WO2023077364A1 - 端面耦合器及光通信装置 - Google Patents

端面耦合器及光通信装置 Download PDF

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Publication number
WO2023077364A1
WO2023077364A1 PCT/CN2021/128741 CN2021128741W WO2023077364A1 WO 2023077364 A1 WO2023077364 A1 WO 2023077364A1 CN 2021128741 W CN2021128741 W CN 2021128741W WO 2023077364 A1 WO2023077364 A1 WO 2023077364A1
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size
waveguide
face coupler
layer
away
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PCT/CN2021/128741
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English (en)
French (fr)
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吴阳博
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华为技术有限公司
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Priority to PCT/CN2021/128741 priority Critical patent/WO2023077364A1/zh
Publication of WO2023077364A1 publication Critical patent/WO2023077364A1/zh

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means

Definitions

  • the present application relates to the field of optical communication, in particular to an end coupler and an optical communication device.
  • optical communication devices based on silicon photonics technology, it mainly includes optoelectronic chips and optical fibers, and optical signals need to be transmitted between optoelectronic chips and optical fibers. Due to the large difference between the mode field diameter (mode field diameter, MFD) of the silicon waveguide of the optoelectronic chip and the mode field diameter of the optical fiber, the mode spot size of the two is greatly different. If the silicon waveguide and optical fiber are directly coupled to propagate optical signals, the coupling loss will be very large.
  • MFD mode field diameter
  • Embodiments of the present application provide an end face coupler and an optical communication device, so as to overcome the problem of large coupling loss in the related art.
  • an end face coupler in a first aspect, includes an intermediate waveguide and a cladding layer, the intermediate waveguide is located in the cladding layer, and the cross section of the intermediate waveguide has a first direction and In a second direction, the first direction is the same as the length direction of the intermediate waveguide, and the second direction is perpendicular to the first direction.
  • the intermediate waveguide includes a first layer body and a second layer body, the first layer body includes a first part and a second part, and the first part and the second part are sequentially connected along the first direction.
  • the size of the first portion in the second direction is not larger than the size of the second portion in the second direction.
  • the second part has two sides along the first direction, and the two sides are parallel to each other.
  • the second layer is stacked on the first layer, and the orthographic projection of the second layer on the cross section of the first layer is located on the first layer of the first layer.
  • the second layer is stacked on the second part and does not exceed the outer edge of the second part.
  • the end of the second layer away from the first part is flush with the end of the second part away from the first part.
  • the end face coupler is arranged between the silicon waveguide and the optical fiber such that an end of the first portion remote from the second portion is coupled to an end of the optical fiber. And, since the end of the second part away from the first part is flush with the end of the second layer away from the first part, the end of the second part away from the first part and the end of the first part are flush with each other. The ends of the second layer away from the first part can be respectively coupled with silicon waveguides.
  • the optical signal output by the optical fiber is coupled into the end face coupler from the end of the first part away from the second part. Since the size of the end of the first part away from the second part is small, the mode spot size Larger, the mode field overlap integral with the optical signal output by the fiber is high.
  • the optical signal As the optical signal propagates, the optical signal enters the second part from the first part, and since the size of the second part is larger than that of the first part, the size of the mode spot decreases accordingly. As the optical signal further propagates, the optical signal enters the part where the second part and the second layer are stacked together, and since this part increases the size of the second layer, the size of the mode spot is further reduced accordingly. In this way, when the optical signal is coupled to the silicon waveguide, the mode spot size matches the mode spot size of the silicon waveguide, reducing the loss of the optical signal when it is coupled between the optical fiber and the silicon waveguide.
  • the first part has two ends in the first direction, the first end of the first part is an end far away from the second part, and the first end of the first part is The two ends are ends close to the second part.
  • the size of the first portion in the second direction gradually increases from the first end of the first portion to the second end of the first portion. That is to say, the optical signal enters from the first end of the first part, and in the process of propagating to the second end of the first part, the size of the mode spot gradually increases until it reaches the second part.
  • the spot size gradually decreases until it is output from the first end of the first part during the process of propagating to the first end of the first part. In this way, the reflection of the optical signal during propagation is also reduced. In addition, it can also reduce the difficulty of manufacturing the first layer, effectively improving the production yield.
  • the size of the second part in the second direction is the same as the size of the second end of the first part in the second direction.
  • the size of the first part in the second direction gradually increases from the first end of the first part to the second end of the first part, it can smoothly transition and connect with the second part , avoiding abrupt changes in dimensions between the first portion and the second portion.
  • Such a design can make the difference of the mode field diameters of adjacent interfaces smaller, effectively reduce the reflection of the optical signal, and reduce the interference. In addition, it can also reduce the difficulty of manufacturing the first layer, effectively improving the production yield.
  • the second layer body includes a third part and a fourth part, and the third part and the fourth part are sequentially connected along the first direction.
  • a dimension of the third portion in the second direction is not greater than a dimension of the fourth portion in the second direction.
  • the second layer is stacked on the second part, which can increase the mode field diameter of the part, so that the corresponding mode spot size can be reduced. Since the optical signal propagates along the first direction, the third part and the fourth part are also sequentially connected along the first direction, so the fourth part is The size above is designed to be larger than the size of the third part in the second direction, so that the mode field diameter of the superimposed part of the second layer and the first layer gradually increases, that is, the size of the mode spot gradually increases. increase. In this way, the difference between the mode field diameters of adjacent interfaces is small, which can effectively reduce the reflection of the optical signal and reduce the interference. In addition, it can also reduce the difficulty of manufacturing the first layer body and the second layer body, effectively improving the manufacturing yield.
  • the third part has two ends in the first direction, the first end of the third part is an end far away from the fourth part, and the third part
  • the second end of the section is the end adjacent to the fourth section.
  • the size of the third portion in the second direction gradually increases from the first end of the third portion to the second end of the third portion. That is to say, the optical signal enters from the first end of the third part, and in the process of propagating to the second end of the third part, the size of the mode spot increases gradually until it propagates to the fourth part.
  • the difference of the mode field diameters of adjacent interfaces is small, which can effectively reduce the reflection of the optical signal and reduce the interference. In addition, it can also reduce the difficulty of manufacturing the second layer, effectively improving the manufacturing yield.
  • the size of the fourth part in the second direction is the same as the size of the second end of the third part in the second direction.
  • the size of the third part in the second direction gradually increases from the first end of the third part to the second end of the third part, it can be smoothly connected with the fourth part Transition and connection avoid abrupt changes in size between the third part and the fourth part.
  • Such a design can make the difference of the mode field diameters of adjacent interfaces smaller, effectively reduce the reflection of the optical signal, and reduce the interference. In addition, it can also reduce the difficulty of manufacturing the second layer, effectively improving the manufacturing yield.
  • a dimension of the fourth portion in the second direction is the same as a dimension of the second portion in the second direction. Since the two sides of the second part extending along the first direction are parallel, and the orthographic projection of the second layer on the cross section of the first layer is located on the side of the first layer In the second part, the two side surfaces of the fourth part extending along the first direction are also parallel, and respectively flush with the two side surfaces of the second part extending along the first direction.
  • Such a design can facilitate the control of the mode field diameters of the second part and the fourth part, reduce the manufacturing difficulty of the first layer body and the second layer body, and effectively improve the manufacturing yield.
  • the first end of the third part is located at the junction of the first part and the second part. Due to the size of the first portion in the second direction, it gradually increases from the first end of the first portion to the second end of the first portion, and the second portion in the second direction remains unchanged, so designing the first end of the third part at the junction of the first part and the second part can better control the change of the mode field diameter of the intermediate waveguide, The manufacturing difficulty of the intermediate waveguide is reduced, and the manufacturing yield is effectively improved.
  • the end face coupler further includes a side waveguide, and the side waveguide and the middle waveguide are spaced apart from each other and arranged in parallel.
  • the first end of the side waveguide is flush with the end of the first part away from the second part, and the size of the side waveguide in the first direction is not larger than that of the middle waveguide in the The dimension in the first direction, ie the second end of the side waveguide does not exceed the middle waveguide in the first direction.
  • the size of the side waveguide in the second direction is the same as the size of the end of the first part away from the second part in the second direction, that is, the side waveguide is in the second direction The dimensions in both directions remain the same.
  • designing side waveguides beside the central optical fiber can improve the coupling efficiency between the optical fiber and the end-face coupler and reduce polarization sensitivity.
  • the optical signal in the side waveguides can be coupled to the central waveguide through adiabatic coupling.
  • the second end of the side waveguide is flush with the junction of the first part and the second part. Such a design can ensure that all optical signals propagating in the side waveguide can be coupled to the second part.
  • the size of the side waveguide in the second direction is the same as the size of the end of the first part away from the second part in the second direction.
  • Such a design can ensure that the coupling loss between the side waveguide and the optical fiber and the coupling loss between the intermediate waveguide and the optical fiber are the same.
  • the manufacturing difficulty of the end face coupler is reduced, and the manufacturing yield is effectively improved.
  • the end face coupler includes at least two side waveguides.
  • the side waveguides of a part of the at least two side waveguides are located on one side of the intermediate waveguide, and the side waveguides of the other part of the at least two side waveguides are located on the side of the intermediate waveguide.
  • the other side That is to say, the side waveguides are located on both sides of the intermediate waveguide, so that the end coupler can be better coupled with the optical fiber, which can improve the coupling efficiency between the optical fiber and the end coupler, and reduce polarization sensitivity. sex.
  • the intermediate waveguide and the side waveguides are located in the same plane. Such a design can facilitate the fabrication of the intermediate waveguide and the side waveguides, and improves the fabrication efficiency of the end-face coupler.
  • an optical communication device in a second aspect, includes an end coupler, an optical fiber, and an optoelectronic chip.
  • the end face coupler is the end face coupler described in the first aspect, the end face coupler is located between the optical fiber and the optoelectronic chip, and the end face coupler is connected to the optical fiber and the optoelectronic chip respectively coupling.
  • An end face coupler is arranged between the silicon waveguide and the optical fiber, so that the end of the first part away from the second part is coupled with one end of the optical fiber. And, since the end of the second part away from the first part is flush with the end of the second layer away from the first part, the end of the second part away from the first part and the end of the first part are flush with each other. The ends of the second layer away from the first part can be respectively coupled with silicon waveguides.
  • the optical signal output by the optical fiber is coupled into the end face coupler from the end of the first part away from the second part. Since the size of the end of the first part away from the second part is small, the mode spot size Larger, the mode field overlap integral with the optical signal output by the fiber is high.
  • the optical signal As the optical signal propagates, the optical signal enters the second part from the first part, and since the size of the second part is larger than that of the first part, the size of the mode spot decreases accordingly. As the optical signal further propagates, the optical signal enters the part where the second part and the second layer are stacked together, and since this part increases the size of the second layer, the size of the mode spot is further reduced accordingly. In this way, when the optical signal is coupled to the silicon waveguide, the mode spot size matches the mode spot size of the silicon waveguide, reducing the loss of the optical signal when it is coupled between the optical fiber and the silicon waveguide.
  • the optical communication device provided by the embodiment of the present application is provided with an end-face coupler between the optical fiber and the silicon waveguide, the end-face coupler can be used to realize low-loss transmission of optical signals between the optical fiber and the silicon waveguide.
  • FIG. 1 is a schematic structural diagram of an end face coupler provided in an embodiment of the present application
  • Fig. 2 is a top view of the intermediate waveguide provided by the embodiment of the present application.
  • Fig. 3 is a top view of the intermediate waveguide provided by the embodiment of the present application.
  • FIG. 4 is a schematic structural diagram of an end face coupler provided in an embodiment of the present application.
  • Fig. 5 is a top view of the middle waveguide and side waveguides provided by the embodiment of the present application.
  • Fig. 6 is a dimension marking diagram of the end face coupler provided by the embodiment of the present application.
  • Fig. 7 is a dimension marking diagram of the end face coupler provided by the embodiment of the present application.
  • FIG. 8 is a schematic structural diagram of an optical communication device provided by an embodiment of the present application.
  • 3000 optoelectronic chip
  • 3100 silicon waveguide
  • optical communication devices based on silicon photonics technology, such as silicon photonics optical modules, silicon photonics on-board light engines, and the like.
  • Such optical communication devices mainly include optoelectronic chips and optical fibers for outputting optical signals. Due to the large difference between the mode field diameter (mode field diameter, MFD) of the silicon waveguide of the optoelectronic chip and the mode field diameter of the optical fiber, the mode spot size of the two is greatly different. If the silicon waveguide and optical fiber are directly coupled, the coupling loss is very large.
  • MFD mode field diameter
  • FIG. 1 is a schematic structural diagram of the end-face coupler.
  • the dotted lines in FIG. 1 represent virtual separation lines between two adjacent parts, and are only used to distinguish two different parts, so as to facilitate understanding of the drawing, and these dotted lines do not have entities. And, the same goes for the rest of the drawings.
  • the end-face coupler includes an intermediate waveguide 1 and a cladding 2 .
  • the cross section of the intermediate waveguide 1 has a first direction a and a second direction b perpendicular to each other, the first direction a is the same as the length direction of the intermediate waveguide 1 , and the intermediate waveguide 1 is located in the cladding 2 .
  • the intermediate waveguide 1 includes a first layer body 11 and a second layer body 12, the first layer body 11 includes a first part 111 and a second part 112 sequentially connected along the first direction a, the size of the first part 111 in the second direction b , not greater than the size of the second portion 112 in the second direction b, and the two sides of the second portion 112 extending along the first direction a are parallel.
  • the second layer 12 is stacked on the first layer 11, and the orthographic projection of the second layer 12 on the cross section of the first layer 11 is located in the second part 112 of the first layer 11, and the second layer
  • the end of the body 12 away from the first part 111 is flush with the end of the second part 112 away from the first part 111 .
  • the above-described end face coupler is configured in an optical communication device such that the end face coupler is arranged between the silicon waveguide and the optical fiber.
  • the end of the first part 111 far away from the second part 112 is coupled with one end of the optical fiber. Since the end of the second part 112 far away from the first part 111 is flush with the end of the second layer 12 far away from the first part 111, the second The end of the part 112 away from the first part 111 and the end of the second layer body 12 away from the first part 111 are respectively coupled to the silicon waveguide. In this way, the configuration of the end-face coupler between the silicon waveguide and the optical fiber is realized.
  • the optical signal output by the optical fiber is coupled into the end face coupler from the end of the first part 111 away from the second part 112, because the end of the first part 111 far away from the second part 112 has a smaller Small, so the mode spot size is large, and the mode field overlap integral with the optical signal output by the fiber is high.
  • the optical signal propagates, the optical signal enters the second portion 112 from the first portion 111 , and since the size of the second portion 112 is larger than that of the first portion 111 , the size of the mode spot decreases accordingly. With the further propagation of the optical signal, the optical signal enters the part where the second part 112 and the second layer body 12 are stacked together.
  • the size of the mode spot is further reduced. Small. In this way, when the optical signal is coupled to the silicon waveguide, the mode spot size matches the mode spot size of the silicon waveguide, reducing the loss of the optical signal when it is coupled between the optical fiber and the silicon waveguide.
  • the optical signal output by the silicon waveguide is coupled into the end face coupler by the end of the second part 112 away from the first part 111, and the end of the second layer body 12 away from the first part, Since the second part 112 and the second layer body 12 are stacked together, the size of the second part 112 is larger and the size of the mode spot is smaller, so that low-loss coupling with the silicon waveguide can be realized.
  • the optical signal propagates, the optical signal enters the first part 111. Since the first part 111 is not stacked with the second layer 12, and the size of the first part 111 is smaller than the size of the second part 112, the size decreases accordingly, and the mold spot The size increases accordingly. In this way, when the optical signal is coupled to the optical fiber, the mode spot size matches the mode spot size of the optical fiber, reducing the loss of the optical signal when it is coupled between the silicon waveguide and the optical fiber.
  • the reason why the end face coupler provided by the embodiment of the present application can reduce the loss of the optical signal when coupling between the optical fiber and the silicon waveguide is precisely because the size of the intermediate waveguide 1 in the second direction b, along the first There is a change in direction a.
  • the first layer body 11 and the second layer body 12 of the intermediate waveguide 1 will be introduced respectively below.
  • FIG. 2 is a top view of the intermediate waveguide 1 , and its viewing angle is that of FIG. 1 .
  • the end of the first part 111 away from the second part 112 is the first end
  • the end of the first part 111 close to the second part 112 is the second end.
  • the size of the first portion 111 in the second direction b gradually increases from the first end of the first portion 111 to the second end of the first portion 111 .
  • the first part 111 is approximately elongated and extends along the first direction a.
  • the optical signal enters the first part 111 from the first end of the first part 111.
  • the mode spot size gradually increases until it propagates to 112 of the second part.
  • the spot size gradually decreases until it is output from the first end of the first part 111 during the process of propagating to the first end of the first part 111 .
  • the reflection of the optical signal during propagation is also reduced.
  • it can also reduce the difficulty of manufacturing the first layer body 11 and effectively improve the manufacturing yield.
  • the first portion 111 has a first side 111a and a second side 111b opposite to each other, and the first side 111a and the second side 111b approximately extend along the first direction a and are located in the second direction b.
  • both the first side 111a and the second side 111b are planes (see FIG. 2 ), and there is an angle between the first side 111a and the second side 111b.
  • the cross section of the first part 111 is a trapezoid
  • the upper base of the trapezoid is at the first end of the first part 111
  • the lower base of the trapezoid is at the bottom of the first part 111. second end.
  • the two waists of the trapezoid are located on the first side 111a and the second side 111b respectively.
  • the cross section of the first part 111 is a triangle, one corner of the triangle is at the first end of the first part 111, the side opposite to the corner is at the second end of the first part 111, and the other two sides of the triangle are respectively at the first end of the first part 111.
  • the cross section of the first portion 111 is an isosceles trapezoid.
  • both the first side 111a and the second side 111b are curved surfaces (see FIG. 3 ), and the first side 111a and the second side 111b extend from the first end of the first part 111 to the second end. Smooth transition, so that the size of the first portion 111 in the second direction b gradually increases from the first end of the first portion 111 to the second end of the first portion 111 .
  • first side 111a and the second side 111b can also have other shapes, as long as the size of the first part 111 in the second direction b is from the first end of the first part 111 to It is sufficient that the second end of the first portion 111 gradually increases.
  • the size of the second part 112 in the second direction b is the same as the size of the second end of the first part 111 in the second direction b.
  • the size of the first part 111 in the second direction b gradually increases from the first end of the first part 111 to the second end of the first part 111, it can smoothly transition to the second part 112 and connected to avoid abrupt size changes between the first part 111 and the second part 112 .
  • Such a design can make the difference of the mode field diameters of adjacent interfaces smaller, effectively reduce the reflection of the optical signal, and reduce the interference. In addition, it can also reduce the difficulty of manufacturing the first layer body 11 and effectively improve the manufacturing yield.
  • the first part 111 of the first layer body 11 has been introduced above, and the second part 112 of the first layer body 11 and the relationship between the second part 112 and the first part 111 will be introduced below.
  • the second layer body 12 includes a third part 121 and a fourth part 122 sequentially connected along the first direction a, and the size of the third part 121 in the second direction b is not larger than The size of the fourth part 122 in the second direction b.
  • the second layer 12 is stacked on the second part 112, which can increase the mode field diameter of this part, so that the corresponding mode spot size can be reduced. Since the optical signal propagates along the first direction a, the third part 121 and the fourth part 122 are also sequentially connected along the first direction a, so the dimension of the fourth part 122 in the second direction b is designed as Being larger than the size of the third portion 121 in the second direction b can make the mode field diameter of the overlapping portion of the second layer 12 and the first layer 11 gradually increase, that is, the mode spot size gradually increases. In this way, the difference between the mode field diameters of adjacent interfaces is small, which can effectively reduce the reflection of the optical signal and reduce the interference. In addition, it can also reduce the difficulty of manufacturing the first layer body 11 and the second layer body 12, effectively improving the manufacturing yield.
  • the end of the third portion 121 away from the fourth portion 122 is the first end
  • the end of the third portion 121 close to the fourth portion 122 is the second end.
  • the size of the third portion 121 in the second direction b gradually increases from the first end of the third portion 121 to the second end of the third portion 121 .
  • the third portion 121 is approximately elongated and extends along the first direction a.
  • the optical signal enters from the first end of the third part 121, and in the process of propagating to the second end of the third part 121, the mode spot The size gradually increases until it propagates to the fourth portion 122 .
  • the difference of the mode field diameters of adjacent interfaces is small, which can effectively reduce the reflection of the optical signal and reduce the interference.
  • it can also reduce the difficulty of manufacturing the second layer body 12 and effectively improve the manufacturing yield.
  • the third portion 121 has a third side 121a and a fourth side 121b opposite to each other, and the third side 121a and the fourth side 121b approximately extend along the first direction a and are located in the second direction b.
  • both the third side 121a and the fourth side 121b are planes (see FIG. 2 ), and there is an included angle between the third side 121a and the fourth side 121b.
  • the cross section of the third part 121 is trapezoidal, the upper base of the trapezoid is at the first end of the third part 121, and the lower base of the trapezoid is at the third end. The second end of portion 121. The two waists of the trapezoid are located on the third side 121a and the fourth side 121b respectively.
  • the cross section of the third part 121 is a triangle, one corner of the triangle is at the first end of the third part 121, the side opposite to the corner is at the second end of the third part 121, and the other two sides of the triangle are They are located on the third side 121a and the fourth side 121b respectively.
  • the cross section of the third part 121 is a right triangle, and the right angle of the right triangle is located at the second end of the third part 121 .
  • the size of the fourth portion 122 in the second direction b is the same as the size of the second portion 112 in the second direction b.
  • the first end of the third part 121 is located at the junction of the first part 111 and the second part 112 .
  • the size of the first part 111 in the second direction b due to the size of the first part 111 in the second direction b, it gradually increases from the first end of the first part 111 to the second end of the first part 111, and the second part 112 is in the second direction b.
  • the size of the third part 121 remains unchanged, so designing the first end of the third part 121 at the junction of the first part 111 and the second part 112 can better control the change of the mode field diameter of the intermediate waveguide 1 . That is to say, during the propagation process of the optical signal, the spot size in the first part 111 changes gradually. After entering the second part 112, if the second layer 12 is not considered, the spot size is Unchanging.
  • designing the first end of the third part 121 at the junction of the first part 111 and the second part 112 can make the optical signal propagate to the second part 112, because the third part 121 is stacked on the second part 112 , and the size of the third part 121 changes gradually, so it is equivalent to increasing the overall size of the second part 112 and the third part 121, so that the size of the mold spot continues to change gradually.
  • FIG. 4 is a schematic structural diagram of an end coupler. In order to better show the structure inside the cladding 2 , FIG. 4 omits the cladding 2 .
  • the end face coupler further includes a side waveguide 3 .
  • the side waveguide 3 and the middle waveguide 1 are spaced apart from each other and arranged in parallel, the first end of the side waveguide 3 is flush with the end of the first part 111 away from the second part 112, and the size of the side waveguide 3 in the first direction a is,
  • the dimension of the side waveguide 3 in the second direction b is no greater than the dimension of the end of the first part 111 away from the second part 112 in the second direction b.
  • the optical signal in the side waveguide 3 can be coupled to the central waveguide through adiabatic coupling, while Devices such as MMI (Multimode Interference, multimode interference coupler) are not needed.
  • MMI Multimode Interference, multimode interference coupler
  • FIG. 5 is a top view of the middle waveguide 1 and side waveguides 3 , and the viewing angle is the top view of FIG. 4 .
  • the second end of the side waveguide 3 is flush with the junction of the first part 111 and the second part 112 .
  • Such a design can ensure that all the optical signals propagating in the side waveguide 3 can be coupled to the second part 112 .
  • the size of the side waveguide 3 in the second direction b is the same as the size of the end of the first part 111 away from the second part 112 in the second direction b.
  • the coupling loss between the side waveguide 3 and the optical fiber and the coupling loss between the intermediate waveguide 1 and the optical fiber can be guaranteed to be the same. Moreover, the manufacturing difficulty of the end face coupler is reduced, and the manufacturing yield is effectively improved.
  • the end-face coupler includes at least two side waveguides 3 .
  • a part of the at least two side waveguides 3 is located on one side of the middle waveguide 1
  • another part of the at least two side waveguides 3 is located on the other side of the middle waveguide 1 .
  • the side waveguides 3 are located on both sides of the intermediate waveguide 1, so that the end coupler can be better coupled with the optical fiber, which can improve the coupling efficiency between the optical fiber and the end coupler, and reduce polarization sensitivity.
  • the end face coupler includes two side waveguides 3, one of the two side waveguides 3 is located on one side of the intermediate waveguide 1, and the other of the two side waveguides 3 is located on one side of the intermediate waveguide 1 .
  • the middle waveguide 1 and the side waveguides 3 are located in the same plane. Such a design can facilitate the manufacture of the middle waveguide 1 and the side waveguide 3, and improves the manufacturing efficiency of the end face coupler.
  • Figure 6 and Figure 7 are the dimensions of the end coupler
  • Figure 6 is the top view of the end coupler
  • Figure 7 is the front view of the end coupler. It should be noted that the size ratio of each part in FIG. 6 and FIG. 7 is only for illustration, and is not limited to the size ratio of each part.
  • the dimensions of each part of the end coupler are as follows.
  • the cladding 2 has a thickness of 4 ⁇ m, the distance between the centerline of the intermediate waveguide 1 and the centerline of the adjacent side waveguides 3 is 1.075 ⁇ m, and the first part 111
  • the end face size of the first end is 150nm*150nm
  • the end face size of the corresponding side waveguide 3 is also 150nm*150nm
  • the length of the first part 111 in the first direction a is 100 ⁇ m
  • the second end of the first part 111 is in the second
  • the dimension on the direction b is 380nm
  • the thickness of the second layer body 12 is 70nm
  • the length of the third part 121 in the first direction a is 10 ⁇ m
  • the dimension of the second end of the third part 121 in the second direction b is 380nm.
  • each part of the above-mentioned end face coupler is taken as examples. In other embodiments, the size of each part of the end face coupler can be adjusted according to actual needs, which is not limited in this application.
  • the mode field overlap integral of the TE (Transverse Electric) mode field of the end coupler and the 3 ⁇ m diameter Gaussian spot (produced by the optical fiber) is 89.9%, considering the refractive index difference between the end coupler and the fiber end face and the mode spot conversion structure, the overall coupling efficiency from the fiber to the silicon waveguide is 83.9%.
  • the mode field overlap integral of the TM (Transverse Magnetic) mode field of the end coupler and the 3 ⁇ m diameter Gaussian spot (produced by the optical fiber) is 92.8%, considering the refractive index difference between the end coupler and the fiber end face and the mode spot conversion structure, the overall coupling efficiency from the fiber to the silicon waveguide is 86.3%.
  • FIG. 8 is a schematic structural diagram of an optical communication device provided by an embodiment of the present application.
  • the end face coupler 1000 is the above end face coupler 1000, the end face coupler 1000 is located between the optical fiber 2000 and the optoelectronic chip 3000, and the end face coupler 1000 is coupled with the optical fiber 2000 and the optoelectronic chip 3000 respectively.
  • An end face coupler 1000 is arranged between the optoelectronic chip 3000 and the optical fiber 2000, and the end of the first part 111 away from the second part 112 is coupled with an end of the optical fiber 2000, because the second part 112 is far away from the end of the first part 111 and the first part
  • the end of the second layer 12 away from the first part 111 is flush, so the end of the second part 112 away from the first part 111 and the end of the second layer 12 away from the first part 111 are respectively coupled with the silicon waveguide 3100 of the optoelectronic chip 3000 .
  • the arrangement of the end face coupler 1000 between the optoelectronic chip 3000 and the optical fiber 2000 is realized, so that the end face coupler 1000 is coupled with the optoelectronic chip 3000 and the optical fiber 2000 respectively.
  • the optical signal output by the optical fiber 2000 is coupled into the end face coupler 1000 from the end of the first part 111 far away from the second part 112, because the first part 111 is far away from the end of the second part 112
  • the size of the end portion is small, so the size of the mode spot is relatively large, and it can be integrated with the mode field of the optical signal output by the optical fiber 2000 to be high.
  • the optical signal propagates, the optical signal enters the second portion 112 from the first portion 111 , and since the size of the second portion 112 is larger than that of the first portion 111 , the size of the mode spot decreases accordingly.
  • the optical signal With the further propagation of the optical signal, the optical signal enters the part where the second part 112 and the second layer body 12 are stacked together. Since this part increases the size of the second layer body 12, the size of the mode spot is further reduced. Small. In this way, when the optical signal is coupled to the silicon waveguide 3100 , the mode spot size matches the mode spot size of the silicon waveguide 3100 , reducing the loss of the optical signal when coupling between the optical fiber 2000 and the silicon waveguide 3100 .
  • the optical signal output by the silicon waveguide 3100 is coupled into the end-face coupling by the end of the second part 112 away from the first part 111, and the end of the second layer body 12 away from the first part.
  • the size is larger and the mode spot size is smaller, which can realize low-loss coupling with the silicon waveguide 3100 .
  • the optical signal enters the first part 111.
  • the size of the first part 111 is not stacked with the second layer 12, and the size of the first part 111 is smaller than the size of the second part 112, the size decreases accordingly, and the mold spot The size increases accordingly.
  • the mode spot size matches the mode spot size of the optical fiber 2000 , reducing the loss of the optical signal when coupling between the silicon waveguide 3100 and the optical fiber 2000 .
  • the optical communication device provided by the embodiment of the present application is provided with the end face coupler 1000 between the optical fiber 2000 and the optoelectronic chip 3000, the end face coupler 1000 can be used to realize the transmission of optical signals between the optical fiber 2000 and the silicon waveguide 3100. low-loss transmission between them.

Abstract

本申请公开了一种端面耦合器及光通信装置，涉及光通信领域。该端面耦合器包括中间波导和包层；在中间波导的横截面上具有相互垂直的第一方向和第二方向，第一方向与中间波导的长度方向相同；中间波导位于包层内，中间波导包括第一层体和第二层体；第一层体包括沿第一方向依次连接的第一部分和第二部分，第一部分在第二方向上的尺寸，不大于第二部分在第二方向上的尺寸，第二部分沿第一方向延伸的两侧面平行；第二层体叠设在第一层体，且第二层体在第一层体的横截面上的正投影，位于第一层体的第二部分内，第二层体远离第一部分的端部与第二部分远离第一部分的端部平齐。本申请实施例提供的端面耦合器及光通信装置，能够解决耦合损耗大的问题。

Description

端面耦合器及光通信装置 技术领域
本申请涉及光通信领域，尤其涉及端面耦合器及光通信装置。
背景技术
对基于硅光子技术的光通信装置来说，主要包括光电芯片和光纤，光电芯片和光纤之间需要传播光信号。由于光电芯片的硅波导的模场直径(mode field diameter，MFD)和光纤的模场直径差异较大，所以二者的模斑尺寸差异较大。若直接将硅波导和光纤进行耦合以传播光信号，将导致耦合损耗非常大。
发明内容
本申请实施例提供了一种端面耦合器及光通信装置，以克服相关技术中存在的耦合损耗大的问题。
第一方面，提供了一种端面耦合器，所述盖端面耦合器包括中间波导和包层，所述中间波导位于所述包层内，在所述中间波导的横截面上具有第一方向和第二方向，所述第一方向与所述中间波导的长度方向相同，所述第二方向与所述第一方向垂直。所述中间波导包括第一层体和第二层体，所述第一层体包括第一部分和第二部分，所述第一部分和所述第二部分沿所述第一方向依次连接。所述第一部分在所述第二方向上的尺寸，不大于所述第二部分在所述第二方向上的尺寸。所述第二部分沿所述第一方向具有两侧面，两侧面相互平行。所述第二层体叠设在所述第一层体上，且所述第二层体在所述第一层体的横截面上的正投影，位于所述第一层体的所述第二部分内，即第二层体叠设在第二部分，且不超过所述第二部分的外边缘。所述第二层体远离所述第一部分的端部，与所述第二部分远离所述第一部分的端部平齐。
本申请实施例提供的端面耦合器，至少具有以下效果：
将所述端面耦合器布置在硅波导和光纤之间，使得所述第一部分远离所述第二部分的端部与光纤的一端部相耦合。并且，由于所述第二部分远离所述第一部分的端部和所述第二层体远离所述第一部分的端部平齐，所以所述第二部分远离所述第一部分的端部和所述第二层体远离所述第一部分的端部能够分别与硅波导相耦合。光纤输出的光信号由所述第一部分远离所述第二部分的端部耦合进所述端面耦合器中，由于所述第一部分远离所述第二部分的端部尺寸较小，所以模斑尺寸较大，能够与光纤输出的光信号的模场重叠积分高。随着光信号的传播，光信号由所述第一部分进入所述第二部分，由于所述第二部分的尺寸大于所述第一部分的尺寸，所以模斑尺寸随之减小。随着光信号的进一步传播，光信号进入第二部分和第二层体叠设在一起的部分，由于该部分增加了第二层体的尺寸，所以模斑尺寸随之进一步的减小。如此一来，使得光信号在耦合至硅波导时，模斑尺寸已经与硅波导的模斑尺寸相匹配，降低了光信号在光纤和硅波导之间耦合时的损耗。
也就是说，通过在光纤和硅波导之间设置本申请实施例提供的端面耦合器，能够实现光 信号在光纤和硅波导之间的低损耗传输。
在本申请的一种实现方式中，所述第一部分在所述第一方向上具有两端，所述第一部分的第一端为远离所述第二部分的端部，所述第一部分的第二端为靠近所述第二部分的端部。在所述第一部分在所述第二方向上的尺寸，由所述第一部分的第一端至所述第一部分的第二端逐渐增大。也就是说，光信号由所述第一部分的第一端进入，在向所述第一部分的第二端传播的过程中，模斑尺寸逐渐增大直至传播至所述第二部分。如此设计，使得相邻界面的模场直径差异较小，能够有效的减少光信号的反射，降低了干扰。相应的，光信号若从所述第一部分的第二端进入，在向所述第一部分的第一端传播的过程中，模斑尺寸逐渐减小直至由所述第一部分的第一端输出。如此一来，同样的减少了传播过程中的光信号的反射。除此之外，还能够降低制作所述第一层体的难度，有效的提高了制作良率。
在本申请的一种实现方式中，所述第二部分在所述第二方向上的尺寸，与所述第一部分的第二端在所述第二方向上的尺寸相同。在所述第一部分在所述第二方向上的尺寸，由所述第一部分的第一端至所述第一部分的第二端逐渐增大后，能够平顺的与所述第二部分过渡且相连，避免了所述第一部分和所述第二部分之间的尺寸出现突兀的变化。如此设计，能够使得相邻界面的模场直径差异较小，有效的减少光信号的反射，降低了干扰。除此之外，还能够降低制作所述第一层体的难度，有效的提高了制作良率。
在本申请的一种实现方式中，所述第二层体包括第三部分和第四部分，所述第三部分和所述第四部分沿所述第一方向依次连接。所述第三部分在所述第二方向上的尺寸，不大于所述第四部分在所述第二方向上的尺寸。第二层体叠设在第二部分上，能够增加该部分的模场直径，使得对应的模斑尺寸减小。由于光信号是沿着所述第一方向传播的，所述第三部分和所述第四部分也是沿着所述第一方向依次连接的，所以将所述第四部分在所述第二方向上的尺寸，设计的大于所述第三部分在所述第二方向上的尺寸，能够使得第二层体和第一层体叠设部分的模场直径逐渐增大，也即模斑尺寸逐渐增大。如此一来，使得相邻界面的模场直径差异较小，能够有效的减少光信号的反射，降低了干扰。除此之外，还能够降低制作所述第一层体和所述第二层体的难度，有效的提高了制作良率。
在本申请的一种实现方式中，所述第三部分在所述第一方向上具有两端，所述第三部分的第一端为远离所述第四部分的端部，所述第三部分的第二端为靠近所述第四部分的端部。在所述第三部分在所述第二方向上的尺寸，由所述第三部分的第一端至所述第三部分的第二端逐渐增大。也就是说，光信号由所述第三部分的第一端进入，在向所述第三部分的第二端传播的过程中，模斑尺寸逐渐增大直至传播至所述第四部分。如此设计，使得相邻界面的模场直径差异较小，能够有效的减少光信号的反射，降低了干扰。除此之外，还能够降低制作所述第二层体的难度，有效的提高了制作良率。
在本申请的一种实现方式中，所述第四部分在所述第二方向上的尺寸，与所述第三部分的第二端在所述第二方向上的尺寸相同。在所述第三部分在所述第二方向上的尺寸，由所述 第三部分的第一端至所述第三部分的第二端逐渐增大后，能够平顺的与所述第四部分过渡且相连，避免了所述第三部分和所述第四部分之间的尺寸出现突兀的变化。如此设计，能够使得相邻界面的模场直径差异较小，有效的减少光信号的反射，降低了干扰。除此之外，还能够降低制作所述第二层体的难度，有效的提高了制作良率。
在本申请的一种实现方式中，所述第四部分在所述第二方向上的尺寸，与所述第二部分在所述第二方向上的尺寸相同。由于所述第二部分沿所述第一方向延伸的两侧面平行，且所述第二层体在所述第一层体的横截面上的正投影，位于所述第一层体的所述第二部分内，所以第四部分沿所述第一方向延伸的两侧面也平行，且分别与所述第二部分沿所述第一方向延伸的两侧面平齐。如此设计，能够便于控制第二部分和第四部分的模场直径，降低了第一层体和第二层体的制作难度，有效的提高了制作良率。
在本申请的一种实现方式中，所述第三部分的第一端位于所述第一部分和所述第二部分的连接处。由于所述第一部分在所述第二方向上的尺寸，由所述第一部分的第一端至所述第一部分的第二端逐渐增大，而所述第二部分在所述第二方向上的尺寸则保持不变，所以将所述第三部分的第一端设计在所述第一部分和所述第二部分的连接处，能够更好的控制所述中间波导的模场直径的变化，降低了所述中间波导的制作难度，有效的提高了制作良率。
在本申请的一种实现方式中，所述端面耦合器还包括旁侧波导，所述旁侧波导与所述中间波导相互间隔且平行布置。所述旁侧波导的第一端与所述第一部分远离所述第二部分的端部平齐，所述旁侧波导在所述第一方向上的尺寸，不大于所述中间波导在所述第一方向上的尺寸，即所述旁侧波导的第二端在所述第一方向上不超过所述中间波导。所述旁侧波导在所述第二方向上的尺寸，与所述第一部分远离所述第二部分的端部在所述第二方向上的尺寸相同，即所述旁侧波导在所述第二方向上的尺寸保持不变。由于光纤的尺寸较大，所以在中心光纤的旁侧设计旁侧波导，能够提高光纤和端面耦合器之间的耦合效率，降低偏振敏感性。并且，随着光信号的传播，由于中间波导的尺寸会增大，而旁侧波导的尺寸则不变，所以通过绝热耦合即可使得旁侧波导中的光信号耦合至中心波导中。
在本申请的一种实现方式中，所述旁侧波导的第二端与所述第一部分和所述第二部分的连接处平齐。如此设计，能够保证在所述旁侧波导内传播的光信号，能够全部耦合至第二部分。
在本申请的一种实现方式中，所述旁侧波导在所述第二方向上的尺寸，与所述第一部分远离所述第二部分的端部在所述第二方向上的尺寸相同。如此设计，能够保证旁侧波导与光纤之间的耦合损耗，以及所述中间波导与光纤之间的耦合损耗相同。并且，降低了端面耦合器的制作难度，有效的提高了制作良率。
在本申请的一种实现方式中，所述端面耦合器包括至少两个所述旁侧波导。至少两个所述旁侧波导中的一部分的所述旁侧波导位于所述中间波导的一侧，至少两个所述旁侧波导中 的另一部分的所述旁侧波导位于所述中间波导的另一侧。也就是说，所述旁侧波导分别位于所述中间波导的两侧，以使得端面耦合器更好的与光纤之间相耦合，能够提高光纤和端面耦合器之间的耦合效率，降低偏振敏感性。
在本申请的一种实现方式中，所述中间波导和所述旁侧波导位于同一平面内。如此设计，能够便于所述中间波导和所述旁侧波导的制作，提高了端面耦合器的制作效率。
第二方面，提供了一种光通信装置，所述光通信装置包括端面耦合器、光纤和光电芯片。所述端面耦合器为第一方面所述的端面耦合器，所述端面耦合器位于所述光纤和所述光电芯片之间，且所述端面耦合器分别与所述光纤和所述光电芯片相耦合。
本申请实施例提供的光通信装置，至少具有以下效果：
在硅波导和光纤之间配置有端面耦合器，使得所述第一部分远离所述第二部分的端部与光纤的一端部相耦合。并且，由于所述第二部分远离所述第一部分的端部和所述第二层体远离所述第一部分的端部平齐，所以所述第二部分远离所述第一部分的端部和所述第二层体远离所述第一部分的端部能够分别与硅波导相耦合。光纤输出的光信号由所述第一部分远离所述第二部分的端部耦合进所述端面耦合器中，由于所述第一部分远离所述第二部分的端部尺寸较小，所以模斑尺寸较大，能够与光纤输出的光信号的模场重叠积分高。随着光信号的传播，光信号由所述第一部分进入所述第二部分，由于所述第二部分的尺寸大于所述第一部分的尺寸，所以模斑尺寸随之减小。随着光信号的进一步传播，光信号进入第二部分和第二层体叠设在一起的部分，由于该部分增加了第二层体的尺寸，所以模斑尺寸随之进一步的减小。如此一来，使得光信号在耦合至硅波导时，模斑尺寸已经与硅波导的模斑尺寸相匹配，降低了光信号在光纤和硅波导之间耦合时的损耗。
也就是说，由于本申请实施例提供的光通信装置在在光纤和硅波导之间设置了端面耦合器，所以能够利用端面耦合器，实现光信号在光纤和硅波导之间的低损耗传输。
附图说明
图1为本申请实施例提供的端面耦合器的结构示意图；
图2为本申请实施例提供的中间波导的俯视图；
图3为本申请实施例提供的中间波导的俯视图；
图4为本申请实施例提供的端面耦合器的结构示意图；
图5为本申请实施例提供的中间波导和旁侧波导的俯视图；
图6为本申请实施例提供的端面耦合器的尺寸标示图；
图7为本申请实施例提供的端面耦合器的尺寸标示图；
图8为本申请实施例提供的光通信装置的结构示意图。
图例说明：
1、中间波导；
11、第一层体；
111、第一部分；111a、第一侧面；111b、第二侧面；112、第二部分；
12、第二层体；
121、第三部分；121a、第三侧面；121b、第四侧面；122、第四部分；
2、包层；
3、旁侧波导；
a、第一方向；b、第二方向；
1000、端面耦合器；
2000、光纤；
3000、光电芯片；3100、硅波导。
具体实施方式
为使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请实施方式作进一步地详细描述。
在相关技术中，存在一些基于硅光子技术的光通信装置，例如硅光光模块、硅光板载光引擎等。在这类光通信装置中，主要包括光电芯片和用于输出光信号的光纤。由于光电芯片的硅波导的模场直径(mode field diameter，MFD)和光纤的模场直径差异较大，所以二者的模斑尺寸差异较大。若直接将硅波导和光纤进行耦合，耦合损耗非常大。
为了解决上述技术问题，本申请实施例提供了一种端面耦合器，图1为该端面耦合器的结构示意图。图1中的虚线表示相邻两个部分之间的虚拟分隔线，仅用于区别两个不同的部分，以便于理解附图，这些虚线并不具有实体。并且，其余的附图同样如此。
参见图1，在本实施例中，该端面耦合器包括中间波导1和包层2。
在中间波导1的横截面上具有相互垂直的第一方向a和第二方向b，第一方向a与中间波导1的长度方向相同，中间波导1位于包层2内。中间波导1包括第一层体11和第二层体12，第一层体11包括沿第一方向a依次连接的第一部分111和第二部分112，第一部分111在第二方向b上的尺寸，不大于第二部分112在第二方向b上的尺寸，第二部分112沿第一方向a延伸的两侧面平行。
第二层体12叠设在第一层体11，且第二层体12在第一层体11的横截面上的正投影，位于第一层体11的第二部分112内，第二层体12远离第一部分111的端部与第二部分112远离第一部分111的端部平齐。
将上述端面耦合器配置在光通信装置中，使得端面耦合器布置在硅波导和光纤之间。第一部分111远离第二部分112的端部与光纤的一端部相耦合，由于第二部分112远离第一部分111的端部和第二层体12远离第一部分111的端部平齐，所以第二部分112远离第一部分111的端部和第二层体12远离第一部分111的端部分别与硅波导相耦合。如此一来，实现了端面耦合器在硅波导和光纤之间的配置。
以光信号由光纤传播至硅波导为例，光纤输出的光信号由第一部分111远离第二部分112的端部耦合进端面耦合器中，由于第一部分111远离第二部分112的端部尺寸较小，所以模斑尺寸较大，能够与光纤输出的光信号的模场重叠积分高。随着光信号的传播，光信号由第一部分111进入第二部分112，由于第二部分112的尺寸大于第一部分111的尺寸，所以模斑尺寸随之减小。随着光信号的进一步传播，光信号进入第二部分112和第二层体12叠设在一 起的部分，由于该部分增加了第二层体12的尺寸，所以模斑尺寸随之进一步的减小。如此一来，使得光信号在耦合至硅波导时，模斑尺寸已经与硅波导的模斑尺寸相匹配，降低了光信号在光纤和硅波导之间耦合时的损耗。
以光信号由硅波导传播至光纤为例，硅波导输出的光信号由第二部分112远离第一部分111的端部，以及第二层体12远离第一部分的端部耦合进端面耦合器中，由于此处第二部分112和第二层体12叠设在一起，所以尺寸较大，模斑尺寸较小，能够实现与硅波导之间低损耗的耦合。随着光信号的传播，光信号进入第一部分111，由于第一部分111未叠设第二层体12，且第一部分111的尺寸小于第二部分112的尺寸，所以尺寸随之减小，模斑尺寸随之增大。如此一来，使得光信号在耦合至光纤时，模斑尺寸已经与光纤的模斑尺寸相匹配，降低了光信号在硅波导和光纤之间耦合时的损耗。
也就是说，通过在光纤和硅波导之间设置本申请实施例提供的端面耦合器，能够实现光信号在光纤和硅波导之间的低损耗传输。
由前文可知，本申请实施例提供的端面耦合器，之所以能够降低光信号在光纤和硅波导之间耦合时的损耗，正是因为中间波导1在第二方向b上的尺寸，沿第一方向a存在变化。下面分别对中间波导1的第一层体11和第二层体12进行介绍。
图2为中间波导1的俯视图，其视角为图1的俯视视角。结合图2，在本实施例中，第一部分111远离第二部分112的端部为第一端，第一部分111靠近第二部分112的端部为第二端。第一部分111在第二方向b上的尺寸，由第一部分111的第一端至第一部分111的第二端逐渐增大。
在上述实现方式中，第一部分111近似为长条形，且沿第一方向a延伸。在光信号传播的过程中，以光信号由光纤传播至硅波导为例，光信号由第一部分111的第一端进入第一部分111，在传播的过程中，模斑尺寸逐渐增大直至传播至第二部分112。如此设计，使得在第一部分111中，相邻界面的模场直径差异较小，能够有效的减少光信号的反射，降低了干扰。相应的，光信号若从第一部分111的第二端进入，在向第一部分111的第一端传播的过程中，模斑尺寸逐渐减小直至由第一部分111的第一端输出。如此一来，同样的减少了传播过程中的光信号的反射。除此之外，还能够降低制作第一层体11的难度，有效的提高了制作良率。
在本实施例中，第一部分111具有相对的第一侧面111a和第二侧面111b，第一侧面111a和第二侧面111b近似于沿第一方向a延伸，且位于第二方向b上。
在本实施例的一种实现方式中，第一侧面111a和第二侧面111b均为平面(参见图2)，第一侧面111a和第二侧面111b之间具有夹角。
在第一侧面111a和第二侧面111b均为平面时，示例性地，第一部分111的横截面为梯形，梯形的上底处于第一部分111的第一端，梯形的下底处于第一部分111的第二端。梯形的两个腰分别处于第一侧面111a和第二侧面111b。或者是，第一部分111的横截面为三角形，三角形的一个角处于第一部分111的第一端，与该角相对的一个边处于第一部分111的第二端，三角形的另外两个边分别处于第一侧面111a和第二侧面111b。在本实施例中，第一部分111的横截面为等腰梯形。
在本实施例的一种实现方式中，第一侧面111a和第二侧面111b均为曲面(参见图3)，第一侧面111a和第二侧面111b由第一部分111的第一端向第二端平滑过渡，以使得第一部分111在第二方向b上的尺寸，由第一部分111的第一端至第一部分111的第二端逐渐增大。
需要说明的是，在其他实施例中，第一侧面111a和第二侧面111b也能够为其他形状，只需使得第一部分111在第二方向b上的尺寸，由第一部分111的第一端至第一部分111的第二端逐渐增大即可。
继续参见图2，在本实施例中，第二部分112在第二方向b上的尺寸，与第一部分111的第二端在第二方向b上的尺寸相同。
在上述实现方式中，在第一部分111在第二方向b上的尺寸，由第一部分111的第一端至第一部分111的第二端逐渐增大后，能够平顺的与第二部分112过渡且相连，避免了第一部分111和第二部分112之间的尺寸出现突兀的变化。如此设计，能够使得相邻界面的模场直径差异较小，有效的减少光信号的反射，降低了干扰。除此之外，还能够降低制作第一层体11的难度，有效的提高了制作良率。
前文对第一层体11的第一部分111进行了介绍，下面对第一层体11的第二部分112，以及第二部分112与第一部分111之间的关系进行介绍。
继续参见图2，在本实施例中，第二层体12包括沿第一方向a依次连接的第三部分121和第四部分122，第三部分121在第二方向b上的尺寸，不大于第四部分122在第二方向b上的尺寸。
第二层体12叠设在第二部分112上，能够增加该部分的模场直径，使得对应的模斑尺寸减小。由于光信号是沿着第一方向a传播的，第三部分121和第四部分122也是沿着第一方向a依次连接的，所以将第四部分122在第二方向b上的尺寸，设计的大于第三部分121在第二方向b上的尺寸，能够使得第二层体12和第一层体11叠设部分的模场直径逐渐增大，也即模斑尺寸逐渐增大。如此一来，使得相邻界面的模场直径差异较小，能够有效的减少光信号的反射，降低了干扰。除此之外，还能够降低制作第一层体11和第二层体12的难度，有效的提高了制作良率。
在本实施例中，第三部分121远离第四部分122的端部为第一端，第三部分121靠近第四部分122的端部为第二端。第三部分121在第二方向b上的尺寸，由第三部分121的第一端至第三部分121的第二端逐渐增大。
在上述实现方式中，第三部分121近似为长条形，且沿第一方向a延伸。在光信号传播的过程中，以光信号由光纤传播至硅波导为例，光信号由第三部分121的第一端进入，在向第三部分121的第二端传播的过程中，模斑尺寸逐渐增大直至传播至第四部分122。如此设计，使得相邻界面的模场直径差异较小，能够有效的减少光信号的反射，降低了干扰。除此之外，还能够降低制作第二层体12的难度，有效的提高了制作良率。
在本实施例中，第三部分121具有相对的第三侧面121a和第四侧面121b，第三侧面121a和第四侧面121b近似于沿第一方向a延伸，且位于第二方向b上。
在本实施例的一种实现方式中，第三侧面121a和第四侧面121b均为平面(参见图2)，第三侧面121a和第四侧面121b之间具有夹角。
在第三侧面121a和第四侧面121b均为平面时，示例性地，第三部分121的横截面为梯形，梯形的上底处于第三部分121的第一端，梯形的下底处于第三部分121的第二端。梯形的两个腰分别处于第三侧面121a和第四侧面121b。或者是，第三部分121的横截面为三角形，三角形的一个角处于第三部分121的第一端，与该角相对的一个边处于第三部分121的第二端，三角形的另外两个边分别处于第三侧面121a和第四侧面121b。在本实施例中，第 三部分121的横截面为直角三角形，且直角三角形的直角位于第三部分121的第二端处。
继续参见图2，在本实施例中，第四部分122在第二方向b上的尺寸，与第二部分112在第二方向b上的尺寸相同。
由于第二部分112沿第一方向a延伸的两侧面平行，且第二层体12在第一层体11的横截面上的正投影，位于第一层体11的第二部分112内，所以第四部分122沿第一方向a延伸的两侧面也平行，且分别与第二部分112沿第一方向a延伸的两侧面平齐。如此设计，能够便于控制第二部分112和第四部分122的模场直径，降低了第一层体11和第二层体12的制作难度，有效的提高了制作良率。
在本实施例中，第三部分121的第一端位于第一部分111和第二部分112的连接处。
在上述实现方式中，由于第一部分111在第二方向b上的尺寸，由第一部分111的第一端至第一部分111的第二端逐渐增大，而第二部分112在第二方向b上的尺寸则保持不变，所以将第三部分121的第一端设计在第一部分111和第二部分112的连接处，能够更好的控制中间波导1的模场直径的变化。也就是说，光信号在传播的过程中，在第一部分111中的阶段，模斑尺寸是逐渐变化的，在进入第二部分112后，若不考虑第二层体12，那么模斑尺寸是不变化的。因此，将第三部分121的第一端设计在第一部分111和第二部分112的连接处，能够使得光信号在传播至第二部分112时，由于第三部分121叠设在第二部分112上，且第三部分121的尺寸逐渐变化，所以相当于增加了第二部分112和第三部分121这一整体的尺寸，使得模斑尺寸的尺寸继续逐渐变化。
由于光纤的尺寸较大，所以若仅设置中间波导1，可能导致耦合效率较低的问题。为了解决这一问题，图4为端面耦合器的结构示意图，为了更好的展示包层2内部的结构，图4省略了包层2。结合图4，在本实施例中，端面耦合器还包括旁侧波导3。旁侧波导3与中间波导1相互间隔且平行布置，旁侧波导3的第一端与第一部分111远离第二部分112的端部平齐，旁侧波导3在第一方向a上的尺寸，不大于中间波导1在第一方向a上的尺寸，旁侧波导3在第二方向b上的尺寸，不大于第一部分111远离第二部分112的端部在第二方向b上的尺寸。
随着光信号的传播，由于中间波导1的尺寸会增大，而旁侧波导3的尺寸则不变，所以通过绝热耦合即可使得旁侧波导3中的光信号耦合至中心波导中，而无需例如MMI(Multimode Interference，多模干涉耦合器)等器件。
图5为中间波导1和旁侧波导3的俯视图，其视角为图4的俯视视角。结合图5，在本实施例中，旁侧波导3的第二端与第一部分111和第二部分112的连接处平齐。
如此设计，能够保证在旁侧波导3内传播的光信号，能够全部耦合至第二部分112。
在本实施例中，旁侧波导3在第二方向b上的尺寸，与第一部分111远离第二部分112的端部在第二方向b上的尺寸相同。
在上述实现方式中，能够保证旁侧波导3与光纤之间的耦合损耗，以及中间波导1与光纤之间的耦合损耗相同。并且，降低了端面耦合器的制作难度，有效的提高了制作良率。
继续参见图5，在本实施例中，该端面耦合器包括至少两个旁侧波导3。至少两个旁侧波导3中的一部分的旁侧波导3位于中间波导1的一侧，至少两个旁侧波导3中的另一部分的旁侧波导3位于中间波导1的另一侧。
也就是说，旁侧波导3分别位于中间波导1的两侧，以使得端面耦合器更好的与光纤之 间相耦合，能够提高光纤和端面耦合器之间的耦合效率，降低偏振敏感性。
示例性地，该端面耦合器包括两个旁侧波导3，两个旁侧波导3中的一个位于中间波导1的一侧，两个旁侧波导3中的另一个位于中间波导1的一侧。
在本实施例中，在本申请的一种实现方式中，中间波导1和旁侧波导3位于同一平面内。如此设计，能够便于中间波导1和旁侧波导3的制作，提高了端面耦合器的制作效率。
图6和图7为端面耦合器的尺寸标示图，图6为端面耦合器的俯视视角，图7为端面耦合器的正视视角。需要说明的是，图6和图7中的各部分的尺寸比例，仅作为示意，不作为对于各部分的尺寸比例限定。端面耦合器各部分的尺寸以下文为准。
结合图6和图7，在本实施例中，包层2的厚度为4μm，中间波导1的中心线与相邻的旁侧波导3的中心线之间的距离为1.075μm，第一部分111的第一端的端面尺寸为150nm*150nm，对应的旁侧波导3的端面尺寸同样为150nm*150nm，第一部分111在第一方向a上的长度为100μm，第一部分111的第二端在第二方向b上的尺寸为380nm，第二层体12的厚度为70nm，第三部分121在第一方向a上的长度为10μm，第三部分121的第二端在第二方向b上的尺寸为380nm。
需要说明的是，以上端面耦合器各部分的尺寸均作为举例。在其他实施例中，端面耦合器各部分的尺寸能够根据实际需求进行调整，本申请对此不作限制。
对端面耦合器进行仿真，得到如下结果：
端面耦合器的TE(Transverse Electric，横电波)模场与3μm直径的高斯光斑(由光纤产生)的模场重叠积分为89.9％，考虑端面耦合器和光纤端面处的折射率差及模斑转换结构，从光纤到硅波导的整体耦合效率为83.9％。
端面耦合器的TM(Transverse Magnetic，横磁波)模场与3μm直径的高斯光斑(由光纤产生)的模场重叠积分为92.8％，考虑端面耦合器和光纤端面处的折射率差及模斑转换结构，从光纤到硅波导的整体耦合效率为86.3％。
图8为本申请实施例提供的一种光通信装置的结构示意图，参加图8，该光通信装置包括端面耦合器1000、光纤2000和光电芯片3000。端面耦合器1000为前文的端面耦合器1000，端面耦合器1000位于光纤2000和光电芯片3000之间，且端面耦合器1000分别与光纤2000和光电芯片3000相耦合。
在光电芯片3000和光纤2000之间配置有端面耦合器1000，第一部分111远离第二部分112的端部与光纤2000的一端部相耦合，由于第二部分112远离第一部分111的端部和第二层体12远离第一部分111的端部平齐，所以第二部分112远离第一部分111的端部和第二层体12远离第一部分111的端部分别与光电芯片3000的硅波导3100相耦合。如此一来，实现了端面耦合器1000在光电芯片3000和光纤2000之间的配置，使得端面耦合器1000分别与光电芯片3000和光纤2000相耦合。
以光信号由光纤2000传播至硅波导3100为例，光纤2000输出的光信号由第一部分111远离第二部分112的端部耦合进端面耦合器1000中，由于第一部分111远离第二部分112的端部尺寸较小，所以模斑尺寸较大，能够与光纤2000输出的光信号的模场重叠积分高。随着光信号的传播，光信号由第一部分111进入第二部分112，由于第二部分112的尺寸大于第一部分111的尺寸，所以模斑尺寸随之减小。随着光信号的进一步传播，光信号进入第二部分 112和第二层体12叠设在一起的部分，由于该部分增加了第二层体12的尺寸，所以模斑尺寸随之进一步的减小。如此一来，使得光信号在耦合至硅波导3100时，模斑尺寸已经与硅波导3100的模斑尺寸相匹配，降低了光信号在光纤2000和硅波导3100之间耦合时的损耗。
以光信号由硅波导3100传播至光纤2000为例，硅波导3100输出的光信号由第二部分112远离第一部分111的端部，以及第二层体12远离第一部分的端部耦合进端面耦合器1000中，由于此处第二部分112和第二层体12叠设在一起，所以尺寸较大，模斑尺寸较小，能够实现与硅波导3100之间低损耗的耦合。随着光信号的传播，光信号进入第一部分111，由于第一部分111未叠设第二层体12，且第一部分111的尺寸小于第二部分112的尺寸，所以尺寸随之减小，模斑尺寸随之增大。如此一来，使得光信号在耦合至光纤2000时，模斑尺寸已经与光纤2000的模斑尺寸相匹配，降低了光信号在硅波导3100和光纤2000之间耦合时的损耗。
也就是说，由于本申请实施例提供的光通信装置在在光纤2000和光电芯片3000之间设置了端面耦合器1000，所以能够利用端面耦合器1000，实现光信号在光纤2000和硅波导3100之间的低损耗传输。
以上所述仅为本申请的示例性实施例，并不用以限制本申请，凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (14)

  1. 一种端面耦合器，其特征在于，包括中间波导(1)和包层(2)；
    在所述中间波导(1)的横截面上具有相互垂直的第一方向和第二方向，所述第一方向与所述中间波导(1)的长度方向相同；
    所述中间波导(1)位于所述包层(2)内，所述中间波导(1)包括第一层体(11)和第二层体(12)；
    所述第一层体(11)包括沿所述第一方向依次连接的第一部分(111)和第二部分(112)，所述第一部分(111)在所述第二方向上的尺寸，不大于所述第二部分(112)在所述第二方向上的尺寸，所述第二部分(112)沿所述第一方向延伸的两侧面平行；
    所述第二层体(12)叠设在所述第一层体(11)，且所述第二层体(12)在所述第一层体(11)的横截面上的正投影，位于所述第一层体(11)的所述第二部分内，所述第二层体(12)远离所述第一部分(111)的端部与所述第二部分(112)远离所述第一部分(111)的端部平齐。
  2. 根据权利要求1所述的端面耦合器，其特征在于，所述第一部分(111)远离所述第二部分(112)的端部为第一端，所述第一部分(111)靠近所述第二部分(112)的端部为第二端；
    所述第一部分(111)在所述第二方向上的尺寸，由所述第一部分(111)的第一端至所述第一部分(111)的第二端逐渐增大。
  3. 根据权利要求2所述的端面耦合器，其特征在于，所述第二部分(112)在所述第二方向上的尺寸，与所述第一部分(111)的第二端在所述第二方向上的尺寸相同。
  4. 根据权利要求2或3所述的端面耦合器，其特征在于，所述第二层体(12)包括沿所述第一方向依次连接的第三部分(121)和第四部分(122)；
    所述第三部分(121)在所述第二方向上的尺寸，不大于所述第四部分(122)在所述第二方向上的尺寸。
  5. 根据权利要求4所述的端面耦合器，其特征在于，所述第三部分(121)远离所述第四部分(122)的端部为第一端，所述第三部分(121)靠近所述第四部分(122)的端部为第二端；
    所述第三部分(121)在所述第二方向上的尺寸，由所述第三部分(121)的第一端至所述第三部分(121)的第二端逐渐增大。
  6. 根据权利要求5所述的端面耦合器，其特征在于，所述第四部分(122)在所述第二方向上的尺寸，与所述第三部分(121)的第二端在所述第二方向上的尺寸相同。
  7. 根据权利要求5或6所述的端面耦合器，其特征在于，所述第四部分(122)在所述第二方向上的尺寸，与所述第二部分(112)在所述第二方向上的尺寸相同。
  8. 根据权利要求5-7任一项所述的端面耦合器，其特征在于，所述第三部分(121)的第一端位于所述第一部分(111)和所述第二部分(112)的连接处。
  9. 根据权利要求1-8任一项所述的端面耦合器，其特征在于，所述端面耦合器还包括旁侧波导(3)；
    所述旁侧波导(3)与所述中间波导(1)相互间隔且平行布置，所述旁侧波导(3)的第一端与所述第一部分(111)远离所述第二部分(112)的端部平齐，所述旁侧波导(3)在所述第一方向上的尺寸，不大于所述中间波导(1)在所述第一方向上的尺寸，所述旁侧波导(3)在所述第二方向上的尺寸，不大于所述第一部分(111)远离所述第二部分(112)的端部在所述第二方向上的尺寸。
  10. 根据权利要求9所述的端面耦合器，其特征在于，所述旁侧波导(3)的第二端与所述第一部分(111)和所述第二部分(112)的连接处平齐。
  11. 根据权利要求9或10所述的端面耦合器，其特征在于，所述旁侧波导(3)在所述第二方向上的尺寸，与所述第一部分(111)远离所述第二部分(112)的端部在所述第二方向上的尺寸相同。
  12. 根据权利要求9-11任一项所述的端面耦合器，其特征在于，包括至少两个所述旁侧波导(3)；
    至少两个所述旁侧波导(3)中的一部分的所述旁侧波导(3)位于所述中间波导(1)的一侧，至少两个所述旁侧波导(3)中的另一部分的所述旁侧波导(3)位于所述中间波导(1)的另一侧。
  13. 根据权利要求9-12任一项所述的端面耦合器，其特征在于，所述中间波导(1)和所述旁侧波导(3)位于同一平面内。
  14. 一种光通信装置，其特征在于，包括端面耦合器(1000)、光纤(2000)和光电芯片(3000)；
    所述端面耦合器(1000)为权利要求1-13任一项所述的端面耦合器(1000)，所述端面耦合器(1000)位于所述光纤(2000)和所述光电芯片(3000)之间，且所述端面耦合器(1000)分别与所述光纤(2000)和所述光电芯片(3000)相耦合。
PCT/CN2021/128741 2021-11-04 2021-11-04 端面耦合器及光通信装置 WO2023077364A1 (zh)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109324372A (zh) * 2018-11-09 2019-02-12 昆明理工大学 一种硅光波导端面耦合器
CN112255727A (zh) * 2020-10-30 2021-01-22 联合微电子中心有限责任公司 端面耦合器和半导体器件
WO2021175082A1 (zh) * 2020-03-02 2021-09-10 苏州旭创科技有限公司 一种模斑变换器及硅光集成芯片
CN113552669A (zh) * 2021-08-27 2021-10-26 东莞铭普光磁股份有限公司 一种端面耦合器及其制备方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109324372A (zh) * 2018-11-09 2019-02-12 昆明理工大学 一种硅光波导端面耦合器
WO2021175082A1 (zh) * 2020-03-02 2021-09-10 苏州旭创科技有限公司 一种模斑变换器及硅光集成芯片
CN112255727A (zh) * 2020-10-30 2021-01-22 联合微电子中心有限责任公司 端面耦合器和半导体器件
CN113552669A (zh) * 2021-08-27 2021-10-26 东莞铭普光磁股份有限公司 一种端面耦合器及其制备方法

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