JP2008015224A - Optical connection device and mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical connection device which facilitates positioning of a prism having a reflection surface with respect to an optical fiber array and prevents Fresnel reflection at the end of the optical fiber, and to provide a method of mounting the optical connection device onto an optical element package. <P>SOLUTION: The optical connection device is equipped with the plurality of optical fibers, the prism having the reflection surface, and a substrate for arraying the optical fibers, wherein the reflection surface is formed at a prescribed angle θ in the range of 0°<θ<90° relative to the axial direction of the core of the optical fibers, the optical fibers are arrayed on the arraying substrate in such a manner that the core axes of the optical fibers are parallel to each other, the prism and the substrate for arraying optical fibers are composed of a light transmitting material that has the same refractive index as that of the core, in addition, the end of the optical fibers and the end face of the prism opposing the fiber ends are joined and the prism and the substrate for arraying optical fibers are joined to form a reflection film on the reflection surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical connection device that optically couples an optical fiber array and an optical device such as a VCSEL or PD, and a mounting method for mounting the optical connection device in a package of the optical device.

  In order to increase the bit rate of information devices such as computers, in-board optical connection in which LSIs such as a CPU and a memory are connected with each other by an optical fiber is promising. In the on-board optical connection, an LSI having an optical signal input / output mechanism is used, and an input / output signal of the LSI is propagated through an optical fiber array.

  Many such optical connection devices have been proposed. Among them, as one of structures in which an optical input / output mechanism is provided in an LSI, a light emitting element is used for electro-optical conversion, and photoelectric conversion is performed by a light receiving element. A structure that couples an optical element called a light receiving element with an optical fiber is one of the promising candidates. A vertical cavity surface emitting laser (VCSEL) is used for electro-optical conversion, and a photodiode (Photo Diode: PD) is used for photoelectric conversion. Further, these optical elements are mounted so that the surface thereof is parallel to the array substrate, and the optical path between the optical elements is bent 90 degrees by a mirror and coupled to the optical fiber via a lens.

  As such an optical connection device, many devices having a structure in which an optical fiber is held in parallel with respect to a substrate on which an optical element is mounted have been devised. In this optical connecting device, the tip of the optical fiber is obliquely polished at 45 degrees with respect to the core axis to form a reflecting surface, while the electrically connected optical element is mounted on the substrate, and the optical fiber is mounted on the substrate surface. The structure is held in parallel. The propagation light in the optical fiber is reflected by the reflecting surface and the 90-degree optical path is switched and the propagating light is incident on the optical element, or the outgoing light from the optical element is reflected by the reflecting surface and the 90-degree optical path is switched and the light is switched. Propagate into the fiber. With such a structure, since the optical fiber and the optical element are parallel to the substrate surface, a small and high-density mounting is possible.

  However, in the optical connecting device having such a structure, the reflected light from the reflecting surface does not collect light in the axial direction of the optical fiber, so that it is received as an elliptical spot having a major axis in the axial direction. Incident on the light receiving portion of the element. In the high-speed optical connection device in which the frequency characteristic is improved by reducing the capacitance of the light receiving element, the coupling efficiency with the elliptical spot light deteriorates because the diameter of the light receiving portion is as small as several tens of μm or less.

  In view of this, an optical connecting device that can efficiently couple an optical fiber array and a light receiving element as shown in FIG. 24 has been devised (see Patent Document 1).

JP 05-273444 A (page 3-4, FIG. 1)

  FIG. 24 shows the structure of the optical connecting device of Patent Document 1. 24, a light receiving element 102 having a light receiving portion 102a is mounted on a substrate 101 such as a printed circuit board, and is electrically connected to an electrode on the substrate 101 by a bonding wire 103. The optical fiber 104 has an outer diameter of 125 μm, for example, and is cleaved to form a light emitting end. The flat lens 105 is a micro lens having a lens effect by providing a refractive index distribution on a glass plate, for example, and a part of which is optically polished on a surface that crosses the optical axis at, for example, 45 degrees, and is a reflective surface. 106 is formed.

  The lens 105 has an optical path of light emitted from the optical fiber 104 and reflected by the reflecting surface 106. One of the two end faces traversed by the optical path faces the light emitting end of the optical fiber 104, and the other end face receives light. It is formed so as to face the light receiving portion 102 a of the element 102. Further, the optical elements 102, 104, and 105 are arranged so that the optical fiber 104 and the light receiving element 102 are optically coupled via the lens 105.

  The light emitted from the optical fiber 104 enters the lens 105, and is collected and reflected by the lens effect due to the refractive index distribution of the lens 105 and the reflecting surface 106, and is emitted from the lens 105, and is incident on the light receiving unit 102 a with high efficiency. Highly efficient coupling can be obtained.

  Furthermore, since the reflecting surface 106, which is an optical path switching unit, and the lens 105 are integrated, the lens 105 can be positioned simultaneously with the positioning of the reflecting surface 106 and the optical fiber 104, so that the mounting process is simplified.

  However, in the structure of the optical connecting device 100 of FIG. 24, since the plurality of optical fibers 104 and the lens 105 are arranged in a line in the x-axis direction, the optical fiber 104 and the lens 105 are precisely arranged in the y-axis direction. It was difficult to position.

  Furthermore, since the light exit end of the optical fiber 104 and the end face of the lens 105 facing the light exit end are spaced apart, a difference in refractive index occurs in the space between the light exit end and the lens 105. Due to the difference in refractive index, a part of the light emitted from the optical fiber 104 is returned to the optical fiber 104 by Fresnel reflection and recombined with the optical fiber 104, so that the coupling efficiency between the optical connecting device 100 and the light receiving element 102 only decreases. Instead, it causes noise.

  Further, when the optical fiber 104 with the light emitting end cleaved is used, the return light due to the Fresnel reflection is re-coupled to the optical fiber 104 as it is, so that the configuration of the optical connecting device 100 prevents and combines the Fresnel reflection. It was impossible to improve efficiency.

  The present invention has been made in view of the above problems, and its purpose is to facilitate positioning of a prism having a reflecting surface and an optical fiber array, and to prevent Fresnel reflection at the end of the optical fiber. An optical connection device and a method of mounting the optical connection device on an optical element package are provided.

The invention according to claim 1 of the present invention includes a plurality of optical fibers, a prism provided with a reflecting surface, and an optical fiber array substrate on which the optical fibers are arrayed.
The reflecting surface is formed at a predetermined angle θ in the range of 0 degree <θ <90 degrees with respect to the axial direction of the core of the optical fiber,
The optical fibers are arranged on the optical fiber arrangement substrate so that the axes of the cores of the optical fibers are parallel to each other,
The prism and the optical fiber array substrate are composed of a light-transmitting material having the same refractive index as that of the core,
Furthermore, the end of the optical fiber and the end face of the prism facing the end are joined, and the prism and the optical fiber array substrate are joined,
A reflection film is formed on the reflection surface.

で設定される角度θｆ（但し、ＲＬ：前記光ファイバの端部と、前記端部と対向する前記プリズムの端面とが接合される接合面でのリターンロス、ｎ１：前記コアの屈折率、ｎ２：前記プリズムの屈折率、λ：前記光ファイバを伝搬する光の波長、ω１：前記光ファイバのモードフィールド半径、とする）が設けられることを特徴とする光接続装置である。 The invention according to claim 2 of the present invention includes a plurality of optical fibers, a prism provided with a reflecting surface, and an optical fiber array substrate on which the optical fibers are arrayed.
The reflecting surface is formed at a predetermined angle θ in the range of 0 degree <θ <90 degrees with respect to the axial direction of the core of the optical fiber,
The optical fibers are arranged on the optical fiber arrangement substrate so that the axes of the cores of the optical fibers are parallel to each other,
The optical fiber array substrate is composed of a light transmissive material,
Furthermore, the end of the optical fiber and the end face of the prism facing the end are joined, and the prism and the optical fiber array substrate are joined,
With respect to a direction perpendicular to the axial direction of the core of the optical fiber, the end portion and the end face of the prism facing the end portion,

(Where RL is the return loss at the joint surface where the end of the optical fiber and the end face of the prism facing the end are joined, n1: the refractive index of the core, n2 The refractive index of the prism, λ: the wavelength of light propagating through the optical fiber, and ω1: the mode field radius of the optical fiber) are provided.

  Further, the invention according to claim 3 of the present invention is the optical connection device according to claim 2, wherein a reflection film is formed on the reflection surface.

Furthermore, the invention according to claim 4 of the present invention is the optical connection device according to any one of claims 1 to 3,
In the optical connecting device, the end portion and the end face of the prism facing the end portion are joined by direct joining or hydrofluoric acid joining.

The invention according to claim 5 of the present invention includes a plurality of optical fibers, a prism provided with a reflecting surface, and an optical fiber array substrate on which the optical fibers are arrayed.
The reflecting surface is formed at a predetermined angle θ in the range of 0 degree <θ <90 degrees with respect to the axial direction of the core of the optical fiber,
The optical fibers are arranged on the optical fiber arrangement substrate so that the axes of the cores of the optical fibers are parallel to each other,
The prism and the optical fiber array substrate are composed of a light-transmitting material having the same refractive index as that of the core,
A GRIN lens is provided at the end of the optical fiber,
Furthermore, the central refractive index of the GRIN lens is set to be the same as the refractive index of the core,
The lens length of the GRIN lens is set to 0.25P (where P is the pitch of the GRIN lens) or more,
The end of the GRIN lens and the end face of the prism facing the end of the GRIN lens are joined, and the prism and the optical fiber array substrate are joined.
A reflection film is formed on the reflection surface.

で設定される角度θｆ（但し、ＲＬ’：前記ＧＲＩＮレンズの端部と、前記ＧＲＩＮレンズの端部と対向する前記プリズムの端面とが接合される接合面でのリターンロス、ｎ３：前記ＧＲＩＮレンズの中心屈折率、ｎ２：前記プリズムの屈折率、λ：前記光ファイバを伝搬する光の波長、ω２：前記ＧＲＩＮレンズの端部でのビームウエスト半径、とする）が設けられることを特徴とする光接続装置である。 The invention according to claim 6 of the present invention includes a plurality of optical fibers, a prism provided with a reflecting surface, and an optical fiber array substrate on which the optical fibers are arrayed.
The reflecting surface is formed at a predetermined angle θ in the range of 0 degree <θ <90 degrees with respect to the axial direction of the core of the optical fiber,
The optical fibers are arranged on the optical fiber arrangement substrate so that the axes of the cores of the optical fibers are parallel to each other,
The optical fiber array substrate is composed of a light transmissive material,
Furthermore, a GRIN lens is provided at the end of the optical fiber, and the lens length of the GRIN lens is set to 0.25P (where P is the pitch of the GRIN lens) or more.
The end of the GRIN lens and the end face of the prism facing the end of the GRIN lens are joined, and the prism and the optical fiber array substrate are joined.
With respect to the direction perpendicular to the axial direction of the end of the GRIN lens, the end of the GRIN lens and the end surface of the prism facing the end of the GRIN lens,

Angle θf (where RL ′ is the return loss at the joint surface where the end of the GRIN lens and the end of the prism facing the end of the GRIN lens are joined, and n3 is the GRIN lens. N2: refractive index of the prism, λ: wavelength of light propagating through the optical fiber, and ω2: beam waist radius at the end of the GRIN lens). It is an optical connection device.

  Further, the invention according to claim 7 of the present invention is the optical connection device according to claim 6, wherein a reflection film is formed on the reflection surface.

Furthermore, the invention according to claim 8 of the present invention is the optical connection device according to claim 5 or 6,
The optical connection device is characterized in that the end of the GRIN lens and the end surface of the prism facing the end of the GRIN lens are joined by direct joining or hydrofluoric acid joining.

Furthermore, the invention according to claim 9 of the present invention is the optical connection device according to any one of claims 1 to 8,
In the optical connection device, the prism and the optical fiber array substrate are bonded by direct bonding or hydrofluoric acid bonding.

Furthermore, an invention according to claim 10 of the present invention is the optical connection device according to any one of claims 1 to 8,
In the optical connection device, the prism and the optical fiber array substrate are integrally formed.

Furthermore, an invention according to an eleventh aspect of the present invention is the optical connection device according to any one of the first to tenth aspects,
A concave mirror is provided on the reflecting surface.

According to a twelfth aspect of the present invention, in the optical connecting device according to any one of the first to tenth aspects of the present invention,
A convex lens part is formed in the light incident / exit part of the said optical connection apparatus, It is an optical connection apparatus characterized by the above-mentioned.

Furthermore, the invention according to claim 13 of the present invention is the optical connection device according to any one of claims 1 to 12,
An optical connection device, wherein an antireflection film is formed at a light incident / exit portion of the optical connection device.

  Furthermore, the invention according to claim 14 of the present invention is that the optical connecting device according to any one of claims 1 to 13 is joined to a package on which an optical element is mounted by direct joining or hydrofluoric acid joining. It is the mounting method of the characteristic optical connection apparatus.

  According to the optical connecting device according to the first, second, fifth and sixth aspects of the present invention, the optical fiber array substrate is provided, and the optical fiber array is arrayed in each groove of the optical fiber array substrate. There is no need to finely adjust each optical fiber with respect to the prism, and positioning of each optical fiber with respect to the prism in the y-axis direction orthogonal to the arrangement direction (x-axis direction) of the optical fiber array is facilitated. Therefore, the optical fibers can be easily and accurately arranged with respect to the optical element.

  Furthermore, according to the optical connecting device according to claim 1 or 5 of the present invention, the optical fiber array substrate and the prism are made of a light transmissive material having the same refractive index as that of the core of the optical fiber. Therefore, Fresnel reflection of light on the optical fiber array substrate and the prism is prevented, and return light to the optical fiber or optical element is eliminated.

  Furthermore, according to the optical connecting device of the second aspect of the present invention, the end of the optical fiber and the end face of the prism facing the end are perpendicular to the axial direction of the core of the optical fiber. On the other hand, since the predetermined angle θf is provided, Fresnel reflection at the end of the optical fiber is prevented, and return light to the optical fiber or optical element is eliminated.

  Further, according to the optical connecting device of the sixth aspect of the present invention, the end of the GRIN lens is connected to the end of the GRIN lens and the end surface of the prism facing the end of the GRIN lens. Since the predetermined angle θf is provided with respect to the direction perpendicular to the axial direction, Fresnel reflection at the end face of the GRIN lens is prevented, and light returning to the optical fiber is eliminated.

  Furthermore, according to the optical connecting device of the third or seventh aspect of the present invention, a material having a small refractive index that does not satisfy the total reflection condition on the reflecting surface can be used for the optical connecting device.

  Furthermore, according to the optical connecting device according to claim 5 or 6 of the present invention, the GRIN lens is provided, and the lens length of the GRIN lens is set to 0.25P so that the light is converted into collimated light. It can be combined with an optical fiber and a light receiving element. Accordingly, since the optical fiber and the light receiving element can be coupled without spreading light, the coupling efficiency between the optical connecting device and the light receiving element is improved.

  In addition, by setting the lens length of the GRIN lens between 0.25P and 0.5P, the light emitted from the optical fiber can be converged and incident on the reflecting surface of the prism. Therefore, since the reflected light from the reflecting surface is also coupled to the light receiving element as convergent light, the coupling efficiency between the optical connecting device and the light receiving element can be further improved. Alternatively, even if the optical element is a light emitting element, the optical element and the optical fiber can be coupled, so that the versatility of the optical connection device is improved.

  Furthermore, according to the optical connecting device of the fourth aspect of the present invention, the Fresnel reflection between the end portion and the end surface is prevented by joining the end portion of the optical fiber and the end surface of the prism. It becomes possible. Therefore, the return light to the optical fiber or the optical element is eliminated.

  Furthermore, according to the optical connecting device of the eighth aspect of the present invention, Fresnel reflection between the end portion of the GRIN lens and the end surface is performed by joining the end portion of the GRIN lens and the end surface of the prism. Can be prevented. Therefore, the return light to the optical fiber or the optical element is eliminated.

  Furthermore, according to the optical connecting device according to claim 9 of the present invention, in addition to the effects provided by the optical connecting device according to each of the claims, the prism and the optical fiber arrangement without using an optical adhesive or an intermediate material. By bonding to the substrate, it is possible to solve problems such as deterioration of moisture resistance of the optical adhesive and the intermediate material, deterioration of high-power light, and deterioration of reliability. In addition, since outgassing from the optical adhesive is prevented, adhesion of outgas to the optical element can also be prevented. Furthermore, in the case of direct bonding or hydrofluoric acid bonding, since the prism and the optical fiber array substrate are bonded at room temperature, the thermal stress and cracking of the prism and the optical fiber array substrate are suppressed, and the bonded portion is peeled off. Can be prevented.

  Furthermore, according to the optical connecting device according to claim 10 of the present invention, in addition to the effects provided by the optical connecting device according to each of the claims, the prism, the optical fiber array substrate, Therefore, the prism and the optical fiber array substrate can always be manufactured in a constant shape, and variations in the outer shape can be eliminated. Accordingly, the variation in the optical path of the reflected light generated on the reflecting surface of the prism due to the variation is prevented, so that the optical element and the optical fiber can be coupled with high efficiency. Furthermore, since the production of the prism and the optical fiber array substrate can be completed with only one molding process, the cost of the optical connecting device can be reduced as the number of manufacturing processes is reduced. .

  Furthermore, according to the optical connecting device of the eleventh aspect of the present invention, in addition to the effects provided by the optical connecting device according to the respective claims, the reflected light on the reflecting surface is condensed and converted into convergent light. Thus, since the light is focused on the optical fiber or the optical element, the coupling efficiency between the optical connection device and the optical element is further improved.

  Furthermore, according to the optical connecting device according to claim 12 of the present invention, in addition to the effect provided by the optical connecting device according to each of the claims, the light is condensed by the convex lens portion and converted into convergent light, Since the light is focused on the optical fiber or the optical element, the coupling efficiency between the optical connecting device and the optical element is further improved.

  Furthermore, according to the optical connecting device of the thirteenth aspect of the present invention, in addition to the effects provided by the optical connecting device according to the respective claims, an antireflection film is formed on the light incident / exit portion of the optical connecting device. Accordingly, return light due to reflection at the light incident / exit portion can be prevented, and the coupling efficiency between the optical element and the optical connecting device can be improved.

  Furthermore, according to the mounting method of the optical connecting device according to claim 14 of the present invention, the optical connecting device and the optical element package are bonded by direct bonding or hydrofluoric acid bonding, thereby eliminating the deterioration of moisture resistance. Various effects can be obtained, such as prevention of deterioration of power with respect to light and securing of reliability, suppression of thermal stress and crack generation of the prism and optical fiber array substrate, and prevention of peeling at the joint portion. Further, outgas generated from the optical adhesive can be prevented from entering the inside of the package through the window and adhering to the optical element.

<First Embodiment>
Hereinafter, a first embodiment of an optical connection device of the present invention will be described with reference to FIGS. Note that the x-axis, y-axis, and z-axis shown in each figure correspond to each other one to one. The optical connecting device 1 of the present invention includes an optical fiber 2, a prism 3, and an optical fiber array substrate 4, and is optically coupled to the optical element 5. As shown in FIG. 3, an optical element 5 is mounted on a package 6, and its outer shape is manufactured by a resin transfer mold or the like. Examples of the optical element 5 include a light receiving element such as a PD or a high-speed operation PD (for example, a PIN photodiode or an avalanche photodiode), and a light emitting element such as a VCSEL. The optical elements 5 are electrically connected to electrodes on the substrate inside the package 6 by bonding wires 7, and a plurality of optical elements 5 are aligned in a horizontal row in the x-axis direction to form an optical element array. Has been. The package 6 is provided with a window portion 6a through which light passes.

  The optical fiber 2 includes a silica-based single mode type or a silica-based multimode type (a silica-based multi-mode type) in which a core 2a and a clad 2b having a refractive index lower than that of the core 2a surround the core 2a. A refractive index distribution type, a step index type) or a plastic optical fiber is preferable (see FIGS. 1 and 4). In the case of FIGS. 1 to 4, the end of the optical fiber 2 is cleaved, and the plurality of optical fibers 2 are arranged in a horizontal row at equal intervals in the x-axis direction so that the axes of the cores 2a are parallel to each other. The optical fiber array is configured by arranging.

  The prism 3 is provided with a reflection surface 3a, and its outer shape is formed by the end surface 3b facing the end of the optical fiber array and the other end surface 3c facing the light emitting portion or the light receiving portion 5a of the optical element 5. Has been. Further, the prism 3 is formed extending in the x-axis direction.

  The reflecting surface 3a has a predetermined angle θ with respect to the axial direction (z-axis direction) of the core 2a of the optical fiber 2 (0 ° <θ <90 ° range: θ is set to 45 ° in this embodiment). Is formed. Further, the end face 3b is formed perpendicular to the x-axis direction that is the surface direction of the optical element 5, and the other end face 3c is formed parallel to the x-axis direction. A reflective film such as a metal film or a dielectric multilayer film is formed on the reflective surface 3a so as to act as a mirror.

  As a material constituting the prism 3, a light transmissive material having the same refractive index as that of the core 2a of the optical fiber 2 is preferable, and specific examples thereof include glass and plastic.

  An optical fiber array substrate (hereinafter referred to as an array substrate) 4 is formed by forming grooves 4a corresponding to the number of optical fibers 2 on a flat substrate surface in parallel at equal intervals in the x-axis direction. Each fiber 2 is arranged in each groove 4a (see FIG. 1). The cross-sectional shape of each groove 4a is V-shaped (hereinafter, the groove 4a is referred to as a V-groove 4a).

  A step is formed on one end side of the formation surface of the V-groove 4a, and the prism 3 is installed at the step. The array substrate 4 and the prism 3 are integrated by joining the flat surfaces of the step and the end faces 3b and 3c of the prism. In order to prevent Fresnel reflection of light due to a difference in refractive index at the joint surface between the prism 3 and the array substrate 4, it is preferable that the prism 3 and the array substrate 4 are made of the same material. By selecting the material in this way, the return light to the optical fiber 2 or the return light to the optical element 5 due to Fresnel reflection is eliminated.

  When the prism 3 and the array substrate 4 are made of glass, each is manufactured by molding, or by grinding and polishing. Moreover, when manufacturing with a plastic, it is suitable to manufacture by the injection molding by a metal mold | die.

  The prism 3 and the array substrate 4 are bonded by optical bonding, direct bonding without using an optical adhesive or an intermediate material (antireflection film, metal film), or hydrofluoric acid bonding. If an optical adhesive is used, the array substrate 4 and the prism 3 can be integrated at a low cost. Further, when power resistance such as coupling of the optical fiber array and the optical element 5 with high power light is required, it is preferable to integrate them by direct bonding or hydrofluoric acid bonding. In the case of bonding using an optical adhesive, Fresnel reflection at the bonding surface of the prism 3-array substrate 4 is prevented by using an optical adhesive having the same refractive index as that of the core 2a and the prism 3.

  On the other hand, in the case of direct bonding or hydrofluoric acid bonding, no optical adhesive or intermediate material is used, so there are problems such as deterioration of moisture resistance of optical adhesive or intermediate material, deterioration of high power light, and deterioration of reliability. Can be eliminated. In addition, since outgassing from the optical adhesive is prevented, adhesion of outgas to the optical element 5 can also be prevented.

  Further, in the case of direct bonding or hydrofluoric acid bonding, the prism 3 and the array substrate 4 are bonded at room temperature. Therefore, the thermal stress and cracking of the prism 3 and the array substrate 4 are suppressed, and Peeling can be prevented.

  Further, if the end surface 3b of the prism 3 and the end portion of the optical fiber 2 are bonded by the optical adhesive as described above, or the direct bonding or hydrofluoric acid bonding, between the end portion and the end surface 3b. Thus, the return light to the optical fiber 2 or the return light to the optical element 5 can be eliminated. In particular, direct bonding or hydrofluoric acid bonding, as described above, eliminates the deterioration of moisture resistance of the optical adhesive, prevents deterioration of high-power light and ensures reliability, and generates thermal stress and cracks in the prism 3 and the optical fiber 2. This is a more preferable joining method because various effects such as suppression and prevention of peeling at the joining portion can be obtained.

  Further, the position of the optical connecting device 1 is adjusted in the x and z axis directions so that the light emitting portion of the optical connecting device 1 and each light emitting portion or light receiving portion 5a of the optical element array face each other in the y axis direction. Then, the optical connecting device 1 and the package 6 are joined. The joining is performed by joining the optical connecting device 1 and the package 6 by the direct joining or hydrofluoric acid joining, and mounting the optical connecting device 1 on the package 6. By joining by direct joining or hydrofluoric acid joining, as described above, the degradation of moisture resistance is eliminated, the deterioration prevention and reliability are ensured for high power light, the suppression of thermal stress and cracking of the prism 3 and the array substrate 4, In addition, various effects such as prevention of peeling at the joint portion can be obtained. Further, outgas generated from the optical adhesive is prevented from entering the inside of the package 6 from the window 6a and adhering to the optical element 5. The thickness and mounting height of the optical element 5 are adjusted as appropriate so that the distance between the optical element 5 and the prism 3 is optimal.

  Next, with reference to FIG. 4, the coupling | bonding of the optical connection device 1 and the optical element 5 is demonstrated. In FIG. 4, the case where the optical element 5 is a light receiving element such as a PD is taken as an example, and the coupling state will be described (hereinafter referred to as the light receiving element 5 as necessary). The light emitted from the optical fiber 2 enters the prism 3, is reflected by the reflecting surface 3 a, and is coupled to the light receiving portion 5 a of the light receiving element 5. As described above, since the reflective film is formed on the reflective surface 3a, the light emitted from the optical fiber 2 in the z-axis direction is totally reflected (reflected) by the reflective surface 3a, and the optical path is 90 degrees in the y-axis direction. Is converted and emitted from the prism 3, passes through the array substrate 4, and is coupled to the light receiving portion 5 a of the light receiving element 5.

An antireflection film is formed on the surface of the array substrate 4 (the surface facing the window portion 6a), which is a light emitting portion of the optical connecting device 1. Examples of the antireflection film include a multilayer film having a thickness of about several hundreds nm made of an inorganic material such as SiO ₂ , TiO _2, or Ta ₂ O ₅ . By forming an antireflection film on the light emitting part, it is possible to prevent return light due to reflection at the light emitting part and improve the coupling efficiency between the light receiving element 5 and the optical connecting device 1.

  FIG. 4 shows a coupling state between the optical connecting device 1 and the optical element 5 when the optical element 5 is a light receiving element. However, the optical element 5 may be replaced with a surface emitting laser called VCSEL. In this case, as shown in FIG. 10, FIG. 4 is a state diagram in which the light emitted from the light emitting portion 5 a of the optical element 5 is reflected by the reflecting surface 3 a and coupled to the core 2 a of the optical fiber 2. When a VCSEL is used, it is preferable that the condensing convex lens 5b is integrally provided on the surface of the light emitting portion 5a. In addition, the location of the optical connection device 1 described as the light emitting portion in FIG. 4 becomes a light incident portion (hereinafter referred to as a light incident / exit portion).

  As described above, it is not necessary to finely adjust each optical fiber 2 with respect to the prism 3 by arranging the optical connecting device 4 in the optical connecting device 1 and arranging the optical fiber array in the V groove 4a. Positioning of each optical fiber 2 with respect to the prism 3 is facilitated in the y-axis direction that is orthogonal to the arrangement direction (x-axis direction) of the optical fiber array. Therefore, the optical fiber 2 can be easily and accurately arranged with respect to the optical element 5.

  The prism 3 and the array substrate 4 may be manufactured by integral molding by molding. As shown in FIG. 5 to FIG. 7, the molds 8 a and 8 b processed into an external shape in which the prism 3 and the array substrate 4 are integrated are accurately positioned, and a glass rod material or preform (hereinafter referred to as a glass material) is interposed therebetween. ) 9 is inserted. A cemented carbide or the like is used as the material of the molds 8a and 8b. Next, in a non-oxidizing atmosphere, the glass material 9 and the molds 8a and 8b are heated up to the vicinity of the softening point of the glass material 9, and the glass material 9 and the molds 8a and 8b are heated to approximately the same temperature by the molds 8a and 8b. 9 is pressurized, and then the mold temperature is lowered below the transition point while maintaining the pressure. Thereafter, the molded glass material 9 is extracted from the molds 8a and 8b. The die-cut glass material 9 becomes an integrally molded product 10 of the prism 3 and the array substrate 4 (see FIG. 8).

  Since the prism 3 and the array substrate 4 are manufactured by a single process by molding, the prism 3 and the array substrate 4 can always be manufactured in a constant shape, and variations in the outer shape are eliminated. Therefore, the optical path of the reflected light generated on the reflecting surface 3a due to the variation can be prevented, and the optical element 5 and the optical fiber 2 can be coupled with high efficiency.

  Furthermore, since the manufacture of the prism 3 and the array substrate 4 can be completed in only one molding process, the cost of the optical connecting device 1 can be reduced as the number of manufacturing processes is reduced. Become.

  Further, when the prism 3 and the array substrate 4 are integrally formed of plastic, an injection molding method may be used.

  In the present embodiment, the structure in which the prism 3 is joined to the step of the array substrate 4 has been described as the joint structure of the prism 3 and the array substrate 4, but instead of this structure, as shown in FIG. It is also possible to change so that the end surface 3b of the prism 3 and one plane of the array substrate 4 are bonded.

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, the same number is attached | subjected to the same location as each said embodiment, and the overlapping description is abbreviate | omitted or simplified and demonstrated. The description will be continued below with the optical element 5 of FIG. 12 as a light receiving element.

  The second embodiment is different from the above embodiments in that a GRIN (Gradient Index) lens 13 for collimating or converging light is provided at the end of the optical fiber 2. When the lens length of the GRIN lens 13 is 0.25P (P: the pitch of the GRIN lens 13), the emitted light from the optical fiber 2 is converted into collimated light as shown in FIG. 12, and is incident on the reflecting surface 3a. The Thereby, since the reflected light reflected by the reflecting surface 3a is also collimated and coupled to the light receiving unit 5a of the light receiving element 5, the light is not spread but coupled to the light receiving unit 5a. The coupling efficiency with 5 is improved.

  Further, when the central refractive index of the GRIN lens 13 can be regarded as the same as the refractive index of the core 2a, the end face 3b of the prism 3 and the end of the GRIN lens 13 are optically bonded as described in the first embodiment. If the bonding is performed by the agent, the direct bonding or the hydrofluoric acid bonding, Fresnel reflection between the end of the GRIN lens 13 and the end surface 3b is prevented, and the return light to the optical fiber 2 (the optical element 5 is a VCSEL). In the case of a light emitting element such as the above, it is possible to eliminate the return light to the optical element 5. In particular, direct bonding or hydrofluoric acid bonding eliminates deterioration of moisture resistance of the optical adhesive, prevents deterioration of high-power light and ensures reliability, suppresses thermal stress and crack generation of the prism 3 and GRIN lens 13, and bonding. This is a more preferable joining method because various effects such as prevention of peeling of a portion can be obtained.

  Further, by setting the lens length of the GRIN lens 13 between 0.25P and 0.5P, convergent light is obtained. As shown in FIG. 13, even if the optical element 5 is a light emitting element called VCSEL, The element 5 and the optical fiber 2 can be coupled. Therefore, the versatility of the optical connection device 1 is enhanced.

  Even if the optical element 5 has a light receiving portion 5a, which is a high-speed operation PD, having a diameter as small as several tens of μm or less, the light emitted from the optical fiber 2 is converged and incident on the reflecting surface 3a of the prism 3. (See FIG. 13). Accordingly, since the reflected light from the reflecting surface 3a is also converted into convergent light and coupled to the light receiving element 5, the coupling efficiency between the optical connecting device 1 and the light receiving element 5 can be further improved.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIGS. In addition, the same number is attached | subjected to the same location as each said embodiment, and the overlapping description is abbreviate | omitted or simplified and demonstrated.

  The third embodiment differs from the above embodiments in that the end of the optical fiber 2 ′ and the end surface 3b ′ of the prism 3 ′ are arranged in the axial direction of the core 2a ′ of the optical fiber 2 ′ (z in the figure). A predetermined angle θf with respect to a direction perpendicular to the axial direction. An angle θf is provided between the end of the optical fiber 2 ′ and the end surface 3b ′ of the prism 3 ′ for the purpose of preventing Fresnel reflection when the demand for return light to the optical fiber 2 ′ or the optical element 5 is severe. It is.

  Hereinafter, the description will be continued by taking the case where the optical element 5 is a light receiving element as an example. When the refractive index of the prism 3 ′ and the array substrate 4 ′ is different from the refractive index of the core 2a ′, the light emitted from the optical fiber 2 ′ is refracted at the end of the optical fiber 2 ′ by providing the angle θf. Thus, the light propagates obliquely upward in the prism 3 ′. The propagating light is reflected by the reflecting surface 3 a and is coupled to the light receiving portion 5 a of the light receiving element 5. As the angle θf is set, the angle θ of the reflecting surface 3a is slightly smaller than the angle θ of the first and second embodiments in the range of 0 degree <θ <90 degrees. By changing the angle θ, the optical path of the reflected light from the reflecting surface 3a can be converted to be parallel to the y-axis direction and coupled to the light receiving unit 5a.

  Even if the refractive indexes of the prism 3 ′ and the array substrate 4 ′ are different from the refractive index of the core 2a ′, the end of the optical fiber 2 ′ and the end surface 3b ′ of the prism 3 ′ facing the end In addition, since a predetermined angle θf is provided with respect to the direction perpendicular to the axial direction of the core 2a ′ of the optical fiber 2 ′, Fresnel reflection at the end of the optical fiber 2 ′ is prevented, and Return light is eliminated.

  From the above description, it is possible to use a light-transmitting material having a refractive index different from that of the core 2a ′ for the prism 3 ′ and the array substrate 4 ′, which is made of the glass or plastic described in the above embodiments. In addition, a silicon single crystal or the like can be used. When the prism 3 ′ and the array substrate 4 ′ are manufactured from a silicon single crystal, they may be manufactured by anisotropic etching or polishing.

  When a high refractive index material such as silicon single crystal is used for the prism 3 ′ and the array substrate 4 ′, the refractive index is higher than the refractive index satisfying the critical angle condition of incident light on the reflecting surface 3a. In this case, since the light is totally reflected by the reflecting surface 3a, the reflecting film as described above is not necessary on the reflecting surface 3a. As a condition for the total reflection of light by the reflecting surface 3a, it is necessary to make the light incident on the reflecting surface 3a at a critical angle or more. Therefore, the angle θ is changed and set so that the incident angle of light becomes a critical angle.

  However, total reflection is not achieved only by changing the angle θ, and it is necessary to select the material of the prism 3 ′ so that the critical angle condition is satisfied by the refractive index of the material of the prism 3 ′. When the optical fiber 2 ′ is a general single mode type, its numerical aperture (NA) is assumed to be 0.1, so that almost all power of light emitted from the optical fiber 2 ′ is included from FIG. 16. The spread angle φ is 12 degrees. Therefore, the incident angle i of light with respect to the reflecting surface 3a is 33 degrees obtained by subtracting the spread angle φ from the angle θ. Furthermore, considering the environment in which the optical fiber array module 1 is used, the ambient atmosphere is considered to be air (refractive index 1), so the refractive index at a critical angle of 33 degrees with respect to air is 1.836 · If the light transmitting material has a refractive index greater than about 1.84, the reflection surface 3a can totally reflect light. As a material suitable for the prism 3 ′, glass, silicon single crystal, or the like having a light transmittance of a refractive index greater than 1.84 can be used.

  Next, with reference to FIG. 16, the coupling | bonding of the optical connection device 1 and the light receiving element 5 is demonstrated. The light emitted from the optical fiber 2 ′ enters the prism 3 ′, is totally reflected by the reflecting surface 3 a, and is coupled to the light receiving portion 5 a of the light receiving element 5. As described above, light is incident on the reflecting surface 3a at the critical angle i, and the refractive index of the prism 3 ′ satisfies the critical angle condition. Therefore, the light emitted from the optical fiber 2 ′ in the z-axis direction is reflected on the reflecting surface. The light is totally reflected by 3a, and the 90-degree optical path is converted in the y-axis direction. Thereafter, the light whose path has been converted is emitted from the prism 3 ′, passes through the array substrate 4 ′, and is coupled to the light receiving portion 5 a of the light receiving element 5. By utilizing total reflection, it is possible to eliminate the propagation loss of light on the reflecting surface 3a.

  Of course, it is also possible to apply a material having a refractive index that does not satisfy the critical angle condition (in this case, 1.84 or less) to the prism 3 '. In this case, since the total reflection condition on the reflection surface 3a cannot be satisfied, it is necessary to form the reflection film as described above on the reflection surface 3a. By forming the reflection film on the reflection surface 3a, a material having a small refractive index that does not satisfy the total reflection condition on the reflection surface 3a can be used for the optical connecting device 1.

  The end face 3 b ′ of the prism 3 ′ and the end of the optical fiber 2 ′ are bonded by an optical adhesive, or the direct bonding or hydrofluoric acid bonding. In particular, direct bonding or hydrofluoric acid bonding is more preferable from the reason of the first embodiment. When a silicon single crystal is used for the prism 3 ′ and the array substrate 4 ′ and bonded with an optical adhesive, the refractive index of the silicon single crystal is as large as 3.48 at 1550 nm. An antireflection film matched with the refractive index of an adhesive or the like is formed.

  The angle θf is obtained as follows. The efficiency with which the light emitted from the optical fiber 2 ′ is reflected by the prism and coupled again to the optical fiber 2 ′ is η ′, and the s wave at the joint surface between the end surface 3b ′ of the prism 3 ′ and the end of the optical fiber 2 ′. , The incident angle of light with respect to the normal of the joint surface is θf, the refraction angle with respect to the normal is θf ′, the wavelength of light propagating through the optical fiber 2 ′, and the optical fiber 2 ′. , The refractive index of the core 2a ′ is n1, and the refractive index of the prism 3 ′ is n2, the return loss RL at the joint surface is expressed by the following equation.

  Assuming that θf and θf ′ are sufficiently small,

  A formula for setting the angle θf expressed as follows is obtained. As shown in Equation 6, the RL specifications of the optical connecting device 1, the refractive index n1 of the core 2a ′, the refractive index n2 of the prism 3 ′, and the wavelength λ of the light that couples the optical fiber 2 ′ and the optical element 5 By determining the mode field radius ω1 of the optical fiber 2 ′, the angle θf can be automatically obtained. As an example of the specific numerical value, when RL> 50 dB, the refractive index n1 = 1.45 of the core 2a ′, and the refractive index n2 = 1.51 of the prism 3 ′, the angle θf may be 5.2 degrees or more. .

  Note that the GRIN lens 13 as described in the second embodiment may be inserted between the end face 3b 'of the prism 3' and the end of the optical fiber 2 '. In this case, as shown in FIG. 18, the end of the GRIN lens 13 and the end surface 3b 'of the prism 3' facing the end are joined by an optical adhesive or the direct joining or hydrofluoric acid joining. In particular, direct bonding or hydrofluoric acid bonding is more preferable from the reason of the second embodiment.

  Set by Equation 7 with respect to the direction perpendicular to the axial direction (z-axis direction in FIG. 18) of the end of the GRIN lens 13 and the end surface 3b ′ of the prism 3 ′ facing the end. By providing the angle θf, the Fresnel reflection at the end face of the GRIN lens 13 is prevented, and the return light to the optical fiber 2 ′ is eliminated. Since the GRIN lens 13 is inserted between the prism 3 ′ and the optical fiber 2 ′, the RL is RL ′ (the prism 3 ′ facing the end of the GRIN lens 13 and the end of the GRIN lens 13). The return loss at the joint surface to which the end surface 3b ′ of the lens is joined), n1 is n3 (center refractive index of the GRIN lens 13), and ω1 is ω2 (beam waist radius at the end of the GRIN lens 13). Respectively.

  In FIG. 15, the optical element 5 can be replaced with a surface emitting laser called VCSEL. In this case, the light emitted from the optical element 5 is reflected by the reflecting surface 3a and coupled to the core 2a 'of the optical fiber 2'. When a VCSEL is used, it is preferable that the condensing convex lens 5b shown in FIG. 10 is integrally provided on the surface of the light emitting portion 5a.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described with reference to FIGS. In addition, the same number is attached | subjected to the same location as each said embodiment, and the overlapping description is abbreviate | omitted or simplified and demonstrated.

  The fourth embodiment is different from each of the above embodiments in that a concave mirror 12 is provided in a reflection surface area where at least light emitted from the optical fiber 2 is reflected in the reflection surface 3a. Concave mirrors 12 having a concave curved surface shape are formed on the reflection surface 3a in the form of an array with the same number as the number of optical fibers 2 and the same pitch as the arrangement pitch of the optical fibers 2.

  Hereinafter, the description will be continued by taking the case where the optical element 5 is a light receiving element as an example. As shown in FIG. 20, the light emitted from the optical fiber 2 enters the reflection surface 3a while spreading at the radiation angle φ ′. Here, due to the concave curved surface shape of the concave mirror 12, the spread incident light is collected and converted into convergent light and condensed on the light receiving unit 5 a of the light receiving element 5. Coupling efficiency is improved.

  When the concave mirror 12 is made of glass, it is produced by molding. Moreover, when manufacturing with a plastic, it is suitable to manufacture by the injection molding by a metal mold | die.

  The optical element 5 can be replaced with a VCSEL called VCSEL. In this case, the light emitted from the optical element 5 is condensed by the concave curved surface shape of the concave mirror 12, converted into convergent light, and condensed and coupled to the core 2a of the optical fiber 2, so that the optical connecting device 1 And the optical element 5 are improved in coupling efficiency.

<Fifth embodiment>
Next, a fifth embodiment of the present invention will be described with reference to FIGS. In addition, the same number is attached | subjected to the same location as each said embodiment, and the overlapping description is abbreviate | omitted or simplified and demonstrated.

  The fifth embodiment differs from the above embodiments in that a convex lens portion 4b is integrally formed at the light incident / exit portion of the optical connecting device 1. Convex lens portions 4 b having a convex curved surface shape are formed on the bottom surface of the array substrate 4 in the form of an array with the same number as the number of the optical fibers 2 and the same pitch as the array pitch of the optical fibers 2.

  Hereinafter, the description will be continued by taking the case where the optical element 5 is a light receiving element as an example. As shown in FIG. 22, the light emitted from the optical fiber 2 is incident on the reflecting surface 3a while spreading at the radiation angle φ ', is reflected, and is incident on the convex lens portion 4b. Here, due to the convex curved surface shape of the convex lens portion 4b, the light that has spread and spread is condensed, converted into convergent light, and condensed on the light receiving portion 5a of the light receiving element 5, so that the optical connecting device 1 and the light receiving element 5 The coupling efficiency is improved.

  When manufacturing the convex lens part 4b with glass, it manufactures by molding. Moreover, when manufacturing with a plastic, it is suitable to manufacture by the injection molding by a metal mold | die.

  The optical element 5 can be replaced with a VCSEL called VCSEL. In this case, the light emitted from the optical element 5 is condensed by the convex curved surface shape of the convex lens portion 4b, converted into convergent light, and condensed and coupled to the core 2a of the optical fiber 2, so that the optical connecting device 1 And the optical element 5 are improved in coupling efficiency. When the convex lens portion 4b is used, the convex lens 5b shown in FIG. 10 is not necessary.

  As shown in FIG. 23, the present embodiment shows the axial direction (z-axis direction in the figure) of the core 2a ′ of the optical fiber 2 ′ on the end portion of the optical fiber 2 ′ and the end surface 3b ′ of the prism 3 ′. It is also possible to change so as to provide the predetermined angle θf with respect to a direction perpendicular to.

  The present invention can be variously modified based on its technical idea. For example, the integrally molded product of the prism 3 and the array substrate 4 shown in FIG. 8 may be made of a silicon single crystal. In the case of integrally molding with a silicon single crystal, it may be manufactured by anisotropic etching or polishing.

  The optical connection device according to the present invention can be used for an optical connection device inside an information device such as a computer.

1 is a perspective view of an optical connection device according to a first embodiment of the present invention. 1 is a side view of an optical connection device according to a first embodiment of the present invention. The schematic diagram showing the state which mounted the optical connection apparatus of FIG. 1 in the optical element package. The schematic diagram showing the propagation state of the light in the optical connection apparatus which concerns on 1st Embodiment. The side view which shows the process of pinching | interposing a glass material between type | molds in the manufacturing method of the integral molding of a prism and the board | substrate for optical fiber arrangement | sequences. The side view which shows the process of pressing a glass material with a type | mold in the manufacturing method of the integral molding of a prism and the board | substrate for optical fiber arrangement | sequences. The side view which shows the process of extracting the glass material shape | molded from the type | mold in the manufacturing method of the integral molding of a prism and the board | substrate for optical fiber arrangement | sequences. The perspective view which shows the integrally molded product which integrated the prism and the board | substrate for optical fiber arrangement | sequences by molding. The perspective view showing the example of a change of the optical connection apparatus which concerns on the 1st Embodiment of this invention. The schematic diagram showing the propagation state of the light of the optical connection apparatus which concerns on 1st Embodiment in case an optical element is a light emitting element. The perspective view of the optical connection apparatus which concerns on the 2nd Embodiment of this invention. The schematic diagram showing the propagation state of the light in the optical connection apparatus which concerns on 2nd Embodiment. The schematic diagram showing the propagation state of the light in the optical connection apparatus of another form which concerns on 2nd Embodiment. The side view of the optical connection apparatus which concerns on the 3rd Embodiment of this invention. The schematic diagram showing the propagation state of light in the optical connecting device concerning a 3rd embodiment. The schematic diagram showing the propagation state of light in case the light is totally reflected on the reflecting surface in the optical connecting apparatus according to the third embodiment. FIG. 16 is an enlarged view of a circled portion A in FIG. 15. The schematic diagram showing the propagation state of the light in the example of a change of the optical connection apparatus concerning 3rd Embodiment. The side view of the optical connection apparatus which concerns on the 4th Embodiment of this invention. The schematic diagram showing the propagation state of light in the optical connecting device concerning a 4th embodiment. The side view of the optical connection apparatus which concerns on the 5th Embodiment of this invention. The schematic diagram showing the propagation state of light in the optical connecting device concerning a 5th embodiment. The schematic diagram showing the propagation state of light in the optical connection apparatus of the example of a change of 5th Embodiment. The perspective view showing an example of the conventional optical connection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical connection apparatus 2 Optical fiber 3 Prism 3a Reflecting surface 3b, 3c End surface 4 Optical fiber arrangement | sequence board | substrate 4a Groove 4b Convex lens part 5 Optical element 5a Light emitting part or light receiving part 6 Package 7 Bonding wire 8a, 8b Type 9 Glass material 10 Integrated Molded item 12 Concave mirror 13 GRIN lens

Claims (14)

A plurality of optical fibers, a prism provided with a reflecting surface, and an optical fiber array substrate on which the optical fibers are arrayed,
The reflecting surface is formed at a predetermined angle θ in the range of 0 degree <θ <90 degrees with respect to the axial direction of the core of the optical fiber,
The optical fibers are arranged on the optical fiber arrangement substrate so that the axes of the cores of the optical fibers are parallel to each other,
The prism and the optical fiber array substrate are composed of a light-transmitting material having the same refractive index as that of the core,
Furthermore, the end of the optical fiber and the end face of the prism facing the end are joined, and the prism and the optical fiber array substrate are joined,
An optical connection device, wherein a reflective film is formed on the reflective surface. A plurality of optical fibers, a prism provided with a reflecting surface, and an optical fiber array substrate on which the optical fibers are arrayed,
The reflecting surface is formed at a predetermined angle θ in the range of 0 degree <θ <90 degrees with respect to the axial direction of the core of the optical fiber,
The optical fibers are arranged on the optical fiber arrangement substrate so that the axes of the cores of the optical fibers are parallel to each other,
The optical fiber array substrate is composed of a light transmissive material,
Furthermore, the end of the optical fiber and the end face of the prism facing the end are joined, and the prism and the optical fiber array substrate are joined,
With respect to a direction perpendicular to the axial direction of the core of the optical fiber, the end portion and the end face of the prism facing the end portion,

(Where RL is the return loss at the joint surface where the end of the optical fiber and the end face of the prism facing the end are joined, n1: the refractive index of the core, n2 The refractive index of the prism, λ: the wavelength of light propagating through the optical fiber, and ω1: the mode field radius of the optical fiber).   3. The optical connection device according to claim 2, wherein a reflection film is formed on the reflection surface. The optical connection device according to any one of claims 1 to 3,
The optical connection device, wherein the end portion and the end face of the prism facing the end portion are joined by direct joining or hydrofluoric acid joining. A plurality of optical fibers, a prism provided with a reflecting surface, and an optical fiber array substrate on which the optical fibers are arrayed,
The reflecting surface is formed at a predetermined angle θ in the range of 0 degree <θ <90 degrees with respect to the axial direction of the core of the optical fiber,
The optical fibers are arranged on the optical fiber arrangement substrate so that the axes of the cores of the optical fibers are parallel to each other,
The prism and the optical fiber array substrate are composed of a light-transmitting material having the same refractive index as that of the core,
A GRIN lens is provided at the end of the optical fiber,
Furthermore, the central refractive index of the GRIN lens is set to be the same as the refractive index of the core,
The lens length of the GRIN lens is set to 0.25P (where P is the pitch of the GRIN lens) or more,
The end of the GRIN lens and the end face of the prism facing the end of the GRIN lens are joined, and the prism and the optical fiber array substrate are joined.
An optical connection device, wherein a reflective film is formed on the reflective surface. A plurality of optical fibers, a prism provided with a reflecting surface, and an optical fiber array substrate on which the optical fibers are arrayed,
The reflecting surface is formed at a predetermined angle θ in the range of 0 degree <θ <90 degrees with respect to the axial direction of the core of the optical fiber,
The optical fibers are arranged on the optical fiber arrangement substrate so that the axes of the cores of the optical fibers are parallel to each other,
The optical fiber array substrate is composed of a light transmissive material,
Furthermore, a GRIN lens is provided at the end of the optical fiber, and the lens length of the GRIN lens is set to 0.25P (where P is the pitch of the GRIN lens) or more.
The end of the GRIN lens and the end face of the prism facing the end of the GRIN lens are joined, and the prism and the optical fiber array substrate are joined.
With respect to the direction perpendicular to the axial direction of the end of the GRIN lens, the end of the GRIN lens and the end surface of the prism facing the end of the GRIN lens,

Angle θf (where RL ′ is the return loss at the joint surface where the end of the GRIN lens and the end of the prism facing the end of the GRIN lens are joined, and n3 is the GRIN lens. N2: refractive index of the prism, λ: wavelength of light propagating through the optical fiber, and ω2: beam waist radius at the end of the GRIN lens). Optical connection device.   7. The optical connection device according to claim 6, wherein a reflection film is formed on the reflection surface. In the optical connecting device according to claim 5 or 6,
An optical connection device, wherein an end of the GRIN lens and the end face of the prism facing the end of the GRIN lens are joined by direct joining or hydrofluoric acid joining. The optical connection device according to any one of claims 1 to 8,
The optical connection device, wherein the prism and the optical fiber array substrate are bonded by direct bonding or hydrofluoric acid bonding. The optical connection device according to any one of claims 1 to 8,
An optical connection device, wherein the prism and the optical fiber array substrate are integrally formed. The optical connection device according to claim 1,
An optical connecting device, wherein a concave mirror is provided on the reflecting surface. The optical connection device according to claim 1,
A convex lens portion is formed at a light incident / exit portion of the optical connection device. The optical connection device according to any one of claims 1 to 12,
An optical connection device, wherein an antireflection film is formed on a light incident / exit portion of the optical connection device.   14. A method for mounting an optical connection device, wherein the optical connection device according to claim 1 is bonded to a package on which an optical element is mounted by direct bonding or hydrofluoric acid bonding.

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