Patent Description:
A waveguide is a guided structure made of an optically-transparent medium (e.g., quartz glass) that transmits electromagnetic waves at optical frequencies. The transmission principle of the waveguide is that on a medium interface with different refractive indexes, the total internal reflection of electromagnetic waves limits optical waves to propagate in the waveguide and a limited area around the waveguide. Waveguides are widely used because of their low transmission loss characteristics.

For example, a waveguide is commonly used in LiDAR to achieve reception of an echo laser signal. However, in a LiDAR with a rotatable reflector, if the reflector rotates before receiving an echo laser signal, the echo laser signal may be offset after passing through the rotated reflector, and the offset echo laser signal cannot be emitted to the waveguide through the reflector, so that the receiving rate of the echo laser signal is low. <CIT> discloses an optical component for a LiDAR sensor system. The optical component may include an optical element having a first main surface and a second main surface opposite to the first main surface, a first lens array formed on the first main surface, and/or a second lens array formed on the second main surface. The optical element has a curved shape in a first direction of the LiDAR sensor system. <CIT> discloses apparatus and methods relating to coupling radiation from an incident beam into a plurality of waveguides with a grating coupler. A grating coupler can have offset receiving regions and grating portions with offset periodicity to improve sensitivity of the grating coupler to misalignment of the incident beam. <CIT> discloses a half-wave arrangement two-dimensional scanning optical phased array based on a flat grating antenna, which comprises a laser light source, a light splitting network, a phase modulator array, a tapered waveguide, a waveguide array of a non-uniform width and a flat grating antenna which are connected in sequence. <CIT> discloses a three-dimensional scanning LiDAR based on one-dimensional optical phased arrays, which comprises a transmitting end, a coherent receiving end and an incoherent receiving end, wherein the transmitting end, the coherent receiving end and the incoherent receiving end are all one-dimensional arrays. A phase control complexity of the three-dimensional scanning phased array is reduced, and a tunable laser with high cost and a grating array antenna with large crosstalk are avoided.

The present application provides an integrated chip comprising a waveguide assembly and a LiDAR, which are used for solving the problem that the receiving rate of echo laser signals is low because the offset echo laser signals cannot be received by a waveguide in the related art.

In a first aspect, the present application provides an integrated chip, which includes a substrate and a waveguide assembly arranged on the substrate, wherein the waveguide assembly is configured for receiving an echo laser signal in a LiDAR, according to independent claim <NUM>.

In a second aspect, the present application provides a LiDAR, which includes an optical scanning device and an integrated chip as described above. The waveguide assembly of the integrated chip is configured for receiving an echo laser signal reflected by a detected target. The optical scanning device is configured for changing a direction of the echo laser signal and enabling the echo laser signal to be directed to the waveguide assembly.

According to the waveguide assembly, the integrated chip and the LiDAR of the present application, the waveguide assembly is designed to include a plurality of single-mode waveguides arranged with intervals, when echo laser signals are offset due to the presence of a walk-off effect, the offset echo laser signals can reach other single-mode waveguides, and therefore avoiding the problem in the related art that the offset echo laser signals cannot be received due to the fact that only a single-mode waveguide is included. Compared with the prior art in which a multi-mode waveguide is directly arranged and offset echo laser signals are received by means of the large width of the multi-mode waveguide, by adopting a plurality of single-mode waveguides in the present application, the problem that the high-order mode of the multi-mode waveguide is triggered when the echo laser signals are received does not exist, namely, there is no loss of lasers of the high-order mode, therefore achieving the advantage of higher receiving rate of echo laser signals. In addition, in one solution, the effective refractive index of at least one single-mode waveguide is designed to be different from an adjacent single-mode waveguide, so that the phase matching condition between two adjacent single-mode waveguides may be broken, thus inhibiting the coupling between two adjacent single-mode waveguides and reducing the crosstalk. In this way, under the same coupling capacity demand, the spacing between two adjacent single-mode waveguides with different effective refractive indexes may be smaller, and offset echo laser signals are less likely to fall onto a blank area between two adjacent single-mode waveguides. Therefore, more offset echo laser signals can fall onto the single-mode waveguides, thereby improving the receiving rate of echo laser signals. In another solution, the coupling performance between two adjacent single-mode waveguides may be weakened through an isolation structure arranged between two adjacent single-mode waveguides, thus reducing the crosstalk between the two single-mode waveguides. In this way, under the same coupling capacity demand, the spacing between two adjacent single-mode waveguides provided with the isolation structure may be smaller, and the offset echo laser signals are less likely to fall onto a blank area between two adjacent single-mode waveguides, thus improving the receiving rate of echo laser signals can be improved. If a same number of single-mode waveguides are used, the smaller the spacing between two adjacent single-mode waveguides is, the smaller the size of the waveguide assembly may be, which is beneficial to decreasing chip area, improving integration level, and reducing cost. If the size of the waveguide assembly is unchanged, a larger number of single-mode waveguides may be accommodated, and the duty ratio between the single-mode waveguides is remarkably reduced.

In order to make the purposes, technical solutions and advantages of the present application clearer, the embodiments of the present application are described in detail with reference to the accompanying drawings.

When accompanying drawings are involved in the description below, the same numbers in different drawings represent the same or similar elements, unless otherwise indicated. The modes of implementation described in the following exemplary embodiments do not represent all modes of implementation consistent with the present application. Rather, they are merely examples of devices and methods consistent with certain aspects of the present application detailed in the appended claims.

In the related art, referring to <FIG>, a LiDAR <NUM>' includes a single-mode waveguide <NUM>' for receiving echo laser signals, and a reflector <NUM>' for deflecting the echo laser signals transmitted to the single-mode waveguide <NUM>'. When the reflector <NUM>' is static, the echo laser signals of the LiDAR <NUM>' may directly reach the single-mode waveguide <NUM>'. When the reflector <NUM>' moves, for example, referring to <FIG>, when the reflector <NUM>' rotates, the echo laser signals emitted from the reflector <NUM>' are offset, such that the echo laser signals emitted from the reflector <NUM>' cannot return to the corresponding single-mode waveguide <NUM>', which means that a walk-off effect occurs, and thus the receiving rate of the echo laser signals is reduced. The farther the detected target is, the larger the movement angular velocity of the reflector <NUM>' is, the more critical the walk-off effect is, and the lower the receiving rate of the echo laser signals is. Based on this, an embodiment of the present application provides a waveguide assembly <NUM>, please referring to <FIG>, the waveguide assembly <NUM> includes a plurality of single-mode waveguides <NUM> arranged with intervals. In the embodiment of the present application, the waveguide assembly <NUM> is designed to include the plurality of single-mode waveguides <NUM> arranged with intervals, and when echo laser signals are offset due to the presence of a walk-off effect, the offset echo laser signals may reach other single-mode waveguides <NUM>, therefore avoiding the problem in the related art that the offset echo laser signals cannot be received due to the fact that only a single-mode waveguide <NUM> is included.

Meanwhile, compared with directly arranging a multi-mode waveguide and receiving offset echo laser signals with the help of the large width of the multi-mode waveguide in the related art, the embodiment of the present application adopts a plurality of single-mode waveguides <NUM> to receive the echo laser signals, there is no problem of triggering the high-order mode of the multi-mode waveguide when receiving the echo laser signals. When the multi-mode waveguide is converted into the single-mode waveguide <NUM>, the lasers of the high-order mode will be lost, so that the remaining echo laser signals in the multi-mode waveguide manner is much less than that of the received echo laser signals, and the wider the multi-mode waveguide is, the larger the conversion loss from the multi-mode waveguide to the single-mode waveguide <NUM> is. That is, compared with the related art in which offset echo laser signals are received by a multi-mode waveguide, the embodiment of the present application has an advantage of a higher receiving rate of echo laser signals as there is no loss of lasers of a high-order mode.

The waveguide assembly <NUM> may be used in the LiDAR <NUM> to receive the echo laser signals, so that when the waveguide assembly <NUM> receives the echo laser signals, the plurality of single-mode waveguides <NUM> may enlarge a receiving field of view of the LiDAR <NUM> to make the angle of the LiDAR <NUM> wider.

In a plurality of single-mode waveguides <NUM>, each single-mode waveguide <NUM> may extend substantially along a first direction x, and the plurality of single-mode waveguides <NUM> may be arranged with intervals substantially along a second direction y that intersects with the first direction x, wherein an included angle between the second direction y and the first direction x may be any value greater than <NUM>° and less than <NUM>°. Preferably, the second direction y may be perpendicular to the first direction x, such that the structural design of the waveguide assembly <NUM> is more compact, which is beneficial to realizing a miniaturized design of the waveguide assembly <NUM>.

An effective refractive index of at least one of a plurality of single-mode waveguides <NUM> is not equal to an effective refractive index of an adjacent single-mode waveguide <NUM>. In the case where a center-to-center spacing of a same single-mode waveguide <NUM> and an adjacent single-mode waveguide <NUM> is equal, if the effective refractive index of the other single-mode waveguide <NUM> is not equal to the effective refractive index of the single-mode waveguide, the crosstalk between the two single-mode waveguides <NUM> is lower compared with the case where the effective refractive index of the other single-mode waveguide <NUM> is equal to the effective refractive index thereof. The effective refractive indexes of the two adjacent single-mode waveguides <NUM> are not equal to each other, so that the phase matching condition between the two adjacent single-mode waveguides <NUM> may be broken, thus inhibiting the coupling between the two adjacent single-mode waveguides <NUM> and reducing the crosstalk. In this way, under the same coupling capability demand, the spacing between two adjacent single-mode waveguides <NUM> with effective refractive indexes not equal to each other may be smaller than the spacing between two adjacent single-mode waveguides <NUM> with effective refractive indexes equal to each other. With smaller spacing between two adjacent single-mode waveguides <NUM>, the offset echo laser signals are less likely to fall onto a blank area between two adjacent single-mode waveguides <NUM>. Therefore, more offset echo laser signals can fall onto the single-mode waveguides <NUM> and be coupled with the single-mode waveguides <NUM>, thereby improving the receiving rate of echo laser signals. If a same number of single-mode waveguides <NUM> are used, the smaller the spacing between two adjacent single-mode waveguides <NUM> is, the smaller the size of the waveguide assembly <NUM> may be, which is beneficial to decreasing chip area, improving integration level and reducing cost. If the size of the waveguide assembly <NUM> is unchanged, a larger number of single-mode waveguides <NUM> may be accommodated, and the duty ratio between the single-mode waveguides <NUM> is remarkably reduced.

Preferably, an effective refractive index of each of a plurality of single-mode waveguides <NUM> may be designed to be not equal to an effective refractive index of an adjacent single-mode waveguide <NUM>. The spacing between all of adjacent two single-mode waveguides <NUM> in the waveguide assembly <NUM> may be designed to be smaller, the receiving rate of the echo laser signals by the waveguide assembly <NUM> may be optimized, and the minimized design of the LiDAR <NUM> may be realized.

Optionally, a width of one of two adjacent single-mode waveguides <NUM> along the second direction y is not equal to a width of the other single-mode waveguide <NUM> along the second direction y. The widths of two adjacent single-mode waveguides <NUM> along the second direction y that are not equal to each other may make effective refractive indexes of the two adjacent single-mode waveguides <NUM> not equal to each other, so that the spacing between the two adjacent single-mode waveguides <NUM> is smaller, and the receiving rate of the echo laser signals is improved. Two adjacent single-mode waveguides <NUM> with widths along the second direction y not equal to each other may be manufactured by adjusting the growth process of the waveguides. The molding process is simple and the production cost is low.

It should be noted that, the coupling capability is strong when two single-mode waveguides <NUM> with the widths along the second direction y equal to each other. When the waveguide assembly <NUM> includes the two single-mode waveguides <NUM> with the widths along the second direction y equal to each other, the coupling between the two single-mode waveguides <NUM> with the widths equal to each other may be inhibited by increasing the spacing between the two single-mode waveguides, thus reducing the crosstalk between the two single-mode waveguides is reduced. Since the increased spacing between the two single-mode waveguides may cause the offset echo laser signals to enter a relatively large blank area between the two single-mode waveguides without being coupled with the single-mode waveguide <NUM>, further, when the spacing between two single-mode waveguides <NUM> with widths along the second direction y equal to each other is relatively large, the number of other single-mode waveguides <NUM> arranged between the two single-mode waveguides with widths not equal to one another may also be increased.

For example, for two single-mode waveguides <NUM> with the widths along the second direction y equal to each other, a single-mode waveguide <NUM> with a different width may be arranged therebetween; a plurality of single-mode waveguides <NUM> (e.g., two, three, four, five, etc.) with different widths may also be arranged therebetween. It can be understood that the larger the number of the single-mode waveguides <NUM> with different widths arranged between the two single-mode waveguides <NUM> with the widths along the second direction y equal to each other is, the smaller the blank area between the two single-mode waveguides is, and the higher the receiving rate of the echo laser signals is. Preferably, two single-mode waveguides <NUM> with different widths may be arranged between two single-mode waveguides <NUM> with widths along the second direction y equal to each other, so as to reduce the number of single-mode waveguides <NUM> between the two single-mode waveguides <NUM> with the widths equal to each other on the basis of reduction in the blank area therebetween, simplify the difficulty of designing the size of the single-mode waveguides <NUM> therebetween, and reduce the production and manufacturing cost.

In the plurality of single-mode waveguides <NUM> of the waveguide assembly <NUM>, two or more adjacent single-mode waveguides <NUM> may be combined to form a waveguide unit <NUM>, and the waveguide assembly <NUM> may include a plurality of waveguide units <NUM> arranged along the second direction y. The waveguide assembly <NUM> is designed to include a plurality of waveguide units <NUM>, so that in an aspect, structural regularity of the waveguide assembly <NUM> may be guaranteed, and receiving capability of echo laser signals at each area of the waveguide assembly <NUM> is approximately balanced, and in another aspect, only one group of waveguide units <NUM> need to be designed and then reuse the design, and thus design difficulty of the waveguide assembly <NUM> may be reduced, and the production and manufacturing cost may be reduced.

It can be understood that two single-mode waveguides <NUM>, three single-mode waveguides <NUM>, four single-mode waveguides <NUM>, or the like may be included in the waveguide unit <NUM>, which is not limited in the embodiment of the present application. When three or more single-mode waveguides <NUM> are included in the waveguide unit <NUM>, the widths of the three or more single-mode waveguides <NUM> in the waveguide unit <NUM> along the second direction y may sequentially increase, sequentially decrease, sequentially increase and then decrease, sequentially decrease and then increase, or the like, which is not limited in the embodiment of the present application.

For example, the waveguide assembly <NUM> may include a first single-mode waveguide 110a, a second single-mode waveguide 110b, a first single-mode waveguide 110a, a second single-mode waveguide 110b, a first single-mode waveguide 110a, a second single-mode waveguide 110b, and the like, which are sequentially arranged along the second direction y. At this time, the first single-mode waveguide 110a and the adjacent second single-mode waveguide 110b located therebehind may be considered as a waveguide unit <NUM> in combination. A width of the first single-mode waveguide 110a along the second direction y may be greater than or less than a width of the second single-mode waveguide 110b along the second direction y. Each waveguide unit <NUM> includes the same of two kinds of single-mode waveguides <NUM>, and the arrangement order of the two single-mode waveguides <NUM> in each waveguide unit <NUM> is the same.

For another example, please referring to <FIG>, the waveguide assembly <NUM> may include a first single-mode waveguide 110a, a second single-mode waveguide 110b, a third single-mode waveguide 110c, a first single-mode waveguide 110a, a second single-mode waveguide 110b, a third single-mode waveguide 110c, and the like, which are sequentially arranged along the second direction y. At this time, the first single-mode waveguide 110a, and the second single-mode waveguide 110b and the third single-mode waveguide 110c adjacent thereto and located therebehind may be considered as a waveguide unit <NUM>. Optionally, the width of the first single-mode waveguide 110a along the second direction y may 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 may be greater than the width of the third single-mode waveguide 110c along the second direction y. Optionally, please referring to <FIG>, the width of the first single-mode waveguide 110a along the second direction y may 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 may be greater than the width of the second single-mode waveguide 110b along the second direction y. At this time, each waveguide unit <NUM> includes the same of three kinds of single-mode waveguides <NUM>, and the arrangement order of the three single-mode waveguides <NUM> in each waveguide unit <NUM> is the same.

For yet another example, please referring to <FIG>, the waveguide assembly <NUM> may include a first single-mode waveguide 110a, a second single-mode waveguide 110b, a third single-mode waveguide 110c, a first single-mode waveguide 110a, a third single-mode waveguide 110c, a second single-mode waveguide 110b, and the like, which are sequentially arranged along the second direction y. At this time, the first single-mode waveguide 110a, and the second single-mode waveguide 110b and the third single-mode waveguide 110c adjacent thereto and located therebehind are considered as a waveguide unit <NUM>, and the rear first single-mode waveguide 110a, and the third single-mode waveguide 110c and the second single-mode waveguide 110b adjacent thereto and located therebehind may be considered as another waveguide unit <NUM>. Optionally, the width of the first single-mode waveguide 110a along the second direction y may 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 may be greater than the width of the second single-mode waveguide 110b along the second direction y. At this time, each waveguide unit <NUM> includes the same of three kinds of single-mode waveguides <NUM>, and the arrangement order of the three single-mode waveguides <NUM> in each waveguide unit <NUM> is different.

It should be noted that each waveguide unit <NUM> may include the same of a plurality of single-mode waveguides <NUM>, and the arrangement order of the plurality of single-mode waveguides <NUM> in each waveguide unit <NUM> may be the same or different, which is not limited in the embodiment of the present application.

Optionally, please referring to <FIG>, when the widths of two adjacent single-mode waveguides <NUM> along the second direction y are not equal to each other, the lengths of two adjacent single-mode waveguides <NUM> along the first direction x may be equal to each other, and the center-to-center spacing h1 between each two adjacent single-mode waveguides <NUM> may be equal, so that the receiving performance of echo laser signals in the waveguide assembly <NUM> is better.

In addition to the above-mentioned inequality of the effective refractive indexes of the two adjacent single-mode waveguides <NUM> achieved by inequality of the widths of the two adjacent single-mode waveguides <NUM> along the second direction y, the inequality of the effective refractive indexes of the two adjacent single-mode waveguides <NUM> is also achieved by inequality of duty ratios of the two adjacent single-mode waveguides <NUM>. Specifically, please referring to <FIG>, at least one of two adjacent single-mode waveguides <NUM> includes a sub-wavelength grating waveguide, and the duty ratios of the two single-mode waveguides <NUM> are not equal to each other.

The sub-wavelength grating waveguide may include a plurality of waveguide portions <NUM> arranged with intervals along the first direction x, wherein each waveguide portion <NUM> and a blank area <NUM> located therebehind are combined to form a period <NUM>, and a duty ratio of the sub-wavelength grating waveguide may be a percentage of a length of the waveguide portion <NUM> along the first direction x in a length of the period <NUM> along the first direction x. The single-mode waveguides <NUM> with different duty ratios may be manufactured by adjusting the growth process of the waveguides, which is simple in forming mode and low in production cost.

In an exemplary solution, one of two adjacent single-mode waveguides <NUM> may include a sub-wavelength grating waveguide, and the other single-mode waveguide <NUM> may be a strip waveguide. The duty ratio of the strip waveguide is <NUM>%, the production process of the strip waveguide is more mature, and the manufacturing mode is simpler. Therefore, designing the waveguide assembly <NUM> to include the strip waveguide, which can simplify the processing process of the waveguide assembly <NUM> and improve the production efficiency.

In another exemplary solution, each of two adjacent single-mode waveguides <NUM> may include a sub-wavelength grating waveguide, and the duty ratios of the two single-mode waveguides <NUM> are not equal to each other. The two adjacent single-mode waveguides <NUM> are each designed to include a sub-wavelength grating waveguide, so that the combination form of the two adjacent single-mode waveguides <NUM> is more diversified, and the application prospect is broad.

Similarly, when the duty ratios of two adjacent single-mode waveguides <NUM> are not equal to each other, in a plurality of single-mode waveguides <NUM> of the waveguide assembly <NUM>, two or more adjacent single-mode waveguides <NUM> may be combined to form a waveguide unit <NUM>, and the waveguide assembly <NUM> may include a plurality of waveguide units <NUM> arranged along the second direction y, wherein, two single-mode waveguides <NUM>, three single-mode waveguides <NUM>, four single-mode waveguides <NUM>, or the like may be included in the waveguide unit <NUM>, which is not limited in the embodiment of the present application. When three or more single-mode waveguides <NUM> are included in the waveguide unit <NUM>, the duty ratios of the three or more single-mode waveguides <NUM> in the waveguide unit <NUM> along the second direction y may sequentially increase, sequentially decrease, sequentially increase and then decrease, sequentially decrease and then increase, or the like, which is not limited in the embodiment of the present application.

For example, please referring to <FIG>, the waveguide assembly <NUM> may include a first single-mode waveguide 110a, a second single-mode waveguide 110b, a first single-mode waveguide 110a, a second single-mode waveguide 110b, a first single-mode waveguide 110a, a second single-mode waveguide 110b, and the like, which are sequentially arranged along the second direction y. At this time, the first single-mode waveguide 110a and the adjacent second single-mode waveguide 110b located therebehind may be considered as a waveguide unit <NUM> in combination. Optionally, the duty ratio of the first single-mode waveguide 110a may be greater than or less than the duty ratio of the second single-mode waveguide 110b. The first single-mode waveguide 110a may be a strip waveguide, and the second single-mode waveguide 110b may be a sub-wavelength grating waveguide. Both of the first single-mode waveguide 110a and the second single-mode waveguide 110b may also be sub-wavelength grating waveguides. At this time, each waveguide unit <NUM> includes the same of two kinds of single-mode waveguides <NUM>, and the arrangement order of the two single-mode waveguides <NUM> in each waveguide unit <NUM> is the same.

For another example, please referring to <FIG>, the waveguide assembly <NUM> may include a first single-mode waveguide 110a, a second single-mode waveguide 110b, a third single-mode waveguide 110c, a first single-mode waveguide 110a, a second single-mode waveguide 110b, a third single-mode waveguide 110c, and the like, which are sequentially arranged along the second direction y. At this time, the first single-mode waveguide 110a, and the second single-mode waveguide 110b and the third single-mode waveguide 110c adjacent thereto and located therebehind may be considered as a waveguide unit <NUM>. Optionally, the duty ratio of the first single-mode waveguide 110a may be greater than the duty ratio of the second single-mode waveguide 110b, and the duty ratio of the second single-mode waveguide 110b may be greater than the duty ratio of the third single-mode waveguide 110c. Optionally, please referring to <FIG>, the duty ratio of the first single-mode waveguide 110a may be greater than the duty ratio of the third single-mode waveguide 110c, and the duty ratio of the third single-mode waveguide 110c may be greater than the duty ratio of the second single-mode waveguide 110b, wherein, the first single-mode waveguide 110a may be a strip waveguide, and both of the second single-mode waveguide 110b and the third single-mode waveguide 110c may be sub-wavelength grating waveguides. All of the first single-mode waveguide 110a, the second single-mode waveguide 110b and the third single-mode waveguide 110c may also be sub-wavelength grating waveguides. At this time, each waveguide unit <NUM> includes the same of three kinds of single-mode waveguides <NUM>, and the arrangement order of the three single-mode waveguides <NUM> in each waveguide unit <NUM> is the same.

For yet another example, please referring to <FIG>, the waveguide assembly <NUM> may include a first single-mode waveguide 110a, a second single-mode waveguide 110b, a third single-mode waveguide 110c, a first single-mode waveguide 110a, a third single-mode waveguide 110c, a second single-mode waveguide 110b, and the like, which are sequentially arranged along the second direction y. At this time, the first single-mode waveguide 110a, and the second single-mode waveguide 110b and the third single-mode waveguide 110c adjacent thereto and located therebehind are considered as a waveguide unit <NUM>, and the rear first single-mode waveguide 110a, and the third single-mode waveguide 110c and the second single-mode waveguide 110b adjacent thereto and located therebehind may be considered as another waveguide unit <NUM>. Optionally, the duty ratio of the first single-mode waveguide 110a may be greater than the duty ratio of the third single-mode waveguide 110c, and the duty ratio of the third single-mode waveguide 110c may be greater than the duty ratio of the second single-mode waveguide 110b, wherein, the first single-mode waveguide 110a may be a strip waveguide, and both of the second single-mode waveguide 110b and the third single-mode waveguide 110c may be sub-wavelength grating waveguides. All of the first single-mode waveguide 110a, the second single-mode waveguide 110b and the third single-mode waveguide 110c may also be sub-wavelength grating waveguides. At this time, each waveguide unit <NUM> includes the same of three kinds of single-mode waveguides <NUM>, and the arrangement order of the three single-mode waveguides <NUM> in each waveguide unit <NUM> is different.

Optionally, referring to <FIG>, when the duty ratios of two adjacent single-mode waveguides <NUM> are not equal to each other, the lengths of two adjacent single-mode waveguides <NUM> along the first direction x may be equal to each other, and the center-to-center spacing h1 between each two adjacent single-mode waveguides <NUM> may be equal, so that the receiving performance of echo laser signals in the waveguide assembly <NUM> is better. It should be noted that, for the sub-wavelength grating waveguide, the length dimension along the first direction x thereof should be the length dimension along the first direction x of all periods <NUM> included in the sub-wavelength grating waveguide, and not only the length dimension along the first direction x of the waveguide portion <NUM> in the sub-wavelength grating waveguide.

Optionally, in the waveguide assembly <NUM>, when two or more single-mode waveguides <NUM> each include a sub-wavelength grating waveguide, the period <NUM> of each sub-wavelength grating waveguide may be equal. In this way, it is convenient to realize that the length of each sub-wavelength grating waveguide along the first direction x is equal, and when the lengths are equal, the number of periods <NUM> included is the same.

It should be noted that, in order to realize that the effective refractive indexes of two adjacent single-mode waveguides <NUM> are not equal, please referring to <FIG>, two adjacent single-mode waveguides <NUM> may have different widths along the second direction y, and may also have different duty ratios. That is, in two adjacent single-mode waveguides <NUM>, the width of one single-mode waveguide <NUM> along the second direction y is not equal to the width of the other single-mode waveguide <NUM> along the second direction y, and at least one single-mode waveguide <NUM> includes a sub-wavelength grating waveguide; the duty ratios of the two single-mode waveguides <NUM> are not equal to each other, such that the structural design of the waveguide assembly <NUM> is more diversified, which can meet different use requirements.

Optionally, please referring to <FIG>, an isolation structure <NUM> may be arranged between at least one of a plurality of single-mode waveguides <NUM> and an adjacent single-mode waveguide <NUM>. The design of the isolation structure <NUM> may weaken the coupling performance between two adjacent single-mode waveguides <NUM>, and reduce the crosstalk between the two single-mode waveguides. Therefore, under the same requirement for coupling capability, the spacing between two single-mode waveguides <NUM> provided with the isolation structure <NUM> may be designed to be smaller, and the offset echo laser signals are less likely to fall onto a blank area between two adjacent single-mode waveguides <NUM>, so that the receiving rate of the echo laser signals can be improved.

Optionally, the isolation structure <NUM> may include a plurality of layers of isolation bars <NUM> arranged with intervals along the second direction y, wherein each layer of isolation bar <NUM> may extend along the first direction x. By adding a periodic sub-wavelength multi-layer structure between two adjacent single-mode waveguides <NUM>, mutual coupling of laser signals in a specific wavelength range in the two adjacent single-mode waveguides <NUM> can be blocked, and the crosstalk of the laser signals in the specific wavelength range between the two adjacent single-mode waveguides <NUM> can be reduced.

The specific wavelength range is related to the period <NUM> and the duty ratio of the isolation bar <NUM>. By changing the period <NUM> and the duty ratio of the isolation bar <NUM>, the laser signals of different wavelength ranges can be blocked. The isolation bar <NUM> may be considered as a structure having a smaller width along the second direction y than the width of the single-mode waveguide <NUM> along the second direction y. Each isolation bar <NUM> and a blank area <NUM> located therebehind along the second direction y may be combined to form a period <NUM>, and the duty ratio of the isolation bar <NUM> may be a percentage of the width of the isolation bar <NUM> along the second direction y in the width of the period <NUM> along the second direction y. Optionally, the number of layers of the isolation bars <NUM> arranged with intervals along the second direction y and included in the isolation structure <NUM> may be two, three, four, five, or the like, which is not limited in the embodiment of the present application. The number of layers of isolation bars <NUM> included in the isolation structure <NUM> between each two adjacent single-mode waveguides <NUM> may be equal or not, the types of the isolation bars <NUM> included in the isolation structure <NUM> between each two adjacent single-mode waveguides <NUM> may be the same or different, which are not limited in the embodiment of the present application, wherein, the different types of the isolation bars <NUM> may be different widths of the isolation bars <NUM> along the second direction y, and the like, which is not limited in the embodiment of the present application.

Optionally, in two adjacent single-mode waveguides <NUM>, the effective refractive indexes of one single-mode waveguide <NUM> and the other single-mode waveguide <NUM> is not equal to each other, and an isolation structure <NUM> may be arranged between the two single-mode waveguides. For example, as shown in <FIG>, in two adjacent single-mode waveguides <NUM>, the width of one single-mode waveguide <NUM> along the second direction y is not equal to the width of the other single-mode waveguide <NUM> along the second direction y, and an isolation structure <NUM> is arranged between the two single-mode waveguides. Referring to <FIG>, in two adjacent single-mode waveguides <NUM>, the duty ratio of one single-mode waveguide <NUM> is not equal to the duty ratio of the other single-mode waveguide <NUM>, and an isolation structure <NUM> is arranged between the two single-mode waveguides. Referring to <FIG>, in two adjacent single-mode waveguides <NUM>, the width of one single-mode waveguide <NUM> along the second direction y is not equal to the width of the other single-mode waveguide <NUM> along the second direction y, the duty ratio of one single-mode waveguide <NUM> is not equal to the duty ratio of the other single-mode waveguide <NUM>, and an isolation structure <NUM> is arranged between the two single-mode waveguides.

Referring to <FIG>, a further unclaimed embodiment of the present application provides another waveguide assembly <NUM> for receiving an echo laser signal in the LiDAR <NUM>, wherein the waveguide assembly <NUM> shown in <FIG> is substantially the same as the waveguide assembly <NUM> shown in <FIG>, except the following aspects. <FIG> shows a waveguide assembly <NUM> in which the width of one single-mode waveguide <NUM> along the second direction y is not equal to the width of an adjacent single-mode waveguide <NUM> along the second direction y; while <FIG> shows a waveguide assembly <NUM> in which the width of one single-mode waveguide <NUM> along the second direction y is equal to the width of an adjacent single-mode waveguide <NUM> along the second direction y. The coupling performance between two adjacent single-mode waveguides <NUM> may be weakened only by arranging the isolation structure <NUM> between the two adjacent single-mode waveguides <NUM>, thus reducing the crosstalk between the two adjacent single-mode waveguides. In this way, under the same coupling capability requirement, the spacing between two single-mode waveguides <NUM> provided with the isolation structure <NUM> may be designed to be smaller, and the offset echo laser signals are less likely to fall onto a blank area between two adjacent single-mode waveguides <NUM>, thereby improving the receiving rate of the echo laser signals.

Optionally, referring to <FIG>, when the isolation structure <NUM> is arranged between two adjacent single-mode waveguides <NUM>, the lengths of two adjacent single-mode waveguides <NUM> along the first direction x may be equal to each other, and the center-to-center spacing h1 between each two adjacent single-mode waveguides <NUM> may be equal, so that the receiving performance of echo laser signals in the waveguide assembly <NUM> is better.

In a second aspect, an embodiment of the present application provides an integrated chip <NUM>. Referring to <FIG>, the integrated chip <NUM> may include a substrate and a waveguide assembly <NUM> arranged on the substrate, and has the advantages of higher receiving rate of echo laser signals, smaller chip size, and the like.

In a third aspect, an embodiment of the present application provides a LiDAR <NUM>. The LiDAR <NUM> may include the integrated chip <NUM> described above, and the waveguide assembly <NUM> of the integrated chip <NUM> is configured for emitting a laser signal to a detected target; and/or, the waveguide assembly <NUM> of the integrated chip <NUM> is configured for receiving the echo laser signal reflected by the detected target, and has the advantages of higher receiving rate of echo laser signals, miniaturized structure and the like.

Optionally, the LiDAR <NUM> may further include an optical scanning device <NUM>, wherein the optical scanning device <NUM> is configured for changing a direction of the echo laser signal and enabling the echo laser signal to be emitted to the waveguide assembly <NUM>. For example, the optical scanning device <NUM> may scan along a vertical direction and/or a horizontal direction. The optical scanning device <NUM> may be any device that can change a light propagation path, such as a MEMS galvanometer, a reflector, a projection prism, a rotating mirror, or the like, which is not limited in the embodiment of the present application.

Claim 1:
An integrated chip, comprising a substrate and a waveguide assembly (<NUM>) arranged on the substrate, wherein the waveguide assembly (<NUM>) is configured for receiving an echo laser signal in a LiDAR and comprises a plurality of single-mode waveguides (<NUM>);
each single-mode waveguide (<NUM>) extends along a first direction;
the plurality of single-mode waveguides (<NUM>) are arranged at intervals along a second direction, the second direction intersecting with the first direction; and
an effective refractive index of at least one single-mode waveguide (<NUM>) is not equal to an effective refractive index of an adjacent single-mode waveguide (<NUM>);
characterized in that,
at least one of two adjacent single-mode waveguides (<NUM>) comprises a sub-wavelength grating waveguide, and duty ratios of the two adjacent single-mode waveguides (<NUM>) are not equal to each other.