CN220626711U

CN220626711U - End-face coupler and gyroscope system

Info

Publication number: CN220626711U
Application number: CN202322208941.1U
Authority: CN
Inventors: 许文渊
Original assignee: Chongqing Zizhe Technology Co ltd
Current assignee: Chongqing Zizhe Technology Co ltd
Priority date: 2023-08-16
Filing date: 2023-08-16
Publication date: 2024-03-19
Anticipated expiration: 2033-08-16

Abstract

The application discloses an end face coupler and a gyroscope system, wherein the end face coupler comprises a substrate; the cladding layer is arranged on one side of the substrate and used for limiting the diffusion of the optical signal; the core layer structure is embedded in the coating layer and comprises an input section, a coupling conversion structure and two output sections, wherein the input section is arranged on one side of the end face coupler, which is to be coupled, the side of the end face coupler, which is to be coupled, is transmitted by the coupling conversion structure, the coupling conversion structure is connected between the input section and the two output sections, the two output sections are arranged on one side of the end face coupler, which is to be coupled, at intervals, in a direction, away from the coupling conversion structure, of the output sections, the cross-sectional area of the output sections is gradually reduced, and the cross-sectional area of the output sections is used for limiting the to-be-coupled wave in a mode field with a preset size. The end face coupler and the gyroscope system can realize low-loss and high-efficiency coupling between the end face coupler and an external optical fiber device, and meet the performance requirement of the gyroscope system.

Description

End-face coupler and gyroscope system

Technical Field

The application belongs to the technical field of photoelectrons, and particularly relates to an end face coupler and a gyroscope system.

Background

The optical gyroscope is an optical sensor for detecting the angular velocity of a moving carrier, and is based on an integrated optical gyroscope of an optoelectronic integration technology, wherein a waveguide is used for replacing an optical fiber, and part of active and passive devices are integrated on a chip. In the integrated optical circuit, because the optical fiber and the waveguide are directly butted, mode field mismatch is caused, coupling efficiency is low, and larger coupling loss is caused, the end face coupler for matching the mode fields of the optical fiber and the waveguide is a key structure for connecting a chip and an external optical fiber device.

At present, a chip and an external optical fiber device are generally coupled and connected through an end face coupler such as a grating coupler, a mode spot converter and the like, the grating coupler is composed of array optical fibers, the coupling efficiency of the grating coupler and the packaging mode of the chip is too low, the packaged array optical fibers are not easy to fix, the optical power loss of an optical gyroscope in the use process is too large, the packaging mode of the mode spot converter is relatively low in coupling loss caused by packaging compared with the packaging mode of the grating coupler, the packaging size is small, the mode spot converter usually adopts single-ended waveguide for output, but the coupling efficiency between the waveguide and the optical fibers of the mode spot converter is low, the loss is large, and the performance requirement of a gyroscope system cannot be met.

Disclosure of Invention

The application provides an end face coupler and a gyroscope system, which can realize low-loss and high-efficiency coupling between the end face coupler and an external optical fiber device and meet the performance requirement of the gyroscope system.

The application provides an end face coupler, wherein, include: a substrate; the cladding layer is arranged on one side of the substrate and used for limiting the diffusion of the optical signal; the core layer structure is embedded in the coating layer and comprises an input section, a coupling conversion structure and two output sections, wherein the input section is arranged on one side of the end face coupler, which is to be coupled, the side of the end face coupler, which is to be coupled, is transmitted by the coupling conversion structure, the coupling conversion structure is connected between the input section and the two output sections, the two output sections are arranged on one side of the end face coupler, which is to be coupled, at intervals, in a direction, away from the coupling conversion structure, of the output sections, the cross-sectional area of the output sections is gradually reduced, and the cross-sectional area of the output sections is used for limiting the to-be-coupled wave in a mode field with a preset size.

The end face coupler as above, wherein one end of the output section far away from the coupling conversion structure is an output end, an excitation interval L1 is arranged between the output ends of the two output sections, and the excitation interval L1 has the following range: l1 is more than or equal to 0.5 mu m and less than or equal to 1.7 mu m.

The end face coupler as above, wherein the output end has a width W, the width W having the following range: w is more than or equal to 0.13 μm and less than or equal to 0.19 μm.

The end face coupler as above, wherein the output section has a length L2, the length L2 having the following range: l2 is more than or equal to 300 mu m.

The end face coupler comprises a core layer structure, wherein the core layer structure comprises two connecting sections which are arranged in one-to-one correspondence with the two output sections, the first ends of the two connecting sections are connected with the coupling conversion structure, the second ends of the connecting sections are connected with the corresponding output sections, and the distance between the two connecting sections is gradually reduced from the first ends of the connecting sections to the second ends.

The end face coupler as above, wherein the connecting section is a curved structure having an arc, the connecting section has a radius of curvature R having the following range: r is more than or equal to 30 mu m.

The end face coupler as above, wherein the coupling conversion structure comprises a conversion input end and two conversion output ends, the conversion input end is connected with the input section, and the two conversion output ends are connected with the first ends of the two connecting sections in a one-to-one correspondence.

The end-face coupler as above, wherein the cladding has a thickness H, and the quasi-coupled wave generated by the co-excitation of the two output sections has a mode spot diameter D, and the thickness H has the following relationship with the mode spot diameter D: h is more than or equal to 1.2D.

The end face coupler comprises a cladding layer, a core layer structure and a core layer structure, wherein the cladding layer comprises an upper cladding layer and a lower cladding layer, the core layer structure is arranged on the top of the lower cladding layer, and the upper cladding layer is coated on the surface of the core layer structure.

On the other hand, the application also provides a gyroscope system, wherein the gyroscope system comprises an optical fiber device, a chip and the end face coupler, and the optical fiber device is connected with the chip through the end face coupler.

The end face coupler comprises a substrate, a cladding layer and a core layer structure, wherein the cladding layer is arranged on one side of the substrate, the core layer structure is embedded in the cladding layer, the core layer structure comprises an input section, a coupling conversion structure and two output sections, the input section is arranged on one side of the end face coupler, into which a quasi-coupling wave is transmitted, and is used for inputting the transmitted quasi-coupling wave into the coupling conversion structure, the coupling conversion structure is connected between the input section and the two output sections, the quasi-coupling wave of the input section can be respectively transmitted to the two output sections, the two output sections are arranged on one side of the quasi-coupling wave in a spaced mode, the quasi-coupling wave can be output to an external device, the cross-sectional area of the output section is gradually reduced along the direction of the output section away from the coupling conversion structure, the quasi-coupling wave can be limited in a mode field with a preset size, and the mode spot conversion of the quasi-coupling wave is realized, so that the mode spot diameter of the output quasi-coupling wave is alternately arranged between the two output sections and the shape setting gradually reduced, the mode spot diameter of the quasi-coupling wave accords with the mode diameter of the optical fiber through which can be passed by the external device, the transmission loss of the quasi-coupling wave can be respectively transmitted to the two output sections, the transmission loss of the quasi-coupling wave can be reduced, the optical fiber loss can be met, the requirements of the optical fiber system and the high-coupling efficiency can be met, and the requirements of a gyroscope can be met, and the coupling system can be realized.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described, and it is possible for a person skilled in the art to obtain other drawings according to these drawings without inventive effort.

Fig. 1 is a schematic diagram of the overall structure of an end-face coupler according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a core layer structure of an end-face coupler according to an embodiment of the present application;

fig. 3 is a cross-sectional view at the output end of an end-face coupler of an embodiment of the present application.

Reference numerals illustrate:

11. a substrate; 12. a cladding layer; 121. an upper cladding layer; 122. a lower cladding layer; 13. a core layer structure; 14. an input section; 15. a coupling conversion structure; 151. a conversion input; 152. a conversion output; 16. an output section; 161. an output end; 17. and a connecting section.

Detailed Description

Features and exemplary embodiments of various aspects of the present application are described in detail below to make the objects, technical solutions and advantages of the present application more apparent, and to further describe the present application in conjunction with the accompanying drawings and the detailed embodiments. It should be understood that the specific embodiments described herein are intended to be illustrative of the application and are not intended to be limiting. It will be apparent to one skilled in the art that the present application may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present application by showing examples of the present application.

As shown in fig. 1 to 3, an embodiment of the present application provides an end-face coupler, including: a substrate 11; a cladding layer 12 provided on one side of the substrate 11, the cladding layer 12 being for restricting diffusion of the optical signal; the core layer structure 13 is embedded in the cladding layer 12, the core layer structure 13 comprises an input section 14, a coupling conversion structure 15 and two output sections 16, the input section 14 is arranged on one side of the end face coupler, which is to be coupled, the coupling conversion structure 15 is connected between the input section 14 and the two output sections 16, the two output sections 16 are arranged on one side of the end face coupler, which is to be coupled, at intervals, along the direction that the output sections 16 are far away from the coupling conversion structure 15, the cross-sectional area of the output sections 16 is gradually reduced, and the cross-sectional area of the output sections 16 is used for limiting the to be coupled in a mode field with a preset size.

In specific implementation, the end-face coupler of the embodiment of the application includes a substrate 11, a cladding layer 12 and a core layer structure 13, the cladding layer 12 is disposed at one side of the substrate 11, the core layer structure 13 is embedded in the cladding layer 12, the core layer structure 13 includes an input section 14, a coupling conversion structure 15 and two output sections 16, the input section 14 is disposed at one side of the end-face coupler, into which a pseudo-coupling wave is transmitted, for inputting the input pseudo-coupling wave into the coupling conversion structure 15, the coupling conversion structure 15 is connected between the input section 14 and the two output sections 16, the pseudo-coupling wave of the input section 14 is respectively transmitted to the two output sections 16, the two output sections 16 are disposed at one side, spaced apart from each other, of the pseudo-coupling wave is transmitted from the pseudo-coupling wave, the pseudo-coupling wave is output to an external device, the cross-section 16 cross-sectional area is gradually reduced along the direction of the output sections 16 away from the coupling conversion structure 15, the pseudo-coupling wave is limited in a predetermined size of the analog field, and the analog-spot conversion of the pseudo-coupling wave is realized, therefore the two output sections 16 are disposed at intervals, and the shape of the cross-section 16 is gradually reduced, the cross-sectional area of the output section 16 is gradually reduced, the pseudo-coupling wave is required to be reduced, and the diameter of the external-coupling wave coupling device is reduced, and the diameter of the fiber-coupling device is required to be reduced, and the diameter is achieved, and the diameter of the fiber-coupling device is and the fiber-optic coupler is reduced.

In addition, the embodiment of the application adopts the coupling encapsulation between the end face coupler and the external optical fiber device, can directly embed the core layer structure 13 in the cladding layer 12, and carries out horizontal encapsulation, and has higher coupling efficiency and installation stability compared with the vertical encapsulation of the array optical fiber and the external optical fiber device.

In specific implementation, two output sections 16 which are arranged at intervals can jointly excite a quasi-coupled wave, the mode spot diameter of the quasi-coupled wave meets the requirement of an external optical fiber device, and the quasi-coupled wave can be coupled into the external optical fiber device, so that the quasi-coupled wave has smaller loss.

Specifically, the quasi-coupled wave is an optical signal applied in a gyro system.

As shown in fig. 1 to 3, in the end-face coupler of the embodiment of the present application, one end of the output section 16 far away from the coupling conversion structure 15 is an output end 161, and an excitation interval L1 is provided between the output ends 161 of the two output sections 16, where the excitation interval L1 has the following range: l1 is more than or equal to 0.5 mu m and less than or equal to 1.7 mu m.

Preferably, the excitation pitch L1 is 1.1 μm, at which the best coupling efficiency achievable for the end-face coupler to the external fiber device is 92%.

As shown in table one, when the width W and the length L2 are both at values that can achieve the optimal coupling efficiency, the excitation interval L1 has the following relationship with the coupling efficiency.

List one

In specific implementation, when the coupling efficiency is greater than or equal to 84%, the coupling requirement of the gyroscope system can be met, so that the coupling efficiency is greater than or equal to 84% in the range of 0.5 μm and L1 and 1.7 μm, the coupling efficiency of the two output sections 16 and the external optical fiber device is higher, the loss of the optical signals input to the external optical fiber device by the two output sections 16 is smaller, and the processing tolerance is larger.

As shown in fig. 3, the end face coupler of the embodiment of the present application, wherein the output end 161 has a width W, the width W has the following range: w is more than or equal to 0.13 μm and less than or equal to 0.19 μm. Within this range, the loss of the optical signal input to the external optical fiber device by the output segments 16 is small, the coupling efficiency of the two output segments 16 and the external optical fiber device is high, and the processing tolerance is large.

Preferably, the width W is 0.17 μm, at which the best coupling efficiency of the end-face coupler with the external optical fiber device is 92% that can be achieved.

As shown in table two, when the excitation interval L1 and the length L2 are both at values that can achieve the optimal coupling efficiency, the width W has the following relationship with the coupling efficiency.

Watch II

	Width W	Coupling efficiency
			Example six	0.13	84％
Example seven	0.15	88.5％
			Example eight	0.17	92％
Example nine	0.19	89％

In specific implementation, when the coupling efficiency is greater than or equal to 84%, the coupling requirement of the gyroscope system can be met, so that the coupling efficiency is greater than or equal to 84% in the range of 0.13 μm and less than or equal to 0.19 μm, the coupling efficiency of the two output sections 16 and the external optical fiber device is higher, the loss of the optical signals input to the external optical fiber device by the two output sections 16 is smaller, and the processing tolerance is larger.

As shown in fig. 2, the end-face coupler of the embodiment of the present application, wherein the output section 16 has a length L2, the length L2 has the following range: l2 is more than or equal to 300 mu m. Within this range, the transmission loss of the output section 16 is small, can be less than 3%, the coupling efficiency of the output section 16 with the external optical fiber device is high, and there is a large processing tolerance.

Preferably, L2. Gtoreq.400 μm, at which length the transmission loss of the output section 16 approaches zero, the best coupling efficiency achievable for the end-face coupler with the external fiber device is 92%.

When the excitation distance L1 is 1.1 μm and the width W is 0.17 μm, and the L2 is not less than 400 μm, the coupling efficiency between the end face coupler and the external optical fiber device is 92%, which is the optimal coupling efficiency between the end face coupler and the external optical fiber device.

As shown in fig. 1 and fig. 2, the end-face coupler according to the embodiment of the present application, where the core layer structure 13 further includes two connection sections 17 that are disposed in one-to-one correspondence with the two output sections 16, first ends of the two connection sections 17 are connected with the coupling conversion structure 15, second ends of the respective connection sections 17 are connected with the corresponding output sections 16, and a distance between the two connection sections 17 is gradually reduced from the direction from the first end to the second end of the connection section 17.

In specific implementation, since the two output sections 16 of the end-face coupler, which are spaced apart, jointly excite an optical signal with a fixed spot diameter, the range of the excitation interval L1 needs to be satisfied, and therefore two connection sections 17 with gradually decreasing intervals need to be disposed between the coupling conversion structure 15 and the two output sections 16, so that when the two output sections 16 are respectively connected to the second ends of the two connection sections 17, the range requirement of the excitation interval L1 can be satisfied, thereby realizing the excitation condition of the optical signal, and further realizing low-loss and high-efficiency coupling between the end-face coupler and the external optical fiber device.

As shown in fig. 1 and 2, the end-face coupler of the embodiment of the present application, wherein the connection section 17 is a curved structure having an arc, the connection section 17 has a radius of curvature R, and the radius of curvature R has the following range: r is more than or equal to 30 mu m.

In specific implementation, the connecting section 17 with the bending structure can reduce loss of an optical signal in the process of passing through the connecting section 17, and the bending radius R is controlled within the range, so that the optical loss caused by over bending of the connecting section 17 can be avoided, and the signal loss caused by the structure of the end face coupler is avoided.

As shown in fig. 2, the end-face coupler according to the embodiment of the present application, in which the coupling conversion structure 15 includes one conversion input end 151 and two conversion output ends 152, the conversion input end 151 is connected to the input section 14, and the two conversion output ends 152 are connected to the first ends of the two connection sections 17 in a one-to-one correspondence.

In specific implementation, the optical signals are input from the input section 14 to the conversion input end 151, and are split equally at the two conversion output ends 152, so that two identical optical signals respectively enter the two connection sections 17, and finally, the two output sections 16 jointly excite an optical signal with a mode spot size meeting the requirement, so that the structure of the coupling conversion structure 15 is arranged to enable the end face coupler to realize the requirement that the two output sections 16 jointly excite the optical signals.

Specifically, the coupling conversion structure 15 is a structure obtained by optimizing MMI (multimode interference), and the MMI is a multimode interference structure, and has the characteristics of low loss and high tolerance, wherein the spectral ratio is 50:50.

As shown in fig. 3, in the end-face coupler of the embodiment of the present application, the cladding 12 has a thickness H, and the quasi-coupled wave generated by the co-excitation of the two output sections 16 has a mode-spot diameter D, where the thickness H has the following relationship with the mode-spot diameter D: h is more than or equal to 1.2D. In this relationship, the quasi-coupling wave can be kept inside the cladding 12, so that the quasi-coupling wave does not leak outside the cladding 12, the loss caused by the leakage is reduced, and the loss of the quasi-coupling wave in the end-face coupler is further reduced.

As shown in fig. 1, in the end-face coupler according to the embodiment of the present application, the cladding layer 12 includes an upper cladding layer 121 and a lower cladding layer 122, the core layer structure 13 is disposed on top of the lower cladding layer 122, and the upper cladding layer 121 is disposed on the surface of the core layer structure 13.

In practical implementation, since the refractive indexes of the cladding layer 12 and the core layer structure 13 are different, most of the optical signals are kept inside the core layer structure 13, so that the optical signals can only propagate in the core layer structure 13, and the loss of the optical signals is reduced, the lower cladding layer 122 is used for covering the bottom of the core layer structure 13, and the upper cladding layer 121 is used for covering other surfaces of the core layer structure 13, so that the whole core layer structure 13 is in the cladding layer 12, and the leakage and loss of the optical signals are avoided.

The embodiment of the application also provides a gyroscope system, wherein the gyroscope system comprises an optical fiber device, a chip and the end face coupler, and the optical fiber device is connected with the chip through the end face coupler.

In specific implementation, the gyroscope system comprises an end-face coupler, the end-face coupler comprises a substrate 11, a cladding 12 and a core layer structure 13, the cladding 12 is arranged on one side of the substrate 11, the core layer structure 13 is embedded in the cladding 12, the core layer structure 13 comprises an input section 14, a coupling conversion structure 15 and two output sections 16, the input section 14 is arranged on one side of the end-face coupler, which is used for inputting the input pseudo-coupling wave into the coupling conversion structure 15, the coupling conversion structure 15 is connected between the input section 14 and the two output sections 16, the pseudo-coupling wave of the input section 14 can be respectively transmitted to the two output sections 16, the two output sections 16 are arranged on one side, which is separated from the pseudo-coupling wave, of the output section 16, the pseudo-coupling wave can be output to an external device, the cross-section area of the output section 16 is gradually reduced along the direction of the output section 16, the pseudo-coupling wave is limited in a simulation field with a preset size, the analog-coupling wave is converted, the two output sections 16 are arranged at intervals, the shape is gradually reduced, the cross-section area of the output section 16 is gradually reduced, the shape is arranged between the two output sections 16 and the output section is connected with the optical fiber system, the diameter of the optical fiber system is reduced, the diameter of the optical fiber is required to be coupled, and the diameter of the optical fiber system is reduced, and the optical fiber system is coupled, and the optical fiber system is reduced, and the loss is achieved, and the diameter and the optical fiber system is required to be reduced.

Specifically, the optical fiber device comprises a connecting optical fiber of a light source assembly and an optical fiber ring, wherein the connecting optical fiber of the light source assembly is connected to one end of a chip through an end face coupler, the other end of the chip is connected with two ends of the optical fiber ring through two end face couplers, after an optical signal sent by the light source assembly enters the chip, the optical signal is divided into two beams of light transmitted along opposite directions through a double Y branch and a polarizing structure inside the chip to enter the optical fiber ring, a Sagnac phase difference is generated in the optical fiber ring and then is transmitted reversely, and finally the optical signal is detected by a detector and converted into an electric signal.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

In the foregoing, only the specific embodiments of the present application are described, and it will be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the systems, modules and units described above may refer to the corresponding processes in the foregoing method embodiments, which are not repeated herein. It should be understood that the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the present application, which are intended to be included in the scope of the present application.

Claims

1. An end-face coupler, comprising:

a substrate (11);

a cladding layer (12) provided on one side of the substrate (11), the cladding layer (12) being configured to limit diffusion of an optical signal;

the core layer structure (13) is embedded in the cladding layer (12), the core layer structure (13) comprises an input section (14), a coupling conversion structure (15) and two output sections (16), the input section (14) is arranged on one side of the end face coupler, which is to be coupled, of the input section (14) and two output sections (16), the coupling conversion structure (15) is connected between the input section (14) and the two output sections (16), the two output sections (16) are arranged on one side of the output section, which is to be coupled, at intervals, along the direction that the output sections (16) are far away from the coupling conversion structure (15), the cross-sectional area of the output sections (16) is gradually reduced, and the cross-sectional area of the output sections is used for limiting the analog coupling waves in a mode field with a preset size.

2. The end-face coupler according to claim 1, characterized in that the end of the output section (16) remote from the coupling conversion structure (15) is an output end (161), the output ends (161) of two output sections (16) having an excitation interval L1 between them, the excitation interval L1 having the following range: l1 is more than or equal to 0.5 mu m and less than or equal to 1.7 mu m.

3. The end-face coupler of claim 2, wherein the output end (161) has a width W, the width W having the following range: w is more than or equal to 0.13 μm and less than or equal to 0.19 μm.

4. The end-face coupler according to claim 1, characterized in that the output section (16) has a length L2, the length L2 having the following range: l2 is more than or equal to 300 mu m.

5. The end-face coupler according to claim 1, characterized in that the core structure (13) further comprises two connection sections (17) arranged in one-to-one correspondence with the two output sections (16), the first ends of the two connection sections (17) are connected with the coupling conversion structure (15), the second ends of the connection sections (17) are connected with the corresponding output sections (16), and the distance between the two connection sections (17) is gradually reduced from the direction from the first end to the second end of the connection sections (17).

6. The end-face coupler according to claim 5, characterized in that the connecting section (17) is a curved structure with an arc, the connecting section (17) having a radius of curvature R with the following range: r is more than or equal to 30 mu m.

7. The end-face coupler according to claim 5, characterized in that the coupling conversion structure (15) comprises one conversion input (151) and two conversion outputs (152), the conversion input (151) being connected to the input section (14), the two conversion outputs (152) being connected in one-to-one correspondence with the first ends of the two connection sections (17).

8. The end-face coupler according to claim 1, characterized in that the cladding (12) has a thickness H, the quasi-coupled wave produced by the co-excitation of the two output sections (16) having a mode spot diameter D, the thickness H having the following relationship with the mode spot diameter D: h is more than or equal to 1.2D.

9. The end-face coupler according to claim 7, wherein the cladding (12) comprises an upper cladding (121) and a lower cladding (122), the core structure (13) is arranged on top of the lower cladding (122), and the upper cladding (121) is arranged to cover the surface of the core structure (13).

10. A gyroscope system comprising an optical fiber device, a chip and a face coupler as claimed in any of claims 1 to 9, the optical fiber device being connected to the chip by the face coupler.