WO2023272690A1

WO2023272690A1 - Ridge waveguide, micro-ring resonator, tunable optical delay line and chip

Info

Publication number: WO2023272690A1
Application number: PCT/CN2021/104047
Authority: WO
Inventors: 牛犇
Original assignee: 深圳市速腾聚创科技有限公司
Priority date: 2021-07-01
Filing date: 2021-07-01
Publication date: 2023-01-05
Also published as: CN117561463A

Abstract

A ridge waveguide (100), a micro-ring resonator (10), a tunable optical delay line (20) and a chip. The ridge waveguide (100) comprises: a bent portion (110), wherein the bent portion (110) comprises an arc section (111) and two arc transition sections (112), the two arc transition sections (112) respectively being located at two ends of the arc section (111) and being connected to the arc section (111); and in a direction from one end of each arc transition section (112) connected to the arc section (111) to the other end of the arc transition section away from the arc section (111), the radius of curvature of the arc transition section (112) being gradually changed to infinity from being equal to the radius of curvature of the arc section (111). The bent portion (110) of the ridge waveguide (100) is configured to comprise the arc transition sections (112), and the radii of curvature of the arc transition sections (112) are gradually changed, such that the transmission loss of the bent portion can be greatly reduced, and the size of the ridge waveguide (100) can be designed to be smaller at the same bending loss, and therefore an apparatus can be miniaturized.

Description

Ridge waveguide, microring resonator, adjustable optical delay line and chip

technical field

The present application relates to the technical field of optical devices, in particular to a ridge waveguide, a microring resonator, an adjustable optical delay line and a chip.

Background technique

The waveguide includes a strip waveguide 100a' and a ridge waveguide 100b', and the waveguide is generally disposed on an isolation layer 200', and the isolation layer 200' is disposed on a substrate 300'. Specifically, referring to FIG. 1, the strip waveguide 100a' has a generally rectangular cross-section; referring to FIG. It is stepped. Under the same process conditions, the transmission loss of the strip waveguide 100a' is relatively large, resulting in a large loss of the optical delay line composed of the strip waveguide 100a', which limits the maximum length and application scenarios of the strip waveguide 100a'; however , compared with the ridge waveguide 100b ′, the strip waveguide 100a ′ has a stronger optical mode field confinement ability, and can realize a low-loss curved waveguide with a smaller radius. Therefore, in order to achieve the same bending loss, the arc-shaped ridge-shaped curved waveguide generally has a much larger radius than the arc-shaped strip-shaped curved waveguide, so that the size of the optical delay line based on the ridge-shaped waveguide 100b' is greatly increased , the manufacturing cost is higher.

Contents of the invention

Embodiments of the present application provide a ridge waveguide, a microring resonator, an adjustable optical delay line, and a chip, by setting the curved portion of the ridge waveguide to include an arc-shaped transition section, and the radius of curvature of the arc-shaped transition section is The tapered form can greatly reduce the transmission loss of the bending part, so that under the same bending loss, the size of the ridge waveguide can be designed to be smaller, thereby enabling the miniaturization of the device. Described technical scheme is as follows;

In the first aspect, the embodiment of the present application provides a ridge waveguide, including:

A curved portion, the curved portion includes a circular arc segment and two arc-shaped transition segments, the two arc-shaped transition segments are located at both ends of the circular arc segment and connected to the circular arc segment, each of the In the direction of the arc transition section from one end connecting the arc section to the end away from the arc section, the radius of curvature of the arc transition section gradually changes from being equal to the radius of curvature of the arc section to gigantic.

In some of these embodiments, it also includes:

For the plurality of straight parts, along the length direction of the ridge waveguide, two adjacent straight parts are connected by at least one curved part.

In some of the embodiments, a plurality of the straight parts and the curved parts are connected to form a linear structure with two ends.

In some of the embodiments, the two end portions of the linear structure are each formed by one of the linear portions.

In some of these embodiments, the straight portion forming one end of the linear structure is a first straight portion, and the ridge waveguide further includes:

The first linear transition part, one end of the first linear transition part is connected to the first straight line part, the other end of the first linear transition part is used to connect with the strip waveguide, and the first line In the direction from one end connecting the first straight line to the end away from the first straight line, the ridge and the bottom of the first linear transition are connected with the first straight line The ridges and bottoms of the section are equal in width and/or height and gradually change until the ridges and bottoms are integrally equal in width and/or height to the strip waveguide.

In some of these embodiments, the width of the ridge and the width of the bottom of the first linear portion are different from the width of the strip waveguide, and the first linear transition portion includes sequentially connected first lines a linear transition section, a second linear transition section, and a third linear transition section, the first linear transition section is connected to the first linear portion, and the third linear transition section is used to connect to the strip waveguide,

In the direction of the first linear transition portion from one end connected to the first linear portion to an end away from the first linear portion, the width of the bottom of the first linear transition section is the same as that of the first linear transition section. The width of the bottom of a straight line portion is equal, and the width of the ridge portion of the first linear transition section gradually changes from being equal to the width of the ridge portion of the first straight line portion to being equal to the width of the strip waveguide The width of the bottom of the second linear transition section is equal to the width of the bottom of the first linear transition section, and the width of the ridge of the second linear transition section is equal to the width of the strip waveguide; The width of the ridge of the third linear transition section is equal to the width of the strip waveguide, and the width of the bottom of the third linear transition section gradually changes from being equal to the width of the bottom of the second linear transition section to being equal to the width of the bottom of the second linear transition section. The widths of the strip waveguides are equal.

In some of these embodiments, it also includes:

A light reflection structure, the light reflection structure is connected to one end of the linear structure.

In some of the embodiments, a plurality of the straight parts and the curved parts are connected to form a ring structure.

In some of these embodiments, the ridges of the straight part and the ridges of the curved part are not equal in width and/or height, and the ridge waveguide further includes a first part connecting the straight part and the curved part. Two linear transition sections, the second linear transition section includes a fourth linear transition section and a fifth linear transition section connected in sequence, the fourth linear transition section is connected to the curved portion, and the fifth linear transition section is connected to all the straight line part,

The ridge of the fourth linear transition section is equal in width and/or height to the ridge of the curved section; the fifth linear transition section is from an end connected to the straight line to an end away from the straight line In the direction of , the ridge of the fifth linear transition section gradually changes from the same width and/or height as the ridge of the straight line to the same width and/or height as the ridge of the fourth linear transition section. equal in height.

In some of these embodiments, along the length direction of the ridge waveguide, the two adjacent straight line portions with an included angle greater than 0° and less than 180° are respectively the second straight line portion and the third straight line portion, and the The second straight line portion and the third straight line portion enclose to form a first section, the second straight line portion and the third straight line portion are connected by a curved portion, and the circle of the curved portion The center of the arc segment is located in the first interval.

In some of these embodiments, along the length direction of the ridge waveguide, the two adjacent and parallel straight line portions are respectively the second straight line portion and the third straight line portion, and the second straight line portion is the same as the first straight line portion. The three straight parts are connected by two curved parts; among the two curved parts, the one connected to the second straight part is the first curved part, and the one connected to the third straight part is the second curved part,

Along the length direction of the second straight portion, the first curved portion and the second curved portion are located on the same side of the second straight portion and the third straight portion, and the second straight portion, the The first curved portion, the second curved portion, and the third straight portion enclose a second section, and the centers of the arc segments of the first curved portion and the second curved portion are located at the the second interval; or

Along the length direction of the second straight part, the first curved part and the second curved part are both located between the second straight part and the third straight part, and the first curved part and the The second straight part encloses to form a third section, the center of the arc segment of the first curved part is located in the third section, and the second curved part and the third straight part enclose to form a third section. Four intervals, the center of the arc segment of the second curved portion is located in the fourth interval.

In some of the embodiments, the ridge waveguide is helically distributed, and in all the helical layers of the ridge waveguide, the distance between two parallel ridge straight waveguides located in adjacent helical layers is smaller than the The radius of curvature of the arc segment.

In some of these embodiments, all the straight parts are sequentially arranged along a first straight direction, and the first straight direction is different from the extending direction of the straight parts; or,

All the linear portions are sequentially arranged along the direction of the first helix; or,

Some of the straight parts are arranged sequentially along the first helical direction, and the remaining part of the straight parts are arranged sequentially along the second helical direction, and the first helical direction is consistent with the second helical direction. The direction of rotation of the wires is the same, and one of the linear portions in the center of the part of the linear portions is connected to the central one of the remaining linear portions through at least one curved portion .

In some of the embodiments, there are multiple bent parts, and the multiple bent parts are connected to form a ring structure.

In a second aspect, an embodiment of the present application provides a microring resonator, including the above-mentioned ridge waveguide.

In a third aspect, an embodiment of the present application provides an adjustable optical delay line, including the above-mentioned ridge waveguide.

In a fourth aspect, the embodiment of the present application provides a chip, including a substrate and the above-mentioned ridge waveguide, and the ridge waveguide is disposed on the substrate.

The ridge waveguide, the microring resonator, the adjustable optical delay line and the chip of the present application, by setting the ridge waveguide to include a curved part, compared with the linear distribution of the ridge waveguide as a whole, it is beneficial to reduce the ridge waveguide Occupy a small space, realize the miniaturization of the equipment and reduce the cost. At the same time, the curved portion is set to include an arc segment and an arc transition segment, and the arc transition segment is from one end connecting the arc segment to the direction away from the end of the arc segment, the radius of curvature of the arc transition segment is equal to the circle The radius of curvature of the arc section is equal and gradually changes to infinity, that is, the radius of curvature of the arc transition section is in a gradual form, which can greatly reduce the transmission loss of the bending part; so that under the same bending loss, the size of the bending part can be designed smaller, Therefore, the occupied space of the ridge waveguide can be reduced, and the miniaturization of the device can be realized.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without creative work.

FIG. 1 is a structural diagram of an optical device including a strip waveguide in the related art;

2 is a structural diagram of an optical device including a ridge waveguide in the related art;

Fig. 3 is a top view of the first type of ridge waveguide provided by the embodiment of the present application;

Fig. 4 is a top view of the bend in the ridge waveguide shown in Fig. 3;

Fig. 5 is a top view of the second ridge waveguide provided by the embodiment of the present application;

Fig. 6 is a top view of a third ridge waveguide provided by an embodiment of the present application;

Fig. 7 is a top view of the fourth ridge waveguide provided by the embodiment of the present application;

Fig. 8 is a top view when the ridge waveguide shown in Fig. 6 is connected to the strip waveguide;

Fig. 9 is a top view of the fifth ridge waveguide provided in the embodiment of the present application when it is connected to the strip waveguide;

Figure 10 is an enlarged view of the structure at P in Figure 9;

Fig. 11 is a top view of the connection between the straight part and the curved part in the ridge waveguide provided by the embodiment of the present application;

Fig. 12 is another top view of the connection between the straight part and the curved part in the ridge waveguide provided by the embodiment of the present application;

Fig. 13 is another top view of the connection between the straight part and the curved part in the ridge waveguide provided by the embodiment of the present application;

Fig. 14 is a top view of the sixth ridge waveguide provided by the embodiment of the present application;

Fig. 15 is a structural diagram of the light reflection structure in the ridge waveguide provided by the embodiment of the present application;

Fig. 16 is another structural diagram of the light reflection structure in the ridge waveguide provided by the embodiment of the present application;

Fig. 17 is another structural diagram of the light reflection structure in the ridge waveguide provided by the embodiment of the present application;

Fig. 18 is a top view of the seventh ridge waveguide provided by the embodiment of the present application;

Fig. 19 is a top view of the eighth ridge waveguide provided by the embodiment of the present application;

Fig. 20 is a top view of the first microring resonator provided by the embodiment of the present application;

Fig. 21 is a top view of the second microring resonator provided by the embodiment of the present application;

Fig. 22 is a top view of the first adjustable optical delay line provided by the embodiment of the present application;

Fig. 23 is a top view of a second adjustable optical delay line provided by an embodiment of the present application;

Fig. 24 is a top view of a third adjustable optical delay line provided by an embodiment of the present application.

detailed description

In order to make the purpose, technical solution and advantages of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings.

When the following description refers to the accompanying drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with aspects of the present application as recited in the appended claims.

In a first aspect, the embodiment of the present application provides a ridge waveguide 100 . 3 and 4, the ridge waveguide 100 includes a curved portion 110, and the curved portion 110 includes a circular arc segment 111 and two arc-shaped transition segments 112, and the two arc-shaped transition segments 112 are respectively located in the circular arc Both ends of the segment 111 are connected to the arc segment 111, and each arc transition segment 112 is in the direction from the end connecting the arc segment 111 to the end far away from the arc segment 111, so The radius of curvature of the arc transition section 112 gradually changes from being equal to the radius of curvature of the arc section 111 to infinity.

In the ridge waveguide 100 of the embodiment of the present application, by arranging the ridge waveguide 100 to include a curved portion 110, compared with the overall distribution of the ridge waveguide 100 in a straight line, it is beneficial to reduce the occupied space of the ridge waveguide 100 and realize the device miniaturization and cost reduction. At the same time, the curved portion 110 is set to include an arc segment 111 and an arc transition segment 112, and the arc transition segment 112 is from the end connecting the arc segment 111 to the direction away from the end of the arc segment 111, and the arc transition segment The radius of curvature of 112 gradually changes from being equal to the radius of curvature of the arc segment 111 to infinity, that is, the radius of curvature of the arc transition segment 112 is in a gradually changing form, which can greatly reduce the transmission loss of the bending part 110; and make the same bending loss Therefore, the size of the curved portion 110 can be designed to be smaller, so that the occupied space of the ridge waveguide 100 can be reduced, and the miniaturization of the device can be realized.

It should be noted that, in the embodiment of the present application, the radius of curvature of a straight line is regarded as infinite, and the radius of curvature of the above-mentioned arc transition section 112 gradually changes from being equal to the radius of curvature of the arc section 111 to infinity, which can be: arc The curvature of the transition section 112 conforms to the curvature of smooth curves such as Euler spirals, trigonometric function curves, exponential function curves, and logarithmic function curves, thereby reducing the transmission loss of the curved portion 110 . The present application intends to illustrate that the radius of curvature of the arc-shaped transition section 112 changes gradually, rather than being directly set to be the same as the radius of curvature of the straight line or arc section 111 .

It can be understood that the number of curved portions 110 can be multiple, and multiple curved portions 110 can be connected to form a ring structure; at this time, the ridge waveguide 100 can be used as the microring 11 in the microring resonator 10, the adjustable light Microloop 21 in delay line 20, etc. Since the curved portion 110 includes a circular arc section 111 and an arc transition section 112, and the radius of curvature of the arc transition section 112 is in a gradual form, the transmission loss of the curved section 110 can be greatly reduced; so that under the same bending loss, the ridge The size of the waveguide 100 can be designed to be smaller, thereby realizing the miniaturization of the device.

It can be understood that the central angle θ of each curved portion 110 may be any value greater than 0° and less than 180°. For example, the central angle θ of the curved portion 110 may be 45°, 60°, 90°, 120°, 135° and so on. Of course, in order to reduce the manufacturing cost of the curved portion 110 and reduce the bending loss of the curved portion 110 , the central angle θ of the curved portion 110 is preferably 90°.

Referring to FIG. 5 , the ridge waveguide 100 may also include a plurality of linear portions 120 arranged at intervals along the length direction of the ridge waveguide 100 , and at least one curved portion 110 may pass between two adjacent linear portions 120 connect. Since the straight part 120 can be arranged more compactly, by setting the ridge waveguide 100 to include the straight part 120 and the curved part 110, the length of the ridge waveguide 100 can be increased to improve the delay effect while reducing the ridge waveguide. 100's take up space. At the same time, both the straight part 120 and the curved part 110 of the present application belong to the ridge waveguide, compared with the optical delay line based on the strip waveguide in the related art, the optical loss is smaller and the performance is better; and compared with the related art In terms of the conversion of two different types of waveguides from the strip waveguide to the ridge waveguide, the conversion loss can be reduced.

It can be understood that a plurality of straight parts 120 and a plurality of curved parts 110 can be connected to form a closed ring structure, as shown in FIG. 5; a plurality of straight parts 120 and a plurality of curved parts 110 can also form a linear structure with two ends. , see Figure 6 and Figure 7. When a plurality of straight parts 120 and a plurality of curved parts 110 are connected to form a closed ring structure, the ridge waveguide 100 can be used as the microring 11 in the microring resonator 10, the microring 21 in the tunable optical delay line 20, etc. . When a plurality of straight parts 120 and a plurality of curved parts 110 are connected to form a linear structure with two ends, the ridge waveguide 100 can be used as an optical delay line, a channel for coupling with the microring 11 in the microring resonator 10 The waveguide 12, the channel waveguide 22 in the adjustable optical delay line 20 for coupling with a plurality of microrings 21, etc.

The structure of the ridge waveguide 100 will be described in detail below when a plurality of straight parts 120 and a plurality of curved parts 110 are connected to form a linear structure with two ends:

Among the two end portions of the linear structure, each end portion may be formed by a straight portion 120 or a curved portion 110 . In order to facilitate the connection between the two ends of the linear structure and other components, referring to FIG. 6 and FIG. 7 , the two ends of the linear structure are preferably each formed by a straight portion 120 . Among the two ends of the linear structure, one end can be used to connect with the strip waveguide 200, and the other end can be provided with a light reflection structure 130 to prolong the transmission path of light waves or be used to connect with optical processors such as optical mixers. connect.

When the two ends of the linear structure used to connect to the strip waveguide 200 are formed by a straight portion 120, referring to FIG. 8 and FIG. 9, if the straight portion 120 is defined as the first straight portion 121, then The ridge waveguide 100 may also include a first linear transition portion 140, one end of the first linear transition portion 140 may be connected to the first linear portion 121, and the other end of the first linear transition portion 140 It can be used to connect with the strip waveguide 200, the first linear transition portion 140 is in the direction from the end connecting the first straight portion 121 to the end away from the first straight portion 121, the The ridges and bottoms of the first linear transition portion 140 can gradually change from being equal in width and/or height to the ridges and bottoms of the first linear transition portion 121 to the point where the ridges and bottoms are integrally aligned with the strips. Shaped waveguides 200 are equal in width and/or height.

Specifically, in one solution, referring to FIG. 9, if the width of the ridge 121a and the width of the bottom 121b of the first straight line 121 are both different from the width of the strip waveguide 200, then the The first linear transition section 140 may include a first linear transition section 141, a second linear transition section 142, and a third linear transition section 143 connected in sequence, and the first linear transition section 141 connects the first linear transition section 141. line portion 121, the third linear transition section 143 is used to connect the strip waveguide 200, and the first linear transition portion 140 is from the end connecting the first straight line portion 121 to the end far away from the first straight line portion. In the direction of one end of the line portion 121, the width of the bottom 141b of the first linear transition section 141 may be equal to the width of the bottom 121b of the first linear section 121, and the width of the first linear transition section 141 The width of the ridge 141a can gradually change from being equal to the width of the ridge 121a of the first linear portion 121 to being equal to the width of the strip waveguide 200; the width of the bottom 142b of the second linear transition section 142 It may be equal to the width of the bottom 141b of the first linear transition section 141, and the width of the ridge 142a of the second linear transition section 142 may be equal to the width of the strip waveguide 200; the third linear transition The width of the ridge 143a of the section 143 may be equal to the width of the strip waveguide 200, and the width of the bottom 143b of the third linear transition section 143 may be equal to the width of the bottom 142b of the second linear transition section 142. gradually change to be equal to the width of the strip waveguide 200 .

In another solution, referring to FIG. 8, if the width of the ridge 121a of the first straight part 121 is equal to the width of the strip waveguide 200, and the bottom 121b of the first straight part 121 The width is not equal to the width of the strip waveguide 200. At this time, the first linear transition portion 140 may only include one linear transition section, which can be denoted as the sixth linear transition section 144, and the sixth linear transition section In the direction of the segment 144 from one end connecting the first straight portion 121 to an end away from the first straight portion 121, the width of the ridge 144a of the sixth linear transition segment 144 is the same as that of the strip waveguide 200. The widths are equal, and the width of the bottom 144 b of the sixth linear transition section 144 gradually changes from being equal to the width of the bottom 121 b of the first linear portion 121 to being equal to the width of the strip waveguide 200 .

It can be understood that when the height of the ridge 121a and the height of the bottom 121b of the first linear portion 121 are not equal to the height of the strip waveguide 200, the above-mentioned first linear transition section 141, the second The width parameter in the linear transition section 142 , the third linear transition section 143 and the sixth linear transition section 144 can be changed to a height parameter, which will not be repeated here.

It should be noted that when the width and/or height of the linear transition section described above gradually changes from the first size to the second size along a certain direction, the change in width and/or height of the linear transition section can satisfy a preset curve. Wherein, the preset curve can be any smooth curve; for example, the preset curve can be a straight line, a parabola, etc., so that the contour surface of the linear transition section is smooth and the transmission loss is small.

In an implementable solution, referring to FIGS. 6 to 8 , the ridges of the straight portion 120 and the ridge of the curved portion 110 can be set to be equal in height and width, and the bottom of the straight portion 120 and the bottom of the curved portion 110 The height and width can be set to be equal, so that the straight portion 120 and the curved portion 110 can be directly connected.

In another practicable solution, referring to Fig. 5 and Fig. 9, the ridges of the straight part 120 and the ridges of the curved part 110 may be different in height and/or width, and the bottom of the straight part 120 and the curved part 110 The bottom of the can also vary in height and/or width. Specifically, when the ridges of the straight portion 120 and the ridges of the curved portion 110 are not equal in width and/or height, referring to FIG. 5 , FIG. 9 and FIG. 10 , the ridge waveguide 100 may further include The second linear transition portion 150 of the curved portion 110, the second linear transition portion 150 may include sequentially connecting the fourth linear transition section 151 and the fifth linear transition section 152, the fourth linear transition section 151 connects the curved portion 110, the ridge 151a of the fourth linear transition section 151 may be equal in width and/or height to the ridge of the curved portion 110; the fifth linear transition section 152 connects the straight line 120, the In the direction of the fifth linear transition section 152 from one end connected to the straight section 120 to an end away from the straight section 120 , the ridge 152 a of the fifth linear transition section 152 can be formed from the ridge of the straight section 120 . The portion is equal in width and/or height and gradually changes to be equal in width and/or height to the ridge 151 a of the fourth linear transition section 151 .

It can be understood that, along the length direction of the ridge waveguide 100 , two adjacent straight line portions 120 may be arranged parallel to each other or at an angle greater than 0° and less than 180°.

Specifically, referring to FIG. 11 , if the two straight line portions 120 adjacent to each other with an included angle greater than 0° and less than 180° are recorded as the second straight line portion 122m and the third straight line portion 123m respectively, the second straight line portion 122m and the third straight portion 123m enclose a first section e, the second straight portion 122m and the third straight portion 123m can be connected by one curved portion 110 , and the curved portion 110 The center of the arc segment 111 is located in the first interval e. By connecting two adjacent straight line portions 120 with angles greater than 0° and less than 180° through only one curved portion 110 , the difficulty of forming the ridge waveguide 100 can be reduced and the production cost can be reduced. Preferably, the angle between two adjacent straight parts 120 connected by only one curved part 110 can be set at an angle of 90°, so that the layout of the ridge waveguide 100 is more compact, and the degree of curvature of the curved part 110 is relatively small, Transmission loss is lower.

Referring to Fig. 12 and Fig. 13, if the two adjacent and parallel straight portions 120 are respectively recorded as the second straight portion 122n and the third straight portion 123n, the second straight portion 122n and the third straight portion 123n can be connected by two said bending parts 110, because the corner between two parallel straight line parts 120 is larger, so the circular arc segment 111 of two bending parts 110 can be connected by two bending parts 110 The radius of curvature of the curved portion 110 is set to be larger, which is closer to the radius of curvature of the straight portion 120 , thereby reducing the transmission loss on the curved portion 110 .

Furthermore, among the two curved portions 110, if the one connecting the second straight portion 122n is designated as the first curved portion 110x, and the one connecting the third straight portion 123n is designated as the second curved portion 110y, in In one solution, referring to FIG. 12 , along the length direction of the second straight portion 122n, the first curved portion 110x and the second curved portion 110y are located between the second straight portion 122n and the third straight portion 122n. On the same side of the portion 123n, the second straight portion 122n, the first curved portion 110x, the second curved portion 110y and the third straight portion 123n enclose a second section f, and the first curved The centers of the arc segments 111 of the portion 110x and the second curved portion 110y are both located in the second interval f. In another solution, referring to FIG. 13 , along the length direction of the second straight portion 122n, the first curved portion 110x and the second curved portion 110y are both located between the second straight portion 122n and the second straight portion 122n. Between the third straight portion 123n, the first curved portion 110x and the second straight portion 122n enclose a third section g, and the center of the arc segment 111 of the first curved portion 110x is located at the In the third section g, the second curved portion 110y and the third straight line portion 123n are enclosed to form a fourth section h, and the center of the arc segment 111 of the second curved portion 110y is located in the fourth section h.

In order to reduce the space occupied by the ridge waveguide 100, in one solution, referring to FIG. 6 to FIG. The linear direction is different from the extending direction of the linear portion 120 . Preferably, the extending directions of the multiple straight portions 120 may be parallel to each other, and the first straight direction may be perpendicular to the extending directions of the straight portions 120 , so that the arrangement of the multiple straight portions 120 is more compact.

In order to reduce the space occupied by the ridge waveguide 100 , in another solution, referring to FIG. 14 , all the straight portions 120 may be arranged in sequence along the first helical direction. When all the straight parts 120 are arranged sequentially along the direction of the first helix, one end of the ridge waveguide 100 will be located at the center of the helix, which is not conducive to the connection with external components. One end of the line center can be provided with a light reflective structure 130, so that after the light wave is transmitted to the light reflective structure 130 through the straight line 120, the curved portion 110, etc., the light reflective structure 130 can reflect the light wave back to the straight line 120 and the curved portion again. 110, so that the transmission path of the light wave can be extended, and the optical delay effect can be improved.

Wherein, the light reflection structure 130 may include a combined device of a beam splitter 131 and a waveguide 132 , a Bragg reflector, a Bragg grating (see FIG. 15 ), a photonic crystal, and the like. Specifically, referring to FIG. 16 , the specific structure of the combined device of the optical splitter 131 and the waveguide 132 may be as follows: two ends of the waveguide 132 are respectively connected to two output ends of the optical splitter 131 . Photonic crystals can be specifically composed of micropillars of rectangular lattice (see Figure 17a), micropores of rectangular lattice (see Figure 17c), micropillars of hexagonal lattice (see Figure 17b), hexagonal crystal lattice At least one composition in the microwells of the lattice (see FIG. 17d).

In order to reduce the space occupied by the ridge waveguide 100, in yet another solution, referring to FIG. 18 , some of the straight parts 120 can be arranged sequentially along the first helical direction, and the rest of the straight parts 120 can be arranged in sequence along the second helical direction, and the first helical direction and the second helical direction have the same helical direction, and one of the linear parts 120 in the center is The straight line portion 120 is connected to the central one of the remaining straight line portions 120 via at least one curved portion 110 . By dividing all the straight parts 120 into the first helical direction and the second helical direction, the straight parts 120 on one helix can be located between the two straight parts 120 on the other helix. , so that the arrangement of the ridge waveguide 100 is more compact and occupies less space. Wherein, the first helical direction and the second helical direction have the same helical direction, which can be understood as: the first helical direction and the second helical direction are both clockwise; or, the first helical direction and the second helical direction are both clockwise; The direction of rotation of the two helix directions is counterclockwise.

Furthermore, when the ridge waveguide 100 has a helical distribution shape, in all the helical layers of the ridge waveguide 100 , the distance between two adjacent and parallel straight line portions 120 may be smaller than the radius of curvature of the arc segment 111 . Specifically, referring to FIG. 18 , if the two linear portions 120 located in adjacent helical layers and parallel to each of the spiral layers of the ridge waveguide 100 are marked as 120s and 120t respectively, it can be seen that the linear portion 120s and the linear portion 120t The distance between them is smaller than the radius of curvature of the arc segment 111 .

Furthermore, in order to improve the integration of the ridge waveguide, referring to FIG. 19 , the ridge waveguide 100 can also include a metamaterial structure 160, and the arrangement of the metamaterial structure 160 can hinder the adjacent curved part 110, straight part 120, first The coupling ability between the linear transition part 140 and the second linear transition part 150, so the distance between the adjacent curved part 110, straight part 120, first linear transition part 140 and second linear transition part 150 can be further reduced , so as to realize the miniaturization of the equipment.

In a second aspect, the embodiment of the present application provides a microring resonator 10 . The microring resonator 10 with high quality factor has many important applications, such as narrow linewidth filter, optical frequency comb based on four-wave mixing effect, and generation of entangled/correlated photon pairs in quantum optics, etc. The microring resonator 10 may include the above-mentioned ridge waveguide 100, referring to Fig. 20 and Fig. 21, the microring resonator 10 may include a microring 11 and a channel waveguide 12 for coupling with the microring 11, wherein the microring 11 and /Or the channel waveguide 12 can be selected from the above-mentioned ridge waveguide 100 . When a light wave with a frequency near the frequency of the microring 11 passes through the channel waveguide 12, due to the existence of the microring 11, the light wave will enter the microring 11 and go around for many times before being output from the channel waveguide 12 again, thus generating additional light delayed effect. Wherein, the specific number and time of the light wave in the microring 11 depends on the quality factor Q of the microring 11, the larger the quality factor Q, the greater the optical delay; and when the frequency of the light wave is closer to the resonance frequency of the microring 11, the light The delay is also greater.

The microring resonator 10 of the present application includes the above-mentioned ridge waveguide 100, because the curved portion 110 of the ridge waveguide 100 includes an arc segment 111 and an arc transition segment 112, and the arc transition segment 112 is connected to the arc segment 111. From one end to the direction away from the end of the arc segment 111, the radius of curvature of the arc transition segment 112 gradually changes from being equal to the radius of curvature of the arc segment 111 to infinity, that is, the radius of curvature of the arc transition segment 112 is in a gradually changing form, which can The transmission loss of the bending part 110 is greatly reduced; compared with the microring resonator based on the strip waveguide in the related art, the quality factor is larger.

In a third aspect, the embodiment of the present application provides an adjustable optical delay line 20 . 22 to 24, the adjustable optical delay line 20 includes a plurality of microrings 21 and a channel waveguide 22 for coupling with the plurality of microrings 21, wherein the microrings 21 and/or the channel waveguide 22 can be selected from the above-mentioned ridge shaped waveguide 100.

The adjustable optical delay line 20 of the present application includes the above-mentioned ridge waveguide 100, because the curved portion 110 of the ridge waveguide 100 includes an arc segment 111 and an arc transition segment 112, and the arc transition segment 112 is connected to the arc segment 111. From one end to the direction away from the end of the arc segment 111, the radius of curvature of the arc transition segment 112 gradually changes from being equal to the radius of curvature of the arc segment 111 to infinity, that is, the radius of curvature of the arc transition segment 112 is in a gradually changing form, which can The transmission loss of the bending part 110 is greatly reduced; the quality factor of the microring 21 is larger, and the performance of the adjustable optical delay line 20 formed by combination is better, the loss is smaller, and the delay is longer.

Specifically, FIG. 22 shows a SCISSOR-type adjustable optical delay line 20, wherein a channel waveguide 22 couples a plurality of microrings 21. When the light wave is near the frequency of the microrings 21, each microring 21 will cause A certain optical delay, so the total optical delay is the sum of the optical delays caused by all the microrings 21 . Figure 23 shows a CROW transmission-type adjustable optical delay line 20, wherein two ends of multiple microrings 21 coupled in series are coupled with two channel waveguides 22, when light enters from one side waveguide, it is first coupled into The nearest first microring 21, then coupled from the first microring 21 to the second microring 21, and so on, until coupled into the last microring 21, finally from another The output of the channel waveguide 22 on the side, since each microring 21 will cause a certain optical delay, the total optical delay is the sum of the optical delays caused by all the microrings 21. Figure 24 shows a CROW reflective adjustable optical delay line 20, wherein one end of a plurality of microrings 21 coupled in series is coupled to a channel waveguide 22, when light enters from one side of the waveguide, it is first coupled into the nearest The first microring 21, then from the first microring 21 coupled to the second microring 21, and so on, ..., until coupled into the last microring 21; then from the last microring 21 Coupled to the penultimate microring 21 again, and so on, ... until coupled into the first microring 21, and finally output from the other side of the channel waveguide 22, under the same conditions, compared to For the above two adjustable optical delay lines 20, each microring 21 can cause twice the optical delay, and the optical delay effect is better.

In a fourth aspect, the embodiment of the present application provides a chip. The chip includes a substrate and any of the aforementioned ridge waveguides 100, and the ridge waveguide 100 is disposed on the substrate.

The chip of the present application includes the above-mentioned ridge waveguide 100, because the curved portion 110 of the ridge waveguide 100 includes an arc segment 111 and an arc transition segment 112, and the arc transition segment 112 is from the end connecting the arc segment 111 to the end far away from the arc. In the direction of one end of the segment 111, the radius of curvature of the arc transition segment 112 gradually changes from being equal to the radius of curvature of the arc segment 111 to infinity, that is, the radius of curvature of the arc transition segment 112 is in a gradually changing form, which can greatly reduce the curvature of the curved portion 110. The transmission loss; so that under the same bending loss, the size of the bending part 110 can be designed to be smaller, so that it can be integrated on the chip.

In the description of the present application, it should be understood that the terms "first", "second" and so on are used for descriptive purposes only, and should not be understood as indicating or implying relative importance. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations. In addition, in the description of the present application, unless otherwise specified, "plurality" means two or more. "And/or" describes the association relationship of associated objects, indicating that there may be three types of relationships, for example, A and/or B may indicate: A exists alone, A and B exist simultaneously, and B exists independently. The character "/" generally indicates that the contextual objects are an "or" relationship.

The above disclosures are only preferred embodiments of the present application, which certainly cannot limit the scope of the present application. Therefore, equivalent changes made according to the claims of the present application still fall within the scope of the present application.

Claims

A ridge waveguide, characterized in that, comprising:

A curved portion, the curved portion includes a circular arc segment and two arc-shaped transition segments, the two arc-shaped transition segments are located at both ends of the circular arc segment and connected to the circular arc segment, each of the In the direction of the arc transition section from one end connecting the arc section to the end away from the arc section, the radius of curvature of the arc transition section gradually changes from being equal to the radius of curvature of the arc section to gigantic.
The ridge waveguide according to claim 1, further comprising:

For the plurality of straight parts, along the length direction of the ridge waveguide, two adjacent straight parts are connected by at least one curved part.
The ridge waveguide according to claim 2, wherein a plurality of said straight parts and said curved parts are connected to form a linear structure with two ends.
The ridge waveguide according to claim 3, wherein both end portions of said linear structure are each formed by one said linear portion.
The ridge waveguide according to claim 4, wherein the straight portion forming one end of the linear structure is a first straight portion, and the ridge waveguide further comprises:

The first linear transition part, one end of the first linear transition part is connected to the first straight line part, the other end of the first linear transition part is used to connect with the strip waveguide, and the first line In the direction from one end connecting the first straight line to the end away from the first straight line, the ridge and the bottom of the first linear transition are connected with the first straight line The ridges and bottoms of the section are equal in width and/or height and gradually change until the ridges and bottoms are integrally equal in width and/or height to the strip waveguide.
The ridge waveguide according to claim 5, wherein the width of the ridge and the width of the bottom of the first linear portion are different from the width of the strip waveguide, and the first linear transition The portion includes a first linear transition section, a second linear transition section and a third linear transition section connected in sequence, the first linear transition section connects the first straight section, and the third linear transition section is used for connected to the strip waveguide,

In the direction of the first linear transition portion from one end connected to the first linear portion to an end away from the first linear portion, the width of the bottom of the first linear transition section is the same as that of the first linear transition section. The width of the bottom of a straight line portion is equal, and the width of the ridge portion of the first linear transition section gradually changes from being equal to the width of the ridge portion of the first straight line portion to being equal to the width of the strip waveguide The width of the bottom of the second linear transition section is equal to the width of the bottom of the first linear transition section, and the width of the ridge of the second linear transition section is equal to the width of the strip waveguide; The width of the ridge of the third linear transition section is equal to the width of the strip waveguide, and the width of the bottom of the third linear transition section gradually changes from being equal to the width of the bottom of the second linear transition section to being equal to the width of the bottom of the second linear transition section. The widths of the strip waveguides are equal.
The ridge waveguide according to claim 3, further comprising:

A light reflection structure, the light reflection structure is connected to one end of the linear structure.
The ridge waveguide according to claim 2, wherein a plurality of said straight line parts and said curved parts are connected to form a ring structure.
The ridge waveguide according to any one of claims 2 to 8, characterized in that the ridges of the straight part and the ridges of the curved part are not equal in width and/or height, and the ridge waveguide It also includes a second linear transition portion connecting the straight line portion and the curved portion, the second linear transition portion includes a fourth linear transition section and a fifth linear transition section connected in sequence, and the fourth linear transition section connects the curved portion, the fifth linear transition section connecting the straight portion,

The ridge of the fourth linear transition section is equal in width and/or height to the ridge of the curved section; the fifth linear transition section is from an end connected to the straight line to an end away from the straight line In the direction of , the ridge of the fifth linear transition section gradually changes from the same width and/or height as the ridge of the straight line to the same width and/or height as the ridge of the fourth linear transition section. equal in height.
The ridge waveguide according to any one of claims 2 to 8, characterized in that, along the length direction of the ridge waveguide, two adjacent straight line portions with an included angle greater than 0° and less than 180° They are respectively a second straight line portion and a third straight line portion, the second straight line portion and the third straight line portion enclose to form a first section, and the second straight line portion and the third straight line portion pass through a The curved portion is connected, and the center of the arc segment of the curved portion is located in the first interval.
The ridge waveguide according to any one of claims 2 to 8, characterized in that, along the length direction of the ridge waveguide, the two adjacent and parallel straight parts are respectively the second straight part and the second straight part. Three straight parts, the second straight part and the third straight part are connected by two curved parts; among the two curved parts, the one connecting the second straight part is the first curved part, what connects the third straight line portion is the second curved portion,

Along the length direction of the second straight portion, the first curved portion and the second curved portion are located on the same side of the second straight portion and the third straight portion, and the second straight portion, the The first curved portion, the second curved portion, and the third straight portion enclose a second section, and the centers of the arc segments of the first curved portion and the second curved portion are located at the the second interval; or

Along the length direction of the second straight part, the first curved part and the second curved part are both located between the second straight part and the third straight part, and the first curved part and the The second straight part encloses to form a third section, the center of the arc segment of the first curved part is located in the third section, and the second curved part and the third straight part enclose to form a third section. Four intervals, the center of the arc segment of the second curved portion is located in the fourth interval.
The ridge waveguide according to any one of claims 2 to 8, wherein the ridge waveguide is helically distributed, and among all the helical layers of the ridge waveguide, two adjacent helical layers and parallel The distance between the two ridge-shaped straight waveguides is smaller than the radius of curvature of the arc segment.
The ridge waveguide according to any one of claims 2 to 8, characterized in that,

All the straight parts are arranged in sequence along the first straight direction, and the first straight direction is different from the extension direction of the straight parts; or,

All the linear portions are sequentially arranged along the direction of the first helix; or,

Some of the straight parts are arranged sequentially along the first helical direction, and the remaining part of the straight parts are arranged sequentially along the second helical direction, and the first helical direction is consistent with the second helical direction. The direction of rotation of the wires is the same, and one of the linear portions in the center of the part of the linear portions is connected to the central one of the remaining linear portions through at least one curved portion .
The ridge waveguide according to claim 1, characterized in that there are multiple curved portions, and the multiple curved portions are connected to form a ring structure.
A microring resonator, characterized by comprising the ridge waveguide according to any one of claims 1-14.
An adjustable optical delay line, characterized by comprising the ridge waveguide according to any one of claims 1-14.
A chip, characterized by comprising a substrate and the ridge waveguide according to any one of claims 1 to 14, the ridge waveguide being arranged on the substrate.