickness of 150 μm.

Next, both ends of the polymer waveguide film were cut perpendicularly to the optical axis using a dicing saw to obtain a polymer optical waveguide film provided with vertical cut surfaces at both ends.

(Production of submount)
A step having a height of 160 μm for attaching a polymer optical waveguide film was formed on a Si substrate having a thickness of 600 μm by the RIE method. Next, using a dicing saw equipped with a 45 ° angled Si blade, a step having a height of 260 μm was cut at an angle of 45 ° with respect to the optical axis to form a 45 ° mirror surface on the submount. Next, after depositing Au with a thickness of 200 nm on the upper surface of the submount, the Au electrode was patterned by photolithography to form an electrode pad for the upper electrode and an electrode pad for the lower electrode. And Si submount was formed by cut | disconnecting the Si substrate in which the electrode pad was formed with the dicer.

(Module implementation)
After aligning each end of the polymer optical waveguide film, it was placed on the film placement surface of a different Ni submount and fixed to the submount using an ultraviolet curable resin for the core.

  Next, the cathode and anode electrodes of the backside light emitting type VCSEL element are connected to the electrode pads on the Si submount, and the cathode and anode electrodes of the backside light receiving photodiode element are connected to the electrode pads on the Si submount. Each was connected. Thus, a bidirectional optical transmission / reception module including a pair of optical transmission / reception units and a polymer optical waveguide film was obtained.

(Evaluation of communication performance)
When the performance of optical transmission / reception was evaluated using a sampling oscilloscope (Agilent Technology: Agilent 86100C) and a pulse pattern generator, a good eye pattern up to 3.125 Gbps could be measured.

(Production of submount)
Example 2 is the same as Example 1 except that a quartz glass submount is formed using a quartz glass substrate having a thickness of 600 μm instead of the Si substrate having a thickness of 600 μm, and a module is configured using this. A bidirectional optical transceiver module was fabricated.

(Evaluation of communication performance)
The performance of optical transmission and reception was evaluated using a sampling oscilloscope (Agilent Technology: Agilent 86100C) and a pulse pattern generator, and a good eye pattern could be measured up to 3.125 Gbps.

  In the optical transmission / reception modules in Examples 1 and 2, the belt-shaped polymer optical waveguide film has high flexibility. Therefore, even if the film is deformed by bending or twisting, the polymer optical waveguide is used. Optical signals can be transmitted and received through an optical waveguide formed on the waveguide film. In addition, it is possible to mount a component by simply mounting a polymer optical waveguide film on the film mounting surface formed on the submount and attaching a light emitting / receiving element. It can be carried out.

  The optical transmission / reception module according to the present invention is not limited to the above-described embodiments, examples, and illustrated examples, and various design changes can be made without departing from the spirit of the invention.

1 is a perspective view schematically showing a configuration example of a bidirectional optical transceiver module according to a first embodiment of the present invention. FIG. It is the top view and sectional drawing which show typically one structural example of the optical transmission / reception part provided with the submount applied to this invention. It is a top view which shows typically the example of 1 mounting of the optical transmission / reception part provided with the submount applied to this invention. It is a conceptual diagram which shows the process of producing the submount applied to this invention. It is a conceptual diagram which shows the other process of producing the submount applied to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bidirectional optical transmission / reception module 11 Polymer optical waveguide film 12 Core part 13 Cladding part 14 Optical waveguides 20 and 21 1st, 2nd optical transmission / reception part 22 Back light emission type light emitting element 22a Micro lens 23 Back surface light reception type light receiving element 24, 25 First and second submounts 24a Film mounting surface 24b Electrode forming surface 24c Mirror surface 24d Metal film 30 Ceramic substrate 31, 33 Electrode pad 32 Amplifier 40 Master 40b Electrode forming surface forming convex portion 40a Film mounting surface formation Concave portion 40c Mirror surface forming concave portion 41 Mold 41a Film mounting surface forming convex portion 41b Electrode forming surface forming concave portion 41c Mirror surface forming convex portion 42 Curable resin substrate 43 Quartz glass substrate

Claims (11)

A polymer optical waveguide film in which an optical waveguide is formed;
A first submount having a first reflecting surface for converting an optical path of incident light; and a back-emitting type light emitting element, wherein one of the polymer optical waveguide films is provided on the first submount. Light having a configuration in which the light emitting element is disposed so that the light is emitted from the light emitting element and the light path is converted by the first reflecting surface and is coupled to the incident end face of the optical waveguide. A transmission unit;
A second submount having a second reflecting surface for converting an optical path of incident light; and a rear light receiving type light receiving element; and the other of the polymer optical waveguide films on the second submount. Light having a configuration in which the light receiving element is disposed so that the light is emitted from the light emitting end face of the optical waveguide and the light path is converted by the second reflecting surface and received by the light receiving element. An optical transceiver module comprising: a receiver. A polymer optical waveguide film in which a transmission optical waveguide and a reception optical waveguide are formed;
A pair of optical transceivers that transmit and receive optical signals bidirectionally through the transmission optical waveguide and the reception optical waveguide;
Each of the pair of optical transmission / reception units on both sides includes a rear light emitting type light emitting element and a rear light receiving type light receiving element, and a submount having a reflecting surface for converting an optical path of incident light, on the submount. The light emitting element is mounted so that an end portion of the polymer optical waveguide film is placed and light emitted from the light emitting element is converted in an optical path by the reflecting surface and coupled to an incident end face of the transmitting optical waveguide. And the light receiving element is arranged such that light emitted from the output end face of the receiving optical waveguide is received by the light receiving element after the optical path is changed by the reflecting surface. Optical transceiver module.   3. The optical transceiver module according to claim 1, wherein the polymer optical waveguide film has a thickness of 50 μm to 200 μm.   The optical transceiver module according to any one of claims 1 to 3, wherein a film surface of the polymer optical waveguide film is bonded to a main surface of the submount.   5. The optical transceiver module according to claim 1, wherein the core portion of the optical waveguide is replicated using a silicone resin mold. 6.   The optical transceiver module according to any one of claims 1 to 5, wherein the core portion of the optical waveguide is manufactured by cutting with a dicing saw.   The optical transmission / reception module according to claim 1 or 2, wherein the submount is made of metal, and a cutting surface formed on the submount by dicing is used as the reflection surface.   3. The optical transceiver module according to claim 1, wherein the submount is made of silicone, and metal is deposited on a cut surface formed on the submount by dicing to form the reflective surface.   3. The optical transceiver module according to claim 1, wherein the submount is made of quartz glass, and a metal is deposited on a cut surface formed on the submount by dicing to form the reflective surface. 4.   10. The metal according to claim 7, wherein the metal is at least one metal selected from the group consisting of gold, silver, nickel, copper, cobalt, aluminum, and titanium, or an alloy thereof. The optical transceiver module described in 1.   3. The optical transceiver module according to claim 1, wherein the light emitting element and the light receiving element are fixed on the submount with the same resin as a resin constituting a core portion of the optical waveguide.

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