JP2005134787A - Optical module and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a platform type optical module having a structure suitable for aligning laser and an SMF, and to provide the manufacturing method therefor. <P>SOLUTION: The optical module 100 is provided with: a first platform substrate 101; a laser diode (LD) 102 for signal transmission and a photodiode 103 for monitoring which are mounted on the first platform substrate 101; a second platform substrate 104 formed with a V groove; an optical fiber 105 fixed on the V groove; and a ferrule 106 for protecting the optical fiber 105. The optical fiber 105 is a composite optical fiber in which a graded index optical fiber is joined to the distal end of a single mode fiber, the optical fiber 105 serving as a lens for widely condensing light existing at the fiber distal end and for guiding the light to the single mode fiber 201. Consequently, even if the composite optical fiber and the LD 102 are deviated from each other in the optical axes, the light from the LD 102 can be fully captured. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical module and a manufacturing method thereof, and more particularly to a platform type optical module having a configuration suitable for alignment of a laser and an optical fiber and a manufacturing method thereof.

  Information technology allows large amounts of information to be transmitted in real time via copper wire, optical fiber, or wireless means. One current trend is to extend the use of optical communication networks to all home appliances used by each home, office, and every individual.

  In addition to the cost of building an optical fiber network infrastructure, optical transceivers (commonly called optical modules) are also a major cost factor. An optical module is disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-324655 (see Patent Document 1). This optical module is a so-called platform type, a semiconductor laser device having a wavelength of 1.3 μm band provided on a silicon substrate, a glass substrate having a groove, and an optical fiber as an optical waveguide embedded in the groove. An optical branching device such as a WDM filter that divides the optical waveguide, and a light receiving element that receives the input signal light guided by the optical branching device and outputs a photocurrent.

  Optical modules used for single-mode optical transmission are connected to single-mode fiber (SMF), but high positional accuracy is required between the laser diode and single-mode fiber to ensure sufficiently high signal power. Is done. As two main methods for achieving this strict requirement, there are an active alignment method and a passive alignment method. In order to optically connect the LD to the single mode fiber, it is considered that position accuracy on the order of 1 μm or less is required in the biaxial direction perpendicular to the optical axis.

  Here, “passive” usually means that the semiconductor laser for emitting laser light is not driven in the alignment step between the laser and the SMF. This is different from active alignment where the intensity of light in the fiber is monitored during the alignment process. In the active alignment, when the optimum value of the light intensity in the fiber is obtained, the relative position between the laser and the SMF is fixed by laser welding and / or adhesion. This active alignment is an established method commonly used in the manufacture of optical modules of the type such as TO-can, mini-DIL, butterfly. This is because the LD is driven to irradiate the core at one end of the fiber with laser light, and the signal level of the light intensity at the other end of the fiber is monitored by a light intensity meter. The relative position of the one end of the fiber with respect to the LD (xyz direction) is adjusted until the intensity of the light monitored at the other end of the fiber reaches a maximum value. The positional configuration of the LD and the fiber is fixed by means such as welding described above.

By the way, as the optical fiber, there is a special optical fiber in addition to the single mode fiber described above. For example, there is known an optical fiber functional component capable of forming a parallel beam conversion system when a functional optical element such as an optical isolator is interposed in an optical fiber waveguide for optical communication (see Patent Document 2). In this optical fiber functional component, a converging rod lens of a predetermined length by a graded index optical fiber (GI fiber) is concentrically connected to each of the facing surfaces of single mode optical fibers (SM fibers). Is. According to this optical fiber functional component, the configuration is simple and downsized, and the GI fiber can function as a collimator. In particular, the technique of the present invention is effectively applied to an optical isolator used in an optical fiber amplifier. Can be applied.
JP 2001-324655 A JP-A-6-138342

  As described above, active alignment is performed in the manufacture of optical modules of the TO-can, mini-DIL, and butterfly types, and even in the platform type optical module, active alignment is performed easily and in a short time. It is hoped that it will be done.

  However, strict positional accuracy is required in the alignment process between the laser and the SMF. Further, since the optical fiber itself is very thin and fragile, it is difficult to perform active alignment by handling the optical fiber itself. Therefore, it is desired that the active alignment for adjusting the laser and the SMF on the substrate be performed easily and in a short time.

  Accordingly, an object of the present invention is to provide a platform type optical module having a configuration suitable for alignment of a laser and an SMF.

  Another object of the present invention is to provide an optical module manufacturing method capable of performing active alignment in a short time.

  The object of the present invention includes at least a first platform substrate, a light emitting device mounted on the first platform substrate, and an optical fiber to which laser light from the light emitting device is input, the optical fiber comprising: This is achieved by an optical module characterized in that it is a synthetic optical fiber in which a gradient index optical fiber is bonded to the tip of a single mode optical fiber.

  According to the present invention, the gradient index optical fiber plays a role as a lens, and the light existing at the tip of the fiber is widely condensed and guided to the single mode optical fiber. Even if it is slightly shifted, light from the light-emitting element can be sufficiently captured. That is, since the accuracy necessary for optical axis alignment is relaxed, alignment in the height direction is performed only with the member accuracy, and there is no need to adjust the height. In addition, high-precision positioning is not required by the synthetic optical fiber in the direction parallel to the substrate. Therefore, there is a high probability that the optimum position is determined by slight adjustment of the position, and active alignment can be performed easily and in a short time.

  In a preferred embodiment of the present invention, the apparatus further comprises a second platform substrate, the optical fiber is fixed on the second platform substrate, and the first platform substrate can carry the second platform substrate, In addition, the second platform substrate is fixed in the position adjustment area. The position adjustment area has a width that can be adjusted in parallel with the mounting surface of the light emitting element.

  According to a preferred embodiment of the present invention, when the optimum value of the intensity of light in the optical fiber is obtained, the ultraviolet curable resin is cured by irradiation of ultraviolet rays, and the relative position between the laser and the optical fiber is fixed. Therefore, the horizontal movement of the optical fiber can be made smooth, and the active alignment of the optical fiber can be made smoothly.

  In a further preferred embodiment of the present invention, the second platform substrate is light transmissive, and the second platform substrate is fixed using an ultraviolet curable resin.

  According to a further preferred embodiment of the present invention, when the second platform substrate is fixed using the ultraviolet curable resin, the ultraviolet rays can be transmitted through the second platform substrate, and the resin is reliably cured. Can do.

  In a further preferred embodiment of the present invention, the ultraviolet curable resin contains a granular material.

  According to a further preferred embodiment of the present invention, the horizontal movement of the second platform substrate 101 can be made smooth, and the active alignment between the LD 102 and the optical fiber 105 can be made smoothly.

  In a further preferred aspect of the present invention, the optical fiber further comprises a ferrule that accommodates one end of the optical fiber, and the optical fiber is fixed on the second platform substrate while being accommodated in the ferrule.

  According to a further preferred embodiment of the present invention, it is easy to handle the optical fiber at the time of active alignment, and the positioning is accurate and easy, and the optical fiber can be attached to the ferrule without going through the second platform substrate. Since it is mounted directly, the second platform board is not necessary, and the number of parts can be reduced.

  In a further preferred embodiment of the present invention, a filter provided so as to divide the optical fiber and a light receiving element for receiving reflected light from the filter are further provided.

  According to a further preferred embodiment of the present invention, it is possible to provide a bidirectional type optical module having a configuration capable of performing active alignment easily and in a short time.

    In a further preferred aspect of the present invention, the light receiving element is provided on the first platform substrate.

    In a further preferred aspect of the present invention, the light receiving element is embedded in the position adjustment region of the first platform substrate.

    In a further preferred aspect of the present invention, the light receiving element is provided on the second platform substrate.

    In a further preferred embodiment of the present invention, a plurality of the light receiving elements are provided.

  The object of the present invention is also to mount a light emitting element on the first platform substrate, and to add a synthetic optical fiber in which a refractive index distribution optical fiber is bonded to the tip of a single mode optical fiber to the first platform substrate. A step of mounting the light-emitting element on the predetermined position, a step of emitting the light-emitting element, and a mounting surface of the light-emitting element while monitoring the amount of light led from the light-emitting element to the synthetic optical fiber And adjusting the relative position with respect to the light emitting element, and fixing the adjusted composite optical fiber on the first platform substrate. It is also achieved by the method.

  In a preferred embodiment of the present invention, the step of mounting the synthetic optical fiber on the first platform substrate fixes the synthetic optical fiber on the second platform substrate while being accommodated directly or in a ferrule. The synthetic optical fiber is mounted on the first platform substrate together with the second platform substrate, and the step of adjusting the relative position of the light emitting element and the synthetic optical fiber includes the synthetic optical fiber It is moved together with the second platform substrate.

  In a further preferred embodiment of the present invention, the step of mounting the synthetic optical fiber on the first platform substrate includes accommodating the synthetic optical fiber in a ferrule, and the synthetic optical fiber together with the ferrule in the first platform. It is mounted on a substrate.

  In a further preferred aspect of the present invention, the step of fixing the synthetic optical fiber on the first platform substrate includes an ultraviolet curable resin on at least one of the first platform substrate, the second platform substrate, or the ferrule. Is applied, and the ultraviolet curable resin is irradiated with ultraviolet rays to bond the second platform substrate or the ferrule onto the first platform substrate.

  In a further preferred embodiment of the present invention, the ultraviolet curable resin contains a granular material.

  As described above, according to the present invention, it is possible to provide a platform type optical module having a configuration suitable for alignment between a laser and an SMF.

  Further, according to the present invention, it is possible to provide an optical module manufacturing method capable of performing active alignment easily and in a short time.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing the structure of an optical module according to a preferred embodiment of the present invention.

  As shown in FIG. 1, the optical module 100 includes a first platform substrate 101, a laser diode (LD) 102 for signal transmission and a monitor photodiode (PD) mounted on the first platform substrate 101. ) 103, a second platform substrate 104 in which a V-groove is formed, an optical fiber 105 fixed to the V-groove on the second platform substrate 104, and a ferrule 106 that protects the optical fiber 105.

  The first platform substrate 101 is a block body made of silicon or the like. The first platform substrate 101 is provided with a step by forming a recess, the second platform substrate 104 is placed on the lower stage, the LD 102 is provided on the middle stage, and the monitoring PD 103 is placed on the upper stage. Is provided. The lower surface is a position adjustment region having a width on which the second platform substrate 104 can be mounted and can be moved in a direction parallel to the mounting surface of the light emitting element to adjust the mounting position. ing.

  The LD 102 is a light emitting element that generates light to be sent to the optical fiber 105. The LD 102 has two light emission surfaces facing each other, one of the light emission surfaces is directed to the V-groove side on the second platform substrate 104, and the other light emission surface is directed to the monitor PD 103 side. Is directed. Therefore, a part of the light emitted from the LD 102 is supplied to the optical fiber 105 positioned by the V groove, and the rest is supplied to the monitor PD 103. The LD 102 is used for data transmission and is driven by a transmission IC (not shown).

  The monitoring PD 103 is a light receiving element used for receiving light from the other light emitting surface of the LD 102 and monitoring its intensity. The output of the monitor PD is supplied to the transmission IC, and the intensity of light from the LD 102 is optimized.

  The second platform substrate 104 is a substrate prepared separately from the first platform substrate 101 in order to adjust the relative position of the optical fiber 105 with respect to the LD 102. The V-groove on the second platform substrate 104 is set to a width and depth that can hold the optical fiber 105. The second platform substrate 104 is light transmissive, and for example, a glass substrate is used. Since the second platform substrate 104 is transparent or semi-transparent, it is possible to transmit ultraviolet rays at the time of bonding and fixing using an ultraviolet curing resin later, and the resin can be reliably cured. As the second platform substrate 104, in addition to a glass substrate, a substrate made of a resin such as acrylic or polycarbonate can be used.

  As is widely known, the optical fiber 105 includes a core and a clad surrounding the core, and is a fiber-shaped optical waveguide configured so that light can be propagated using a difference in refractive index between the two. It is. Although details will be described later, the optical fiber 105 used in the present invention is a synthetic optical fiber, in which a refractive index distribution optical fiber (GIF) is bonded to the tip of a single mode fiber (SMF).

  The ferrule 106 is a cylindrical body that can hold the optical fiber 105. One end of the optical fiber 105 is terminated in the ferrule 106, and the two optical fibers can be optically coupled by connecting to the other ferrule.

  FIG. 2 is a schematic diagram schematically showing the configuration of the synthetic optical fiber 105.

As shown in FIG. 2, the synthetic optical fiber 105 used in the present invention is composed of two parts. The first part is a single mode fiber (SMF) 201 and the second part is one or more graded index (graded index) fiber (GIF) 202 bonded to one end of the SMF. . The second part GIF 202 is used as a tip part for receiving the laser light emitted from the LD 102. The reflectivity of the GIF 202 varies as the following equation changes with the radial distance from the core of the optical fiber.
n ² (r) = n (core) {1-2Δ (r / α) ^α }
Here, (r) is a reflectance at a distance r in the radial direction from the central axis of the optical fiber, n (core) is a reflectance of the core of the optical fiber, r is a distance in the radial direction from the center of the fiber, Δ is {n (core) −n (clad)} / n (core), and α is a constant. The most common GIF reflectance is a quadratic function of the radial distance from the central axis of the fiber.

  The graded-index optical fiber 202 serves as a lens, and collects light existing at the tip of the fiber widely and guides it to the single mode fiber 201. Therefore, when the optical axis of the synthetic optical fiber and the LD 102 is slightly shifted. Even if it exists, the light from LD102 can be taken in enough.

  FIGS. 3A to 3D are cross-sectional views showing specific examples of the structure of the synthetic optical fiber 105.

  A synthetic optical fiber 105 </ b> A shown in FIG. 3A has an SMF 201 and a GIF 202, and the tip surface of the GIF 202 is flat. The SMF 201 has a core 201a and a clad 201b. The GIF 202 has a core 202a and a clad 202b. The diameter of the core 202a of the GIF 202 is set larger than the diameter of the core 201a of the SMF 201.

  A synthetic optical fiber 105B shown in FIG. 3B has an SMF 201 and a GIF 202, and the tip of the GIF 202 is tapered. Therefore, the core 202a of the GIF 202 is also tapered. Other features are the same as those of the synthetic optical fiber 105A shown in FIG.

  A synthetic optical fiber 105C shown in FIG. 3C has an SMF 201 and a GIF 202, and the tip of the GIF 202 has a substantially spherical shape. Other features are the same as those of the synthetic optical fiber 105A shown in FIG. Various other shapes are conceivable as the shape of the tip of the GIF 202.

  A synthetic optical fiber 105 </ b> D illustrated in FIG. 3D includes an SMF 201, a first GIF 202, and a second GIF 203. The core diameter 202 of the first GIF 202 and the core diameter of the second GIF 203 are different from each other. The distal end portion of the first GIF 202 which is the most distal end has a spherical shape, and the core 202 a is thinner than the core 203 a of the second GIF 203.

  The synthetic optical fiber 105 as described above is completed by separately preparing SMF and GIF, fusing them together, and cutting the GIF to have a predetermined length.

  4 is a side cross-sectional view taken along line YY of the optical module 100 shown in FIG.

  As shown in FIG. 4, the second platform substrate 104 is placed on the lower surface 101 c of the first platform substrate 101, and the second platform substrate 104 is made of the first platform substrate by an ultraviolet curable resin 108. 101 is fixed. The height from the lower stage surface 101c to the middle stage surface 101b of the first platform substrate 101, the thickness of the second platform substrate 104, and the depth of the V groove are determined by the light emission position of the LD 102 and the height of the core of the optical fiber 105. Appropriate values are set so that the positions of the directions coincide with each other. Further, a reflective surface 101d is provided between the upper stage surface 101a and the middle stage surface 101b of the first platform substrate 101 so that the light emitted from the LD 102 is guided to the monitoring PD 103.

  In the optical module 100 configured as described above, since the accuracy required for optical axis alignment is relaxed by the synthetic optical fiber, the alignment in the height direction is performed only by the member accuracy, and the height needs to be adjusted. There is no. Furthermore, since the optical fiber is fixed on the second platform substrate, it is easy to handle the optical fiber during active alignment, and the positioning of the optical fiber becomes accurate and easy.

  Next, manufacture of the optical module 100 described above will be described.

  FIG. 5 is a schematic perspective view schematically showing the manufacturing process of the optical module.

  As shown in FIG. 5, in the manufacture of the optical module 100, first, a silicon block body to be the first platform substrate 101 is prepared, and the block body is processed by chemical etching or mechanical dicing. A recess and other steps having a width and depth capable of disposing the second platform substrate 104 are formed on the upper surface of the substrate. Thereafter, an insulating film such as an oxide film or a nitride film is formed on the substrate surface, and electrodes and wiring patterns such as bonding pads are formed on the insulating film. The monitoring PD 103 and LD 102 are mounted on the upper stage surface 101a and the middle stage surface 101b of the first platform substrate 101, respectively.

  The platform thus produced is accommodated in the subpackage.

  FIG. 6 is a schematic perspective view showing the configuration of the subpackage, and shows a state before the platform is mounted.

  As shown in FIG. 6, the subpackage 160 is obtained by attaching a frame member 162 made of resin to a lead frame 161.

  In manufacturing the subpackage, first, a lead frame 161 including a die pad 161a and leads 161b is prepared. Such a lead frame 161 can be manufactured by punching or etching a metal plate. Next, the die pad 161a and one end of the lead 161b are mechanically connected by a heat resistant resin such as PPS (Polyphenylene Sulfide), and each lead terminal and the outer frame of the lead frame are mechanically connected. . Such a process is called a pre-mold. The die pad 161a, the lead 161b, and each lead 161b are physically separated and electrically insulated, but are mechanically integrated by a pre-mold. The subpackage main body 162a is a resin surrounding the die pad 161a, and the outer resin further surrounding the subpackage 161a is a lead support member 162b. A part of the subpackage main body 162 is provided with a concave portion 162Y from which the ferrule can be pulled out.

  FIG. 7 is a schematic perspective view showing the configuration of the subpackage 160, and shows a state after the platform is mounted.

  Next, as shown in FIG. 7, the first platform substrate 101 on which the LD 102 and the monitor PD 103 are mounted is mounted on the die pad in the subpackage 160, and the electrode pattern on the first platform substrate 101 and a predetermined pattern Are electrically connected by bonding wires. Here, it is preferable to conduct a screening test by passing an electronic signal to the LD 102 via a lead connected to the bonding wire. The purpose of the screening test is to find an initial failure of the LD 102 by continuously supplying an operating current of, for example, several hundred mA to the LD 102 for several hours. By monitoring the intensity of the detection signal obtained from the monitoring PD 103, an initial failure of the LD 102 can be found. Subsequent manufacturing steps are performed only for work-in-progress products that pass the screening test, and initial defective products are eliminated, so that useless processes can be omitted.

  FIG. 8 is a schematic perspective view showing the configuration of the subpackage 160 and shows a state in which the optical fiber 105 is mounted together with the second platform substrate 104.

  First, the end of the optical fiber 105 where the GIF is not provided is inserted into the ferrule 106 and fixed. Next, the optical fiber 105 is accommodated along the V-groove on the second platform substrate 104 and fixed in the V-groove by welding or adhesion. In addition, when fixing with solder, it is necessary to form metal films, such as gold | metal | money (Au), on the fixed surface. Although not shown, an optical fiber of a light intensity meter for alignment is also connected to the other of the ferrule 106. Then, after UV curable resin is applied to the bottom surface of the second platform substrate 104, the first platform substrate 101 side, or both, the optical fiber 105 is first and the second platform substrate 104 together with the second platform substrate 104, as shown in FIG. Placed on the platform substrate 101. At this time, the second platform substrate 104 is handled by the suction type collet chuck of the mounting device, and is positioned with high precision and reliably placed at a predetermined position on the first platform substrate 101. As a result, the end face of the optical fiber is substantially opposite to the light emitting face of the LD. Next, active alignment of the LD and the optical fiber is performed.

  FIG. 9 is a schematic block diagram for explaining the active alignment system.

  In the active alignment, first, a signal is input to the LD 102 to drive the LD 102 to emit light. The core at one end of the optical fiber 105 is irradiated with laser light, and the light intensity is monitored by a light intensity meter connected to the other end of the optical fiber 105. Here, if the light intensity is equal to or higher than a predetermined level, it is determined that the relative position between the LD 102 and the optical fiber 105 is appropriate, and the ultraviolet curable resin is cured by the irradiation of the ultraviolet light from the UV lamp, thereby the LD and the optical fiber. Relative position is fixed.

  On the other hand, if the light intensity is lower than the predetermined level, the position of the optical fiber 105 together with the second platform substrate 104 is extended until the light intensity monitored at the other end of the optical fiber 105 reaches the maximum value. The relative position of the optical fiber 105 with respect to the LD 102 is adjusted by moving in the horizontal direction (x direction) orthogonal to the current direction. The member dimensions such as the thickness of the second platform substrate 104, the dimension of the V-groove, and the height of the light emitting portion of the LD102 are compared with the accuracy (about several tens of μm) required for optical coupling between the optical fiber 105 and the LD102. It is not necessary to adjust the vertical direction (z direction) of the second platform substrate 104, and the required accuracy in the optical axis direction (y direction) is loose. There is no. When the optimum value of the light intensity in the optical fiber 105 is obtained, the ultraviolet curable resin is cured by irradiating ultraviolet rays, and the relative position between the laser and the optical fiber is fixed. In the optical module according to the present embodiment, since a synthetic optical fiber having a tip portion constituted by GIF is used, there is a high probability that the optimum position is determined by a slight adjustment of the position, and active alignment is easily performed. And it can be performed in a short time.

  Next, a silicone gel is applied on all optical elements such as the PD 103 and the LD 102. This silicone gel mainly serves as a buffer material that ensures the propagation of an optical signal between the PD 103 and the optical fiber and protects each optical element such as the LD 102 from external mechanical stress. Therefore, external mechanical stress is absorbed by the silicone gel. Then, the opening of the subpackage is sealed with a transfer mold. The optical module 100 is completed through the above steps.

  FIG. 10 is a schematic diagram showing the configuration of an optical module according to another preferred embodiment of the present invention.

  As shown in FIG. 10, the optical module 300 is of a two-way communication type. In addition to the configuration of the optical module 100 shown in FIG. 1, a slit 111 that divides an optical fiber, and a slit inserted into the slit. The WDM filter 112 and the reception PD 113 arranged in the traveling direction of the light separated by the WDM filter 112 are further provided. For example, the transmission wavelength on the user side in optical communication is 1.31 μm and the reception wavelength is 1.55 μm. The WDM filter 112 transmits light having a transmission wavelength of 1.31 μm and reflects light having a reception wavelength of 1.55 μm. It is configured. The light reflected by the WDM filter 112 is received by the receiving PD 113. In particular, in this embodiment, the receiving PD 113 is disposed on the upper surface of the second platform substrate. Other configurations are the same as those of the optical module 100 shown in FIG. 1, and a synthetic optical fiber is used as the optical fiber 105.

  In the manufacture of the optical module 300, after the optical fiber 105 is fixed in the V groove on the second platform substrate 101, a slit for dividing the optical fiber 105 is formed, and the WDM filter 112 is fixed in the slit. The receiving PD 113 is also fixed at a predetermined position on the second platform substrate 101. The second platform substrate 101 is mounted on the first platform substrate, and the position of the second platform substrate 104 is moved under the system shown in FIG. 9, so that the active alignment of the LD 102 and the optical fiber 105 is performed. Done. Thus, the present invention can be applied not only to a transmission-only optical module but also to a bidirectional optical module.

  FIG. 11 is a schematic perspective view showing a state in which a silicone gel is applied to the optical module 300 shown in FIG.

  As shown in FIG. 11, silicone gel 114 is applied on optical elements such as PD 103, LD 102, and WDM filter 112 and optical fiber 105. This silicone gel 114 mainly serves as a buffer material that ensures the propagation of an optical signal between the PD 103 and the optical fiber 105 and protects each optical element such as the LD 102 from external mechanical stress. . Therefore, external mechanical stress is absorbed by the silicone gel.

  FIG. 12 is a schematic perspective view showing still another embodiment of the bidirectional optical module.

  As shown in FIG. 12, this bidirectional optical module 400 is different from the optical module 300 shown in FIG. 10 in that it includes two WDM filters and two reception PDs 113A and 113B having different characteristics. . Two slits 111A and 111B for dividing the optical fiber 105 are also formed, and two WDM filters 112A and 112B having different reception wavelengths are provided in each slit. When two wavelengths of 1.55 μm and 1.49 μm are used as reception wavelengths, a first WDM filter 112A configured to transmit light having a transmission wavelength of 1.31 μm and reflect light having a reception wavelength of 1.49 μm; A second WDM filter 112B configured to transmit light having a transmission wavelength of 1.31 μm and reflect light having a reception wavelength of 1.55 μm is used. Corresponding to these, the first receiving PD 113A and the second receiving PD 113B are provided on the second platform substrate. The other points are the same as those of the optical module shown in FIG.

  Even in the manufacture of the optical module 400, after the optical fiber 105 is fixed to the V-groove on the second platform substrate 104, two slits 111A and 111B for dividing the optical fiber 105 are formed, and a WDM filter is formed in each slit. 112A and 112B are fixed, and two receiving PDs 113A and 113B are also fixed at predetermined positions on the second platform substrate 104, respectively. The second platform substrate 104 is mounted on the first platform substrate 101, and the position of the second platform substrate 101 is moved under the system shown in FIG. Is done. Thus, the present invention can be applied to various optical modules.

  FIG. 13 is a schematic cross-sectional view showing the configuration of an optical module according to still another preferred embodiment of the present invention.

  As shown in FIG. 13, in the optical module 500, when the second platform substrate 104 is bonded onto the first platform substrate 101, the ultraviolet curable resin 109 mixed with the granular material 109z is used. . Other configurations are the same as those of the optical module shown in FIG. The granular material 109z functions as a spacer, and plays a role in smoothly moving the second platform substrate 101 in the horizontal direction when the optical fiber 105 is aligned. Therefore, this granular material 109z is preferably spherical, but may not be strictly spherical. As described above, when the UV curable resin 109 containing granular materials is used, the active alignment between the LD 102 and the optical fiber 105 can be smoothly performed.

  FIG. 14 is a schematic perspective view showing the configuration of an optical module according to another preferred embodiment of the present invention.

  As shown in FIG. 14, in the optical module 600, the ferrule 106 into which the synthetic optical fiber 105 is inserted is directly placed on the first platform substrate 101. An ultraviolet curable resin is used for fixing the ferrule 106 on the first platform substrate 101. Other configurations are the same as those of the optical module 100 shown in FIG. According to this embodiment, as in the case where the optical fiber is fixed on the second platform substrate, it is easy to handle the optical fiber at the time of active alignment, and the positioning is accurate and easy. Since the optical fiber is directly placed together with the ferrule without going through the second platform substrate, the second platform substrate becomes unnecessary and the number of components can be reduced.

  FIG. 15 is a schematic perspective view showing the configuration of an optical module according to still another embodiment of the present invention.

  As shown in FIG. 15, this optical module 700 is a bidirectional optical module including a receiving PD, and includes a slit 111 formed in a ferrule, a WDM filter 112 inserted in the slit, and a WDM filter. A reception PD 113 is further provided in the traveling direction of the light reflected by the light 112. Unlike the bidirectional optical module shown in FIG. 10, the reception PD 113 is provided on the first platform substrate on the side of the ferrule 106. As shown in the figure, the signal light transmitted through the optical fiber is reflected by the WDM filter 112, bent in the direction of 90 degrees to the right, and received by the receiving PD 113 in that direction. As described above, the present invention can also be applied to a bidirectional optical module that is configured without using the second platform substrate and that includes a receiving PD.

  FIG. 16 is a schematic perspective view showing the configuration of an optical module according to still another embodiment of the present invention.

  As shown in FIG. 16, this optical module 800 is a bidirectional optical module having a receiving PD. The receiving PD is accommodated in a recess 101g formed on the lower surface of the first platform substrate. Is different from the optical module 700 shown in FIG. Therefore, the direction of the slit 111 and the WDM filter 112 is set to the direction in which the reflected light is applied to the reception PD 113. Other configurations are substantially the same as those of the optical module 700 shown in FIG. In the case of such a configuration, it is not necessary to secure a mounting area for the receiving PD 113 on the upper surface of the first platform substrate 101, so that the area can be used as a mounting area for other components.

  FIG. 17 is a schematic perspective view showing the configuration of an optical module according to still another preferred embodiment of the present invention.

  As shown in FIG. 17, in this optical module 900, the ferrule 106 into which the synthetic optical fiber is inserted is fixed to the V groove on the second platform substrate 104, and the second platform substrate 104 is fixed to the first platform. It is placed directly on the substrate 101. Other configurations are the same as those of the optical module shown in FIG. According to this embodiment, since the ferrule 106 into which the synthetic optical fiber is inserted is placed on the first platform substrate 101 via the second platform substrate 104, it is easy to handle the optical fiber during assembly. Positioning is accurate and easy.

  The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the present invention. Needless to say.

  For example, in the above-described embodiment, the case where the second platform substrate is a light-transmitting substrate such as a glass substrate has been described, but the present invention is not limited to this and does not have light-transmitting property. A substrate may be used as the second platform substrate.

  In the above-described embodiment, the case where the first platform substrate has a step including an upper surface, a middle surface, and a lower surface has been described as an example. However, the number of steps may be any number. That is, in the present invention, the first platform substrate can be mounted on the second platform substrate below the mounting surface of the LD, and moved in a direction parallel to the mounting surface of the LD to mount the second platform substrate. The position adjustment area | region should just be provided with the width which can adjust a position.

  Furthermore, in the above-described embodiment, the case where the second platform substrate is mounted on the first platform substrate has been described as an example. However, the present invention is not limited to this, and a common structure such as a die pad is used. The first platform substrate and the second platform substrate may be independently mounted on the substrate.

FIG. 1 is a schematic perspective view showing the structure of an optical module according to a preferred embodiment of the present invention. FIG. 2 is a schematic diagram schematically showing the configuration of the synthetic optical fiber 105. FIGS. 3A to 3D are cross-sectional views showing specific examples of the structure of the synthetic optical fiber 105. 4 is a side cross-sectional view taken along line YY of the optical module 100 shown in FIG. FIG. 5 is a schematic perspective view schematically showing the manufacturing process of the optical module. FIG. 6 is a schematic perspective view showing the configuration of the subpackage, and shows a state before the platform is mounted. FIG. 7 is a schematic perspective view showing the configuration of the subpackage, and shows a state after the platform is mounted. FIG. 8 is a schematic perspective view showing the configuration of the subpackage, and shows a state in which an optical fiber is mounted together with the second platform substrate. FIG. 9 is a schematic block diagram for explaining the active alignment system. FIG. 10 is a schematic diagram showing the configuration of an optical module according to another preferred embodiment of the present invention. FIG. 11 is a schematic perspective view showing a state in which a silicone gel is applied to the optical module 300 shown in FIG. FIG. 12 is a schematic perspective view showing still another embodiment of the bidirectional optical module. FIG. 13 is a schematic cross-sectional view showing the configuration of an optical module according to still another preferred embodiment of the present invention. FIG. 14 is a schematic perspective view showing the configuration of an optical module according to another preferred embodiment of the present invention. FIG. 15 is a schematic perspective view showing the configuration of an optical module according to still another embodiment of the present invention. FIG. 16 is a schematic perspective view showing the configuration of an optical module according to still another embodiment of the present invention. FIG. 17 is a schematic perspective view showing the configuration of an optical module according to still another preferred embodiment of the present invention.

Explanation of symbols

100 Optical module 101 First platform substrate 101a Upper stage surface 101b Middle stage surface 101c Lower stage surface 101c Upper stage surface 101d Reflective surface 101g Recess 102 Laser diode (LD)
103 optical fiber 104 second platform substrate 105 (synthetic) optical fiber 105A synthetic optical fiber 105B synthetic optical fiber 105C synthetic optical fiber 105D synthetic optical fiber 106 ferrule 108 ultraviolet curable resin 109 ultraviolet curable resin 109z granular material 111 slit 111A slit 111B slit 112 WDM filter 112A WDM filter 112B WDM filter 114 Silicone gel 160 Subpackage 161 Lead frame 161a Die pad 161b Lead 162a Subpackage body 162b Lead support member 162Y Subpackage body recess 201 Single mode fiber 202 Refractive index distribution optical fiber 300 Optical module 400 Optical module 400 Optical module 500 Optical module 600 Optical module 700 Optical module 800 Optical module 900 Optical module

Claims (17)

A first platform substrate;
A light emitting device mounted on the first platform substrate;
Comprising at least an optical fiber to which laser light from the light emitting element is input;
The optical fiber is a synthetic optical fiber in which a refractive index distribution optical fiber is bonded to a tip portion of a single mode optical fiber. A second platform substrate;
The optical fiber is fixed on the second platform substrate;
The first platform substrate is
A position adjustment region having a width on which the second platform substrate can be mounted and the mounting position can be adjusted by moving the second platform substrate in a direction parallel to the mounting surface of the light emitting element;
The optical module according to claim 1, wherein the second platform substrate is fixed in the position adjustment region. The second platform substrate is light transmissive;
The optical module according to claim 2, wherein the second platform substrate is fixed using an ultraviolet curable resin.   The optical module according to claim 3, wherein the ultraviolet curable resin includes a granular material. A ferrule that houses one end of the optical fiber;
5. The optical module according to claim 2, wherein the optical fiber is fixed on the second platform substrate while being accommodated in the ferrule. 6. A filter provided to sever the optical fiber;
The optical module according to claim 2, further comprising a light receiving element that receives reflected light from the filter.   The optical module according to claim 6, wherein the light receiving element is provided on the first platform substrate.   The optical module according to claim 6, wherein the light receiving element is embedded in the position adjustment region of the first platform substrate.   The optical module according to claim 6, wherein the light receiving element is provided on the second platform substrate.   The optical module according to claim 6, comprising a plurality of the light receiving elements. A ferrule that houses one end of the optical fiber;
The optical module according to claim 1, wherein the optical fiber is fixed on the first platform substrate while being accommodated in the ferrule. A filter provided to sever the optical fiber;
The optical module according to claim 11, further comprising a light receiving element that receives reflected light from the filter. Mounting a light emitting element on a first platform substrate;
Mounting a synthetic optical fiber in which a graded index optical fiber is bonded to the tip of a single mode optical fiber at a predetermined position on the first platform substrate;
Causing the light emitting element to emit light;
Adjusting the relative position of the light emitting element by moving the synthetic optical fiber in a direction parallel to the mounting surface of the light emitting element while monitoring the amount of light derived from the light emitting element to the synthetic optical fiber;
A method of manufacturing an optical module, comprising: fixing the adjusted synthetic optical fiber on the first platform substrate. Mounting the synthetic optical fiber on the first platform substrate,
Fixing the synthetic optical fiber on the second platform substrate directly or in a state accommodated in a ferrule;
The synthetic optical fiber is mounted on the first platform substrate together with the second platform substrate,
The step of adjusting the relative position of the light emitting element and the synthetic optical fiber is as follows:
The method of manufacturing an optical module according to claim 13, wherein the synthetic optical fiber is moved together with the second platform substrate. Mounting the synthetic optical fiber on the first platform substrate,
Accommodating the synthetic optical fiber in a ferrule;
The method of manufacturing an optical module according to claim 13, wherein the synthetic optical fiber is mounted on the first platform substrate together with the ferrule. Fixing the synthetic optical fiber on the first platform substrate comprises:
An ultraviolet curable resin is applied to at least one of the first platform substrate, the second platform substrate, or the ferrule, and the ultraviolet curable resin is irradiated with ultraviolet rays, so that the second platform substrate or the ferrule is moved to the first platform substrate. The method of manufacturing an optical module according to claim 14 or 15, wherein the optical module is bonded onto a single platform substrate.   The method of manufacturing an optical module according to claim 13, wherein the ultraviolet curable resin includes a granular material.

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