Waveguide terminator and optical module

Abstract

The utility model relates to the technical field of optical communication, in particular to a waveguide terminator and an optical module.The waveguide terminator comprises an optical absorber and a transmission waveguide which are stacked and arranged at intervals; wherein the transmission waveguide comprises a first waveguide section and a second waveguide section, and the second waveguide section is located in a projection area of the light absorber and used for diverging a light field. One end of the first waveguide section is connected with the second waveguide section, and the other end of the first waveguide section extends out of the projection area of the light absorber and is used for transmitting externally input incident light to the second waveguide section. And the included angle between the tangent line of the first waveguide section at the boundary of the projection area of the light absorber and the boundary is smaller than 90 degrees, so that a small amount of light reflected at the boundary of which the refractive index suddenly changes can enter the cladding to be dissipated, additional return loss is avoided as far as possible, and the return loss of the optical chip can be further reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical communication technology, in particular to a waveguide terminator and an optical module. BACKGROUND

[0002] The waveguide terminator is an optical device used to absorb or dissipate optical signals in the waveguide, so as to effectively terminate the transmission of the waveguide.

[0003] Return loss is an important indicator in the field of communication, which is used to evaluate the performance of lines and equipment. Excessive return loss may cause signal attenuation, interference and other problems, affecting the quality of communication. Therefore, controlling the return loss plays a key role in ensuring stable and reliable signal transmission.

[0004] There are some branches in the optical chip link that do not need to be probed. At the end of these branches, a waveguide terminator is usually connected to absorb or dissipate the residual light output by these branches, so as to reduce the return loss of the optical chip. However, the optical signal usually enters the waveguide terminator through the waveguide in a perpendicular manner. This incidence will cause a large reflection at the interface where the refractive index changes greatly. This part of reflected light will return along the original waveguide, resulting in additional return loss. CONTENT

[0005] The present application provides a waveguide terminator and an optical module to solve the technical problem that the existing waveguide terminator produces additional return loss.

[0006] The present application provides a waveguide terminator, comprising:

[0007] a cladding layer;

[0008] a light absorber arranged in the cladding layer;

[0009] a transmission waveguide arranged in the cladding layer and having a spacing with the light absorber in a direction perpendicular to the surface of the cladding layer;

[0010] The transmission waveguide comprises a first waveguide segment and a second waveguide segment. The second waveguide segment is located in the projection area of the light absorber and is used to diverge the light field. One end of the first waveguide segment is connected to the second waveguide segment, and the other end extends out of the projection area of the light absorber and is used to transmit the incident light input from outside to the second waveguide segment.

[0011] The incident light is transmitted from the first waveguide segment to the second waveguide segment and is diverged by the second waveguide segment. The light absorber is used to absorb the diverged light. The incident light transmitted in the first waveguide segment will be partially reflected at the boundary of the projection area to form reflected light.

[0012] The included angle between the tangent of the first waveguide segment at the boundary of the projection region of the light absorber and the boundary is less than 90°, so that the reflected light is reflected out of the transmission waveguide to the cladding layer;

[0013] The projection region of the light absorber is the projection of the light absorber on the waveguide layer where the transmission waveguide is located.

[0014] In an embodiment of the present application, the included angle is α, and the included angle satisfies: 20°≤α≤40°.

[0015] In an embodiment of the present application, the first waveguide segment is a multi-mode waveguide.

[0016] In an embodiment of the present application, the width of the multi-mode waveguide is W1, and the width satisfies: 1.5μm

[0017] ≤W1≤3μm.

[0018] In an embodiment of the present application, the second waveguide segment has a first end and a second end, and the first end is connected to the first waveguide segment; the width of the second waveguide segment at each position in the extension direction thereof gradually decreases along the direction towards the second end, and the width of the second end is 200nm to 400nm.

[0019] In an embodiment of the present application, the second waveguide segment is arranged in a spiral inward from the first end.

[0020] In an embodiment of the present application, the second waveguide segment is an Archimedes spiral waveguide.

[0021] In an embodiment of the present application, the second waveguide segment is a multi-mode waveguide structure with sudden change or a fan-shaped focusing grating waveguide structure.

[0022] In an embodiment of the present application, the interval is greater than or equal to 80nm and less than or equal to 300nm.

[0023] In an embodiment of the present application, the transmission waveguide is one of a silicon nitride waveguide, a lithium niobate waveguide, or a silicon oxynitride waveguide.

[0024] In an embodiment of the present application, the first waveguide segment is a curved waveguide, and the curved waveguide includes one of an Euler curved waveguide, a Bessel curved waveguide, a cosine curved waveguide, or a sine curved waveguide.

[0025] In an embodiment of the present application, the absorber includes a first semiconductor layer and a second semiconductor layer, the second semiconductor layer is an absorbing layer, and the second semiconductor layer is stacked on the side of the first semiconductor layer away from the transmission waveguide.

[0026] In an embodiment of the present application, the material of the second semiconductor layer includes one of germanium, doped silicon, indium phosphide, or indium gallium arsenide.

[0027] In an embodiment of the present application, the material of the first semiconductor layer comprises one of intrinsic silicon and doped silicon.

[0028] In an embodiment of the present application, the thickness of the second semiconductor layer is greater than or equal to 300 nm.

[0029] In an embodiment of the present application, the absorber comprises a doped silicon layer for absorbing the divergent light.

[0030] Correspondingly, the present application also provides a waveguide terminator comprising the waveguide terminator described in the above embodiments.

[0031] One of the above technical solutions has the following advantages or beneficial effects:

[0032] The angle between the tangent of the first waveguide segment at the boundary of the projection area of the light absorber and the boundary is less than 90°, the first waveguide segment is arranged to cross the boundary of the refractive index mutation of the waveguide terminator in an inclined manner, so that the reflected light formed by the light entering the waveguide terminator and being reflected at the boundary of the refractive index mutation can enter the cladding and be dissipated, and will not return along the original path, thereby avoiding additional return loss as much as possible, further reducing the return loss of the optical chip, and ensuring the stability and reliability of signal transmission. BRIEF DESCRIPTION OF DRAWINGS

[0033] The technical solutions and other beneficial effects of the present application will become apparent from the following detailed description of the specific embodiments of the present application, combined with the accompanying drawings.

[0034] Figure 1 is a cross-sectional view of the waveguide terminator provided by an embodiment of the present application;

[0035] Figure 2 is a structural schematic view of the waveguide terminator provided by an embodiment of the present application;

[0036] Figure 3 is a light field simulation schematic view of the waveguide terminator provided by an embodiment of the present application;

[0037] Figure 4 is a structural schematic view of the waveguide terminator provided by another embodiment of the present application;

[0038] Figure 5 is a structural schematic view of the waveguide terminator provided by still another embodiment of the present application;

[0039] Figure 6 is a cross-sectional view of the waveguide terminator provided by still another embodiment of the present application. DETAILED DESCRIPTION

[0040] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of the present application.

[0041] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the term "and / or" in the present application is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that there are three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents an "or" relationship between the associated objects without special description.

[0042] A waveguide terminator is an optical device used to absorb or dissipate optical signals in an optical waveguide to effectively terminate the transmission of the waveguide. There are two technical solutions for the waveguide terminator: dissipative and absorptive. The dissipative waveguide terminator dissipates optical signals by using the mismatch of curvature between the straight waveguide and the curved waveguide at the interface and the scattering phenomenon caused by the curved waveguide structure; the absorptive waveguide terminator uses a specific coupling structure to guide the optical signals into the material with strong absorption capacity to complete the absorption. Compared with the absorptive waveguide terminator, the dissipative waveguide terminator occupies a large area and easily affects other photonic devices around, causing signal crosstalk. The absorptive waveguide terminator has a sudden change of effective refractive index of the waveguide, and the optical signal usually enters the waveguide terminator in a perpendicular manner, and a large reflection will occur at the interface where the refractive index changes, thereby causing additional backwave loss.

[0043] Therefore, the present application provides a waveguide terminator, which helps to reduce the additional backwave loss and ensure the stability and reliability of signal transmission.

[0044] Specifically, referring to Figures 1 to 3 , Figure 1 is a cross-sectional view of a waveguide terminator provided by an embodiment of the present application, Figure 2 is a structural schematic view of a waveguide terminator provided by an embodiment of the present application, Figure 3is a schematic diagram of an optical field simulation of a waveguide terminator provided in an embodiment of the present application. The waveguide terminator is disposed on a substrate 10 and includes a cladding layer 20, an optical absorber 30, and a transmission waveguide 40. The optical absorber 30 and the transmission waveguide 40 are disposed in the cladding layer 20 and have a spacing 70 from the optical absorber 30 in a direction perpendicular to a surface of the cladding layer 20. In this embodiment, the spacing 70 is greater than or equal to 80 nm and less than or equal to 300 nm. Specifically, the cladding layer 20 is disposed on a side surface of the substrate 10. The substrate 10 can be a silicon material, or a sapphire, quartz, or other material, which is not limited herein. The cladding layer 20 can be made of a silicon dioxide material. The direction perpendicular to the surface of the cladding layer 20 can be understood as a stacking direction of the cladding layer 20 and the substrate 10.

[0045] The transmission waveguide 40 includes a first waveguide segment 410 and a second waveguide segment 420. The second waveguide segment 420 is located in a projection area 340 of the optical absorber 30 and is used to diverge an optical field. One end of the first waveguide segment 410 is connected to the second waveguide segment 420, and the other end extends out of the projection area of the optical absorber 30 and is used to transmit externally input incident light 51 to the second waveguide segment 420. The externally input incident light 51 can refer to light outside the waveguide terminator in an optical chip, for example, the light can be transmitted from other waveguides in the optical chip and coupled to the transmission waveguide 40 of the waveguide terminator. The incident light 51 is transmitted by the first waveguide segment 410 to the second waveguide segment 420 and is diverged by the second waveguide segment 420, and the optical absorber 30 is used to absorb the diverged light.

[0046] The incident light 51 transmitted in the first waveguide section 410 will be partially reflected at the boundary 341 of the projection area 340 of the light absorber 30 to form the reflected light 52. Here, the projection area 340 of the light absorber 30 is the projection of the light absorber 30 on the waveguide layer 60 where the transmission waveguide 40 is located. The included angle between the tangent line P of the first waveguide section 410 at the boundary 341 of the projection area 340 of the light absorber 30 and the boundary 341 is a, and the included angle a is less than 90°, so that the reflected light 52 is reflected out of the transmission waveguide 40 to the cladding layer 20. Specifically, in the process of entering the waveguide terminator, the externally input incident light 51 will be reflected at the interface of the effective refractive index mutation of the waveguide, that is, the boundary 341 of the projection area 340 of the light absorber 30. In this embodiment, the included angle a between the tangent line P of the first waveguide section 410 at the boundary 341 of the projection area 340 of the light absorber 30 and the boundary 341 is less than 90°, that is, the first waveguide section 410 is arranged to cross the refractive index mutation boundary of the waveguide terminator in an inclined manner, so that the reflected light formed after the light enters the waveguide terminator and is reflected at the refractive index mutation boundary can enter the cladding layer 20 and be dissipated, and will not return along the original path, thereby avoiding additional return loss as much as possible, further reducing the return loss of the optical chip, and ensuring the stability and reliability of signal transmission.

[0047] In an embodiment, the included angle a between the tangent line P of the first waveguide section 410 at the boundary 341 of the projection area 340 of the light absorber 30 and the boundary 341 further satisfies: 20°≤a≤40°, that is, the size of the included angle a is preferably in the range of 20° to 40°. It can be understood that the angle range of the included angle a can be reasonably adjusted according to the material of the light absorber 30 to achieve better return loss. When the light absorber 30 selects different materials, the specific value of the included angle a is also different.

[0048] In an embodiment, the first waveguide section 410 is a multi-mode waveguide. The width of the multi-mode waveguide is W1, and satisfies: 1.5μm≤W1≤3μm. It can be understood that the width of the multi-mode waveguide may be different for different materials. Compared with the single-mode waveguide, the effective refractive index mutation of the multi-mode waveguide at the interface is smaller than that of the single-mode waveguide, which can reduce the light reflection at the interface and is beneficial to further reduce the return loss and ensure the stability and reliability of signal transmission.

[0049] In some embodiments, the first waveguide segment 410 is a curved waveguide, which can be an Euler curved waveguide, a Bessel curved waveguide, a cosine curved waveguide, a sine curved waveguide, etc. In other embodiments, the first waveguide segment 410 can also be a straight waveguide, or a combination of a straight waveguide and a curved waveguide. For example, the first waveguide segment 410 can be straight at the portion in contact with the boundary 341 of the projection region 340, and the angle a between the straight portion and the boundary 341 of the projection region 340 can be an acute angle. The connection portion between the first waveguide segment 410 and the second waveguide segment 420 can be curved to achieve a smooth transition between the first waveguide segment 410 and the second waveguide segment 420.

[0050] Further, referring to Figure 2 , the second waveguide segment 420 has a first end 421 and a second end 422, and the first end 421 is connected to the first waveguide segment 410. The width of the second waveguide segment 420 gradually decreases along the direction towards the second end 422. In this embodiment, the width of the second waveguide segment 420 at the connection position with the first waveguide segment 410 is the same as the width of the first waveguide segment 410, and the width of the second end 422 of the second waveguide segment 420 is 200 nm to 400 nm. In other embodiments, the width of the first end 421 of the second waveguide segment 420 can be different from the width of the first waveguide segment 410, and the first waveguide segment 410 can be connected to the second waveguide segment 420 through a mode spot converter. In this way, the width of the second waveguide segment 420 gradually decreases, which can well diverge the light field, so that the light absorber 30 can better absorb the light signal and minimize the echo loss.

[0051] In an embodiment, the second waveguide segment 420 is spirally arranged inward from the first end 421. Specifically, the second waveguide segment 420 can be an Archimedes spiral waveguide, etc. Of course, in other embodiments of the present application, the second waveguide segment 420 can also be other diverging waveguide structures, such as the abrupt multimode waveguide structure shown in Figure 4 , or the fan-shaped focusing grating waveguide structure shown in Figure 5 , etc., which are not limited herein.

[0052] In this embodiment, the transmission waveguide 40 is a silicon nitride waveguide. In other embodiments, the transmission waveguide 40 can also be other materials capable of achieving low-loss transmission of light signals, such as lithium niobate waveguides or silicon oxynitride waveguides, etc., which are not limited herein.

[0053] In an embodiment, the absorber 30 comprises a first semiconductor layer 310 and a second semiconductor layer 320, the second semiconductor layer 320 being an absorbing layer, and the second semiconductor layer 320 being stacked on a side of the first semiconductor layer 310 opposite to the transmission waveguide 40. For example, the second semiconductor layer 320 can be partially embedded in the side of the first semiconductor layer 310 opposite to the transmission waveguide 40, or the second semiconductor layer 320 can be stacked on the surface of the side of the first semiconductor layer 310 opposite to the transmission waveguide 40, and the second semiconductor layer 320 is not embedded in the first semiconductor layer 310.

[0054] In the embodiment, the first semiconductor layer 310 can be made of silicon material, such as intrinsic silicon or doped silicon. The second semiconductor layer 320 is made of germanium material, and the second semiconductor layer 320 can be grown on the first semiconductor layer 310 by, for example, epitaxial process. In the embodiment, the orthographic projection of the first semiconductor layer 310 on the surface of the cladding layer 20 is greater than or equal to the orthographic projection of the second semiconductor layer 320 on the surface of the cladding layer 20, and the orthographic projection of the first semiconductor layer 310 on the surface of the cladding layer 20 covers the orthographic projection of the second semiconductor layer 320 on the surface of the cladding layer 20, so as to provide sufficient epitaxial growth space for the second semiconductor layer 320. For example, in the case that the second semiconductor layer 320 is embedded in the side of the first semiconductor layer 310 opposite to the transmission waveguide 40, a groove can be made on the side of the first semiconductor layer 310 opposite to the transmission waveguide 40, and then the second semiconductor layer 320 can be epitaxially grown in the groove. Alternatively, the second semiconductor layer 320 can be epitaxially grown directly on the surface of the side of the first semiconductor layer 310 opposite to the transmission waveguide 40.

[0055] In the embodiment, the thickness of the second semiconductor layer 320 is greater than or equal to 300 nm. By reasonably setting the thickness of the second semiconductor layer 320, the embodiment is beneficial to make the absorption of the second semiconductor layer 320 to light more sufficient.

[0056] In this embodiment, the material of the transmission waveguide 40 is silicon nitride, and the transmission waveguide 40 is integrated on the side of the first semiconductor layer 310 opposite to the second semiconductor layer 320 by a back integration process. In the front integration process of the waveguide terminal, since an electrode structure needs to be laid on the second semiconductor layer 320, the transmission waveguide 40 cannot overlap the second semiconductor layer 320. Therefore, the silicon nitride waveguide terminal integrated by the front integration process is generally dissipative. If the waveguide terminal integrated by the front integration process is to be made into an absorptive type, the optical signal can only be guided into a silicon waveguide and then transmitted to a germanium material region for absorption, wherein the coupling structure from the silicon nitride to the silicon waveguide introduces new return loss. In this application, the second semiconductor layer 320 is stacked on the side of the first semiconductor layer 310 opposite to the transmission waveguide 40, that is, the transmission waveguide 40 is made on the side of the first semiconductor layer 310 opposite to the second semiconductor layer 320 by a back integration process. On the one hand, this can avoid the problem that silicon nitride cannot overlap the germanium material region, and does not affect the electrode structure on the side of the second semiconductor layer 320 opposite to the transmission waveguide 40, making the metal wiring more convenient. In this way, electricity and light can be distributed on different sides of the light absorber 30 without interfering with each other. On the other hand, light can be directly dispersed from the second waveguide segment 420 of the transmission waveguide 40 and then absorbed by the light absorber 30, without additional coupling structure to affect the return loss in the optical transmission process.

[0057] In other embodiments, the material of the transmission waveguide 40 can also be lithium niobate, silicon, silicon oxynitride, etc. The material of the light absorber 30 can also be other materials that can be used for optical-electric detectors in the communication waveband, such as doped silicon, indium phosphide, indium gallium arsenide, etc. The nk coefficient of these materials is relatively large, and is not limited herein. Here, the nk coefficient is a parameter describing the speed of light propagation in a substance, wherein n represents the refractive index and k represents the absorption coefficient. By selecting appropriate materials and adjusting their nk values, the speed of light propagation, absorption capacity, etc. can be controlled to achieve the desired optical function.

[0058] Please refer to Figure 6 , Figure 6 is a cross-sectional view of a waveguide terminal provided in another embodiment of the application.

[0059] Different from the above embodiments, the structure of the light absorber 30 in this embodiment is different from that of the above light absorber 30. In this embodiment, the light absorber 30 only includes a doped silicon layer 330, which is used to absorb the dispersed light. The light absorber 30 provided in this embodiment only needs to be doped on a silicon layer to form a doped silicon layer 330, and can be used to absorb light. The process of the light absorber 30 in this embodiment is simpler, and the transmission waveguide 40 can be integrated on one side of the doped silicon layer 330 by a front integration process or a back integration process, which has a wider application range and makes the structural design of the waveguide terminal more flexible.

[0060] In addition, an embodiment of the present application also provides an optical module comprising the waveguide terminator of any of the above embodiments. The waveguide terminator has been described in detail in the above embodiments, and will not be described here again. Specifically, the optical module can comprise a photonic integrated chip, the photonic integrated chip integrating the waveguide terminator and other optical links, the optical links can comprise semiconductor optical devices and other waveguides, and the waveguide terminator can be connected to the branch end of the optical links.

[0061] In addition, the present application also provides a processing flow of the waveguide terminator, comprising the following steps:

[0062] S1: providing a semiconductor-on-insulator wafer, for example, a Silicon On Insulator (SOI) wafer, comprising a substrate, a buried oxide layer and a silicon layer, fabricating a germanium-silicon light absorber on the front surface of the wafer through etching, epitaxial growth and other processes, and covering the fabrication of the cladding layer and other front surface structures;

[0063] S2: turning over the wafer with the light absorber 30 and bonding with a new substrate 10, the substrate can be used as a support substrate of the wafer to ensure the stability of the wafer;

[0064] S3: polishing off the original substrate and the buried oxide layer of the wafer, retaining a thin buried oxide film as part of the cladding layer, and polishing;

[0065] S4: fabricating the transmission waveguide 40 in the above embodiments on the buried oxide film, and making the included angle between the tangent P of the transmission waveguide 40 at the boundary 341 of the projection area 340 of the light absorber 30 and the boundary 341 an acute angle, so as to ensure that the optical signal is inclined to enter the waveguide terminator.

[0066] S5: covering the lower cladding layer on the side of the transmission waveguide 40 away from the light absorber 30, the lower cladding layer together with the buried oxide film and the upper cladding layer forming the cladding layer 20.

[0067] It can be understood that in step S1, the light absorber 30 can be other materials of photodetectors that can be used in the communication band, such as silicon, indium phosphide, indium gallium arsenide, etc., which are not limited here. In step S4, the material of the transmission waveguide 40 can be a material that can realize low-loss transmission of optical signals, such as silicon nitride, lithium niobate, silicon, silicon oxynitride, etc., which are not limited here.

[0068] In summary, the included angle between the tangent of the first waveguide section at the boundary of the projection area of the light absorber and the boundary is less than 90°. By arranging the first waveguide section to cross the boundary of the refractive index mutation of the waveguide terminal in an inclined manner, the reflected light formed after a small amount of reflection at the boundary of the refractive index mutation can enter the cladding and be dissipated when the light enters the waveguide terminal, so as not to return along the original path, thereby avoiding additional return loss as much as possible, further reducing the return loss of the optical chip, and ensuring the stability and reliability of signal transmission.

[0069] The above is only some of the embodiments of the present application, and does not limit the application in any form. The protection scope of the embodiments of the present application is not limited thereto. Any simple modification, equivalent change and modification easily thought of by those skilled in the art within the technical range disclosed by the embodiments of the present application should be covered within the protection scope of the embodiments of the present application.

Claims

1. A waveguide terminator, comprising: The waveguide terminal device comprises: a cladding layer; a light absorber arranged in the cladding layer; a transmission waveguide arranged in the cladding layer and having a spacing with the light absorber in a direction perpendicular to a surface of the cladding layer; wherein the transmission waveguide comprises a first waveguide segment and a second waveguide segment, the second waveguide segment is located in a projection area of the light absorber and is used for diverging a light field; one end of the first waveguide segment is connected to the second waveguide segment, and the other end of the first waveguide segment extends out of the projection area of the light absorber and is used for transmitting an incident light inputted from outside to the second waveguide segment; the incident light is transmitted from the first waveguide segment to the second waveguide segment and is diverged by the second waveguide segment, and the light absorber is used for absorbing the diverged light; the incident light transmitted in the first waveguide segment will be partially reflected at a boundary of the projection area to form a reflected light; an included angle between a tangent of the first waveguide segment at the boundary of the projection area of the light absorber and the boundary is less than 90°, so that the reflected light is reflected out of the transmission waveguide to the cladding layer; the projection area of the light absorber is a projection of the light absorber on a waveguide layer where the transmission waveguide is located.

2. The waveguide terminator of claim 1, wherein, The included angle is α, and the included angle satisfies 20°≤α≤40°.

3. The waveguide terminator of claim 1, wherein, The first waveguide segment is a multimode waveguide.

4. The waveguide terminal device according to claim 3, wherein a width of the multimode waveguide is W1, and the width satisfies 1.5 μm≤W1≤3 μm.

5. The waveguide terminator of claim 3, wherein, two ends of the second waveguide segment are a first end and a second end respectively, the first end is connected to the first waveguide segment; a width of the second waveguide segment at each position in an extension direction of the second waveguide segment gradually decreases along a direction towards the second end; a width of the second end is 200 nm to 400 nm.

6. The waveguide terminal device according to claim 5, wherein the second waveguide segment is arranged in a spiral inward from the first end.

7. The waveguide terminal device according to claim 6, wherein the second waveguide segment is an Archimedes spiral waveguide.

8. The waveguide terminal device according to claim 1, wherein the second waveguide segment is a sudden multimode waveguide structure or a fan-shaped focusing grating waveguide structure.

9. The waveguide terminal device according to claim 1, wherein the spacing is greater than or equal to 80 nm and less than or equal to 300 nm.

10. The waveguide terminator of claim 1, wherein, the transmission waveguide is one of a silicon nitride waveguide, a lithium niobate waveguide, and a silicon oxynitride waveguide.

11. The waveguide terminator of claim 1, wherein, the first waveguide segment is a curved waveguide, and the curved waveguide comprises one of an Euler curved waveguide, a Bessel curved waveguide, a cosine curved waveguide, and a sine curved waveguide.

12. The waveguide terminator of claim 1, wherein, the absorber comprises a first semiconductor layer and a second semiconductor layer, the second semiconductor layer is an absorbing layer, and the second semiconductor layer is stacked on a side of the first semiconductor layer away from the transmission waveguide.

13. The waveguide terminator of claim 12, wherein, a material of the second semiconductor layer comprises one of germanium, doped silicon, indium phosphide, and indium gallium arsenide.

14. The waveguide terminator of claim 12, wherein, a material of the first semiconductor layer comprises one of intrinsic silicon and doped silicon.

15. The waveguide terminator of claim 12, wherein, a thickness of the second semiconductor layer is greater than or equal to 300 nm.

16. The waveguide terminal device according to claim 1, wherein The absorber includes a doped silicon layer for absorbing the diverging light.

17. An optical module characterized by comprising: The waveguide terminator includes any one of claims 1-16.

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