Waveguide assembly, integrated chip, and lidar

Abstract

The embodiment of the application discloses a waveguide assembly, an integrated chip and a laser radar. The waveguide assembly comprises a plurality of single-mode waveguides which are distributed at intervals, and the effective refractive index of at least one single-mode waveguide is different from the effective refractive index of another adjacent single-mode waveguide. The application can make the offset echo laser signal reach other single-mode waveguides, and improve the receiving rate of the offset echo laser signal. Compared with receiving the offset echo laser signal by means of a large width of a multimode waveguide, there is no problem of triggering the high-order mode of the multimode waveguide, and the echo laser signal has the advantage of higher receiving rate. In addition, the effective refractive indexes of the two adjacent single-mode waveguides are different, which can break the phase matching condition between the two adjacent single-mode waveguides, thereby suppressing the coupling between the two adjacent single-mode waveguides, reducing the crosstalk, making the distance between the two adjacent single-mode waveguides smaller, realizing the size reduction of the waveguide assembly, saving the chip area, improving the integration, and reducing the cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser detection, and in particular to a waveguide assembly, an integrated chip and a laser radar. BACKGROUND

[0002] A waveguide is a guiding structure for transmitting optical frequency electromagnetic waves, which is composed of an optical transparent medium (such as quartz glass). The transmission principle of the waveguide is that the total reflection of electromagnetic waves on the interface between media with different refractive indices makes the light wave propagate in a limited area around the waveguide. The waveguide is widely used due to its low-loss transmission characteristics.

[0003] For example, a waveguide is usually used in a laser radar to receive a return laser signal. However, for a laser radar with a rotatable mirror, if the mirror rotates before the return laser signal is received, the return laser signal will be offset after passing through the rotated mirror, and the offset return laser signal cannot be emitted to the waveguide through the mirror, resulting in a low return laser signal receiving rate. SUMMARY

[0004] The present application provides a waveguide assembly, an integrated chip and a laser radar, which are used to solve the problem of low return laser signal receiving rate caused by the fact that the offset return laser signal cannot be received by the waveguide in the related art.

[0005] In a first aspect, the present application provides a waveguide assembly for receiving a return laser signal in a laser radar, the waveguide assembly comprising:

[0006] a plurality of single-mode waveguides, each of the single-mode waveguides extending along a first direction, and the plurality of single-mode waveguides being spaced apart along a second direction intersecting the first direction, and among the plurality of single-mode waveguides, an effective refractive index of at least one single-mode waveguide is different from an effective refractive index of an adjacent single-mode waveguide.

[0007] In a second aspect, the present application provides an integrated chip comprising:

[0008] a substrate;

[0009] The waveguide assembly described above is arranged on the substrate.

[0010] In a third aspect, the present application provides a laser radar comprising the integrated chip described above, and the waveguide assembly in the integrated chip is used to receive a return laser signal reflected by a detected target.

[0011] In a fourth aspect, the present application provides a waveguide assembly for receiving a return laser signal in a laser radar, the waveguide assembly comprising:

[0012] A plurality of single-mode waveguides, each of the single-mode waveguides extending along a first direction, and the plurality of single-mode waveguides being spaced apart along a second direction intersecting the first direction, and at least one of the single-mode waveguides being provided with a separation structure from an adjacent one of the single-mode waveguides.

[0013] In a fifth aspect, the present application provides an integrated chip, comprising:

[0014] a substrate;

[0015] a waveguide assembly as described above, the waveguide assembly being provided on the substrate.

[0016] In a sixth aspect, the present application provides a laser radar, comprising the integrated chip as described above, the waveguide assembly in the integrated chip being configured to receive the echo laser signal reflected by a detected target.

[0017] The waveguide assembly, integrated chip and laser radar of the present application are designed to include multiple single-mode waveguides spaced apart. When the walk-off effect causes the offset echo laser signal, the offset echo laser signal can reach other single-mode waveguides, thereby avoiding the problem that the offset echo laser signal cannot be received due to the inclusion of only a single single-mode waveguide in the related art. Compared with the related art, which directly sets a multi-mode waveguide and uses the large width of the multi-mode waveguide to receive the offset echo laser signal, the multiple single-mode waveguides do not have the problem of triggering the high-order mode of the multi-mode waveguide when receiving the echo laser signal, i.e., the problem of the high-order mode light being lost, thus having the advantage of higher echo laser signal reception rate. In one scheme, the effective refractive index of at least one single-mode waveguide is designed to be different from the effective refractive index of the adjacent other single-mode waveguide, which can break the phase matching condition between the adjacent two single-mode waveguides, thereby suppressing the coupling between the adjacent two single-mode waveguides and reducing the crosstalk. In this way, under the same coupling capacity requirement, the spacing between the adjacent two single-mode waveguides with different effective refractive indexes can be made smaller, and the possibility of the offset echo laser signal falling into the blank area between the adjacent two single-mode waveguides is smaller, thereby enabling more offset echo laser signals to fall into the single-mode waveguide and couple with the single-mode waveguide, thereby improving the reception rate of the echo laser signal. In another scheme, a separation structure is provided between the adjacent two single-mode waveguides, which can weaken the coupling performance between the adjacent two single-mode waveguides through the separation structure, thereby reducing the crosstalk between them. In this way, under the same coupling capacity requirement, the spacing between the two single-mode waveguides provided with the separation structure can be designed to be smaller, and the possibility of the offset echo laser signal falling into the blank area between the adjacent two single-mode waveguides is smaller, thereby improving the reception rate of the echo laser signal. The smaller the spacing between the adjacent two single-mode waveguides is, the smaller the size of the waveguide assembly can be if the same number of single-mode waveguides is used, which is beneficial to saving chip area, improving integration, and reducing cost. If the size of the waveguide assembly is unchanged, a larger number of single-mode waveguides can be accommodated, and the spacing ratio between the single-mode waveguides can be significantly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0019] Figure 1 is a schematic diagram of the optical path of the echo laser signal of the laser radar in the related art in a state;

[0020] Figure 2 is Figure 1 A schematic diagram of the optical path of the return laser signal of the laser radar shown in another state;

[0021] Figure 3 is Figure 1 A schematic diagram of the optical path of the return laser signal of the laser radar shown in yet another state;

[0022] Figure 4 is a structural schematic diagram of a first waveguide assembly provided by an embodiment of the present application;

[0023] Figure 5 is a structural schematic diagram of a second waveguide assembly provided by an embodiment of the present application;

[0024] Figure 6 is a structural schematic diagram of a third waveguide assembly provided by an embodiment of the present application;

[0025] Figure 7 is a structural schematic diagram of a fourth waveguide assembly provided by an embodiment of the present application;

[0026] Figure 8 is a structural schematic diagram of a fifth waveguide assembly provided by an embodiment of the present application;

[0027] Figure 9 is a structural schematic diagram of a sixth waveguide assembly provided by an embodiment of the present application;

[0028] Figure 10 is a structural schematic diagram of a seventh waveguide assembly provided by an embodiment of the present application;

[0029] Figure 11 is a structural schematic diagram of an eighth waveguide assembly provided by an embodiment of the present application;

[0030] Figure 12 is a structural schematic diagram of a ninth waveguide assembly provided by an embodiment of the present application;

[0031] Figure 13 is a structural schematic diagram of a tenth waveguide assembly provided by an embodiment of the present application;

[0032] Figure 14 is a structural schematic diagram of an eleventh waveguide assembly provided by an embodiment of the present application;

[0033] Figure 15 is a structural schematic diagram of a twelfth waveguide assembly provided by an embodiment of the present application;

[0034] Figure 16 is a structural schematic diagram of a thirteenth waveguide assembly provided by an embodiment of the present application;

[0035] Figure 17is a structural schematic diagram of a fourteenth waveguide assembly provided by an embodiment of the present application;

[0036] Figure 18 is a structural schematic diagram of a fifteenth waveguide assembly provided by an embodiment of the present application;

[0037] Figure 19 is an optical path schematic diagram of a return laser signal of a laser radar in a state;

[0038] Figure 20 is Figure 19 is an optical path schematic diagram of a return laser signal of a laser radar in another state;

[0039] Figure 21 is Figure 19 is an optical path schematic diagram of a return laser signal of a laser radar in yet another state. DETAILED DESCRIPTION

[0040] In order to make the objects, technical solutions and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0041] The following description refers to the accompanying drawings. Unless otherwise noted, like numbers in different drawings refer to the same or similar elements. The following description of the example embodiments is not meant to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the appended claims.

[0042] In the related art, referring to Figure 1 , the laser radar 1' includes a single-mode waveguide 10' for receiving a return laser signal, and a mirror 20' for deflecting the return laser signal transmitted to the single-mode waveguide 10'. When the mirror 20' is stationary, the return laser signal of the laser radar 1' can directly reach the single-mode waveguide 10'; and when the mirror 20' moves, for example, referring to Figure 2 and Figure 3 , when the mirror 20' rotates, it will cause the return laser signal emitted through the mirror 20' to be offset, so that the return laser signal emitted through the mirror 20' cannot return to the corresponding single-mode waveguide 10', and a walk-off effect occurs, reducing the reception rate of the return laser signal. The farther the detection target is, the greater the angular velocity of the mirror 20' is, the more serious the walk-off effect is, and the lower the reception rate of the return laser signal is. Based on this, an embodiment of the present application provides a waveguide assembly 100, referring to Figure 4The waveguide assembly 100 includes a plurality of single-mode waveguides 110 distributed at intervals. In an embodiment, the waveguide assembly 100 is designed to include a plurality of single-mode waveguides 110 distributed at intervals. When the walk-off effect causes the offset echo laser signal, the offset echo laser signal can reach other single-mode waveguides 110, thereby avoiding the problem that the offset echo laser signal cannot be received due to the single single-mode waveguide 110 in the related art.

[0043] Meanwhile, in an embodiment, the plurality of single-mode waveguides 110 receive the echo laser signal. Compared with the related art in which the multimode waveguide is directly arranged and the large width of the multimode waveguide is used to receive the offset echo laser signal, the problem of triggering the high-order mode of the multimode waveguide when the echo laser signal is received does not exist. The light of the high-order mode is lost when the multimode waveguide is converted to the single-mode waveguide 110. Therefore, the echo laser signal remaining after the multimode waveguide is used is much less than the received echo laser signal. The wider the multimode waveguide is, the greater the conversion loss from the multimode waveguide to the single-mode waveguide 110 is. That is, compared with the related art in which the offset echo laser signal is received by the multimode waveguide, the embodiment has the advantage of higher echo laser signal reception rate because the light of the high-order mode is not lost.

[0044] The waveguide assembly 100 can be used to receive the echo laser signal in the laser radar 1. Thus, when the waveguide assembly 100 receives the echo laser signal, the plurality of single-mode waveguides 110 can expand the receiving field angle of the laser radar 1, thereby realizing the wide-angle of the laser radar 1.

[0045] Each single-mode waveguide 110 can extend along the first direction x, and the plurality of single-mode waveguides 110 can be distributed at intervals along the second direction y intersecting the first direction x. The angle between the second direction y and the first direction x can be any value greater than 0° and less than 90°. Preferably, the second direction y can be perpendicular to the first direction x, so that the structure of the waveguide assembly 100 is more compact, thereby facilitating the miniaturization design of the waveguide assembly 100.

[0046] Optionally, in the plurality of single-mode waveguides 110, the effective refractive index of at least one single-mode waveguide 110 can be different from the effective refractive index of an adjacent other single-mode waveguide 110. For the same single-mode waveguide 110, if the center-to-center spacing of the single-mode waveguide 110 and the adjacent other single-mode waveguide 110 is equal, the crosstalk between the two single-mode waveguides 110 with different effective refractive indices is lower than that between the two single-mode waveguides 110 with equal effective refractive indices. The different effective refractive indices of the adjacent two single-mode waveguides 110 can break the phase matching condition between the adjacent two single-mode waveguides 110, thereby suppressing the coupling between the adjacent two single-mode waveguides 110 and reducing the crosstalk. In this way, under the same coupling capability requirement, the spacing between the adjacent two single-mode waveguides 110 with different effective refractive indices can be smaller than that between the adjacent two single-mode waveguides 110 with equal effective refractive indices. The smaller the spacing between the adjacent two single-mode waveguides 110 is designed, the less likely the offset return laser signals fall into the blank area between the adjacent two single-mode waveguides 110, thereby enabling more offset return laser signals to fall on and couple with the single-mode waveguides 110, improving the reception rate of the return laser signals. The smaller the spacing between the adjacent two single-mode waveguides 110 is designed, the smaller the size of the waveguide assembly 100 can be if the same number of single-mode waveguides 110 is used, which is beneficial to saving chip area, improving integration, and reducing cost. If the size of the waveguide assembly 100 is unchanged, more single-mode waveguides 110 can be accommodated, significantly reducing the proportion of empty spaces between the single-mode waveguides 110.

[0047] Preferably, in the plurality of single-mode waveguides 110, the effective refractive index of each single-mode waveguide 110 can be designed to be different from the effective refractive index of an adjacent other single-mode waveguide 110. This enables the spacing between all adjacent two single-mode waveguides 110 in the waveguide assembly 100 to be designed to be smaller, optimizes the reception rate of the return laser signals by the waveguide assembly 100, and enables the minimization design of the lidar 1.

[0048] Optionally, in the adjacent two single-mode waveguides 110, the width of one single-mode waveguide 110 along the second direction y can be different from the width of the other single-mode waveguide 110 along the second direction y. The different widths of the adjacent two single-mode waveguides 110 along the second direction y can achieve the different effective refractive indices of the adjacent two single-mode waveguides 110, thereby achieving the reduction of the spacing between the adjacent two single-mode waveguides 110 and improving the reception rate of the return laser signals. The adjacent two single-mode waveguides 110 with different widths along the second direction y can be obtained by adjusting the growth process of the waveguide, which is simple in forming process and low in production cost.

[0049] It should be noted that the coupling between two single-mode waveguides 110 with equal width along the second direction y is stronger, so when the waveguide assembly 100 includes two single-mode waveguides 110 with equal width along the second direction y, the coupling between the two single-mode waveguides 110 with equal width can be suppressed by increasing the spacing between the two single-mode waveguides 110 with equal width, thereby reducing the crosstalk between the two single-mode waveguides 110 with equal width. Since the increased spacing between the two single-mode waveguides 110 with equal width can cause the offset echo laser signal to enter a larger blank area between the two single-mode waveguides 110 with equal width without being coupled by the single-mode waveguide 110, further, when the spacing between the two single-mode waveguides 110 with equal width along the second direction y is large, the number of other single-mode waveguides 110 with unequal width arranged between the two single-mode waveguides 110 with equal width along the second direction y can also be increased.

[0050] As for the two single-mode waveguides 110 with equal width along the second direction y, one single-mode waveguide 110 with unequal width can be arranged between the two single-mode waveguides 110 with equal width, or multiple single-mode waveguides 110 with unequal width, such as two, three, four, five, etc. It can be understood that the more single-mode waveguides 110 with unequal width arranged between the two single-mode waveguides 110 with equal width along the second direction y, the smaller the spacing between the two single-mode waveguides 110 with equal width, and the higher the reception rate of the echo laser signal. Preferably, two single-mode waveguides 110 with unequal width can be arranged between the two single-mode waveguides 110 with equal width along the second direction y, so as to reduce the number of single-mode waveguides 110 between the two single-mode waveguides 110 with equal width, simplify the size design difficulty of the single-mode waveguides 110 between the two single-mode waveguides 110 with equal width, and reduce the production cost.

[0051] Among the plurality of single-mode waveguides 110 of the waveguide assembly 100, two or more adjacent single-mode waveguides 110 can be combined to form a waveguide unit 120, and the waveguide assembly 100 can include a plurality of waveguide units 120 distributed along the second direction y. Designing the waveguide assembly 100 to include a plurality of waveguide units 120 can ensure the structural regularity of the waveguide assembly 100, and achieve approximately equal reception capability of echo laser signals at each region of the waveguide assembly 100. On the other hand, only one set of waveguide units 120 needs to be designed during design, and then the same set of waveguide units 120 can be used repeatedly, which can reduce the design difficulty of the waveguide assembly 100 and reduce the production cost.

[0052] It can be understood that the waveguide unit 120 can include two single-mode waveguides 110, three single-mode waveguides 110, four single-mode waveguides 110, etc., and the present application does not limit this. When the waveguide unit 120 includes three or more single-mode waveguides 110, the widths of the three or more single-mode waveguides 110 along the second direction y can be sequentially increased, sequentially decreased, first increased and then decreased, first decreased and then increased, etc., and the present application does not limit this.

[0053] For example, the waveguide assembly 100 can include first single-mode waveguides 110a, second single-mode waveguides 110b, first single-mode waveguides 110a, second single-mode waveguides 110b, first single-mode waveguides 110a, second single-mode waveguides 110b, and so on, distributed in sequence along the second direction y. At this time, the first single-mode waveguide 110a and the adjacent second single-mode waveguide 110b located behind it can be combined as a waveguide unit 120. Among them, the width of the first single-mode waveguide 110a along the second direction y can be greater than or less than the width of the second single-mode waveguide 110b along the second direction y. At this time, each waveguide unit 120 includes the same two kinds of single-mode waveguides 110, and the arrangement order of the two kinds of single-mode waveguides 110 in each waveguide unit 120 is the same.

[0054] For another example, referring to Figure 5 , the waveguide assembly 100 can include first single-mode waveguides 110a, second single-mode waveguides 110b, third single-mode waveguides 110c, first single-mode waveguides 110a, second single-mode waveguides 110b, third single-mode waveguides 110c, and so on, distributed in sequence along the second direction y. At this time, the first single-mode waveguide 110a and the adjacent second single-mode waveguide 110b, third single-mode waveguide 110c located behind it can be combined as a waveguide unit 120. Optionally, the width of the first single-mode waveguide 110a along the second direction y can be greater than the width of the second single-mode waveguide 110b along the second direction y, and the width of the second single-mode waveguide 110b along the second direction y can be greater than the width of the third single-mode waveguide 110c along the second direction y. Optionally, referring to Figure 6 , the width of the first single-mode waveguide 110a along the second direction y can be greater than the width of the third single-mode waveguide 110c along the second direction y, and the width of the third single-mode waveguide 110c along the second direction y can be greater than the width of the second single-mode waveguide 110b along the second direction y. At this time, each waveguide unit 120 includes the same three kinds of single-mode waveguides 110, and the arrangement order of the three kinds of single-mode waveguides 110 in each waveguide unit 120 is the same.

[0055] For another example, referring to Figure 7, the waveguide assembly 100 can include the first single-mode waveguide 110a, the second single-mode waveguide 110b, the third single-mode waveguide 110c, the first single-mode waveguide 110a, the third single-mode waveguide 110c, the second single-mode waveguide 110b, and so on, which are sequentially distributed along the second direction y. At this time, the first single-mode waveguide 110a, the second single-mode waveguide 110b located adjacent to the rear of the first single-mode waveguide 110a, and the third single-mode waveguide 110c located adjacent to the rear of the second single-mode waveguide 110b can be regarded as a waveguide unit 120, and the first single-mode waveguide 110a located adjacent to the rear of the second single-mode waveguide 110b, the second single-mode waveguide 110b located adjacent to the rear of the first single-mode waveguide 110a, and the third single-mode waveguide 110c located adjacent to the rear of the third single-mode waveguide 110c can be regarded as another waveguide unit 120. Optionally, the width of the first single-mode waveguide 110a along the second direction y can be greater than the width of the third single-mode waveguide 110c along the second direction y, and the width of the third single-mode waveguide 110c along the second direction y can be greater than the width of the second single-mode waveguide 110b along the second direction y. At this time, each waveguide unit 120 includes the same three kinds of single-mode waveguides 110, and the arrangement order of the three kinds of single-mode waveguides 110 in each waveguide unit 120 is different.

[0056] It should be noted that each waveguide unit 120 can include the same plurality of single-mode waveguides 110, and the arrangement order of the plurality of single-mode waveguides 110 in each waveguide unit 120 can be the same or different, which is not limited in the embodiments of the present application.

[0057] Optionally, referring to Figures 4 to 7 When the widths of the adjacent two single-mode waveguides 110 along the second direction y are different, the length dimensions of the adjacent two single-mode waveguides 110 along the first direction x can be equal, and the center spacing h1 between each adjacent two single-mode waveguides 110 can be equal. In this way, the echo laser signal receiving performance of the waveguide assembly 100 is better.

[0058] In addition to the above, the effective refractive indexes of the adjacent two single-mode waveguides 110 can be different by means of different duty cycles of the adjacent two single-mode waveguides 110. Specifically, referring to Figure 8 of the two single-mode waveguides 110 are different.

[0059] The subwavelength grating waveguide can include a plurality of waveguide sections 111 spaced apart along the first direction x, each waveguide section 111 and a blank area 112 located behind the waveguide section 111 form a period 113, and the duty cycle of the subwavelength grating waveguide can be a percentage of a length of the waveguide section 111 along the first direction x in a length of the period 113 along the first direction x. The single-mode waveguide 110 with different duty cycles can be obtained by adjusting the growth process of the waveguide, and the forming method is simple and the production cost is low.

[0060] In an exemplary scheme, among two adjacent single-mode waveguides 110, one single-mode waveguide 110 can include a subwavelength grating waveguide, and the other single-mode waveguide 110 can be a strip waveguide. The duty cycle of the strip waveguide is 100%, and the production process of the strip waveguide is more mature and the manufacturing method is simpler. Therefore, designing the waveguide assembly 100 to include a strip waveguide can simplify the processing technology of the waveguide assembly 100 and improve the production efficiency.

[0061] In another exemplary scheme, among two adjacent single-mode waveguides 110, both single-mode waveguides 110 can include subwavelength grating waveguides, and the duty cycles of the two single-mode waveguides 110 are different. Designing both adjacent single-mode waveguides 110 to include subwavelength grating waveguides can make the combination of the two adjacent single-mode waveguides 110 more diversified, and the application prospect is broad.

[0062] Similarly, when the duty cycles of the two adjacent single-mode waveguides 110 are different, among the plurality of single-mode waveguides 110 of the waveguide assembly 100, two or more adjacent single-mode waveguides 110 can be combined to form a waveguide unit 120, and the waveguide assembly 100 can include a plurality of waveguide units 120 distributed along the second direction y. Among the waveguide units 120, there can be two single-mode waveguides 110, three single-mode waveguides 110, four single-mode waveguides 110, etc., and the embodiments of the present application do not limit this. When there are three or more single-mode waveguides 110 in the waveguide unit 120, the duty cycles of the three or more single-mode waveguides 110 in the waveguide unit 120 along the second direction y can be sequentially increased, sequentially decreased, first increased and then decreased, first decreased and then increased, etc., and the embodiments of the present application do not limit this.

[0063] For example, please refer to Figure 8, the waveguide assembly 100 can include first single-mode waveguides 110a, second single-mode waveguides 110b, first single-mode waveguides 110a, second single-mode waveguides 110b, first single-mode waveguides 110a, second single-mode waveguides 110b, and so on, which are sequentially distributed along the second direction y. At this time, the first single-mode waveguide 110a and the adjacent second single-mode waveguide 110b located behind the first single-mode waveguide 110a can be regarded as a waveguide unit 120. Alternatively, the duty cycle of the first single-mode waveguide 110a can be greater than or less than the duty cycle of the second single-mode waveguide 110b. The first single-mode waveguide 110a can be a strip waveguide, and the second single-mode waveguide 110b can be a subwavelength grating waveguide. The first single-mode waveguide 110a and the second single-mode waveguide 110b can also be subwavelength grating waveguides. At this time, each waveguide unit 120 includes the same two types of single-mode waveguides 110, and the arrangement order of the two types of single-mode waveguides 110 in each waveguide unit 120 is the same.

[0064] For another example, please refer to Figure 9 , the waveguide assembly 100 can include first single-mode waveguides 110a, second single-mode waveguides 110b, third single-mode waveguides 110c, first single-mode waveguides 110a, second single-mode waveguides 110b, third single-mode waveguides 110c, and so on, which are sequentially distributed along the second direction y. At this time, the first single-mode waveguide 110a and the adjacent second single-mode waveguide 110b, third single-mode waveguide 110c located behind the first single-mode waveguide 110a can be regarded as a waveguide unit 120. Alternatively, the duty cycle of the first single-mode waveguide 110a can be greater than the duty cycle of the second single-mode waveguide 110b, and the duty cycle of the second single-mode waveguide 110b can be greater than the duty cycle of the third single-mode waveguide 110c. Alternatively, please refer to Figure 10 , the duty cycle of the first single-mode waveguide 110a can be greater than the duty cycle of the third single-mode waveguide 110c, and the duty cycle of the third single-mode waveguide 110c can be greater than the duty cycle of the second single-mode waveguide 110b. The first single-mode waveguide 110a can be a strip waveguide, and the second single-mode waveguide 110b and the third single-mode waveguide 110c can be subwavelength grating waveguides. The first single-mode waveguide 110a, the second single-mode waveguide 110b, and the third single-mode waveguide 110c can also be subwavelength grating waveguides. At this time, each waveguide unit 120 includes the same three types of single-mode waveguides 110, and the arrangement order of the three types of single-mode waveguides 110 in each waveguide unit 120 is the same.

[0065] For another example, please refer to Figure 11, the waveguide assembly 100 can include the first single-mode waveguide 110a, the second single-mode waveguide 110b, the third single-mode waveguide 110c, the first single-mode waveguide 110a, the third single-mode waveguide 110c, the second single-mode waveguide 110b, and so on, which are sequentially distributed along the second direction y. At this time, the first single-mode waveguide 110a, the second single-mode waveguide 110b and the third single-mode waveguide 110c located adjacent to the rear of the first single-mode waveguide 110a can be regarded as a waveguide unit 120, and the first single-mode waveguide 110a, the second single-mode waveguide 110b and the third single-mode waveguide 110c located adjacent to the rear of the first single-mode waveguide 110a can be regarded as another waveguide unit 120. Optionally, the duty cycle of the first single-mode waveguide 110a can be greater than the duty cycle of the third single-mode waveguide 110c, and the duty cycle of the third single-mode waveguide 110c can be greater than the duty cycle of the second single-mode waveguide 110b. Wherein, the first single-mode waveguide 110a can be a strip waveguide, and the second single-mode waveguide 110b and the third single-mode waveguide 110c can be subwavelength grating waveguides. The first single-mode waveguide 110a, the second single-mode waveguide 110b and the third single-mode waveguide 110c can also be subwavelength grating waveguides. At this time, each waveguide unit 120 includes the same three kinds of single-mode waveguides 110, and the arrangement order of the three kinds of single-mode waveguides 110 in each waveguide unit 120 is different.

[0066] It should be noted that each waveguide unit 120 can include the same plurality of single-mode waveguides 110, and the arrangement order of the plurality of single-mode waveguides 110 in each waveguide unit 120 can be the same or different, which is not limited in the embodiments of the present application.

[0067] Optionally, referring to Figures 9 to 11 When the duty cycles of the two adjacent single-mode waveguides 110 are different, the length dimension of the two adjacent single-mode waveguides 110 along the first direction x can be equal, and the center distance h1 between each two adjacent single-mode waveguides 110 can be equal. So that the echo laser signal receiving performance of the waveguide assembly 100 is better. It should be noted that, for the subwavelength grating waveguide, the length dimension along the first direction x should be the length dimension of all the periods 113 included in the subwavelength grating waveguide along the first direction x, rather than only the length dimension of the waveguide part 111 in the subwavelength grating waveguide along the first direction x.

[0068] Optionally, in the waveguide assembly 100, when the two or more single-mode waveguides 110 all include subwavelength grating waveguides, the periods 113 of the respective subwavelength grating waveguides can be equal. In this way, it is convenient to realize that the lengths of the respective subwavelength grating waveguides along the first direction x are equal and the number of periods 113 included when the lengths are equal is the same.

[0069] It should be noted that, in order to realize that the effective refractive indexes of the two adjacent single-mode waveguides 110 are different, please refer to Figures 12 to 14The widths of the two adjacent single-mode waveguides 110 in the second direction y can be different, or the duty cycles of the two adjacent single-mode waveguides 110 can be different. That is, the width of one of the two adjacent single-mode waveguides 110 in the second direction y is different from the width of the other single-mode waveguide 110 in the second direction y, and at least one of the single-mode waveguides 110 includes a subwavelength grating waveguide, and the duty cycles of the two single-mode waveguides 110 are different. This makes the structural design of the waveguide assembly 100 more diversified, and can meet different use requirements.

[0070] Optionally, referring to Figure 15 Among the plurality of single-mode waveguides 110, at least one single-mode waveguide 110 and an adjacent single-mode waveguide 110 can be provided with an isolation structure 130. The design of the isolation structure 130 can weaken the coupling performance between the two adjacent single-mode waveguides 110 and reduce the crosstalk between them. Thus, under the same coupling capability requirement, the spacing between the two single-mode waveguides 110 provided with the isolation structure 130 can be designed to be smaller, and the probability of the offset echo laser signal falling into the blank area between the two adjacent single-mode waveguides 110 is smaller, thereby improving the reception rate of the echo laser signal.

[0071] Optionally, the isolation structure 130 can include a plurality of layers of isolation strips 131 spaced apart in the second direction y, and each layer of isolation strips 131 can extend in the first direction x. By adding a periodic subwavelength multilayer structure between the two adjacent single-mode waveguides 110, the mutual coupling of laser signals of a specific wavelength range in the two adjacent single-mode waveguides 110 can be blocked, and the crosstalk of laser signals of the specific wavelength range between the two adjacent single-mode waveguides 110 can be reduced.

[0072] The specific wavelength range is related to the period 133 and the duty cycle of the isolation strips 131. By changing the period 133 and the duty cycle of the isolation strips 131, the blocking of laser signals of different wavelength ranges can be realized. The isolation strip 131 can be regarded as a structure with a smaller width along the second direction y than the single-mode waveguide 110 along the second direction y. Each isolation strip 131 and the blank area 132 located behind it along the second direction y can combine to form a period 133. The duty cycle of the isolation strip 131 can be the percentage of the width of the isolation strip 131 along the second direction y in the width of a period 133 along the second direction y. Optionally, the isolation structure 130 can include two, three, four, five or more layers of isolation strips 131 spaced along the second direction y. The number of layers of isolation strips 131 included in the isolation structure 130 between each adjacent two single-mode waveguides 110 can be equal or unequal. The types of isolation strips 131 included in the isolation structure 130 between each adjacent two single-mode waveguides 110 can be the same or different. The types of isolation strips 131 can be different in that the width of the isolation strip 131 along the second direction y is different, and the like.

[0073] Optionally, in the two adjacent single-mode waveguides 110, the width of one single-mode waveguide 110 along the second direction y can be different from the width of the other single-mode waveguide 110 along the second direction y, and the two single-mode waveguides 110 can be provided with the isolation structure 130. Referring to Figure 15 , the width of one single-mode waveguide 110 along the second direction y can be different from the width of the other single-mode waveguide 110 along the second direction y, and the two single-mode waveguides 110 can be provided with the isolation structure 130. Referring to Figure 16 , the duty cycle of one single-mode waveguide 110 can be different from the duty cycle of the other single-mode waveguide 110, and the two single-mode waveguides 110 can be provided with the isolation structure 130. Referring to Figure 17 , the width of one single-mode waveguide 110 along the second direction y can be different from the width of the other single-mode waveguide 110 along the second direction y, and the duty cycle of one single-mode waveguide 110 can be different from the duty cycle of the other single-mode waveguide 110, and the two single-mode waveguides 110 can be provided with the isolation structure 130.

[0074] Referring to Figure 18 , the present embodiment provides another waveguide assembly 100 for receiving a return laser signal in a laser radar 1, Figure 18 The waveguide assembly 100 shown in Figure 15 The waveguide assembly 100 shown in is substantially the same as the waveguide assembly 100 shown in Figure 15In the waveguide assembly 100 shown, the width of one single-mode waveguide 110 along the second direction y is not equal to the width of the adjacent other single-mode waveguide 110 along the second direction y; and Figure 18 In the waveguide assembly 100 shown, the width of one single-mode waveguide 110 along the second direction y is equal to the width of the adjacent other single-mode waveguide 110 along the second direction y, and the coupling performance between the two adjacent single-mode waveguides 110 can be weakened and the crosstalk between the two can be reduced only by arranging the isolation structure 130 between the two adjacent single-mode waveguides 110, so that the spacing between the two single-mode waveguides 110 provided with the isolation structure 130 can be designed to be smaller under the same coupling capability requirement, and the probability of the offset echo laser signal falling into the blank area between the two adjacent single-mode waveguides 110 is smaller, thereby improving the reception rate of the echo laser signal.

[0075] Optionally, referring to Figures 15 to 18 When the isolation structure 130 is arranged between the two adjacent single-mode waveguides 110, the length of the two adjacent single-mode waveguides 110 along the first direction x can be equal, and the center spacing h1 between each two adjacent single-mode waveguides 110 can be equal, so that the echo laser signal reception performance of the waveguide assembly 100 is better.

[0076] In a second aspect, an embodiment of the present application provides an integrated chip 10. Referring to Figures 19 to 21 The integrated chip 10 can include a substrate and a waveguide assembly 100 arranged on the substrate, and has the advantages of higher echo laser signal reception rate, smaller chip size, etc.

[0077] In a third aspect, an embodiment of the present application provides a laser radar 1. The laser radar 1 can include the integrated chip 10 described above, the waveguide assembly 100 in the integrated chip 10 is used to emit laser signals to a detection target; and / or, the waveguide assembly 100 in the integrated chip 10 is used to receive echo laser signals reflected by the detection target, and has the advantages of higher echo laser signal reception rate, smaller structure, etc.

[0078] Optionally, the laser radar 1 can further include a light scanning device 20, the light scanning device 20 is used to change the direction of the echo laser signal and make the echo laser signal shoot towards the waveguide assembly 100. For example, the light scanning device 20 can scan in the vertical direction and / or the horizontal direction. The light scanning device 20 can be any device that can change the light propagation path, such as a MEMS mirror, a reflecting mirror, a projection prism, or a rotating mirror, and the present application is not limited thereto.

[0079] Optionally, the laser radar 1 can also include an optical collimator 30. Taking the optical scanning device 20 as a MEMS mirror as an example, in a coaxial transmitting and receiving system, the MEMS mirror is responsible for transmitting and receiving light. The laser signal emitted by the single-mode waveguide 110 on the integrated chip 10 can become parallel light emission after passing through the optical collimator 30, and the received echo light by the MEMS mirror is also parallel light. When the MEMS mirror is stationary, the optical path of the emitted laser signal and the optical path of the received echo laser signal are reversible, and the echo laser signal can be focused into the single-mode waveguide 110 on the integrated chip 10 after the optical collimator 30. When the MEMS mirror rotates, the MEMS mirror will rotate by an angle Δθ in the process of emitting laser signals to the detection target and receiving the echo laser signals reflected by the detection target. As a result, the echo laser signals emitted by the MEMS mirror will be deflected by 2Δθ compared to the laser signals reaching the MEMS mirror, so that the echo laser signals emitted by the MEMS mirror cannot return to the corresponding single-mode waveguide 110. Due to the difference in effective refractive index between the two adjacent single-mode waveguides 110 designed in the embodiment of the present application, and the closer distance between the two adjacent single-mode waveguides 110, more offset echo laser signals can be transmitted to other single-mode waveguides 110, thereby improving the reception rate of the echo laser signals.

[0080] The above only discloses the preferred embodiments of the present application, and of course cannot limit the scope of the rights of the present application, so the equivalent changes made according to the claims of the present application still fall within the scope covered by the present application.

Claims

1. A waveguide assembly, characterized in that, The waveguide assembly, used for receiving echo laser signals in a lidar system, includes: Multiple single-mode waveguides are provided, each of which extends along a first direction and is spaced apart along a second direction that intersects with the first direction. At least one of the single-mode waveguides is provided with an isolation structure between it and another adjacent single-mode waveguide to reduce the spacing between the two adjacent single-mode waveguides. One of the single-mode waveguides has a width along the second direction equal to the width of the adjacent single-mode waveguide along the second direction. An isolation structure is provided between the two adjacent single-mode waveguides. The isolation structure includes multiple layers of isolation strips spaced apart along the second direction, and each layer of isolation strips extends along the first direction. The isolation structure includes a periodic subwavelength multilayer structure. Specifically, by changing the period and duty cycle of the isolation strip, it is possible to block laser signals of different wavelength ranges; the width of the isolation strip along the second direction is smaller than the width of the single-mode waveguide along the second direction; the isolation strip and the blank area located behind it along the second direction form a period, and the duty cycle of the isolation strip is the percentage of the width of the isolation strip along the second direction in the width of a period along the second direction.

2. The waveguide assembly as described in claim 1, characterized in that, In the plurality of single-mode waveguides, the effective refractive index of at least one single-mode waveguide is not equal to the effective refractive index of the adjacent single-mode waveguide.

3. The waveguide assembly as described in claim 2, characterized in that, In the plurality of single-mode waveguides, the effective refractive index of each single-mode waveguide is different from the effective refractive index of the adjacent single-mode waveguide.

4. The waveguide assembly as described in claim 2, characterized in that, In two adjacent single-mode waveguides, the width of one single-mode waveguide along the second direction is not equal to the width of the other single-mode waveguide along the second direction.

5. The waveguide assembly as described in claim 2, characterized in that, In two adjacent single-mode waveguides, at least one of the single-mode waveguides includes a subwavelength grating waveguide, and the duty cycles of the two adjacent single-mode waveguides are not equal.

6. The waveguide assembly as described in claim 2, characterized in that, In two adjacent single-mode waveguides, the width of one single-mode waveguide along the second direction is not equal to the width of the other single-mode waveguide along the second direction, and at least one single-mode waveguide includes a subwavelength grating waveguide, and the duty cycles of the two adjacent single-mode waveguides are not equal.

7. The waveguide assembly as described in claim 5 or 6, characterized in that, Of two adjacent single-mode waveguides, one of the single-mode waveguides includes a subwavelength grating waveguide, and the other single-mode waveguide is a strip waveguide; or In two adjacent single-mode waveguides, both single-mode waveguides include a subwavelength grating waveguide.

8. The waveguide assembly as described in any one of claims 2 to 6, characterized in that, Two or more adjacent single-mode waveguides are combined to form a waveguide unit, and the waveguide assembly includes a plurality of waveguide units distributed along the second direction.

9. The waveguide assembly as described in claim 2, characterized in that, In the plurality of single-mode waveguides, the center-to-center spacing between any two adjacent single-mode waveguides is equal.

10. An integrated chip, characterized in that, include: substrate; The waveguide assembly according to any one of claims 1 to 9, wherein the waveguide assembly is disposed on the substrate.

11. A lidar, characterized in that, The integrated chip of claim 10 is included, wherein the waveguide component in the integrated chip is used to receive the echo laser signal reflected by the probed target.

12. A lidar as described in claim 11, characterized in that, Also includes: An optical scanning device is used to change the direction of the echo laser signal and direct the echo laser signal toward the waveguide assembly.

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