阅读说明：本技术 一种用于硅光波导连接和耦合的光纤制作方法及加热装置 (optical fiber manufacturing method and heating device for silicon optical waveguide connection and coupling ) 是由 苏习明 胡江民 张锋 郜军红 于 2019-09-20 设计创作，主要内容包括：本申请公开了一种用于硅光波导连接和耦合的光纤制作方法及加热装置,属于光纤通信技术领域。首先将与模斑变换器输出模场匹配的细芯光纤进行局部加热,以使细芯光纤加热区域的纤芯模场增大到单模光纤的纤芯宽度,然后在细芯光纤的纤芯增大区域最中间截断细芯光纤,最后在细芯光纤的纤芯增大区域的断点处与一单模光纤进行熔接。由于采用局部加热的方式,将与模斑变换器输出模场连接的细芯光纤的纤芯模场扩大后再与单模光纤熔接,使得单模光纤与模斑变换器输出模场达到最优的耦合效率及最低的耦合损耗,同时采用这种方式连接和耦合的光纤具有低成本,生产效率高,耦合损耗低,适合大批量生产。(The application discloses an optical fiber manufacturing method and a heating device for silicon optical waveguide connection and coupling, and belongs to the technical field of optical fiber communication. The method comprises the steps of firstly, locally heating a thin core optical fiber matched with an output mode field of a mode spot converter to enable a fiber core mode field of a heating area of the thin core optical fiber to be increased to the width of a fiber core of a single mode optical fiber, then cutting off the thin core optical fiber at the middle of the fiber core increasing area of the thin core optical fiber, and finally welding the thin core optical fiber with the single mode optical fiber at a breakpoint of the fiber core increasing area of the thin core optical fiber. The mode of local heating is adopted, the fiber core mode field of the thin-core optical fiber connected with the output mode field of the spot size converter is enlarged and then is welded with the single-mode optical fiber, so that the single-mode optical fiber and the output mode field of the spot size converter achieve the optimal coupling efficiency and the lowest coupling loss.)

1. A method of fabricating an optical fiber for coupling and connecting a silicon optical waveguide, comprising:

Locally heating the thin core optical fiber matched with the output mode field of the mode spot converter to increase the fiber core mode field of the heating area of the thin core optical fiber to the fiber core width of the single mode optical fiber;

Cutting off the thin-core optical fiber at the middle most of the core enlarged area of the thin-core optical fiber;

and welding the end face of the core enlarged region of the thin-core optical fiber with a single-mode optical fiber.

2. The method of claim 1, wherein the temperature at which the thin core optical fiber is locally heated is at least 1300 ℃.

3. the method of claim 1, wherein the fine core optical fiber is locally heated using a hydrogen-oxygen flame.

4. The method of claim 1, wherein the fine-core fiber has a core width of 3 um; and/or the fiber core width of the single-mode optical fiber is 8-9 um.

5. The method of claim 1, further comprising:

And coupling and connecting one end of the thin-core optical fiber non-fiber core enlarged region with a waveguide of a silicon photonic device through the mode spot converter.

6. The method of claim 1, further comprising:

And carrying out secondary high-temperature heating treatment on the welding point of the thin-core optical fiber and the single-mode optical fiber.

7. The method of claim 6, wherein said subjecting the fusion splice of the core-spun optical fiber and the single-mode optical fiber to a second high temperature heating process comprises:

connecting the other end of the single mode fiber with a laser source, and connecting the other end of the thin core fiber with an optical power meter;

Then carrying out high-temperature heating treatment on the welding point of the thin-core optical fiber and the single-mode optical fiber, and monitoring the change of the power value of the optical power meter in the treatment process;

And when the power value of the optical power meter is not increased or the power output curve reaches the highest point, stopping the high-temperature heating treatment.

8. The utility model provides a coupling optical fiber, its characterized in that, the fibre core width of coupling optical fiber one end is 9um, and the width of other end fibre core is 3 um.

9. A heating device for manufacturing an optical fiber for connecting and coupling a silicon optical waveguide is characterized by comprising an optical fiber fixing device and two hydrogen-oxygen flame nozzles; the optical fiber fixing device is used for locally fixing the thin-core optical fiber matched with the output mode field of the spot size converter; the two hydrogen-oxygen flame nozzles are used for locally heating the thin-core optical fiber fixed by the optical fiber fixing device from two sides so as to increase the fiber core mode field of the thin-core optical fiber heating area to the fiber core width of the single-mode optical fiber; after the fiber core mode field of the thin core fiber heating area is increased to the width of the fiber core of the single mode fiber, the thin core fiber is cut off in the fiber core increasing area and is welded with the single mode fiber at a break point.

10. the heating device of claim 9, further comprising a laser light source and an optical power meter; when the high-temperature heating treatment is carried out on the fusion joint of the thin core optical fiber and the single mode optical fiber, one end of the single mode optical fiber after fusion is connected with the laser light source, one end of the thin core optical fiber is connected with the optical power meter, the laser light source is used for emitting a light source with a fixed wavelength, and the optical power meter is used for monitoring the change of the power value of light received by one end of the thin core optical fiber; when the power value monitored by the optical power meter is not increased or the power output curve reaches the highest point, the heating device stops heating.

Technical Field

the application belongs to the technical field of optical fiber communication, and particularly relates to an optical fiber manufacturing method and a heating device for silicon optical waveguide connection and coupling.

Background

in recent years, with the development of silicon optical technology, the application of silicon optical integration is gradually mature, and the market thereof is gradually opened. In the field of optical fiber communication technology, more and more optical devices adopt silicon optical technology. The coupling and packaging of silicon photonic devices has been a popular field of silicon photonic research and also a research difficulty. In a conventional optical device coupling package, a single mode optical fiber can be easily coupled and aligned with a conventional waveguide, laser, detector, etc. However, the size of the silicon photonic waveguide adopting the CMOS (complementary metal oxide semiconductor) process is greatly reduced, for example, the waveguide size of the silicon photonic device based on the SOI material is only 0.3um to 0.5um, the fiber core of the standard single mode fiber coupled with the waveguide is 8 um to 10um, and the large difference between the physical sizes of the two is large, so that the large mode field mismatch during coupling is caused, and the coupling loss is extremely high. Although the existing scheme adds an end face coupler (SSC (single-mode solid state transducer)) in front of a silicon waveguide, the waveguide with the width of 0.5um can be enlarged to 3um mode field output, and the coupling loss with a single-mode fiber is reduced, but the 3um mode field and a 9um fiber core of the single-mode fiber still have large mode field mismatch, and the coupling loss cannot be completely reduced.

Disclosure of Invention

the application discloses an optical fiber manufacturing method and a heating device for silicon optical waveguide connection and coupling, which match standard single-mode optical fibers with a mode field of a silicon photonic waveguide to achieve optimal coupling efficiency and lowest coupling loss.

According to a first aspect, there is provided in one embodiment a method of fabricating an optical fiber for silicon optical waveguide connection and coupling, comprising:

Locally heating the thin core optical fiber matched with the output mode field of the mode spot converter to increase the fiber core mode field of the heating area of the thin core optical fiber to the fiber core width of the single mode optical fiber;

Cutting off the thin-core optical fiber at the middle most of the core enlarged area of the thin-core optical fiber;

And welding the end face of the core enlarged region of the thin-core optical fiber with a single-mode optical fiber.

Further, the temperature at which the thin core optical fiber is locally heated is at least 1300 ℃.

Further, the thin-core optical fiber is locally heated by using hydrogen-oxygen flame.

Further, the fiber core width of the fine-core optical fiber is 3 um; and/or the fiber core width of the single-mode optical fiber is 8-9 um.

further, still include:

And coupling and connecting one end of the thin-core optical fiber non-fiber core enlarged region with a waveguide of a silicon photonic device through the mode spot converter.

Further, still include:

And carrying out secondary high-temperature heating treatment on the welding point of the thin-core optical fiber and the single-mode optical fiber.

Further, the performing of the secondary high-temperature heating process on the fusion-splicing point of the thin-core optical fiber and the single-mode optical fiber includes:

Connecting the other end of the single mode fiber with a laser source, and connecting the other end of the thin core fiber with an optical power meter;

Then carrying out high-temperature heating treatment on the welding point of the thin-core optical fiber and the single-mode optical fiber, and monitoring the change of the power value of the optical power meter in the treatment process;

And when the power value of the optical power meter is not increased or the power output curve reaches the highest point, stopping the high-temperature heating treatment.

According to a second aspect, an embodiment provides a coupling fiber having a core width of 9um at one end and a core width of 3um at the other end.

Further, the one end that the fibre core width is 9um is used as coupling fiber's input, and the one end that the fibre core width is 3um is used as coupling fiber's output.

Further, the coupling fiber is obtained by the method of the first aspect.

According to a third aspect, an embodiment provides a heating device for manufacturing an optical fiber for silicon optical waveguide connection and coupling, which comprises an optical fiber fixing device and two hydrogen-oxygen flame nozzles; the optical fiber fixing device is used for locally fixing the thin-core optical fiber matched with the output mode field of the spot size converter; the two hydrogen-oxygen flame nozzles are used for locally heating the thin-core optical fiber fixed by the optical fiber fixing device from two sides so as to increase the fiber core mode field of the thin-core optical fiber heating area to the fiber core width of the single-mode optical fiber; after the fiber core mode field of the thin core fiber heating area is increased to the width of the fiber core of the single mode fiber, the thin core fiber is cut off in the fiber core increasing area and is welded with the single mode fiber at a break point.

Further, the device also comprises a laser light source and an optical power meter; when the high-temperature heating treatment is carried out on the fusion joint of the thin core optical fiber and the single mode optical fiber, one end of the single mode optical fiber after fusion is connected with the laser light source, one end of the thin core optical fiber is connected with the optical power meter, the laser light source is used for emitting a light source with a fixed wavelength, and the optical power meter is used for monitoring the change of the power value of light received by one end of the thin core optical fiber; when the power value monitored by the optical power meter is not increased or the power output curve reaches the highest point, the heating device stops heating.

according to the method and the heating device for manufacturing the optical fiber for connecting and coupling the silicon optical waveguide, firstly, the thin-core optical fiber matched with the output mode field of the mode spot converter is locally heated so that the fiber core mode field of the heating area of the thin-core optical fiber is increased to the fiber core width of the single-mode optical fiber, then the thin-core optical fiber is cut off in the fiber core increasing area of the thin-core optical fiber, and finally the single-mode optical fiber is welded at the break point of the fiber core increasing area of the thin-core optical fiber. The mode of local heating is adopted, the fiber core mode field of the thin-core optical fiber matched with the output mode field of the spot size converter is widened and then is welded with the single-mode optical fiber, so that the single-mode optical fiber and the output mode field of the spot size converter achieve the optimal coupling efficiency and the lowest coupling loss, and meanwhile, the optical fiber connected and coupled by adopting the mode has low cost, high production efficiency and low coupling loss and is suitable for mass production.

Drawings

FIG. 1 is a schematic diagram of a waveguide and spot size converter connection for a silicon photonic device;

FIG. 2 is a schematic diagram showing a waveguide width comparison of a single mode fiber and a spot transformer;

FIG. 3 is a schematic flow chart illustrating a method for fabricating an optical fiber for silicon optical waveguide coupling and coupling in one embodiment;

FIG. 4 is a schematic illustration of localized heating of a thin core optical fiber according to one embodiment;

FIG. 5 is a schematic diagram of a break point of a fine core optical fiber according to an embodiment;

FIG. 6 is a schematic diagram of fusion splicing of a fine-core fiber to a single-mode fiber according to one embodiment;

FIG. 7 is a schematic diagram of a connection of a single mode fiber to a spot-size converter in accordance with an embodiment;

FIG. 8 is a schematic view of a weld spot being subjected to a secondary high temperature heat treatment in one embodiment;

FIG. 9 is a schematic view of a weld spot being subjected to a secondary high temperature heat treatment in one embodiment;

FIG. 10 is a schematic diagram of a coupling fiber according to an embodiment.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.

the numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).

referring to fig. 1 and fig. 2, a schematic diagram of a connection between a waveguide of a silicon photonic device and a spot-size converter and a schematic diagram of a comparison between waveguide widths of a single-mode fiber and a spot-size converter are shown, and a key part of a silicon photonic device packaging technology is to realize coupling connection between an optical signal in a chip and an external optical signal (mostly, an optical fiber). The core diameter of the single-mode optical fiber is about 8-10 microns, the size of the cross section of the waveguide of the silicon photonic device is smaller than 1 micron, the size difference of the two is large, severe mode field mismatch is caused, and coupling loss is large. Therefore, a special spot size converter needs to be designed at the input/output end of the chip to realize mode field matching and improve coupling efficiency. The spot-size converter has two modes of end face coupling and vertical grating coupling. The grating coupler has low coupling efficiency and is not favorable for packaging, and is mostly used for design test of silicon photonic devices. The end face coupling has the characteristics of simple packaging process, high coupling efficiency and the like, and is widely applied. The end face coupling is realized by directly aligning the waveguide cross section of the chip input/output port with the cross section of the optical fiber through the spot-size converter, so that the mode field of the single-mode optical fiber is matched with the mode field of the silicon waveguide, and the optimal coupling efficiency is achieved. The design mechanism of the cantilever beam wedge-shaped spot size converter is widely adopted as a mature design due to small product size and excellent optical indexes. The coupling method of the conventional planar waveguide chip is to align and couple with the end face waveguide of the chip through a Fiber Array (FA). The coupling end face of the chip and the optical fiber array only uses one glue, and simultaneously realizes refractive index matching and strength bonding. However, in the silicon photonic device designed by the cantilever beam structure, the periphery of the end surface waveguide is suspended and is connected with the chip main body only by the cantilever, and the structure is sensitive to stress, so that the cantilever structure can be damaged when the stress is large, and the chip is scrapped. The hard glue selected by the conventional coupling mode can generate larger stress due to environmental change, and cannot be used for coupling of the cantilever beam waveguide chip. In addition, the bottom of the end face of the chip is provided with a bulge (the protruding part is larger than the coupling distance), the conventional optical fiber array cannot be used, the optical fiber array with a special specification needs to be customized for coupling alignment, the manufacturing process of the optical fiber array is complex, the processing difficulty is high, the cost is higher, and the coupling process with the chip is complex.

in the manufacturing method and the heating device for optical fiber connection and coupling in the embodiment of the invention, the thin-core optical fiber matched with the output mode field of the spot size converter is locally heated to increase the fiber core mode field of the heating area of the thin-core optical fiber to the fiber core width of the single-mode optical fiber, then the thin-core optical fiber is cut off in the fiber core increasing area of the thin-core optical fiber, and finally the thin-core optical fiber is welded with the single-mode optical fiber at the breakpoint of the fiber core increasing area of the thin-core optical fiber. The mode of local heating is adopted, the fiber core mode field of the thin-core optical fiber matched with the output mode field of the spot size converter is widened and then is welded with the single-mode optical fiber, so that the single-mode optical fiber and the output mode field of the spot size converter achieve the optimal coupling efficiency and the lowest coupling loss, and meanwhile, the optical fiber connected and coupled by adopting the mode has low cost, high production efficiency and low coupling loss and is suitable for mass production.