WO2021149589A1

WO2021149589A1 - Optical component

Info

Publication number: WO2021149589A1
Application number: PCT/JP2021/001090
Authority: WO
Inventors: 基博中原; 有島　功一
Original assignee: 株式会社中原光電子研究所
Priority date: 2020-01-20
Filing date: 2021-01-14
Publication date: 2021-07-29
Also published as: JPWO2021149589A1

Abstract

The purpose of the present invention is to provide an optical component that is easily produced and is capable of optical input/output at any position of a SiPh chip.　The optical component according to the present invention comprises: a waveguide (PLC 30) in which a plurality of cores 31 are arranged in a line; gradient index lenses (GRIN lenses) 41 arranged so that the optical axes thereof are in a different direction than the optical axis direction of the waveguide, the number of GRIN lenses 41 being equal to the number of cores of the waveguide; and a reflecting surface 35 for bending the direction of light emitted from one end of the GRIN lenses 41 and coupling the light to the respective cores 31 of the waveguide.

Description

Optical parts

The present disclosure relates to optical components for coupling light to a fiber array.

In optical communication, electrical signal data is converted into light and transmitted over an optical fiber. Silicon photonics (SiPh) optical transceivers are sometimes used to convert electrical signals into light. The silicon photonics (SiPh) type optical transceiver is equipped with a SiPh chip in which an optical circuit is formed. A typical SiPh chip is a silicon substrate in which a core through which light propagates and a grating coupler (GC) that outputs light from the core are formed. Light is output from the GC in a direction substantially perpendicular to the surface of the SiPh chip (see, for example, Non-Patent Document 1).
The following description and drawings show examples of vertical emission, but are not limited to this. Needless to say, in addition to the grating coupler, the light propagating from the core due to mirror reflection is emitted in the direction perpendicular to the substrate surface.

On the other hand, optical data needs to be transmitted horizontally to the SiPh chip. Therefore, Non-Patent Document 1 discloses a structure in which light output perpendicular to the surface of the SiPh chip is received by the tip of the optical fiber and then the optical fiber is bent at approximately 90 degrees. In particular, optical transceivers are required to have a low height with respect to the surface of the SiPh chip (low profile) in order to reduce the size. An optical component that receives light vertically output from the substrate with a low profile and bends it in the horizontal direction is called a "low profile coupler (LPC)".

In the case of an optical fiber LPC, giving a steep bend to the optical fiber causes problems such as breakage and bending loss due to bending stress. Therefore, as shown in FIG. 1, some LPCs do not use an optical fiber. FIG. 1 is a cross-sectional view for explaining LPC. In FIG. 1, reference numeral 10 is a SiPh chip, reference numeral 20 is a fiber array, and reference numeral 30 is a planar lightwave circuit (PLC). The SiPh chip 10 includes a chip substrate 11, a core 12, and a grating 13. The fiber array 20 includes a core 21 and a clad 22 of the optical fiber 200b, a V-groove substrate 23 on which the optical fiber 200b is arranged, and a lid 24 for fixing the optical fiber 200b to the V-groove substrate 23. The PLC 30 includes a PLC substrate 34, a core 31, a lower clad 32 and an upper clad 33. One end of the PLC 30 is polished diagonally (for example, about 45 degrees with respect to the longitudinal direction of the core 31).

Since the upper clad 33 of the PLC 30 is usually about 30 μm, the light emitted from the grating 13 of the SiPh chip 10 in the direction perpendicular to the surface of the SiPh chip 10 does not spread so much and can reach the core 31 of the PLC 30 with low loss. Since the end surface (reflection surface 35) of the core 31 is polished diagonally (for example, 45 degrees) as described above, the emitted light Lt emitted from the grating 13 is reflected by the reflection surface 35 and changes its direction to the core 31. Propagate in the longitudinal direction of. The emitted light Lt propagates through the core 31 of the PLC 30 and is coupled to the core 21 of the fiber array 20. With such a structure, it is not necessary to bend the optical fiber, and problems of fracture and bending loss due to bending stress can be solved.

On the other hand, the LPC having the structure of FIG. 1 has the following problems.
(Problem A)
As shown in FIG. 1, the fiber array has a lid 24 (thickness is about 1 mm), and the lid 24 interferes with the chip substrate 11 of the SiPh chip 10, so that the arrangement of the fiber array 20 is limited to the end of the SiPh chip 10. NS. Considering the loss of light, it is not preferable to lengthen the core 31 length of the PLC 30 or to form a bent portion in the core 31. That is, the LPC having the structure of FIG. 1 has a problem that it is difficult to input / output light at an arbitrary position of the SiPh chip 10.
(Problem B)
When polishing the end portion of the PLC diagonally, a lid (thickness of about 500 μm) covering the upper clad 33 is usually arranged. However, in the case of the LPC as shown in FIG. 1, if such a lid is arranged, the light emitted from the SiPh chip 10 passes through the thick lid, so that the amount of light that can be combined with the core 31 of the PLC 30 decreases due to attenuation and spread of light. do. Therefore, in the case of the LPC as shown in FIG. 1, since the polishing operation for forming the reflecting surface 35 is performed without providing the lid, there is a problem that cracks are generated in the vicinity of the reflecting surface 35 and the productivity is lowered.

Therefore, in order to solve the above problems, it is an object of the present invention to provide an optical component capable of inputting / outputting light at an arbitrary position of the SiPh chip and easy to produce.

In order to achieve the above object, the optical component according to the present invention is provided with a refractive index distribution type lens that collects the light emitted from the SiPh chip.

Specifically, the optical component according to the present invention is
A waveguide in which multiple cores are parallel,
A refractive index distribution type lens (GRIN lens) having the same number as the core of the waveguide, which is arranged so that the optical axis is in a direction different from the optical axis direction of the waveguide.
A reflective surface that bends the direction of light emitted from one end of the GRIN lens and couples the light to each of the cores of the waveguide.
To be equipped.

Here, the waveguide can be a fiber array in which a plurality of optical fibers are arranged in parallel. That is, in this embodiment, the end portion of the fiber array is polished diagonally to form a reflective surface on the core of each optical fiber.
The optical component according to the present invention can collect the light emitted from the SiPh chip with a GRIN lens, and can be coupled to each core (reflecting surface) with low loss even if a lid is present in the fiber array. In this embodiment, since the PLC does not exist, the above-mentioned problem B is solved. Further, since this embodiment does not use a PLC, interference between the lid of the fiber array and the chip substrate of the SiPh chip is eliminated, and the fiber array can be arranged on any surface of the SiPh chip. That is, the present embodiment can also solve the problem A.

As another form, the waveguide can be a plane lightwave circuit (PLC: Planar Lightwave Circuit) on which the core is formed. In this case, on the side opposite to the reflective surface side of the PLC, a fiber array composed of a plurality of optical fibers connected to each of the cores of the PLC is further provided.

In the optical component according to the present invention, the light emitted from the SiPh chip can be collected by the GRIN lens and can be coupled to the core with low loss. Therefore, the distance from the exit portion of the SiPh chip to the core of the PLC is increased. Is possible. Therefore, in this embodiment, a lid can be provided on the PLC, and the occurrence of cracks at the time of forming the reflecting surface can be reduced. That is, this embodiment can solve the problem B. Further, if the thickness of the lid of the PLC is increased so that the lid of the fiber array does not come into contact with the surface of the SiPh chip, the fiber array can be arranged on any surface of the SiPh chip. That is, the present embodiment can also solve the problem A.

The above description has described the configuration of the reflective surface formed in the core of the PLC or optical fiber. That is, when the optical axis direction of the waveguide is the X axis, the direction in which the cores are parallel is the Y axis, and the direction perpendicular to the X axis and the Y axis is the Z axis, the reflecting surface is the Y. It is characterized in that it is a cut surface obtained by cutting one end of the waveguide in a plane parallel to the axis and non-parallel to the X-axis and the Z-axis.

It is preferable that one end of the GRIN lens is in direct contact with the waveguide. Here, "directly in contact with the waveguide" means that one end of the GRIN lens is in contact with the clad of the optical fiber of the fiber array or the lower clad layer of the PLC described above. That is, the GRIN lens is embedded in the lid of the fiber array or the lid of the PLC described above. Since one end of the GRIN lens is in direct contact with the waveguide in this way, it is possible to reduce the profile of the optical component.

As another form of the reflecting surface, when the optical axis direction of the waveguide is the X axis, the direction in which the cores are parallel is the Y axis, and the direction perpendicular to the X axis and the Y axis is the Z axis, the above The reflecting surface may be a prism having a plane parallel to the Y-axis and non-parallel to the X-axis and the Z-axis.

An optical component having such a configuration is such that a plurality of lights radiated in a direction perpendicular to the surface of the substrate from the surface of the substrate on which the optical circuit is formed are incident on the other end of the GRIN lens. It is characterized in that it is arranged on the surface of the substrate.

The above inventions can be combined as much as possible.

The present invention can provide an optical component that can input and output light at an arbitrary position on the SiPh chip and is easy to produce.

It is a figure explaining a problem. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the arrangement of the GRIN lens of the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the structure of the fiber array of the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the arrangement of the GRIN lens of the optical component which concerns on this invention, and the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a figure explaining the optical component which concerns on this invention. It is a table explaining the design example of the optical component which concerns on this invention.

Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments.
In particular, the GRIN lens length is described within 1/2 pitch, but since the GRIN lens characteristics are periodic with respect to the lens length standardized by the pitch, it is not limited to the described lens length. do not have.
In addition, the components having the same reference numerals in the present specification and the drawings shall indicate the same components.

(Embodiment 1)
FIG. 2 is a cross-sectional view illustrating the optical component (LPC) of the present embodiment. The waveguide of the present embodiment is a planar lightwave circuit (PLC: Planar Lightwave Circuit) 30 in which a core 31 is formed. The PLC 30 has a lower clad 32, a plurality of cores 31, and an upper clad 33 on the substrate 34. A waveguide is formed by covering the plurality of cores 31 with a lower clad 32 and an upper clad 33.

This optical component is
A waveguide (PLC30) in which a plurality of cores 31 are parallel and
A refractive index distribution type lens (GRIN lens) 41 having the same number as the core of the waveguide, which is arranged so that the optical axis is in a direction different from the optical axis direction of the waveguide.
A reflecting surface 35 that bends the direction of the light emitted from one end of the GRIN lens 41 and couples the light to each core 31 of the waveguide.
To be equipped.

Here, when the optical axis direction of the waveguide is the X axis, the direction in which the cores 31 are parallel is the Y axis, and the direction perpendicular to the X axis and the Y axis is the Z axis.
The reflection surface 35 is a cut surface obtained by cutting one end of the waveguide in a plane parallel to the Y axis and non-parallel to the X axis and the Z axis. For example, when the emission angle from the SiPh substrate is vertical, the angle formed by the reflecting surface 35 with the XY plane is 45 degrees.
The reflective surface 35 may be formed by polishing one end of the PLC 30 instead of cutting it.

This optical component further includes a fiber array 20 composed of a plurality of optical fibers 200b connected to each of the cores 31 of the PLC 30 on the side opposite to the side of the reflective surface 35 of the PLC 30. The optical fiber 200b is composed of a core 21 and a clad 22. For example, the optical fiber 200b propagates light having a wavelength of the emitted light Lt in a single mode. A fiber array 20 is formed by inserting a plurality of optical fibers 200b into the V-groove of the V-groove substrate 23 and pressing the plurality of optical fibers 200b with the lid 24.

FIG. 3 is a diagram illustrating the GRIN lens 41. As shown in FIG. 3A, the GRIN lenses 41 are arranged in the same number as the number of optical fibers parallel to the fiber array 20 (the number of cores 31 of the PLC 30). In this embodiment, there are four GRIN lenses 41. The GRIN lens 41 is fixed by the support 40. The center spacing of the GRIN lens 41 is the same as the center spacing of the core 31 of the PLC 30. The center spacing of the cores 31 of the PLC 30 is the same as the center spacing of the plurality of cores 12 of the substrate (SiPh chip) 11.

In this optical component, as shown in FIG. 2, a support 40 for fixing the GRIN lens 41 is arranged between the PLC 30 and the substrate (SiPh chip) 11. In this case, when the PLC 30 and the fiber array 20 are connected so that the optical axes of the core 31 and the core 21 are aligned, the thickness of the PLC 30 (thickness in the Z direction) and the support 40 are the thickness of the fiber array 20 (thickness in the Z direction). It should be the same as or thicker than (thickness of). _{That is, the distance h 0} between the fiber array 20 and the substrate (SiPh chip) 11 is 0 or more. Therefore, since the lid 24 of the fiber array 20 and the substrate (SiPh chip) 11 do not interfere with each other, there are no restrictions on the arrangement of the main optical components on the substrate (SiPh chip) 11.

That is, this optical component is a GRIN lens regardless of the location of a plurality of lights radiated from the surface of the substrate 11 on which the optical circuit is formed in the direction perpendicular to the surface of the substrate 11 to any of the surfaces of the substrate 11. It can be arranged on the surface of the substrate 11 so that it is incident on the other end of the 41.

The light propagating through each core 12 of the substrate (SiPh chip) 11 is emitted from the surface of the substrate (SiPh chip) 11 in the Z direction by the grating 13. The emitted light is incident on the other end of the corresponding GRIN lens 41 and is focused on the reflecting surface 35 formed on the core 31.

FIG. 4 shows this situation in an enlarged manner. The light Lt emitted from the surface of the substrate (SiPh chip) 11 may be diffused light or parallel light. In either case, the pitch of the GRIN lens 41 is adjusted in order to concentrate the light Lt on the reflecting surface 35. FIG. 4A shows a case where the emitted light Lt is diffused. In this case, the GRIN lens 41 has a 1/4 pitch to a 1/2 pitch. FIG. 4B shows a case where the emitted light Lt is parallel light. In this case, the GRIN lens 41 has a 1/4 pitch or less. As shown in FIG. 4C, a spacer 47 for adjusting the height (Z direction) of the PLC 30 may be arranged between the support 40 and the substrate (SiPh chip) 11. Even if the spacer 47 is arranged, the emitted light Lt can be focused on the reflecting surface 35 by adjusting the pitch of the GRIN lens 41. Further, the spacer 47 can also adjust the condensing position of the emitted light Lt in the Z direction.
The adjustment in the X-axis and Y-axis directions for concentrating the emitted light Lt on the reflecting surface 35 can be performed by shifting the PLC 30 in the X-axis and Y-axis directions on the support 40.

The emitted light Lt is converted from the Z direction to the X direction by the reflecting surface 35, and propagates through the core 31 in the direction of the fiber array 20. At the connection between the PLC 30 and the fiber array 20, light is coupled from the core 31 to the core 21 and propagates through the fiber array 20.

Further, this optical component is polished after the support 40 is adhered to the upper clad 33 when the reflective surface 35 is formed on the PLC 30. Therefore, the support 40 becomes a lid, and it is possible to prevent cracks from occurring in the vicinity of the reflective surface 35 during the polishing operation. Therefore, this optical component can improve the productivity.

(Embodiment 2)
FIG. 5 is a cross-sectional view illustrating the optical component (LPC) of the present embodiment. The waveguide of this embodiment is a fiber array 20 in which a plurality of optical fibers 200b are arranged in parallel. The optical fiber 200b is composed of a core 21 and a clad 22. A fiber array 20 is formed by inserting a plurality of optical fibers 200b into the V-groove of the V-groove substrate 23 and pressing the plurality of optical fibers 200b with the lid 24.

This optical component is
A waveguide (fiber array 20) in which a plurality of cores 21 are paralleled, and
A refractive index distribution type lens (GRIN lens) 41 having the same number as the core of the waveguide, which is arranged so that the optical axis is in a direction different from the optical axis direction of the waveguide.
A reflecting surface 35 that bends the direction of the light emitted from one end of the GRIN lens 41 and couples the light to each core 21 of the waveguide.
To be equipped.

Here, when the optical axis direction of the waveguide is the X axis, the axis in which the cores 21 are parallel is the Y axis, and the direction perpendicular to the X axis and the Y axis is the Z axis.
The reflection surface 35 is a cut surface obtained by cutting one end of the waveguide in a plane parallel to the Y axis and non-parallel to the X axis and the Z axis. For example, when the emission angle from the SiPh substrate is vertical, the angle formed by the reflecting surface 35 with the XY plane is 45 degrees.
The reflective surface 35 may be formed by polishing one end of the fiber array 20 instead of cutting.

The GRIN lens 41 and the support 40 are the same as those in FIG. 3 described in the first embodiment.

In this optical component, as shown in FIG. 5, a support 40 for fixing the GRIN lens 41 is arranged between the fiber array 20 and the substrate (SiPh chip) 11. The light propagating through each core 12 of the substrate (SiPh chip) 11 is emitted from the surface of the substrate (SiPh chip) 11 in the Z direction by the grating 13. The emitted light is incident on the other end of the corresponding GRIN lens 41, passes through the lid 24, and is focused on the reflecting surface 35 formed on the core 21. The emitted light Lt is converted from the Z direction to the X direction by the reflecting surface 35 and propagates through the core 21.

FIG. 6 shows this situation in an enlarged manner. The light Lt emitted from the surface of the substrate (SiPh chip) 11 may be diffused light or parallel light. In either case, the pitch of the GRIN lens 41 is adjusted in order to concentrate the light Lt on the reflecting surface 35 via the lid 24. FIG. 6A shows a case where the emitted light Lt is diffused. In this case, the GRIN lens 41 has a 1/4 pitch to a 1/2 pitch. FIG. 6B shows a case where the emitted light Lt is parallel light. In this case, the GRIN lens 41 has a 1/4 pitch or less. As shown in FIG. 6C, a spacer 47 for adjusting the height (Z direction) may be arranged between the support 40 and the substrate (SiPh chip) 11. Even if the spacer 47 is arranged, the emitted light Lt can be focused on the reflecting surface 35 by adjusting the pitch of the GRIN lens 41.
The adjustment in the X-axis and Y-axis directions for concentrating the emitted light Lt on the reflecting surface 35 can be performed by shifting the fiber array 20 in the X-axis and Y-axis directions on the support 40. can.

Therefore, it is not necessary to use PLC30 for this optical component as in the optical component of FIG. Since the PLC 30 is not used, the lid 24 of the fiber array 20 and the substrate (SiPh chip) 11 do not interfere with each other as in the optical component of FIG. 1, so that the arrangement of the main optical component on the substrate (SiPh chip) 11 is restricted. It disappears.

Further, this optical component is polished with the lid 24 adhered when the fiber array 20 reflecting surface 35 is formed. Therefore, it is possible to prevent cracks from occurring in the vicinity of the reflective surface 35 during the polishing operation. Therefore, this optical component can improve the productivity.

(Embodiment 3)
In the second embodiment, the structure of the fiber array 20 has been described as a V-groove shape in which optical fibers are arranged on a V-groove substrate 23 and pressed by a lid 24, but a capillary type in which an optical fiber is inserted into a capillary may also be used. FIG. 7 is a diagram illustrating an optical component using a capillary type fiber array 20. FIG. 7A is a cross-sectional view illustrating the optical component (LPC) of the present embodiment. This optical component differs from the optical component of FIG. 5 in that a capillary type fiber array 20 is used.

This optical component has the same functions and effects as the optical component using the V-groove type fiber array 20 shown in FIG. This optical component has an advantageous effect on the optical component using the V-groove type fiber array 20 of FIG. 5 in the following points. FIG. 8A is a cross-sectional view illustrating the capillary 25. The capillary 25 has a hole 28 into which the optical fiber 200b is inserted. In this example, there are four holes 28. The position of the hole 28 can be accurately set during the manufacture of the capillary 25. That is, the capillary type fiber array 20 can control the distance d from the surface on the substrate (SiPh chip) 11 side to the core 21 of the optical fiber 200b, and the distance d can be made as narrow as possible. By reducing the distance d, the distance until the emitted light Lt from the substrate (SiPh chip) 11 reaches the core 21 (reflection surface 35) of the optical fiber 200b can be shortened, and the coupling efficiency can be improved. ..

The distance d can be shortened to such an extent that cracks do not occur during polishing when the reflective surface 35 is created, and specifically, it can be set to a minimum of about 50 μm.

Further, FIG. 15A shows a case where the GRIN lenses 41 are two-dimensionally arranged in a staggered pattern. That is, even if the light emitted from the SiPh chip 11 is arranged in two dimensions of 4 × 3 instead of in a row, it can be focused by the GRIN lens 41 corresponding to each emission. Further, when the capillary 25 as shown in FIG. 8B is used and the reflection positions on the reflection surface 35 in the Z-axis direction are different (heights d1, d2, d3), the pitch of the GRIN lens 41 is adjusted. As shown in FIG. 15B, the emitted light Lt can be coupled to each core 21 of the fiber array 20.

(Embodiment 4)
FIG. 9 is a cross-sectional view illustrating the optical component (LPC) of the present embodiment. The difference between the present optical component and the optical component of the first embodiment is that the reflecting surface 35 is a prism having a plane parallel to the Y-axis and non-parallel to the X-axis and the Z-axis.

The light emitted from the substrate (SiPh chip) 11 enters the other end of the corresponding GRIN lens 41 and is focused on the reflecting surface 35 which is a prism. The emitted light Lt is converted from the Z direction to the X direction by the reflecting surface 35, and propagates through the core 31 in the direction of the fiber array 20. At the connection between the PLC 30 and the fiber array 20, light is coupled from the core 31 to the core 21 and propagates through the fiber array 20.

Similar to the optical component of the first embodiment, the optical component does not interfere with the lid 24 of the fiber array 20 and the substrate (SiPh chip) 11, so that the arrangement of the optical component on the substrate (SiPh chip) 11 is limited. There is no. That is, this optical component is a GRIN lens regardless of the location of a plurality of lights radiated from the surface of the substrate 11 on which the optical circuit is formed in the direction perpendicular to the surface of the substrate 11 to any of the surfaces of the substrate 11. It can be arranged on the surface of the substrate 11 so that it is incident on the other end of the 41.

Further, unlike the optical component of the first embodiment, this optical component does not require polishing work. Therefore, cracks do not occur at the end of the PLC 30, and the productivity of optical components can be improved.
In this optical component, the adjustment of the X direction and the Y direction for condensing the emitted light Lt on the reflecting surface 35 is performed by shifting the PLC 30 and the prism 35 in the X direction and the Y direction on the support 40. Can be done. Further, in order to couple the emitted light Lt from the reflecting surface 35 to the core 21 of the fiber array 20, the height (position in the Z direction) of the core 31 of the PLC 30 may be adjusted by using the spacer 37.

(Embodiment 5)
FIG. 10 is a cross-sectional view illustrating the optical component (LPC) of the present embodiment. The difference between the present optical component and the optical component of the second embodiment is that the reflecting surface 35 is a prism having a plane parallel to the Y-axis and non-parallel to the X-axis and the Z-axis.

The GRIN lens 41 of this optical component preferably has a pitch of 1/4 to 1/2. The path of light near the prism will be described with reference to FIG. The light Lt emitted from the surface of the substrate (SiPh chip) 11 is diffused light.

The light emitted from the substrate (SiPh chip) 11 enters the other end of the corresponding GRIN lens 41 and is focused on the reflecting surface 35 which is a prism. The emitted light is converted from the Z direction to the X direction by the reflecting surface 35, is incident on the core 21 of the fiber array 20, and propagates through the core 21. The distance hs between the grating 13 and the GRIN lens 41 can be adjusted with a spacer or the like.

Similar to the optical component of the second embodiment, the optical component does not interfere with the lid 24 of the fiber array 20 and the substrate (SiPh chip) 11, so that the arrangement of the optical component on the substrate (SiPh chip) 11 is limited. There is no. That is, this optical component is a GRIN lens regardless of the location of a plurality of lights radiated from the surface of the substrate 11 on which the optical circuit is formed in the direction perpendicular to the surface of the substrate 11 to any of the surfaces of the substrate 11. It can be arranged on the surface of the substrate 11 so that it is incident on the other end of the 41.

Further, unlike the optical component of the second embodiment, this optical component does not require polishing work and can improve the productivity of the optical component.

(Embodiment 6)
FIG. 12 is a cross-sectional view illustrating the optical component (LPC) of the present embodiment. The difference between this optical component and the optical component of the second embodiment is that the reflecting surface 35 is a prism having a plane parallel to the Y-axis and non-parallel to the X-axis and the Z-axis, and reflected by the prism. A GRIN lens 43 that couples the emitted light Lt to the core 21 of the fiber array 20 is further provided. The GRIN lens 43 is held by the support 42.

It is preferable that the GRIN lens 41 and the GRIN lens 43 of this optical component have a 1/4 pitch or less. The path of light near the prism will be described with reference to FIG. The light Lt emitted from the surface of the substrate (SiPh chip) 11 is diffused light.

The light Lt emitted from the substrate (SiPh chip) 11 is incident on the other end of the corresponding GRIN lens 41 and is irradiated to the reflecting surface 35 which is a prism as parallel light. The emitted light Lt is converted from the Z direction to the X direction by the reflecting surface 35. After that, the emitted light Lt is focused on the core 21 of the fiber array 20 by the GRIN lens 43, and is incident on one end of the core 21 of the fiber array 20. The emitted light Lt propagates through the core 21.

Further, unlike the optical component of the second embodiment, the optical component does not require polishing work, and the productivity of the optical component can be improved.
In order to concentrate the emitted light Lt on the core 21, the prism 35 and the support 42 can be shifted on the support 40 in the X direction and the Y direction.

(Embodiment 7)
In the first to sixth embodiments, an example in which the emission light Lt is emitted from the core 12 of the substrate (SiPh chip) 11 by the grating 13 has been described. The light emitted from the substrate (SiPh chip) 11 is not limited to these examples. For example, the emitted light may be the light emitted by a surface emitting laser (VCSEL) arranged on the substrate (SiPh chip) 11. Since a VCSEL has a high numerical aperture, a high NA (UHNA: Ultra High NA) waveguide is required to couple the light emitted from the VCSEL to the fiber array.

FIG. 14 is an optical component in which the waveguide of the optical component described in the first embodiment is UHNA. Hereinafter, the differences between the present optical component and the optical component described in the first embodiment will be described. This optical component includes UHNA PLC30a. Further, in the fiber array 20, the optical fiber 200a of UHNA and the optical fiber 200b described in the first embodiment are connected in series. The optical fiber 200a and the optical fiber 200b are TEC (Thermally-diffused Expanded Core) fused at the connection portion 200c.

Since this optical component includes UHNA PLC30a, high NA light can be coupled to the core 21 of the optical fiber. FIG. 14 shows an example in which the emitted light Lt from the VCSEL 201 on the substrate (SiPh chip) 11 is coupled to the core 21 of the optical fiber.
VCSEL 201 of the substrate (SiPh chip) 11 is juxtaposed by the number of cores 21. The emitted light Lt is emitted from the VCSEL 201 in the Z direction. The emitted light is incident on the other end of the corresponding GRIN lens 41 and is focused on the reflecting surface 35 formed on the core 31. The emitted light Lt is converted from the Z direction to the X direction by the reflecting surface 35. Here, since PLC30a is UHNA, the one from VCSEL201 can be coupled to the core 31. Then, the emitted light Lt is propagated through the core 31 in the direction of the fiber array 20.

The emitted light Lt is coupled to the fiber array 20 from the PLC 30a, but since the PLC 30a is UHNA, it is desirable that the fiber array side is also UHNA. Therefore, the fiber array 20 of this optical component includes a UHNA optical fiber 200a on the PLC30a side. The emitted light Lt is coupled from the PLC 30a to the core 21a of the UHNA optical fiber 200a, and is coupled to the core 21 of the normal optical fiber 200b via the TEC fusion connection.

(Embodiment 8)
FIG. 16 is a cross-sectional view illustrating the optical component (LPC) of the present embodiment. This optical component is a form in which the lid 24 is eliminated from the optical component described in the second embodiment (FIG. 5). In this optical component, the optical fiber 200b arranged on the V-groove substrate 23 is held by the support 40 instead of the lid 24. That is, in this optical component, one end of the GRIN lens 41 is in direct contact with the optical fiber 200b which is a waveguide.

The reflecting surface 35, the GRIN lens 41, and the support 40 are the same as those described in the first embodiment.

The light emitted from the substrate (SiPh chip) 11 in the Z direction is the same as that described in the second embodiment.
In the optical component of the second embodiment, the light from the substrate (SiPh chip) 11 irradiates the reflecting surface 35 after passing through the GRIN lens 41, the lid 24, and the cladding 22 on the SiPh substrate 11 side of the optical fiber 200b. .. On the other hand, in this optical component, the light from the substrate (SiPh chip) 11 passes through the GRIN lens 41 and the clad 22 on the SiPh substrate 11 side of the optical fiber 200b, and then irradiates the reflecting surface 35.

FIG. 17 shows this situation in an enlarged manner. The light Lt emitted from the surface of the substrate (SiPh chip) 11 may be diffused light or parallel light. In either case, the pitch of the GRIN lens 41 is adjusted in order to concentrate the light Lt directly on the reflecting surface 35. FIG. 17A shows a case where the emitted light Lt is diffused. In this case, the GRIN lens 41 has a 1/4 pitch to a 1/2 pitch. FIG. 17B shows a case where the emitted light Lt is parallel light. In this case, the GRIN lens 41 has a 1/4 pitch or less. As shown in FIG. 17C, a spacer 47 for adjusting the height (Z direction) may be arranged between the support 40 and the substrate (SiPh chip) 11. Even if the spacer 47 is arranged, the emitted light Lt can be focused on the reflecting surface 35 by adjusting the pitch of the GRIN lens 41.
The adjustment in the X-axis and Y-axis directions for concentrating the emitted light Lt on the reflecting surface 35 can be performed by shifting the fiber array 20 in the X-axis and Y-axis directions on the support 40. can.

It is not necessary to use PLC30 for this optical component as in the optical component of FIG. The support 40 is used as a substitute for the lid 24 without using the PLC 30, and the lid 24 of the fiber array 20 and the substrate (SiPh chip) 11 do not interfere with each other as in the optical component of FIG. Therefore, there are no restrictions on the arrangement of the main optical components on the substrate (SiPh chip) 11.

Further, this optical component is polished in a state where the support 40 is adhered when the reflective surface 35 is formed on the fiber array 20. Therefore, it is possible to prevent cracks from occurring in the vicinity of the reflective surface 35 during the polishing operation. Therefore, this optical component can improve the productivity.

Further, since the lid 24 is eliminated in this optical component, the profile can be made lower than the configuration of the second embodiment. FIG. 18 is a diagram illustrating a design example of the optical component. In FIG. 18, the substrate (SiPh chip) 11 is not displayed. φ _G is the diameter of the GRIN lens 41. φ _P is the diameter of the optical fiber 200b including the coating 29. _{_{_{H V (= H 1 + H}}} 2 + H 3) is the thickness of the V-groove substrate 23. H ₃ is the radius of the core of the optical fiber 200b (cladding radius). H ₂ is the radius of the optical fiber 200b (φ _P / 2). H ₁ is set to be greater than or equal to _{the radius (φ P} / 2) of the optical fiber 200b and 0.5 mm or less in consideration of the strength of the optical component.

FIG. 19 is a table summarizing examples of each design value. The diameter of the optical fiber 200b including the coating 29 is φ _P = 0.25 mm for each type of optical component. Therefore, H ₂ = 0.125 mm and H ₃ = 0.0625 mm. Further, in this example, H ₁ = 0.125 mm.

Type _1, φ _G = 0.06mm, a P G = 0.490mm, fiber array thickness (optical component height) is 0.803Mm.
Type _2, φ _G = 0.08mm, a P G = 0.653mm, fiber array thickness (optical component height) is 0.966Mm.
Type _3, φ _G = 0.125mm, a P G = 1.022mm, fiber array thickness (optical component height) is 1.335Mm.
As described above, the thickness of the optical component of the present embodiment is about 1 mm, and low profile can be achieved.

In the present embodiment, the fiber array 20 in which a plurality of optical fibers 200b are arranged in parallel has been described, but the same applies even if the waveguide in the first embodiment (FIG. 2) is PLC30. When the waveguide is PLC30, "one end of the GRIN lens is in direct contact with the waveguide" means that one end of the GRIN lens 41 is in direct contact with the upper clad layer 33 of the PLC 30.

(Other embodiments)
In the seventh embodiment, the optical component in which the waveguide is UHNA is described for the optical component of the first embodiment. Similarly, for the optical components of the second to sixth embodiments, the emission light Lt from the VCSEL 201 on the substrate (SiPh chip) 11 can be coupled to the core 21 of the optical fiber 200b by converting the waveguide into a UHNA.

Note that the structures of the optical components described in each of the above embodiments can be combined as much as possible.

The optical component according to the present invention can be applied to LPC.

10: SiPh chip 11: Substrate (SiPh chip)
12: Core 13: Grating 20:

Fiber array

21, 21a: Core 22: Clad 23: V-groove substrate 24: Lid 25: Capillary 28: Hole 29:

Coating

30, 30a: PLC
31: Core 32: Lower clad 33: Upper clad 34: PLC substrate 35: Reflective surface 37: Spacer 40, 42: Support 41, 43: GRIN lens 47: Spacer 200a: Optical fiber 200b: Optical fiber 200c: Connection part 201 : VCSEL

Claims

A waveguide in which multiple cores are parallel,
A refractive index distribution type lens (GRIN lens) having the same number as the core of the waveguide, which is arranged so that the optical axis is in a direction different from the optical axis direction of the waveguide.
A reflective surface that bends the direction of light emitted from one end of the GRIN lens and couples the light to each of the cores of the waveguide.
Optical parts equipped with.
The optical component according to claim 1, wherein the waveguide is a fiber array in which a plurality of optical fibers are arranged in parallel.
The optical component according to claim 1, wherein the waveguide is a plane lightwave circuit (PLC: Planar Lightwave Circuit) in which the core is formed.
The optical component according to claim 3, further comprising a fiber array composed of a plurality of optical fibers connected to each of the cores of the PLC on the side opposite to the reflective surface side of the PLC.
When the optical axis direction of the waveguide is the X direction, the direction in which the cores are parallel is the Y direction, and the direction perpendicular to the X direction and the Y direction is the Z direction.
Any of claims 1 to 4, wherein the reflecting surface is a cut surface obtained by cutting one end of the waveguide in a plane parallel to the Z direction and non-parallel to the X direction and the Y direction. Optical parts listed in the direction.
The optical component according to any one of claims 1 to 5, wherein the GRIN lens is in direct contact with the waveguide at one end.
When the optical axis direction of the waveguide is the X direction, the direction in which the cores are parallel is the Y direction, and the direction perpendicular to the X direction and the Y direction is the Z direction.
The optical component according to any one of claims 1 to 4, wherein the reflecting surface is a prism having a plane parallel to the Z direction and non-parallel to the X direction and the Y direction.
A plurality of lights radiated from the surface of the substrate on which the optical circuit is formed in the direction perpendicular to the surface of the substrate are arranged on the surface of the substrate so as to be incident on the other end of the GRIN lens. The optical component according to any one of claims 1 to 7.