JP2016024439A - Optical circuit component, and connection structure of optical circuit component and optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical circuit component designed to downsize an optical circuit component and simplify an alignment mechanism for connecting an optical fiber and the optical circuit component, and a connection structure of the optical circuit component and the optical fiber.SOLUTION: An optical circuit component 1 has a circuit board 10, a first core 11 formed on the circuit board 10 and configuring an optical waveguide for signal use, and a second core 12 and a third core 13 formed on the circuit board 10 and configuring an optical waveguide for alignment use, and a fourth core 14 configuring an optical waveguide for connecting the second core 12 and the third core 13. One tip of the first core 11, one tip of the second core 12, and one tip of the third core 13 are formed, with the core ends in a row, on one side of the circuit board 10, and the fourth core 14 has a bent section in a portion configured from silicon, the other tip of the second core 12 and the other tip of the third core 13 being connected.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical circuit component in which an optical waveguide is formed, and a connection structure between the optical circuit component and an optical fiber, for example, an optical circuit component made of a silicon photonics chip.

Now that a wide range of applications for information processing systems and information transmission systems is advancing, large-scale integration and high functionality equivalent to those of electronic circuits are also demanded for optical circuits that play a role in these.
In recent years, as a technique for realizing large-scale integration and high performance of an optical circuit, an optical waveguide having a silicon (Si) thin wire as a core and a photodiode (hereinafter referred to as “PD: Photo Diode”) composed of germanium (Ge). ) Is integrated on the same semiconductor substrate, and a silicon photonics (hereinafter referred to as “SiPh”) technology is expected.

In the SiPh technology, an optical circuit based on a channel-type optical waveguide having Si as a core and SiO ₂ as a cladding is formed on, for example, an SOI (Silicon-on Insulator) substrate. The optical waveguide formed by the SiPh technology has a relative refractive index difference Δ of about 40% between the Si core and the SiO ₂ cladding, which is several tens of times larger than that of the silica-based optical waveguide. That is, the optical waveguide based on the SiPh technology has the following excellent characteristics because the optical confinement effect due to a large refractive index difference is very strong.

  For example, in the optical waveguide based on the SiPh technology, the core size of the optical waveguide having a square cross section that satisfies the single mode condition in the infrared region for communication near the wavelength of 1550 nm is about 300 nm × 300 nm, which is one hundredth of that of the silica-based optical waveguide. The cross-sectional area is characteristic. In addition, the optical waveguide based on the SiPh technology has a feature that the minimum radius of curvature that can be bent without loss is about several μm, which is one thousandth of the minimum radius of curvature of the silica-based optical waveguide. Due to these features, large-scale integration of optical circuits using SiPh technology is expected.

  In addition, since the SiPh technology generally uses an SOI substrate, it can be monolithically integrated with an electronic circuit, and an optical power density of about 100 MW / cm 2 can be easily obtained, so that an optical nonlinear effect can be efficiently expressed. Yes, with great potential in terms of functionality. Furthermore, from the viewpoint of manufacturing technology, since a mature Si semiconductor microfabrication technology can be applied, it is easy to form a fine pattern and is excellent in mass productivity.

  As described above, the SiPh technology has excellent characteristics, and in recent years, various optical devices based on Si thin-wire optical waveguides such as ring resonators, splitters, and arrayed waveguide grating type wavelength filters have been used. Research and development is ongoing.

  However, it has been pointed out that there are significant problems in the basic characteristics of optical waveguides in the practical application of these ultrafine optical devices based on Si wires.

  The first problem is that the optical coupling loss becomes very large due to the large difference in mode field size between the optical fiber for optical input / output and the Si thin-wire optical waveguide. In general, the mode field size of the Si fine wire optical waveguide is about 300 nm. On the other hand, the mode field diameter of a normal single mode optical fiber (hereinafter also referred to as “SMF: Single-mode optical fiber”) is about 9 μm, and an optical fiber having a high relative refractive index difference of about 2%. Even if it is, it is about 4 μm. That is, the cross-sectional area of the optical fiber is 100 to 1000 times larger than that of the Si fine wire optical waveguide. Therefore, even if an optical fiber having a large mode field is directly connected to a Si thin-wire optical waveguide, a loss of 20 dB or more is generated, so that it is not practically used. Further, there is a problem that the wavelength characteristics are extremely deteriorated due to the end face reflection.

In order to solve such a problem of coupling loss, an inversely tapered spot size conversion (hereinafter referred to as “SSC: Spot-size-converter”) is conventionally used as a connection structure between an optical fiber and a Si fine wire optical waveguide. The structure is known (see Non-Patent Document 1).
The SSC structure is composed of a heat-insulating reverse tapered Si thin wire and a large-diameter optical waveguide for connection that covers it. A Si core (for example, 300 nm × 300 nm) composed of a thin Si wire becomes tapered in a large-diameter optical waveguide for connection and eventually disappears. Light leaking from the tapered portion of the Si core is captured by the outer large-diameter optical waveguide. Since this process is adiabatic, little reflection or loss occurs.

  Further, the large-diameter optical waveguide for connection described above is a single mode optical waveguide having a relative refractive index difference of about 3% using SiOx having a refractive index of about 1.51 as a core and SiO2 as a cladding. It has a core with a large diameter of 3 μm. Therefore, it is possible to connect with low loss by connecting an optical fiber having a high relative refractive index difference with a mode field diameter of about 4 μm and a large-diameter optical waveguide. In addition, the end part connected to the optical fiber in this large-diameter optical waveguide has the same structure as the end part of a planar optical waveguide circuit (PLC: Planar Lightwave Circuit) constituted by a silica-based optical waveguide.

  The application of the SSC structure described above makes it possible to connect the Si thin-line optical waveguide and the optical fiber with low loss. However, in order to actually realize the connection structure between the Si thin-line optical waveguide and the optical fiber, Accurate alignment (hereinafter also referred to as “alignment”) between the fiber and the large-diameter optical waveguide for connection is required.

As a technique for aligning an optical fiber and a large-diameter optical waveguide for connection, for example, Patent Document 1 discloses a technique used for connecting an optical circuit and an optical fiber to a PLC component having an optical waveguide constituting a PLC circuit. Proposed technology to provide an optical waveguide for the core, arrange one input / output end face of the aligning optical waveguide on the same end face as the input / output end face of the input / output waveguide of the PLC circuit, and place the other on the opposite end face Has been.
FIG. 16 is a diagram showing an example of an alignment mechanism for connecting an optical circuit component having a conventional alignment optical waveguide disclosed in Patent Document 1 and an optical fiber block for optical input / output. In the figure, for simplicity, one of a plurality of optical fibers included in the optical fiber block 91 is connected to one alignment optical waveguide 901 provided on the end face of the optical circuit component 90. An alignment mechanism 900 is shown for the purpose.

  The alignment of the optical fiber block 91 with respect to the optical circuit component 90 is performed as follows, for example. First, the light output from the light source 96 is input to the end of the aligning optical waveguide 901 on the end face 90A side via the input optical fiber 94 and the optical fiber block 91. As a result, light is output from the end portion of the aligning optical waveguide 901 on the end face 90B side. Next, the output light of the aligning optical waveguide 901 is input to the optical power meter 97 via the output optical fiber 95, and the optical fiber moving device is controlled by the controller 98 so that the light intensity of the input output light is maximized. 92 and 93 are moved. As a result, alignment of the optical fiber block 91 with respect to the optical circuit component 90 can be performed with high accuracy.

Japanese Patent Laid-Open No. 2004-4907

T. Shoji, et al., "Low loss mode size converter from 0.3 μm square Si wire waveguides to singlemode fibers", ELECTRONICS LETTERS, Vol.38, No.25, pp.1669-1670, 5th December 2002.

  However, it has been clarified that the technique described in Patent Document 1 has the following problems. That is, in the alignment mechanism 900 described above, since the output optical fiber 95 must be connected not only to the end surface 90A of the optical circuit component 90 but also to the end surface 90B on the opposite side, the two optical fiber moving devices 92, 93 and a control device 98 for properly controlling them separately are required, which causes a problem that the device is enlarged and the configuration is complicated.

  Further, depending on the layout of the optical circuit on the optical circuit component, there are cases where the both ends of the aligning optical waveguide cannot necessarily be formed on the opposite end surfaces of the optical circuit component. For example, in the case where a germanium photodiode (hereinafter referred to as “GePD”) is built in an optical circuit, an input optical signal is converted into an electrical signal by GePD formed in the optical circuit. In this case, since the optical signal cannot be taken out from the end of the aligning optical waveguide, the above aligning mechanism cannot be employed. In order to align an optical fiber block for such an optical circuit component, for example, it is necessary to detect an electrical signal from GePD and align the optical fiber block so that the electrical signal is maximized. is there. However, in this case, since it is necessary to separately provide an alignment electrode pad for detecting an electrical signal from GePD, the area of the optical circuit is increased and the scale of the optical circuit component is increased. There was a problem. In this case, since a probe or the like for connecting to the electrode pad is required, there is a problem that the configuration of the alignment mechanism is complicated.

  The present invention has been made to solve the above-described problems, and aims to simplify the alignment mechanism for connecting an optical fiber and an optical circuit component while reducing the size of the optical circuit component. For the purpose.

  An optical circuit component (1 to 4) according to the present invention includes a substrate (10) having a substantially rectangular shape in plan view, and a first core (11, 21, 31) formed on the substrate and constituting an optical waveguide for signals. ), A second core and a third core (12, 13) that are formed on the substrate and constitute an aligning optical waveguide, and are formed on the substrate, at least part of which is made of silicon, A fourth core (14, 24, 34, 44) constituting an optical waveguide connecting the second core and the third core, one end of the first core, and the second core One end portion and one end portion of the third core are formed side by side along one side (10A) of the substrate, and the fourth core is made of silicon. The portion has a bent portion, and connects the other end of the second core and the other end of the third core. And wherein the door.

  In the optical circuit component, the first core, the second core, and the third core are formed such that a core end portion is aligned with one side of the substrate in a plan view, and the first core is a plan view. In, it may be arranged between the second core and the third core.

  The optical circuit component (1, 1A) further includes a fifth core (15) formed on the substrate and made of silicon, the first core covering one end of the fifth core. The sixth core is formed of silicon, one end portion is covered and connected to the other end portion of the second core, and the sixth core (141) has a first bent portion (1410). , A seventh core (142) having a second bent portion (1420) and having one end portion covered with and connected to the other end portion of the third core, and the other end of the sixth core. An eighth core (143) that covers an end, the other end of the seventh core, and a part of the fifth core and intersects the fifth core in plan view, , The second core, the third core, and the eighth core have a refractive index higher than that of silicon. It may be constructed from old material.

  In the optical circuit component (2, 2A, 3, 3A), the fourth core is made of silicon, one end portion is covered and connected to the other end portion of the second core, and the first bent portion A fifth core (141) having (1410) and a sixth core having a second bent portion (1420) composed of silicon and having one end covered and connected to the other end of the third core (142) and a seventh core (243, 343) that covers the other end of the fifth core and the other end of the sixth core and intersects the first core in plan view. The first core, the second core, the third core, and the seventh core are made of a material having a refractive index smaller than that of silicon, and the first core and the seventh core intersect each other. May be formed as a single unit.

  The optical circuit component (3, 3A) further includes an eighth core (35) made of silicon and formed on the substrate, and the eighth core is identical to the first core in plan view. A portion (351) extending in the direction may be provided, and the seventh core may intersect the eighth core at a portion where the first core and the eighth core overlap in a plan view.

  In the optical circuit component, the material having a refractive index smaller than that of silicon may include silicon oxide or silicon nitride.

  The optical circuit component (1A, 2A, 3A) may include a plurality of the first cores (11_1 to 11_4, 21_1 to 21_4, 31_1 to 31_4).

  The connection structure between the optical fiber and the optical circuit component according to the present invention is arranged corresponding to the arrangement interval of the optical circuit component (1), the first core, the second core, and the third core. An optical fiber block (7) having a first optical fiber (71), a second optical fiber (72), and a third optical fiber (73), wherein the optical circuit component and the optical fiber block are the first optical fiber block (7). The end surface (11A) of the one end of the core and the end surface (71A) of the core of the first optical fiber face each other, and the end surface (12A) of the one end of the second core and the second light The end face (72A) of the core of the fiber faces, and the end face (13A) of the one end of the third core and the end face (73A) of the core of the third optical fiber face each other and are connected. It is characterized by that.

  As described above, according to the present invention, it is possible to simplify the alignment mechanism for connecting the optical fiber and the optical circuit component while reducing the size of the optical circuit component.

FIG. 1 is a diagram schematically illustrating a connection structure between an optical circuit component and an optical fiber block according to the first embodiment. FIG. 2 is a diagram schematically showing the structure of the optical waveguide of the optical circuit component according to the first embodiment. FIG. 3A is a diagram schematically showing an SSC structure of a connection portion between a core made of silicon and a core having a refractive index smaller than that of silicon, viewed from a direction P in FIG. FIG. 3B is a diagram schematically showing an SSC structure of a connection portion between a core made of silicon and a core having a refractive index smaller than that of silicon, viewed from a direction Q in FIG. FIG. 3C is a diagram schematically showing an SSC structure of a connection portion between a core made of silicon and a core having a refractive index smaller than that of silicon, viewed from a direction R in FIG. FIG. 4 is a diagram schematically showing a structure of a portion where the alignment optical waveguide and the signal optical waveguide intersect in the optical circuit component according to the first embodiment. FIG. 5 is a diagram showing an alignment mechanism for aligning the optical fiber block with respect to the optical circuit component according to the first embodiment. FIG. 6 is a diagram illustrating a positional relationship between the optical fiber block after alignment and the optical circuit component. FIG. 7 is a diagram schematically showing a planar structure of an optical circuit component having a plurality of signal optical waveguides according to the first embodiment. FIG. 8 is a diagram schematically showing a connection structure between the optical circuit component and the optical fiber block according to the second embodiment. FIG. 9 is a diagram schematically showing the structure of a portion where the alignment optical waveguide and the signal optical waveguide intersect in the optical circuit component according to the second embodiment. FIG. 10 is a diagram schematically showing a planar structure of an optical circuit component having a plurality of optical waveguides for signals according to the second embodiment. FIG. 11 is a diagram schematically illustrating a connection structure between the optical circuit component and the optical fiber block according to the third embodiment. FIG. 12 is a diagram schematically showing a structure of a portion where the alignment optical waveguide and the signal optical waveguide intersect in the optical circuit component according to the third embodiment. FIG. 13 is a diagram schematically showing a planar structure of an optical circuit component having a plurality of optical waveguides for signals according to the third embodiment. FIG. 14A is a diagram schematically illustrating a connection structure between the optical circuit component and the optical fiber block according to Embodiment 4. FIG. 14B is a diagram schematically showing a structure of an end portion of a core constituting a signal optical waveguide in the optical circuit component according to Embodiment 4. FIG. 15 is a diagram schematically illustrating a connection structure between another optical circuit component and the optical fiber block according to the fourth embodiment. FIG. 16 is a diagram showing an example of an alignment mechanism for connecting a conventional optical circuit component having an alignment optical waveguide and an optical fiber block for optical input / output.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< Embodiment 1 >>
FIG. 1 is a diagram schematically showing a connection structure between an optical circuit component and an optical fiber block according to an embodiment of the present invention. This figure shows a connection structure between an optical circuit component and an optical fiber block in plan view.

The optical fiber block 7 has a structure in which a plurality of optical fibers 71 to 73 are sandwiched and fixed by a plate-like member 70 from above and below. The optical fibers 71 to 73 are, for example, single mode fibers (SMF) having a mode field diameter (MFD) of about 4 μm. The optical fiber 71 is for propagating light (hereinafter referred to as “signal light”) SL that is used for communication. The optical fibers 72 and 73 are used for aligning light (alignment) when aligning (aligning) the optical fiber block 7 with the optical circuit component 1 in the assembly process of connecting the optical circuit component 1 and the optical fiber block 7. Hereinafter, it is referred to as “alignment light.”) For propagating AL.
The optical fibers 71 to 73 are arranged along a direction perpendicular to the light guiding direction. The optical fiber 71 is disposed between the optical fiber 72 and the optical fiber 73. The arrangement pitch of the optical fibers 71 to 73 is set corresponding to the arrangement of the cores 11 to 13 of the optical circuit component 1 described later.

The optical circuit component 1 is, for example, a silicon photonics chip (hereinafter referred to as “SiPh chip”) in which an optical circuit is formed on a substrate 10 by SiPh technology.
The substrate 10 is made of, for example, an SOI substrate. A plurality of optical waveguides constituting an optical circuit are formed on the substrate 10. In FIG. 1, only the optical waveguide as an optical input / output interface unit with the optical fiber block 7, which is a characteristic part of the optical circuit component 1 according to the present embodiment, is illustrated among the plurality of optical waveguides. The illustration of the optical waveguide is omitted.

The optical circuit component 1 has cores 11 to 15 as a plurality of cores constituting the optical waveguide.
The core 11, the core 12, and the core 13 are formed side by side along one side of the substrate 10 in a plan view, and one end of the core 11, one end of the core 12, and the core 13 One end is formed side by side on the same end surface 10 </ b> A of the substrate 10.

  The core 11 constitutes a signal optical waveguide for inputting (or outputting) the signal light SL through the optical fiber block 7. The core 11 is disposed between the core 12 and the core 13 in plan view.

  The cores 12 and 13 constitute an optical waveguide for propagating alignment light. The core 14 is at least partially made of silicon, and constitutes an optical waveguide that connects the aligning core 12 and the core 13. The core 14 is formed by bending a portion made of silicon, thereby connecting the other end of the core 12 and the other end of the core 13.

  The core 15 has one end connected to the core 11 and the other end connected to, for example, an optical circuit (not shown) at the subsequent stage. For example, the core 15 propagates the signal light input to the core 11 via the optical fiber block 7 to the subsequent optical circuit.

Here, specific structures of the cores 11 to 13 and the core 15 will be described.
FIG. 2 is a diagram schematically showing the structure of the optical waveguide of the optical circuit component according to the first embodiment. In the figure, the structures of the core 11 and the core 15 are typically shown.

The core 15 is formed by processing silicon (Si) on the lower cladding layer 18. The cross-sectional size (thickness × width) of the core 15 is, for example, 220 nm × 440 nm. The lower cladding layer 18 is a silicon oxide film (SiO ₂ ) and has a thickness of 3 μm, for example. In the present embodiment, the lower clad layer 18 is described as a buried oxide (BOX) layer of an SOI substrate constituting the substrate 10, but the present invention is not limited to this.

  The core 11 is formed on the lower cladding layer 18 so as to cover one end 150 of the core 15. The core 11 is made of a material having a refractive index smaller than that of silicon, for example. Examples of the material having a refractive index smaller than that of silicon include silicon oxide (SiOx), silicon nitride, and the like whose oxygen coupling rate is adjusted so that the refractive index is smaller than that of silicon. The cross-sectional size (thickness × width) of the core 11 is, for example, 3 μm × 3 μm. The refractive index of the core 11 with respect to light with a wavelength of 1.55 μm is, for example, 1.51, and the refractive index of the lower cladding layer 18 is, for example, 1.46. As a result, the core 11 constitutes a large-diameter single mode optical waveguide having a relative refractive index difference of about 3.3%.

  The cores 12 and 13 are formed of the same material and the same cross-sectional size (thickness × width) as the core 11, and constitute a large-diameter single mode optical waveguide like the core 11.

  The upper cladding layer 16 is formed on the lower cladding layer 18 so as to cover the core 11 and the core 15. The thickness of the upper cladding layer 16 formed on the core 11 is, for example, 7 μm.

The connecting portion between the core 11 and the core 15 has a spot size conversion (SSC) structure.
3A to 3C are diagrams schematically showing the structure of the connecting portion 110 between the core 11 and the core 15. 3A schematically shows the structure of the connecting portion 110 when viewed from the direction P in FIG. 2, and FIG. 3B schematically shows the structure of the connecting portion 110 when viewed from the direction Q in FIG. FIG. 3C schematically shows the structure of the connecting portion 110 when viewed from the direction R in FIG.

  As shown in FIG. 3A to FIG. 3C, in the connecting portion 110 between the core 11 and the core 15, the end 150 of the core 15 covered with the large-diameter core 11 becomes a tapered taper with the core width becoming narrower toward the tip. It has an SSC structure formed to have a shape. According to this, as described above, the core 11 and the core 15 can be optically connected with low loss.

Next, a specific structure of the core 14 will be described.
As shown in FIG. 1, the core 14 constituting the aligning optical waveguide is formed so as to intersect with the core 15 constituting the signal optical waveguide in plan view. The core 14 includes a core 141, a core 142, and a core 143.

  The core 141 has one end connected to the core 12 and the other end connected to the core 143. The core 142 has one end connected to the core 13 and the other end connected to the core 143. As shown in FIG. 1, the cores 141 and 142 are made of silicon and have a partially bent shape (hereinafter referred to as a “bent portion”), and the other of the core 141 via the core 143. And the other end of the core 142 are arranged to face each other. The bent portion 1410 of the core 141 and the bent portion 1420 of the core 142 are formed in an arc shape, for example. The radii of curvature of the bent portion 1410 of the core 141 and the bent portion 1420 of the core 142 can be reduced to a range where the loss of the optical waveguide is allowed, for example, about 10 μm.

  The connecting portion between the core 141 and the core 12 and the connecting portion between the core 142 and the core 13 have the same SSC structure as the connecting portion 110 between the core 11 and the core 15 described above.

The core 143 is formed so as to intersect with the core 15 made of silicon, and constitutes an optical waveguide that connects the core 141 and the core 142.
FIG. 4 is a diagram schematically showing a structure of a portion where the alignment optical waveguide and the signal optical waveguide intersect in the optical circuit component according to the first embodiment. In the figure, the illustration of the upper cladding layer 16 is omitted.
As shown in the figure, the core 143 covers the other end of the core 141, the other end of the core 142, and a part of the core 15 on the substrate 10 (lower clad layer 18). It is formed and extends across the core 15 in plan view. The core 143 is made of the same material (for example, SiOx) as the cores 11 to 13 and has the same cross-sectional size as the cores 11 to 13.

  The connecting portion between the core 143 and the core 141 and the connecting portion between the core 143 and the core 142 have the same SSC structure as the connecting portion 110 between the core 11 and the core 15 described above.

  For example, when the alignment light AL is input to the end face 12A of the alignment core 12 during alignment of the optical fiber block 7, the alignment light AL propagates as follows. First, the alignment light AL input to the end surface 12A of the alignment core 12 is input to the core 141 via the SSC unit 1411. The aligning light AL input to the core 141 propagates through the core 141, changes the waveguide direction by a bent portion 1410 formed in the middle of the core 141, and is input to the core 143 via the SSC portion 1412. . The alignment light AL input to the core 143 propagates through the core 143 and is input to the core 142 via the SSC unit 1421. The alignment light AL input to the core 142 propagates through the core 142, the waveguide direction is changed by a bent portion 1420 formed in the middle of the core 142, and is input to the core 13 via the SSC portion 1421. . The alignment light AL input to the core 13 propagates through the core 13 and is output from the end face 13A of the core 13.

  According to the core 14 having the above structure, the alignment light AL input to one alignment core can be output from the other alignment core with low loss. Further, by forming a bent portion in the middle of the cores 141 and 142 made of silicon, the bending radius is smaller than that in the case of forming a bent portion in the middle of the core made of SiOx having a refractive index smaller than that of silicon. The light guiding direction can be changed. This makes it possible to reduce the area occupied by the aligning optical waveguide formed on the SiPh chip.

Next, a method for aligning the optical fiber block 7 with respect to the optical circuit component 1 will be described.
FIG. 5 is a diagram showing an alignment mechanism for aligning the optical fiber block with respect to the optical circuit component according to the present embodiment.
As shown in the figure, the alignment mechanism 100 includes a light source 80, an input optical fiber 81, an output optical fiber 82, an optical power meter 83, a control device 84, an optical fiber block moving device 85, and a stage 86. ing.

The stage 86 is a support base for supporting and fixing the optical circuit component 1.
The optical fiber block moving device 85 includes a support member for supporting and fixing the optical fiber block 7. The optical fiber block moving device 85 moves in the X direction, the Y direction, and the Z direction in accordance with a control signal from the control device 84 in a state where the optical fiber block 7 is fixed to the support member. Alignment (alignment) with respect to the optical circuit component 1 is performed.

  The light source 80 emits alignment light (alignment light). The input optical fiber 81 is an optical fiber that connects the optical fiber block 7 fixed to the optical fiber block moving device 85 and the light source 80, and the alignment light AL emitted from the light source 80 is adjusted by the optical fiber block 7. It inputs into the optical fiber for hearts (for example, optical fiber 72).

  The output optical fiber 82 is an optical fiber that connects the optical fiber block 7 fixed to the optical fiber block moving device 85 and the optical power meter 80, and an optical fiber for alignment of the optical fiber block 7 (for example, an optical fiber). 73) The alignment light AL output from 73) is input to the optical power meter 83. The optical power meter 83 is a device that measures the intensity of input light and outputs a measurement result. The control device 84 controls the optical fiber block moving device 85 by generating a control signal for controlling the optical fiber block moving device 85 based on the measurement result of the optical power meter 83.

The alignment procedure of the optical fiber block 7 using the alignment mechanism 100 will be described.
First, the optical circuit component 1 is fixed on the stage 86 and the optical fiber block 7 is fixed to the optical fiber block moving device 85. Next, the optical fiber block 7 is roughly aligned with the optical circuit component 1 fixed to the stage 86 manually or automatically by image recognition using a camera from above. Specifically, the waveguide direction of the alignment optical fiber 72 and the waveguide direction of the alignment core 12 of the optical circuit component 1 are aligned, and the waveguide of the alignment optical fiber 73 is aligned. The optical fiber block moving device 85 is moved so that the direction and the waveguide direction of the alignment core 13 of the optical circuit component 1 are aligned.

  Next, alignment light AL is emitted from the light source 80. The alignment light AL emitted from the light source 80 is input to the alignment optical fiber 72 of the optical fiber block 7 through the input optical fiber 81. The alignment light AL input to the optical fiber 72 propagates through the optical fiber 72 and is input to the alignment core 12 provided on the end face of the optical circuit component 1. The alignment light AL input to the core 12 propagates to the alignment core 13 via the core 14 and is output from the end of the core 13. The alignment light AL output from the end of the core 13 propagates through the alignment optical fiber 73 of the optical fiber block 7 and is input to the optical power meter 83 via the output optical fiber 82. The controller 84 controls the optical fiber block moving device 85 so as to align the optical fiber block 7 so that the light intensity of the aligning light measured by the optical power meter 83 is maximized.

FIG. 6 shows the positional relationship between the optical fiber block 7 and the optical circuit component 1 after alignment.
In the figure, the structure of the optical circuit component 1 as viewed from the end face 10A side is schematically shown. In the figure, the optical fibers 71 to 73 are indicated by dotted lines.
As shown in the figure, after alignment, the end surface 72A of the core of the alignment optical fiber 72 and the end surface 12A of the alignment core 12 face each other, and the end surface of the core of the alignment optical fiber 73 73A and the end face 13A of the aligning core 13 face each other, and the end face 71A of the core of the signal optical fiber 71 and the end face 11A of the signal core 11 face each other.

  Here, “opposite” means that the two end faces are in a position where they face each other in front of each other, not only when the optical axes of the corresponding cores are arranged on the same straight line, but also optically This includes the case where the optical axes are arranged with some errors within the allowable range of loss.

  When alignment of the optical fiber block 7 is completed, the end face of the optical fiber block 7 is fixed to the end face of the optical circuit component 1 (end face of the SiPh chip) using, for example, an adhesive. Thereby, the alignment work is completed. In addition, the said adhesive agent is comprised from the material by which refractive index was adjusted so that an optical loss may not arise between the cores 11-13 in the optical circuit component 1, and the optical fibers 71-73, for example, ultraviolet rays It is composed of an adhesive material such as a curable epoxy type or acrylic type.

  By aligning the optical fiber block 7 as described above, the core 11 and the signal optical fiber 71 constituting the signal optical waveguide are connected with low loss, and the optical fiber and the optical circuit component are connected. A connection structure can be realized.

  As described above, according to the optical circuit component 1 according to the present embodiment, since both end surfaces of the cores 12 and 13 for inputting and outputting the aligning light are formed on one end surface 10A of the optical circuit component 1, the optical fiber It is possible to simplify the alignment mechanism for connecting the optical circuit component and the optical circuit component. That is, according to the optical circuit component 1, two optical fiber moving devices and a control device for separately controlling them are not required as in the above-described conventional alignment mechanism 900 (see FIG. 16). Thus, the alignment mechanism can be simplified. As a result, the number of work steps in the aligning work is reduced as compared with the prior art, and the aligning work becomes easy.

Further, according to the optical circuit component 1 according to the present embodiment, a core 12 for inputting and outputting alignment light by forming a part of the core 14 from silicon and bending the part formed from the silicon, Since 13 are connected to each other, the aligning optical waveguide can be formed with a low loss and a small area. Thereby, the SiPh chip provided with the aligning optical waveguide can be realized with a smaller area than the conventional one, and the manufacturing cost of the optical circuit component can be expected to be reduced.
That is, according to the optical circuit component 1 according to the present embodiment, it is possible to simplify the alignment mechanism while reducing the size of the optical circuit component.

  In this embodiment, the case where there is one signal optical waveguide is illustrated, but the present invention is not limited to this, and there may be a plurality of signal optical waveguides.

  FIG. 7 is a diagram schematically showing a planar structure of an optical circuit component having a plurality of signal optical waveguides according to the first embodiment. In the figure, the same components as those of the optical circuit component 1 described above are denoted by the same reference numerals, and detailed description thereof is omitted. Further, although the figure illustrates the case where four signal optical waveguides are formed, the number of signal optical waveguides is not particularly limited.

  As shown in the figure, the optical circuit component 1A includes cores 11_1 to 11_4 and cores 15_1 to 15_4 that constitute an optical waveguide for signals. The cores 11_1 to 11_4 are arranged along the end surface 10A between the aligning core 12 and the aligning core 13 in plan view. The cores 11_1 to 11_4 are formed of the same material (for example, SiOx) as the core 11 described above and have the same structure. The cores 15_1 to 15_4 are formed of the same material (silicon) as the core 15 described above and have the same structure. Similarly to the core 11 and the core 15, the cores 15_1 to 15_4 and the cores 11_1 to 11_4 are connected to each other by the SSC structure, respectively. Similarly to the core 15 described above, the core 143 is formed so as to intersect with the cores 15_1 to 15_4.

  The optical fiber block 7 includes four optical fibers 71_1 to 71_4 for signal in addition to the optical fibers 72 and 73 for alignment. The optical fibers 71_1 to 71_4 for signals are respectively arranged in the optical fiber block 7 at an arrangement pitch corresponding to the arrangement of the cores 11_1 to 11_4.

  According to the optical circuit component 1A having a plurality of signal optical waveguides, the alignment mechanism can be simplified while reducing the size of the optical circuit components in the same manner as the optical waveguide 1 having one signal optical waveguide. It becomes possible.

<< Embodiment 2 >>
The optical circuit component according to the second embodiment is related to the first embodiment in that the alignment optical waveguide and the signal optical waveguide intersect at cores made of a material having a refractive index smaller than that of silicon. The optical circuit component 1 is different from the optical circuit component 1 in other points. In the optical circuit component 2 according to the second embodiment, the same components as those in the optical circuit component 1 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 8 is a diagram schematically showing a connection structure between the optical circuit component and the optical fiber block according to the second embodiment.
As shown in the figure, the optical circuit component 2 includes cores 21 and 25 that constitute an optical waveguide for signals and cores 12, 13, and 24 that constitute an optical waveguide for alignment.

  The core 24 includes cores 141 and 142 made of silicon and a core 243 made of a material having a refractive index smaller than that of silicon. As shown in FIG. 8, the core 243 is formed on the substrate 10 (lower clad layer 18) so as to intersect with the core 21 in a plan view. Hereinafter, the core 243 and the core 21 will be described in detail.

FIG. 9 is a diagram schematically showing the structure of a portion where the alignment optical waveguide and the signal optical waveguide intersect in the optical circuit component according to the second embodiment. In the figure, the illustration of the upper cladding layer 16 is omitted.
As shown in the figure, the core 243 includes the other end portion of the core 141 and the other end portion of the core 142 on the substrate 10 (lower clad layer 18), similarly to the core 143 according to the first embodiment. And extends across the core 21 in plan view. As shown in FIG. 9, the connecting portion between the core 243 and the core 141 and the connecting portion between the core 243 and the core 142 have the SSC structure as in the optical circuit component 1 according to the first embodiment. Have.

  The core 21 is formed on the substrate 10 (lower cladding layer 18) so as to cover one end portion (SSC portion) 250 of the core 25, similarly to the core 11 according to the first embodiment.

  The core 21 and the core 243 are made of the same material (for example, SiOx or silicon nitride) having a refractive index smaller than that of silicon, similarly to the cores 12 and 13. As shown in FIG. 9, the core 21 and the core 243 are integrally formed as, for example, a cross-shaped structure in which two cores intersect each other. The intersection angle between the core 21 and the core 243 is, for example, 90 degrees. The cross-sectional size (thickness × width) of the core 21 and the core 243 is the same as that of the core 11 and the core 143 according to the first embodiment, and is, for example, 3 μm × 3 μm.

  For example, when the alignment light AL is input to the end face 12A of the alignment core 12 during alignment of the optical fiber block 7, the alignment light AL propagates as follows. First, the alignment light AL input to the end face 12 </ b> A of the core 12 propagates through the core 12 and is input to the core 243 via the core 141. The alignment light AL input to the core 243 propagates through the core 243, passes through the intersection of the core 243 and the core 21, and is input to the core 142. Thereafter, the alignment light AL input to the core 142 propagates through the core 142, is input to the core 13, propagates through the core 13, and is output from the end face 13A of the core 13. On the other hand, during normal use after alignment, the signal light SL that is the object of communication is input to the end face 21 </ b> A of the signal core 21 via the signal optical fiber 71 of the optical fiber block 7. The signal light SL input to the end face 21 </ b> A of the signal core 21 propagates through the core 21, is input to the core 25, and propagates through the core 25 to a subsequent optical circuit (not shown).

8 and 9 illustrate the case where there is one signal optical waveguide, but there may be a plurality of signal optical waveguides.
FIG. 10 is a diagram schematically showing a planar structure of an optical circuit component having a plurality of optical waveguides for signals according to the second embodiment. In the figure, the same components as those of the optical circuit component 2 described above are denoted by the same reference numerals, and detailed description thereof is omitted. Further, although the figure illustrates the case where four signal optical waveguides are formed, the number of signal optical waveguides is not particularly limited.

As shown in the figure, the optical circuit component 2A includes four cores 21_1 to 21_4 and four cores 25_1 to 25_4 that constitute an optical waveguide for signals. The cores 21_1 to 21_4 are arranged along the end face 10A between the aligning core 12 and the aligning core 13 in plan view. The cores 21_1 to 21_4 are formed of the same material (for example, SiOx) as the core 21 described above, and have the same structure. The cores 25_1 to 25_4 are made of the same material (silicon) as the core 25 described above and have the same structure. Similarly to the core 21 and the core 25, the cores 25_1 to 25_4 and the cores 21_1 to 21_4 are connected to each other through the SSC structure.
Similarly to the core 25 described above, the core 243 is formed so as to intersect with the cores 21_1 to 21_4.

  As described above, according to the optical circuit components 2 and 2A according to the second embodiment, as with the optical circuit component 1 according to the first embodiment, the alignment mechanism is simplified while reducing the size of the optical circuit component. It becomes possible.

Further, in the optical circuit components 2 and 2A according to the second embodiment, the alignment optical waveguide and the signal optical waveguide are cores (core 243 and core 21) made of a material having a refractive index smaller than that of silicon. Therefore, the present invention is particularly effective when applied to, for example, an optical circuit component having AWG (Arrayed Waveguide Grating).
For example, in FIG. 10, if the optical circuit component 2A has an AWG structure in which the cores 25_1 to 25_4 made of silicon are removed and the cores 21_1 to 21_4 made of SiOx or silicon nitride are extended and connected to the optical circuit in the subsequent stage, An AWG-structured optical circuit component having an aligning optical waveguide can be realized in a small area.

<< Embodiment 3 >>
In the optical circuit component 3 according to the third embodiment, the core constituting the alignment optical waveguide includes both a core made of silicon constituting the optical waveguide for signal and a core made of a material having a refractive index smaller than that of silicon. Is different from the optical circuit component 1 according to the first embodiment, and is otherwise the same as the optical circuit component 1. In the optical circuit component 3 according to the third embodiment, the same components as those in the optical circuit component 1 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 11 is a diagram schematically illustrating a connection structure between the optical circuit component and the optical fiber block according to the third embodiment.
As shown in the figure, the optical circuit component 3 includes cores 31 and 35 that constitute a signal optical waveguide, and cores 12, 13, and 34 that constitute an aligning optical waveguide.

  The core 34 includes cores 141 and 142 made of silicon and a core 343 made of a material (for example, SiOx) having a refractive index smaller than that of silicon. As shown in FIG. 11, the core 343 is formed on the substrate 10 (lower cladding layer 18) so as to intersect the core 31 and the core 35 in a plan view. Hereinafter, the core 343, the core 31, and the core 35 will be described in detail.

FIG. 12 is a diagram schematically showing a structure of a portion where the alignment optical waveguide and the signal optical waveguide intersect in the optical circuit component according to the third embodiment.
As shown in the figure, the core 35 is made of silicon similarly to the core 15 according to the first embodiment, and a part including the end portion (SSC portion) 350 of the core 35 is covered with the core 31. ing. 11 and 12, the core 35 has a portion 351 that overlaps with the core 31 and extends in the same direction in plan view.

  The core 343 and the core 31 are made of the same material (for example, SiOx or silicon nitride) having a refractive index smaller than that of silicon, similarly to the core 243 and the core 21 according to the second embodiment. It is integrally formed as an intersecting cross-shaped structure. The core 343 intersects the cores 31 and 35 at a portion 351 where the core 31 and the core 35 overlap in a plan view. That is, the core 343 is formed so as to intersect with both the core 31 and the core 35 constituting the signal optical waveguide. The intersection angle between the core 343 and the cores 31 and 35 is, for example, 90 degrees. The cross-sectional size (thickness × width) of the core 31 and the core 343 is the same as that of the core 11 and the core 143 according to the first embodiment, and is, for example, 3 μm × 3 μm.

  For example, when the alignment light AL is input to the end face 12A of the alignment core 12 during alignment of the optical fiber block 7, the alignment light AL propagates as follows. First, the alignment light AL input to the end face 12 </ b> A of the core 12 propagates through the core 12 and is input to the core 343 via the core 141. The alignment light AL input to the core 343 propagates through the core 343 and is input to the core 142 through a portion where the core 343 and the core 31 intersect. Thereafter, the alignment light AL input to the core 142 propagates through the core 142, is input to the core 13, propagates through the core 13, and is output from the end face 13A of the core 13.

  On the other hand, during normal use after alignment, the signal light SL that is the object of communication is input to the end face 31 A of the signal core 31 through the signal optical fiber 71 of the optical fiber block 7. The signal light SL input to the end surface 31A of the signal core 31 propagates through the core 31, is input to the core 35, passes through a portion where the core 35 and the core 343 intersect, and then passes through the optical circuit (see FIG. (Not shown).

  At this time, since the clad covering the upper portion of the portion 351 is uniformly formed of SiOx or the like (core 31), the core 35 does not have a portion where the refractive index changes in the upper portion of the portion 351. Reflections and confusion are less likely to occur. Thereby, the loss generated in the core 35 can be suppressed, and the signal light can be propagated to the subsequent optical circuit with lower loss.

  As described above, according to the optical circuit component 3 according to the third embodiment, as with the optical circuit component 1 according to the first embodiment, the alignment mechanism can be simplified while reducing the size of the optical circuit component. It becomes possible.

  Further, according to the optical circuit component 3 according to the third embodiment, the core 343 constituting the alignment optical waveguide is formed so as to intersect with both the core 31 and the core 35 constituting the signal optical waveguide. Therefore, since the refractive index of the upper clad of the core 35 does not change, reflection of light propagating through the core 35 and generation of confusion can be suppressed, and loss of the core 35 due to the provision of the aligning optical waveguide can be suppressed. Occurrence can be suppressed.

  11 and 12 exemplify the case where there is one signal optical waveguide, there may be a plurality of signal optical waveguides.

  FIG. 13 is a diagram schematically showing a planar structure of an optical circuit component having a plurality of optical waveguides for signals according to the third embodiment. In the figure, the same components as those of the optical circuit component 3 described above are denoted by the same reference numerals, and detailed description thereof is omitted. Further, although the figure illustrates the case where four signal optical waveguides are formed, the number of signal optical waveguides is not particularly limited.

As shown in the figure, the optical circuit component 3A has four cores 31_1 to 31_4 and four cores 35_1 to 35_4 that constitute an optical waveguide for signals. The cores 31_1 to 31_4 are disposed along the end face 10A between the aligning core 12 and the aligning core 13 in plan view. The cores 31_1 to 31_4 are formed of the same material (for example, SiOx) as the core 31 described above and have the same structure. The cores 35_1 to 35_4 are made of the same material (silicon) as the core 35 described above and have the same structure. Similarly to the core 31 and the core 35, the cores 35_1 to 35_4 and the cores 31_1 to 31_4 are connected to each other by the SSC structure.
Similarly to the core 35 described above, the core 343 is formed by intersecting the cores 31_1 to 31_4 and the cores 35_1 to 35_4.

  According to the optical circuit component 3A, as with the optical waveguide 3 having one optical waveguide for signals, it is possible to simplify the alignment mechanism while reducing the size of the optical circuit component. It is possible to suppress the occurrence of loss in the cores 35_1 to 35_4 due to the provision of the optical waveguide for the heart.

<< Embodiment 4 >>
The optical circuit component 4 according to the fourth embodiment is different from the optical circuit component 1 according to the first embodiment in that the alignment optical waveguide and the signal optical waveguide do not intersect with each other. This is the same as the circuit component 1. In the optical circuit component 4 according to the fourth embodiment, the same components as those in the optical circuit component 1 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 14A is a diagram schematically illustrating a connection structure between the optical circuit component and the optical fiber block according to Embodiment 4.
As shown in the figure, the optical circuit component 4 includes cores 11 and 45 that constitute an optical waveguide for signals, cores 12, 13, and 44 that constitute an optical waveguide for alignment, and a photodiode 46. Prepare.

  FIG. 14B is a diagram schematically showing the structure of the end portion of the core 45 constituting the optical waveguide for signals in the optical circuit component according to Embodiment 4. As shown in the figure, the core 45 is made of silicon similarly to the core 15 according to the first embodiment, and is covered with the core 11 at one end portion (SSC portion) 450 of the core 45. Yes.

  The photodiode 46 is disposed at the other end of the core 45, converts light input to the core 11 and propagated through the core 45 into an electrical signal. The photodiode 46 is, for example, a germanium photodiode (GePD). The electric signal converted by the photodiode 46 is supplied to an electronic circuit or the like (not shown).

  The core 44 includes cores 141 and 142 made of silicon and a core 443 made of a material having a refractive index smaller than that of silicon (for example, SiOx, silicon nitride, etc.). As shown in FIG. 15, the core 443 is different from the core 143 according to the first embodiment and the core 243 according to the second embodiment, and does not cross the core 45 or the core 11 in a plan view. Lower clad layer). According to this, the alignment light AL input to one alignment core 12 can be output from the other alignment core 13 with low loss.

  As described above, according to the optical circuit component 4 according to the fourth embodiment, as with the optical circuit component 1 according to the first embodiment, the alignment mechanism can be simplified while reducing the size of the optical circuit component. It becomes possible.

  Further, according to the optical circuit component 4 according to the fourth embodiment, it is not necessary to detect the electrical signal from the photodiode in order to align the optical fiber block as in the conventional case. An alignment electrode pad or the like for detection is not required, and the optical circuit component can be miniaturized as compared with the prior art.

  Furthermore, according to the optical circuit component 4 according to the fourth embodiment, since a probe or the like for connecting to the electrode pad is not necessary, the alignment mechanism for the optical circuit component having the conventional alignment electrode pad, In comparison, the apparatus can be simplified.

14A illustrates the case where the core 44 for connecting the alignment core 12 and the core 13 is composed of cores 141 and 142 made of silicon and a core 443 made of a material having a refractive index smaller than that of silicon. However, the present invention is not limited to this, and as shown in FIG. 15, the core 44 that connects the alignment core 12 and the core 13 may be constituted by a single core made of silicon.
In this case, the core 44 is formed by a core 444 made of silicon, and the core 12 and the core 13 are connected by bending two portions of the core 444.

  According to this, as in the case where the core 44 is formed of two types of core materials as shown in FIG. 14A, it is possible to simplify the alignment mechanism while reducing the size of the optical circuit component. .

  As mentioned above, although the invention made by the present inventors has been specifically described based on the embodiment, the present invention is not limited thereto, and various modifications can be made without departing from the scope of the invention.

  For example, in the above embodiment, the case where the signal cores 11, 21, and 31 of the optical circuit components 1 to 4 are disposed between the two cores 12 and 13 for alignment in a plan view is illustrated. Not limited to this. For example, the alignment cores 12 and 13 may be arranged side by side, and the signal cores 11, 21 and 31 may be arranged side by side on either one of the alignment cores 12 and 13. According to this, as with the above-described embodiment, it is possible to simplify the alignment mechanism while reducing the size of the optical circuit component.

  1-4, 1A, 2A, 3A ... optical circuit components, 10 ... substrate, 10A ... end face of substrate, 11-15, 24, 25, 34, 35, 44, 45, 141-143, 243, 343, 443, 11_1 to 11_4, 15_1 to 15_4, 21_1 to 21_4, 25_1 to 25_4, 31_1 to 31_4, 35_1 to 35_4 ... core, 16 ... upper clad layer, 18 ... lower clad layer, 11A-13A, 21A, 31A ... end face of the core, 1410, 1420 ... bent portion, 150, 250, 350, 450, 1411, 1421, 1412, 1422 ... SSC portion, 7 ... optical fiber block, 71-73, 71_1-71_4 ... optical fiber, 71A-73A ... optical fiber End face, 80 ... light source, 81 ... input optical fiber, 82 ... output optical fiber, 83 ... optical power meter, 4 ... control unit, 85 ... optical fiber block moving device, 86 ... stage, the portion overlapping with the core 31 in the 351 ... core 35, SL ... signal light, AL ... aligning light.

Claims (8)

A substantially rectangular substrate in plan view;
A first core formed on the substrate and constituting a signal optical waveguide;
A second core and a third core which are formed on the substrate and constitute an alignment optical waveguide;
A fourth core formed on the substrate, at least part of which is made of silicon, and constituting an optical waveguide connecting the second core and the third core;
One end portion of the first core, one end portion of the second core, and one end portion of the third core are formed on one side of the substrate side by side with the core end portion,
The fourth core has a bent portion in a portion made of silicon, and connects the other end of the second core and the other end of the third core. parts. The optical circuit component according to claim 1,
The first core, the second core, and the third core are formed such that core ends are arranged side by side on one side of the substrate in a plan view,
The optical circuit component, wherein the first core is disposed between the second core and the third core in plan view. The optical circuit component according to claim 1 or 2,
A fifth core formed on the substrate and made of silicon;
The first core is formed to cover one end of the fifth core,
The fourth core is
A sixth core made of silicon, having one end covered with and connected to the other end of the second core, and a first bent portion;
A seventh core made of silicon, having one end covered and connected to the other end of the third core, and having a second bent portion;
An eighth core that covers the other end of the sixth core, the other end of the seventh core, and a portion of the fifth core and intersects the fifth core in plan view;
The first core, the second core, the third core, and the eighth core are made of a material having a refractive index smaller than that of silicon. The optical circuit component according to claim 1 or 2,
The fourth core is
A fifth core made of silicon, having one end connected to the other end of the second core and having a first bent portion;
A sixth core made of silicon, having one end connected to the other end of the third core and having a second bent portion;
A seventh core that covers the other end of the fifth core and the other end of the sixth core and intersects the first core in plan view;
The first core, the second core, the third core, and the seventh core are made of a material having a refractive index smaller than that of silicon,
The first core and the seventh core are formed integrally with a common intersection. The optical circuit component according to claim 4,
An eighth core formed on the substrate and made of silicon;
The eighth core has a portion that overlaps the first core and extends in the same direction in plan view;
The optical circuit component, wherein the seventh core intersects the eighth core at a portion where the first core and the eighth core overlap in plan view. In the optical circuit component according to any one of claims 3 to 5,
The optical circuit component, wherein the material having a refractive index smaller than that of silicon includes silicon oxide or silicon nitride. In the optical circuit component according to any one of claims 1 to 6,
An optical circuit component comprising a plurality of the first cores. An optical circuit component according to any one of claims 1 to 7,
An optical fiber block having a first optical fiber, a second optical fiber, and a third optical fiber arranged corresponding to an arrangement interval of the first core, the second core, and the third core;
In the optical circuit component and the optical fiber block, the end surface of the one end of the first core and the end surface of the core of the first optical fiber face each other, and the end of the one end of the second core. An end face and an end face of the core of the second optical fiber face each other, and an end face of the one end of the third core and an end face of the core of the third optical fiber face each other and are connected. Connection structure of optical fiber and optical circuit components.

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