JP4113578B2 - Manufacturing method of optical module - Google Patents

Description

The present invention relates to a method of manufacturing an optical module.

  In recent years, optical modules used for optical communication and the like have been developed. This optical module is configured by combining a plurality of optical components such as a light emitting element, a light receiving element, and an optical fiber for transmitting light. Optical modules have many problems from the viewpoint of cost reduction and high performance regarding the coupling between a light emitting element and an optical transmission body such as an optical fiber. In particular, a single mode fiber used for optical transmission has a core diameter as small as several μm, and the requirements for mounting errors are very severe. Conventionally, a ball lens is used to reduce the mounting tolerance between the fiber and the light emitting element, and active type mounting in which the light emitting element is operated and mounted at the same time has been performed. However, the use of a ball lens increases the number of parts, and the active mounting has a very complicated manufacturing process, which increases the product cost of the optical module.

  Therefore, passive alignment that performs alignment without operating the light emitting element and the light receiving element is indispensable for cost reduction. In general, a method of manufacturing and assembling a fixing member is used as the method. However, the mechanical accuracy of the fixing member is required, the elastic coefficient and the thermal expansion coefficient are limited, and the number of parts is increased, so that cost reduction is difficult. In particular, when a plastic mold or the like is used for cost reduction, there is a problem that the yield of optical coupling and long-term reliability are lacking. Also, with this method, multimode fiber can be mounted, but single-mode fiber cannot be mounted with high accuracy.

  Also in light emitting devices, vertical cavity surface emitting lasers that emit light perpendicularly from the substrate surface can be improved in terms of reducing power consumption and cost of optical transmission modules. Yes. A surface emitting laser can be driven at a low threshold value of 1 mA or less, can perform wafer level inspection, and does not require cleavage accuracy, so that the cost can be reduced. However, the same problem as described above also occurs in the optical coupling between such a surface emitting laser and an optical fiber.

  Therefore, a method for producing a guide hole for coupling with an optical fiber with an accuracy of photolithography has been proposed. Patent Documents 1 and 2 propose a method using a thick film photoresist as a guide for an optical fiber. However, in this method, the mounting accuracy is determined by the outer shape of the optical fiber. The outer shape of the optical fiber and the optical axis do not necessarily coincide with each other, which causes a mounting error of several μm. Further, by matching the outer shape, the process is poor in yield due to the influence of scratches and burrs on the outer shape of the optical fiber. It is desirable that there are fitting protrusions that are aligned with the optical axis in the light emitting region or the like.

  On the other hand, a method of mounting an optical fiber by directly fixing a fiber fixing member on the surface side on which the surface optical element is formed has been proposed. For example, in Patent Document 3, as shown in FIG. 1, protrusions (large protrusions 22 and small protrusions 23B) for fitting a fiber fixing member (fiber block 14) to the surface of the surface emitting laser element 18 are provided. A structure in which a guide hole 26 is formed at a position corresponding to the light emitting portion of the light emitting laser 18 is shown. In FIG. 1, 12 is a module substrate, 16 is an optical fiber, 24 is a fiber insertion hole, and 26 and 27 are guide holes. In this conventional example, the alignment between the optical axis and the projection is very good by providing the projection for fitting in the light emitting region of the surface emitting laser. However, since the protrusion and the optical fiber are not directly joined to each other and are fitted to the fixing member for the optical fiber, a mounting error between the fixing member and the optical fiber is included here. That is, even if the fixing member for the optical fiber and the surface emitting laser are mounted with high accuracy, the mounting accuracy between the surface emitting laser and the optical fiber is not high.

Further, in Patent Document 4, in the mounting of an optical fiber and a microlens, as shown in FIGS. 2A, 2B, and 2C, a protrusion for fitting in a region through which a light beam passes is provided. A method has been proposed. In this method, the photolitho of the projection is performed using the light condensing function of the microlens, and the depression is formed using the concentration distribution of the optical fiber. In each method, a structure used for fitting for self-alignment can be formed, and mounting with very high accuracy is possible. As described above, it is effective for mounting optical elements such as a microlens and an optical fiber, but this method cannot be mounted with a light emitting element or a light receiving element.
JP 2002-214486 A JP 2002-33546 A JP-A-11-307869 Patent No. 2615400

The present invention mounts a light emitting element or a light receiving element and an optical element that transmits light from the light emitting element or light to the light receiving element at low cost and with high accuracy so that the distance between them is about several μm or less. be capable of, thereby, is aimed at the optical coupling to provide a method for manufacturing a high-performance optical modules.

In order to achieve the above object, the invention described in claim 1 is a method of manufacturing an optical module comprising a light emitting element or a light receiving element and an optical element that transmits light from the light emitting element or light to the light receiving element.
Providing the first structure by photolithography in the light emitting region or the light receiving region on the surface of the light emitting device or the light receiving device;
Providing a second structure in alignment with the first structure on the optical element side by photolithography ;
It fitted a first structure and a second structure, by heating the fitting portion between the first structure and the second structure, the first structure and the second structure By softening and deforming at least one of the first structure and the second structure so that the thickness of the gap existing between the first structure and the second structure is less than or equal to the wavelength of light used by the optical module,
A gray scale mask is used as a photomask for the photolithography process .

According to a second aspect of the present invention , in the method of manufacturing an optical module according to the first aspect, a material having a higher hardness of the first structure and the second structure is a convex surface, and a smaller one is a concave surface. It is characterized by being.

Further, an invention according to claim 3, wherein, in the method of manufacturing an optical module according to claim 1 Symbol placement, the higher melting point of the material of the first structure and the second structure is convex, the lower one it is characterized in that it is concave.

Further, an invention according to claim 4, wherein, in the method of manufacturing an optical module according to claim 1, wherein a larger the convex refractive index of the material of the first structure and the second structure, the smaller is It is characterized by a concave surface.

According to a fifth aspect of the present invention, in the method of manufacturing an optical module according to any one of the first to fourth aspects, the optical element is an optical fiber, and the second structure is an optical fiber core. It is characterized in that provided in the region.

According to invention of Claim 1 thru | or 5 , It is a manufacturing method of the optical module which consists of a light emitting element or a light receiving element, and the optical element which transmits the light from a light emitting element, or the light to a light receiving element,
Providing the first structure by photolithography in the light emitting region or the light receiving region on the surface of the light emitting device or the light receiving device;
Providing a second structure in alignment with the first structure on the optical element side by photolithography ;
The first structure and the second structure are fitted to each other, the fitting portion between the first structure and the second structure is heated, and the first structure and the second structure are By softening and deforming at least one of the first structure and the second structure so that the thickness of the gap existing between the first structure and the second structure is less than or equal to the wavelength of light used by the optical module,
As a photomask for the photolithography process, a grayscale mask is used ,
The fitting portion between the first structure and the second structure is heated, and the thickness of the gap existing between the first structure and the second structure is increased. By setting the wavelength to be shorter than the wavelength, in the first and second structures, the reflection of light can be greatly reduced, and the light coupling efficiency can be improved.

In particular, according to claim 2, according to the third aspect of the present invention, first, by defining the relative hardness and the melting point of the second structure, it is only stress relaxation concave. Since the stress relaxation on the concave surface covers a wider range than the stress relaxation on the convex surface, the disturbance of the refractive index distribution in the region through which transmitted light passes is relatively small. Thereby, the aberration deterioration of light can be reduced and an optical module with high coupling efficiency can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  When matching with the outer shape of the fiber as in Patent Document 1, there is an error between the optical axis and the outer shape of the fiber, and the mounting accuracy is lowered. On the other hand, as shown in Patent Document 4, if the structure used for fitting is on the optical axis, high-precision mounting is possible. However, in Patent Document 4, when an optical fiber and a microlens are joined, for example, when a light emitting element, a microlens, and an optical fiber are mounted, an error may occur in the mounting of the light emitting element and the optical fiber. An optical module includes a light emitting element or a light receiving element and an optical element (for example, an optical fiber) as constituent elements, and it is necessary to improve mounting accuracy between the optical element (for example, an optical fiber) and the light emitting element or the light receiving element.

  Therefore, the present invention is an optical module comprising a light emitting element or a light receiving element and an optical element that transmits light from the light emitting element or light to the light receiving element, and the light emitting area or light receiving area on the surface of the light emitting element or light receiving element. The first structure is provided on the optical element side, and the second structure having a shape matching the first structure is provided on the optical element side, and the first structure and the second structure emit light. It is characterized in that it can be fitted so that the distance between the element or the light receiving element and the optical element is about several μm or less.

  If the structure used for fitting as shown in Patent Document 4 is in the light emitting element or the light receiving element, highly accurate mounting is possible. However, for example, the light emitted from the light emitting element has a divergence angle, and the light spreads by moving away from the light emitting surface. Therefore, in the present invention, the first structure provided in the light emitting region or the light receiving region on the surface of the light emitting element or the light receiving element and the second structure provided on the optical element side include the light emitting element or the light receiving element. It is characterized in that it can be fitted so that the distance from the optical element is about several μm or less. Thereby, the light emitting element or the light receiving element and the optical element can be installed in the vicinity of about several μm or less. For example, although the light emitted from the light emitting element has a divergence angle, the optical element (for example, an optical fiber) By being in the vicinity of the light emitting element or the light receiving element, the spread of light can be suppressed to a low level.

  For example, when the light emitting element is a surface emitting laser, the surface is a mirror surface, and it is difficult to make a structure on the surface. Therefore, in this case, a film made of a material different from the mirror surface is formed on the upper surface of the mirror surface of the surface emitting laser, and a structure is formed in the film. Accordingly, the light emitting element and the optical element can be fitted and mounted using the structure formed in the light emitting element and the optical element.

  As described above, according to the present invention, it is possible to directly and optically couple the light emitting element or the light receiving element and the optical element without using the micro lens in a form using the high accuracy of the fitting structure. become.

  That is, according to the present invention, an optical module including a light emitting element or a light receiving element and an optical element that transmits light from the light emitting element or light to the light receiving element, the light emitting region on the surface of the light emitting element or the light receiving element or A first structure is provided in the light receiving region, and a second structure having a shape matching the first structure is also provided on the optical element side. The first structure and the second structure are Since the fitting is possible so that the distance between the light emitting element or the light receiving element and the optical element is about several μm or less, the low cost manufacturing process of the light emitting element or the light receiving element and the optical element (for example, optical fiber) Mounting accuracy can be increased, and a high-precision and low-cost optical module can be provided.

  In the optical module of the present invention, the optical element is, for example, an optical fiber. In this case, the second structure can be provided in the core region of the optical fiber. That is, the optical fiber can be selectively etched because the impurity concentration differs only in the core region. Thereby, a structure can be made in the core region in a self-aligned manner in an easy manner.

  That is, for example, the core diameter in the single mode fiber and the light emitting region of the surface emitting laser are approximately the same. Therefore, if the light emitted from the surface emitting laser leaks without entering the core of the optical fiber, the optical coupling efficiency is lowered. Therefore, it is desirable that light from the surface emitting laser enter the optical fiber core as much as possible. As described above, by providing the second structure in the core region of the optical fiber, the light from the surface emitting laser can be surely entered into the core of the optical fiber, and the optical coupling efficiency can be improved.

  In the optical module of the present invention, the fitting portion between the first structure and the second structure can have a function of refracting light. In this case, the light emitted from the light emitting element is refracted and collected, so that the divergence angle of the light beam can be suppressed, thereby improving the optical coupling efficiency between the light emitting element or the light receiving element and the optical element. Can be improved.

  That is, for example, the core diameter in the single mode fiber and the light emitting region of the surface emitting laser are approximately the same. Therefore, if the light emitted from the surface emitting laser leaks without entering the core of the optical fiber, the optical coupling efficiency is lowered. Therefore, it is desirable that light from the surface emitting laser enter the optical fiber core as much as possible. As described above, by providing the fitting portion between the first structure and the second structure with a function of refracting light, light from the surface emitting laser can be reliably put into the core of the optical fiber. The optical coupling efficiency can be improved.

  When the fitting portion between the first structure and the second structure has a function of refracting light, the material having the higher refractive index of the first structure and the second structure is made convex. The smaller one can be concave. In this way, when the refractive index of the material constituting the convex surface is higher, the fitting portion can have a function of condensing light like a convex lens, and the function of condensing light like a convex lens. By providing the fitting portion having the distance between the optical element and the light emitting element, the mounting accuracy can be relaxed and the optical coupling efficiency can be improved.

  In the optical module of the present invention described above, the thickness of the gap existing between the first structure and the second structure is preferably equal to or less than the wavelength of the light used. In other words, an air layer is formed in the gap existing between the first structure and the second structure, and the air layer has a low refractive index and causes reflection. However, when the thickness of the air layer is equal to or less than the wavelength of the light used, the light does not feel this refractive index and is not reflected. Thus, since the thickness of the gap existing between the first structure and the second structure is equal to or less than the wavelength of the light used, the first and second structures Can be significantly reduced, and the light coupling efficiency can be improved.

  Further, in the above-described optical module of the present invention, the material having the higher hardness of the first structure and the second structure can be a convex surface and the smaller one can be a concave surface.

  That is, when fitting and mounting the light emitting element or the light receiving element and the optical element, the light emitting element or the light receiving element and the optical element are pressed against each other, whereby the first and second structures are deformed. . By utilizing this deformation, it is possible to realize a gap thickness equal to or less than the wavelength of the light used as the gap thickness between the first structure and the second structure. At this time, if the material is deformed, the refractive index of the material is distorted. Therefore, it is desirable to relax the stress as much as possible. Whether the deformation is predominantly caused by the first or second structure depends on the hardness relationship of the first and second structures. When the convex surface is softer, stress relaxation on the convex surface is concentrated only on the convex surface portion, the residual stress becomes very large, and the aberration deterioration of transmitted light is severe. In the present invention, since the material of the convex surface is hardened, the concave surface side is deformed. The concave surface has a wide stress relaxation region, and the residual stress in the light transmission region is small.

  In the optical module of the present invention described above, the higher melting point in the material of the first structure and the second structure can be a convex surface, and the smaller one can be a concave surface. When fitting and mounting, by heating the fitting portion, the first and second structures can be softened and deformed, whereby the first structure and the second structure The thickness of the gap existing between the two can be made equal to or less than the wavelength of the light being used. At this time, only one of the first and second structures can be softened by adjusting the temperature. When the softening point of the material on the concave side is low, only the concave surface can be softened and deformed. At this time, if the material is deformed, the refractive index of the material is distorted. Therefore, it is desirable to relax the stress as much as possible. When the convex surface is deformed, stress relaxation on the convex surface is concentrated only on the convex surface portion, the residual stress becomes very large, and the aberration deterioration of transmitted light is severe. In the present invention, the concave surface has a lower melting point, so that the concave surface is deformed. The concave surface has a wide stress relaxation region, and the residual stress in the light transmission region is small.

  Further, it is preferable to have a photolithography process in the step of manufacturing the first structure or the second structure in the optical module of the present invention described above, and to use a gray scale mask as a photomask in the photolithography process. .

  In the gray scale mask method, a mask used for photolithography is expressed in gradation by fine dots with transmittance of 1 and 0 or expressed in halftone. By gradation expression, bright part and dark part are created, and by exposing this to photoresist, the dark part is high, the bright part is low (in the case of positive resist), and the height is expressed including the intermediate height. A resist shape can be obtained. By devising the mask shape in this way, the resist can be processed into a three-dimensional and arbitrary shape (details of a gray scale mask manufacturing method are disclosed in JP-A-11-177123, JP-A-2000-280366, etc.). Have been). By using a grayscale mask, the concave and convex shapes can be arbitrarily shaped. Thereby, the first and second structures are respectively shaped into appropriate shapes, and the thickness of the gap existing between the first structure and the second structure is less than the wavelength of the light used. Can be satisfied. That is, there is no gap between the concave surface and the convex surface (a gap can be prevented between the first structure and the second structure), and an optical module with high coupling efficiency can be provided.

  In the optical module of the present invention described above, a plurality of light emitting elements or light receiving elements and optical elements can be arranged to form an array. By using such an array, a plurality of elements can be mounted simultaneously, and the manufacturing cost (mounting cost) can be reduced.

  FIG. 3 is a diagram illustrating the optical module according to the first embodiment of the present invention. As shown in FIG. 3, the optical module of the first embodiment includes a surface emitting laser and an optical fiber, and first and second structures are provided on the respective surfaces. Here, the first structure is provided in the light emitting region of the surface emitting laser, the second structure is provided in the core region at the tip of the optical fiber, and the first and second structures are fitted. Can be combined.

First, the second structure can be manufactured in the manner shown in, for example, the literature “MOC 1995 Proceedings p62” and the literature “1998 IEEE / LEOS Summer Topical Meeting Proceedings p57”. In Example 1, one end of the optical fiber was produced by a chemical etching method using an HF—NH ₄ F buffer solution. A quartz-based single-core single-mode fiber having a GeO ₂ doping concentration of about 3 to 15 mol% was used as the optical fiber. Impurities are contained in the core portion of the optical fiber, and the etching rate for the hydrogen fluoride solution is different. For this reason, by giving an appropriate condition, the core portion is selectively left in a conical or convex shape. Since the second structure is created using the concentration distribution of the core, it is self-assembled that can be automatically created in the core portion, and its positional accuracy is very good. By controlling the concentration and etching time of hydrogen fluoride, the shape can be controlled arbitrarily.

Specifically, the clad diameter of the optical fiber is 125 μm, and the core diameter is 10 μm. Further, hydrofluoric acid (HF) having a concentration of 47 wt% was used. Further, ammonium fluoride (NH ₄ F) having a concentration of 50 wt% to 100 wt% was used. Further, the buffer solution was subjected to etching for 1 hour at a volume ratio of HF: NH ₄ F: H ₂ O = X: 1: 1, with X being 0.02 to 0.8. The solution temperature was kept constant at 20 ° C. at room temperature of 20 ° C., and the etching time was changed every hour from 1 hour to 6 hours. Etching was performed by dropping 10 μl of liquid paraffin by fixing the optical fiber end protruding from 1.5 ml of the buffer solution at 1 mm below the liquid surface. Thereby, a convex shape having a diameter of about 10 μm and a height of about 3 μm was produced as the second structure. The relative positional deviation from the core of the second structure was not more than sub μm. The physical properties of the second structure were a refractive index of 1.5, a Young's modulus of 7.3 Pa, and a melting point of 1600 ° C.

FIG. 4 is a diagram showing a surface emitting laser used in the optical module of Example 1. The surface emitting laser of FIG. 4 is configured as a GaInNAs surface emitting laser. Referring to FIG. 4, the surface-emitting type semiconductor laser device in Example 1 is ¼ times the oscillation wavelength in each medium on an n-GaAs substrate having a surface orientation (100) of 3 inches. thickness using a _{n-Al x Ga 1-x} as (x = 0.9) and the n-GaAs consisting 35 cycles stacked periodic structure alternately n- semiconductor distributed Bragg reflector (lower semiconductor distributed Bragg reflector: An undoped lower GaAs spacer layer, a four-layer GaInNAs well layer and a five-layer GaNPAs barrier layer, and an undoped upper GaAs spacer layer are formed thereon. ing. A p-semiconductor distributed Bragg reflector (upper semiconductor distributed Bragg reflector: also simply referred to as an upper reflector) is formed thereon. The upper reflector is formed by alternately stacking C-doped p-Al _x Ga _1-x As (x = 0.9) and p-GaAs at a thickness that is ¼ times the oscillation wavelength in each medium. It is composed of a periodic structure (for example, 25 periods). A selective oxidation layer made of AlAs is provided with a thickness of, for example, 30 nm at a position near the active layer in the upper reflecting mirror. The uppermost GaAs layer of the upper reflecting mirror also serves as a contact layer that contacts the electrode.

The surface emitting laser shown in FIG. 4 is manufactured by MOCVD, and TMG (trimethylgallium), TMI (trimethylindium), AsH ₃ (arsine), and DMHy are used as raw materials for the GaInNAs active layer by MOCVD. (Dimethylhydrazine) was used. Further, the carrier gas was used H _2. DMHy decomposes at a low temperature and is suitable for low temperature growth of 600 ° C. or less, and is a preferable raw material when growing a quantum well layer having a large strain required for low temperature growth. When the strain is large as in the active layer of the GaInNAs surface-emitting type semiconductor laser element of Example 1, low temperature growth that is non-equilibrium is preferable. In Example 1, the GaInNAs layer was grown at 540 ° C.

Then, a mesa having a predetermined size was formed by exposing at least the side surface of the p-AlAs selective oxidation layer, and the AlAs that appeared on the side surface was oxidized from the side surface with water vapor to form an Al _x O _y current narrowing portion. Next, the etched portion is filled with polyimide and flattened, the polyimide on the upper reflecting mirror having the p contact portion and the light emitting portion is removed, and a p-side electrode is formed in addition to the light emitting portion on the p contact layer. In addition, an n-side electrode was formed on the back surface of the substrate. The diameter of the light emitting portion is about 8 μm, and the current narrowing portion is about 5 μm in diameter. Further, the diameter of the outgoing light at the exit surface is about 8 μm, and the divergence angle is about 10 °.

  And in this Example 1, resin transparent with respect to an emitted wavelength is apply | coated to the polyimide upper part. The transparent resin is subjected to photolithography etching and becomes the first structure. Resin having a refractive index of about 1.3 is used, Young's modulus is 0.2 Pa, and melting point is 200 ° C. On the other hand, as described above, the second structure is quartz, and as physical properties, the refractive index is 1.5, the Young's modulus is 7.3 Pa, and the melting point is 1600 ° C. The first structure is a concave surface, and the second structure is a convex surface, and these numerical values satisfy claims 4, 6, and 7.

More specifically, the first structure is manufactured as follows. In other words, the process was designed so that the resin had a film thickness of about 5 μm using spin coating. About 5 μm of resist is applied on the resin. The resist is exposed using a gray scale mask. An arbitrary shape can be formed by using a gray scale mask. At this time, when the previous p-side electrode is formed, an alignment mark is formed, and the mask position is determined while observing the alignment mark with an infrared microscope. As a result, the patterning can maintain the positional accuracy on the order of sub-μm. The patterned resist is transferred to a transparent resin by dry etching. The dry etching conditions can control the shape to be transferred by controlling the gas flow rate ratio, etching time, and bias voltage. This time, C ₄ F ₈ and Ar were added at a ratio of 1: 1 as gas. The etching depth is about 5 μm, and there is almost no resist residue. As a result, a concave surface shape was formed as the first structure, and the shape was substantially the same as that of the previous optical fiber.

  FIG. 5 shows a form in which an optical fiber is mounted on the surface emitting laser shown in FIG. As shown in FIG. 5, the first structure (concave surface shape) and the second structure (convex surface shape) are fitted to each other, thereby realizing high-precision mounting. Hereinafter, a mounting method of the optical fiber and the surface emitting laser will be described in more detail.

  As shown in FIG. 6, the optical fiber is fixed to a fixing jig, and is arranged so that the end surface on which the second structure (convex shape) is formed faces upward. The parallelism between the fixture and the optical fiber matches with high accuracy. Particles serving as spacers are arranged on the surface of the fixing jig. For this spacer, a resin having a diameter of several μm as used in a liquid crystal panel was used. At this time, the position of the core of the optical fiber is measured with a microscope and stored in a personal computer. Next, the back surface of the surface emitting laser is held by a vacuum suction collet. The collet and the emission position of the surface emitting laser are recorded on a personal computer. Accordingly, the surface emitting laser can be moved onto the optical fiber with a mounting accuracy that can be observed with an optical microscope. In this state, accuracy on the order of μm can be realized. In the surface emitting laser, the back surface is held by a collet, and the first structure (concave shape) on the front surface is in contact with the second structure (convex shape) on the optical fiber. Next, the vacuum suction of the collet is weakened and a force is applied to the collet downward. At this time, the surface emitting laser chip moves to the position where the first and second structures are most closely matched. In this state, the surface emitting laser substrate is heated. The heating temperature was such that only the surface of the first structure was slightly melted. Thereby, only the outermost surface of the resin that is the first structure provided in the surface emitting laser can be melted, and the gap formed between the first structure and the second structure is eliminated. be able to. Next, an optical fiber fixing jig and a surface emitting laser chip are fixed.

  FIG. 7 is a diagram showing an optical module according to Embodiment 2 of the present invention. The optical module according to the second embodiment includes a plurality of optical fibers and a plurality of surface emitting lasers. First and second structures are provided on the respective surfaces, and the first and second structures are fitted and mounted. It has come to be. Here, the first structure is provided in the light emitting region of the surface emitting laser, the second structure is provided in the core region at the tip of the optical fiber, and the first and second structures are fitted. Can be implemented. The feature of the second embodiment is that optical fibers and surface emitting lasers are arranged in an array.

  In the core region of each optical fiber, the second structure can be formed by the method described in the first embodiment. In order to bundle a plurality of optical fibers, each optical fiber is fixed by a fixing tool. The fixing method is to fix to the fixing fixture with a resin rich in elasticity, and if it is about several μm, it can be moved by external force.

  In addition, the method for manufacturing each surface emitting laser is the same as that in Example 1, and a plurality of the respective light emitting portions are arranged on the same surface. The intervals between the light emitting portions are set to be the same as those of the above-described optical fiber fixing fixture. Each optical fiber is fixed to a fixing jig, and is arranged so that the end surface on which the second structure is formed faces upward. Thereafter, the mounting method is almost the same as that of the first embodiment. However, since each optical fiber and the fixing fixture are fixed by an elastic resin, when they are fitted, they move along the same. Thereafter, in the fitted state, a fixing resin is poured to firmly fix the optical fiber and the fixing fixture.

  FIG. 8 is a diagram showing an optical module according to Embodiment 3 of the present invention. The optical module according to the third embodiment includes a plurality of microlenses and a plurality of light receiving elements. The first and second structures are provided on the respective surfaces and are fitted by the first and second structures. It is to be implemented. Here, the first structure is provided in the light receiving region of the light receiving element, and the second structure is provided in the center of the microlens.

In Example 3, a microlens is produced by processing a quartz substrate into a wafer shape. That is, first, a resist is applied to a wafer, and a lens shape is exposed to the resist using a gray scale mask. The film thickness of the resist is about 30 μm and can be controlled uniformly by controlling the rotation speed of the spin coater. Dry etching is performed using the resist processed into a lens shape as a mask. In dry etching, the shape of the microlens can be controlled by controlling the gas flow rate ratio and bias power. This time, etching was performed with Ar and C ₄ F ₈ gases of 10 sccm and 10 sccm, respectively. The etching rate was about 0.3 μm / minute, and the etching was performed for about 60 minutes and about 18 μm. The surface emitting laser was manufactured in the same manner as described in Example 1. The mounting method is the same as the method described in the second embodiment.

The present invention is used in an optical transceiver used for optical communication.

It is a figure which shows a prior art example. It is a figure which shows a prior art example. It is a figure which shows the optical module of Example 1 of this invention. FIG. 3 is a diagram illustrating a surface emitting laser used in the optical module of Example 1. It is a figure which shows the form which mounted the optical fiber in the surface emitting laser shown in FIG. It is a figure which shows the mounting method of a surface emitting laser and an optical fiber. It is a figure which shows the optical module of Example 2 of this invention. It is a figure which shows the optical module of Example 3 of this invention.

Claims (5)

A method of manufacturing an optical module comprising a light emitting element or a light receiving element and an optical element for transmitting light from the light emitting element or light to the light receiving element,
Providing the first structure by photolithography in the light emitting region or the light receiving region on the surface of the light emitting device or the light receiving device;
Providing a second structure in alignment with the first structure on the optical element side by photolithography ;
The first structure and the second structure are fitted to each other, the fitting portion between the first structure and the second structure is heated, and the first structure and the second structure are By softening and deforming at least one of the first structure and the second structure so that the thickness of the gap existing between the first structure and the second structure is less than or equal to the wavelength of light used by the optical module,
A method of manufacturing an optical module, wherein a gray scale mask is used as a photomask in the photolithography process . The method of manufacturing an optical module according to claim 1, wherein the first structure and the second structure are made of a material whose hardness is convex and a surface having a small hardness is concave. Production method. The method of manufacturing an optical module according to claim 1, wherein the higher melting point in the material of the first structure and the second structure is a convex surface, and the smaller one is a concave surface. Production method. 2. The optical module manufacturing method according to claim 1, wherein the material having the first structure and the second structure having a higher refractive index is a convex surface and the smaller one is a concave surface. Manufacturing method. 5. The method of manufacturing an optical module according to claim 1, wherein the optical element is an optical fiber, and the second structure is provided in a core region of the optical fiber. A method for manufacturing an optical module.

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