WO2023015438A1

WO2023015438A1 - Optical phased array chip and laser radar

Info

Publication number: WO2023015438A1
Application number: PCT/CN2021/111753
Authority: WO
Inventors: 汪敬
Original assignee: 深圳市速腾聚创科技有限公司
Priority date: 2021-08-10
Filing date: 2021-08-10
Publication date: 2023-02-16
Also published as: CN114945836A; CN114945836B

Abstract

An optical phased array chip and laser radar. The optical phased array chip comprises a substrate layer (100), a buried oxide layer (200), a first waveguide layer (300), an oxide layer (400), a second waveguide layer (500) and upper cladding (600) that are arranged in sequence, wherein a phase shifter assembly (730) is formed on the first waveguide layer (300); and two inter-layer converter assemblies (800) are formed between the first waveguide layer (300) and the second waveguide layer (500). The laser radar comprises a laser radar transmitting system, a receiving system and a signal processing system, wherein the laser radar transmitting system comprises a laser device and the optical phased array chip. According to the optical phased array chip and the laser radar, the process requirements of the fabrication of various devices in the optical phased array chip are reduced, and the performance of the optical phased array chip is improved.

Description

Optical phased array chip and lidar

technical field

The present application relates to the technical field of laser radar, in particular to an optical phased array chip and laser radar.

Background technique

The optical phased array chip is an important part of the all-solid-state lidar system, which has the advantages of complete solid-state, high reliability, small size, and convenient control. Generally speaking, devices such as couplers, phase shifters, and transmitting antennas are installed on the optical phased array chip, and the devices are connected through waveguides. At present, the waveguide material used in optical phased array chips generally adopts one of silicon-on-insulator (SOI) materials, silicon nitride materials, III-V materials, and the like.

technical problem

One of the objectives of the embodiments of the present application is to provide an optical phased array chip and a laser radar.

technical solution

The technical scheme that the embodiment of the present application adopts is:

In the first aspect, an optical phased array chip is provided, including a substrate layer, a buried oxide layer, a first waveguide layer, an oxide layer, a second waveguide layer, and an upper cladding layer arranged in sequence; wherein, the second waveguide layer has a thermo-optic coefficient lower than the thermo-optic coefficient of the first waveguide layer;

A coupler, an optical splitter, and a transmitting antenna assembly are formed on the second waveguide layer; a phase shifter assembly is formed on the first waveguide layer; a two interlayer converter assemblies; wherein the coupler is in signal communication with the optical splitter through the second waveguide layer, and the optical splitter is in signal communication with the phase shifter assembly through one of the interlayer converter assemblies signal communication, and the phase shifter component is in signal communication with the transmitting antenna component through another interlayer converter component.

In one embodiment, the second waveguide layer is divided into a first part and a second part arranged at intervals, the coupler and the optical splitter are formed on the first part, and the transmitting antenna assembly is formed on the On to the second part.

In one embodiment, the first waveguide layer is located between the first part and the second part, and one end of the first waveguide layer is connected to the first waveguide layer through one of the interlayer converter components. Respective ends of one part are in signal communication, and the other end of said first waveguide layer is in signal communication with corresponding ends of said second part through another said interlayer converter assembly.

In one embodiment, both ends of the first waveguide layer are stacked with corresponding ends of the two parts in the second waveguide layer.

In one embodiment, the optical splitter has multiple signal output terminals;

The phase shifter assembly includes a plurality of phase shifters communicated with a plurality of signal output ends of the optical splitter in one-to-one correspondence;

The transmitting antenna assembly includes a plurality of transmitting antennas in one-to-one communication with the plurality of phase shifters.

In one embodiment, the signal output end of the first part has a plurality of first waveguide segments corresponding one-to-one to the plurality of signal output ends of the optical splitter;

The second part includes a plurality of second waveguide sections arranged in sequence, and the plurality of second waveguide sections are set in one-to-one correspondence with the plurality of first waveguide sections; each of the second waveguide sections is provided with a said transmit antenna;

The first waveguide layer includes a plurality of third waveguide sections arranged in sequence, and the plurality of third waveguide sections are set in one-to-one correspondence with the plurality of first waveguide sections; each of the third waveguide sections is provided with a said phase shifter;

One of the interlayer converter assemblies includes a plurality of first interlayer converters disposed between the plurality of third waveguide segments and the plurality of first waveguide segments in one-to-one correspondence;

Another interlayer converter assembly includes a plurality of second interlayer converters disposed between the plurality of third waveguide segments and the plurality of first waveguide segments in one-to-one correspondence.

In one embodiment, when the vertical distance between the second waveguide layer and the first waveguide layer is greater than 50nm and less than 400nm, the optical signals in the two waveguide layers in the same interlayer converter can pass through Evanescent wave coupling realizes interlayer conversion.

In one embodiment, the first waveguide segment and the third waveguide segment are located in the first interlayer converter, and the second waveguide segment and the third waveguide segment are located in the first Parts inside the two interlayer converters are all tapered; both the first interlayer converter and the second interlayer converter are tapered waveguide mode converters.

In one embodiment, when the vertical distance between the second waveguide layer and the first waveguide layer is greater than 1 μm and less than 4 μm, the first waveguide segment and the third waveguide segment are located on the first layer A grating structure is formed on the part inside the interlayer converter, and the part where the second waveguide section and the third waveguide section are located in the second interlayer converter; Optical signals in oppositely arranged waveguide sections can realize interlayer conversion through the grating structure.

In one embodiment, the grating structure is fan-shaped.

In one embodiment, the light emitting angle or the light receiving angle of the grating structure is 0-90°.

In one embodiment, the light emitting angle or the light receiving angle of the grating structure is 0-60°.

In one embodiment, the first waveguide layer is a silicon waveguide layer, and the second waveguide layer is a silicon nitride waveguide layer.

In a second aspect, a laser radar is provided, including a laser radar transmitting system, a receiving system, and a signal processing system. The laser radar transmitting system includes a laser and the above-mentioned optical phased array chip.

In a third aspect, an automatic driving device is provided, including the above-mentioned laser radar and a vehicle body, the laser radar is installed on the vehicle body.

Beneficial effect

The beneficial effect of the optical phased array chip provided by the embodiment of the present application is that: the optical phased array chip provided by the embodiment of the present application uses two waveguides with different materials to make two waveguide layers, and the optical phased array chip Each device is separately arranged on two waveguide layers.

The beneficial effect of the laser radar provided by the embodiment of the present application is that the laser radar provided by the embodiment of the present application includes a laser and the above-mentioned optical phased array chip.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings that need to be used in the embodiments or exemplary technical descriptions. Obviously, the accompanying drawings in the following descriptions are only for this application. For some embodiments, those skilled in the art can also obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic diagram of the frame structure of the connection relationship between the devices in the optical phased array chip provided by the embodiment of the present application;

Fig. 2 is a schematic structural diagram of an optical phased array chip provided by an embodiment of the present application;

FIG. 3 is a schematic top view of the first part of the second waveguide layer used in the embodiment of the present application and the device located on the first part; in the figure, the first interlayer converter is not shown;

Fig. 4 is a schematic top view of the second part of the second waveguide layer used in the embodiment of the present application and the device located on the second part; in the figure, the second interlayer converter is not shown;

Fig. 5 is a schematic top view of the first waveguide layer used in the embodiment of the present application and the device located on the first waveguide layer; in the figure, the first interlayer converter and the second interlayer converter are not shown;

Fig. 6 is a schematic diagram of the propagation path of light in one of the second interlayer converters when the distance between the second waveguide layer and the first waveguide layer is relatively close;

Fig. 7 is a top view structural schematic diagram of two waveguide sections in Fig. 6;

Fig. 8 is a schematic diagram of the propagation path of light in one of the second interlayer converters when the distance between the second waveguide layer and the first waveguide layer is relatively long;

FIG. 9 is a schematic top view of the two waveguide sections in FIG. 8 .

Embodiments of the present invention

In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present application.

It should be noted that when a component is referred to as being “fixed on” or “disposed on” another component, it may be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element. The orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. are based on the orientation or positional relationship shown in the drawings, and are for convenience of description only, rather than indicating or implying the referred device Or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the application, and those of ordinary skill in the art can understand the specific meanings of the above terms according to specific situations. The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of technical features. "Plurality" means two or more, unless otherwise clearly and specifically defined.

In order to illustrate the technical solutions provided by the present application, detailed descriptions will be given below in conjunction with specific drawings and embodiments.

Please refer to FIG. 1 and FIG. 2 , some embodiments of the present application provide an optical phased array chip, including a substrate layer 100, a buried oxide layer 200, a first waveguide layer 300, an oxide layer 400, and a second waveguide layer arranged in sequence. layer 500 and upper cladding layer 600. Specifically, the buried oxide layer 200 , the first waveguide layer 300 , the oxide layer 400 , the second waveguide layer 500 and the upper cladding layer 600 are manufactured layer by layer by epitaxial growth technology. It should be noted that the lengths of the second waveguide layer 500 and the first waveguide layer 300 are set according to needs, and are generally shorter than the length of the substrate layer 100. In areas beyond the coverage of the first waveguide layer 300, the oxide layer 400 and the buried oxide layer 200; in the region beyond the coverage of the second waveguide layer 500, the upper cladding layer 600 is connected to the oxide layer 400.

The thermo-optic coefficient of the second waveguide layer 500 is lower than that of the first waveguide layer 300 . A coupler 700, an optical splitter 710, and a transmitting antenna assembly 720 are formed on the second waveguide layer 500; a phase shifter assembly 730 is formed on the first waveguide layer 300; a Two interlayer converter components 800; wherein, the coupler 700 is in signal communication with the optical splitter 710 through the second waveguide layer 500, and the optical splitter 710 is in signal communication with the phase shifter component 730 through one of the interlayer converter components 800, for phase shifting Transmitter component 730 is in signal communication with transmit antenna component 720 through another layer-to-layer converter component 800 .

The transmitting antenna component 720 mentioned here can be a single transmitting antenna 721, and can also be a combination of multiple transmitting antennas 721, which is not limited here; similarly, the phase shifter component 730 can be a single phase shifter 731, or a combination of multiple transmitting antennas 721. It may be a combination of a plurality of phase shifters 731 , which is not limited here. Specifically, the coupler 700, the transmitting antenna assembly 720, the phase shifter assembly 730, and the interlayer converter assembly 800 can be manufactured through a CMOS process after the corresponding waveguide layers are formed. When in use, first connect the output end of the laser 910 to the input end of the coupler 700 through a waveguide, and then the laser 910 sends a light source signal to the coupler 700, and the coupler 700 couples the light source signal to the inside of the optical phased array chip, through the layer The interlayer converter component 800 is delivered to the phase shifter component 730, which changes its phase, and then is transmitted to the transmitting antenna component 720, and the transmitting antenna component 720 transmits the above-mentioned light source signal into free space.

During the process of implementing this application, the inventors found that at least the following problems existed in the prior art:

Due to the frequency modulated continuous wave (Frequency Modulated Continuous Wave (FMCW) technology lacks low-cost frequency-modulated light sources. At present, lidar mainly uses pulsed lidar using Time of Flight (ToF) technology. Silicon-on-insulator waveguides among the above-mentioned waveguide materials are not suitable for transmitting particularly high-power optical signals, which limits the application of time-of-flight technology in optical phased array chips; although silicon nitride waveguides can accommodate large optical power, they are more suitable for The fabrication of optical phased array chips in pulsed lidar, but the power consumption of optical phased array chips made of silicon nitride waveguides is relatively large.

After research, among the waveguide materials used in optical phased array chips, some materials have a strong ability to confine light, and can realize the preparation of highly integrated optical phased array chips, but the process requirements for using these materials to prepare optical phased array chips Generally higher, especially for the transmitting antenna assembly 720, it is difficult to realize a weakly coupled large-aperture antenna with a small comb shape; and some materials have weaker ability to confine light, but can accommodate larger optical power. Materials with strong light confinement ability can produce the transmitting antenna assembly 720 with smaller coupling coefficient and larger aperture under the same process conditions.

In addition, the inventors found during the development process that materials with weak light confinement ability generally have low thermo-optic coefficients, so the heating efficiency of the phase shifter assembly 730 made of these materials is low, which will lead to a large power consumption. Materials with a strong confinement ability to light generally have a higher thermo-optic coefficient, which is conducive to reducing the power consumption of the phase shifter assembly 730, and can realize a high-speed phase shifter assembly 730 by using an ion implantation process, which can greatly improve the optical phase control. The working speed of the array chip.

Based on the above theory, the optical phased array chip provided by this application uses two waveguides with different materials to make two waveguide layers, then avoids the shortcomings of each waveguide layer, and makes full use of its excellent characteristics to make the optical phased array chip Each device in the method is prepared on a more suitable waveguide layer, thereby reducing the process requirements for device manufacturing, so that in the same optical phased array chip, the optical splitter 710 with high process tolerance can also be prepared. The high-efficiency, low-power phase shifter component 730 can also prepare a weakly coupled large-aperture transmitting antenna component 720, and supports a high-power ToF working mode. At the same time, each of the above-mentioned devices can be processed in a silicon base through a CMOS process, so the size of the optical phased array chip can be effectively reduced and the integration degree can be improved.

More specifically, the ability of the second waveguide layer 500 to confine light is weaker than that of the first waveguide layer 300, that is, the size of the functional device realized by the first waveguide layer 300 is larger than that realized by the second waveguide layer 500. Functional devices, that is, the process constraints required by the first waveguide layer 300 are weaker than those required by the second waveguide layer 500 .

In an optional embodiment, the first waveguide layer 300 is a silicon waveguide layer, and the second waveguide layer 500 is a silicon nitride waveguide layer. Among them, the silicon waveguide layer has a strong ability to confine light and has a high thermo-optic coefficient, which is conducive to reducing the power consumption of the phase shifter component 730, and can realize a high-speed phase shifter component 730 by using ion implantation technology, which can greatly improve the performance of the phase shifter component 730. Improve the operating rate of the optical phased array. The confinement of light by the silicon nitride waveguide layer is slightly weaker than that of the silicon waveguide layer, and the antenna made by using this waveguide can produce an antenna with a smaller coupling coefficient and a larger aperture than the silicon waveguide layer under the same process conditions. Moreover, the silicon nitride waveguide material can accommodate large optical power, which is more suitable for the production of optical phased array chips in pulsed laser radar. In addition, these two materials are used in optical phased arrays, and the preparation technology is relatively mature. The optical phased array chip provided by this application is prepared by using these two materials, which is highly practicable.

In the above embodiment, the coupler 700, the optical splitter 710 and the transmitting antenna assembly 720 can be implemented on the silicon nitride waveguide layer, the phase shifter assembly 730 can be implemented on the silicon waveguide layer, and the interlayer converter assembly 800 has silicon waveguide layer and silicon nitride waveguide layer. And since good quality commercial SOI wafers are currently available in the industry, the silicon nitride waveguide layer is generally above the silicon waveguide layer. The silicon nitride waveguide layer can accommodate a large amount of optical power, so it will not affect the function of the coupler 700 , the optical splitter 710 and the transmitting antenna assembly 720 . After being split by the optical splitter 710 , the optical power of each channel is significantly reduced, so the functions of the phase shifter component 730 and the interlayer converter component 800 will not be affected. Of course, in other embodiments, the first waveguide layer 300 and the second waveguide layer 500 may also use other materials, as long as the above functions can be realized.

2 to 5, in one embodiment, the second waveguide layer 500 is divided into a first part 510 and a second part 520 arranged at intervals, a coupler 700 and a splitter 710 are formed on the first part 510, and the transmitting antenna assembly 720 is formed on the second portion. This can not only reduce the material required for the second waveguide layer 500, but also prevent the signal from the optical splitter 710 from directly entering the transmitting antenna assembly 720 without passing through the phase shifter assembly 730, thereby ensuring the stability of the optical phased array chip's working performance.

The above-mentioned first waveguide layer 300 is located between the first part 510 and the second part 520, and one end of the first waveguide layer 300 is in signal communication with the corresponding end of the first part 510 through one of the interlayer converter components 800, the first waveguide The other end of the layer 300 is in signal communication with the corresponding end of the second part 520 through another interlayer converter assembly 800 . Specifically, the phase shifter component 730 is disposed in the middle of the first waveguide layer 300, the input end is in signal communication with the output end of the optical splitter 710 through one of the interlayer converter components 800, and the output end is through another interlayer converter component 800 Communicate with the input of the transmit antenna assembly 720 . The entire optical phased array chip has a compact structure and meets its manufacturing requirements.

Both ends of the first waveguide layer 300 are respectively stacked with corresponding ends of the two parts of the second waveguide layer 500 . In this way, the volume of the interlayer converter assembly 800 is the smallest, and the structure of the entire optical phased array chip is compact, meeting its manufacturing requirements.

Optical splitter 710 has multiple signal output terminals. The phase shifter component 730 includes a plurality of phase shifters 731 connected to a plurality of signal output ends of the optical splitter in a one-to-one correspondence. The transmitting antenna assembly 720 includes a plurality of transmitting antennas 721 communicating with a plurality of phase shifters in one-to-one correspondence. Specifically, a plurality of phase shifters 731 and a plurality of transmitting antennas 721 can be respectively arranged in an array to realize their regular arrangement and meet the miniaturization design requirement of an optical phased array chip.

Referring to FIG. 2 to FIG. 5 , in one embodiment, the signal output end of the first part 510 has a plurality of first waveguide segments 511 corresponding to the plurality of signal output ends of the optical splitter 710 . The second part 520 includes a plurality of second waveguide segments 521 arranged in sequence, and the plurality of second waveguide segments 521 are arranged in one-to-one correspondence with the plurality of first waveguide segments 511 . Each second waveguide segment 521 is provided with a transmitting antenna 721 . The first waveguide layer 300 includes a plurality of third waveguide segments 310 arranged in sequence, and the plurality of third waveguide segments 310 are arranged in one-to-one correspondence with the plurality of first waveguide segments 511 . Each third waveguide segment 310 is provided with a phase shifter 731 .

One of the interlayer converter components 800 includes a plurality of first interlayer converters 810 disposed between the plurality of third waveguide segments 310 and the plurality of first waveguide segments 511 in one-to-one correspondence. Another interlayer converter assembly 800 includes a plurality of second interlayer converters 820 disposed between the plurality of third waveguide segments 310 and the plurality of first waveguide segments 511 in one-to-one correspondence.

That is, the optical phased array chip provided by this application is provided with a plurality of first interlayer converters 810, a plurality of second interlayer converters 820, a plurality of phase shifters 731, and a plurality of transmitting antennas 721, wherein the first layer The numbers of inter-converters 810, second-layer inter-converters 820, phase shifters 731, and transmit antennas 721 are the same. And each device is installed on the corresponding waveguide section one by one, so that the optical signal can be transmitted to each transmitting antenna 721 along a single path after being split by the optical splitter 710, and then transmitted to the free space by the transmitting antenna 721. The functions of each device in this embodiment are as follows: the coupler 700 is used to couple the light in the laser 910 to the inside of the optical phased array chip, and the output end is connected to the input end of the optical splitter 710 . The optical splitter 710 is used to equally distribute the optical signal to each input port of the first inter-layer switch 810 . The first interlayer converter 810 is used to realize the conversion of the optical signal from the first waveguide layer 300 to the second waveguide layer 500; the phase shifter 731 is used to change the phase of the optical signal, so that the adjacent phases of the optical signals in each channel The difference is kept fixed, and the output signal will enter the input of the interlayer converter. The second interlayer converter 820 is used to convert the optical signal from the second waveguide layer 500 to the first waveguide layer 300 , and the output signal will enter the input end of the transmitting antenna 721 . The transmitting antenna 721 is used to transmit the optical signals in each channel to free space.

The optical phased array chip provided by this embodiment can realize signal transmission between corresponding devices by means of each waveguide section in the waveguide layer, without adding additional signal transmission structures, so that the overall structure of the optical phased array chip is compact and facilitates its miniaturization preparation.

Based on the existing chip manufacturing process, there are generally two situations for the vertical distance between the second waveguide layer 500 and the first waveguide layer 300: one situation is that the distance between the two waveguide layers is relatively close, and the vertical distance between the two waveguide layers is The spacing is within the range of greater than 50nm and less than 400nm; in another case, the distance between the two waveguide layers is relatively long, and the vertical spacing between them is within the range of greater than 1 μm and less than 4 μm. For these two cases, the structures of the first inter-layer converter 810 and the second inter-layer converter 820 will also change accordingly.

Specifically, please refer to FIG. 6 and FIG. 7, when the vertical distance between the second waveguide layer 500 and the first waveguide layer 300 is greater than 50nm and less than 400nm, the distance between the first waveguide layer 300 and the second waveguide layer 500 is relatively close. Generally speaking, there is a relatively thin oxide layer 400 between the two layers, so that the optical signals in the two waveguide layers located in the same interlayer converter can achieve interlayer conversion through evanescent wave coupling. In this embodiment, both the first interlayer converter 810 and the second interlayer converter 820 can use any type of interlayer converter that can realize evanescent wave coupling, and the first interlayer converter located on the same waveguide segment 810 and the second inter-layer converter 820 may adopt the same model or different models, which are not limited here.

Please refer to FIG. 6 and FIG. 7, in an optional embodiment, the first waveguide section 511 and the third waveguide section 310 are located in the first interlayer converter 810, and the second waveguide section 521 and the third waveguide section The portion of the segment 310 located in the second inter-layer transition 820 is tapered. Both the first interlayer converter 810 and the second interlayer converter 820 are tapered waveguide mode converters. Specifically, the optical path directions of the two tapered mode converters located on the same third waveguide segment 310 are opposite, and the optical path direction of the tapered mode converter located at the input end is converted from the second waveguide layer 500 to the first waveguide layer 300 , the optical path direction of the tapered mode converter at the output end is converted from the first waveguide layer 300 to the second waveguide layer 500 .

The mode effective refractive index of light in the first waveguide layer 300 decreases as the width decreases, while the mode effective refractive index in the second waveguide layer 500 increases as the width increases, so as long as the two tapered waveguide modes are reasonably designed The width of both sides of the converter can make the mode effective refractive index in the first waveguide layer 300 equal to the mode effective refractive index of the second waveguide layer 500 at a certain position, so as long as the length of the tapered waveguide mode converter is sufficient Long, the light can be slowly converted from the first waveguide layer 300 to the second waveguide layer 500 . The whole conversion process is stable and the technology is mature.

Please refer to FIG. 8 and FIG. 9, when the vertical distance between the second waveguide layer 500 and the first waveguide layer 300 is greater than 1 μm and less than 4 μm, the distance between the first waveguide layer 300 and the second waveguide layer 500 is relatively far, generally It is said that there will be a relatively thick oxide layer 400 between the two layers. In this way, in each interlayer converter, the light in the first waveguide layer 300 will not undergo evanescent wave coupling with the light in the second waveguide layer 500 , which is realized by using two layers of gratings here. Specifically, the first waveguide segment 511 and the third waveguide segment 310 are located in the first interlayer converter 810, and the second waveguide segment 521 and the third waveguide segment 310 are located in the second interlayer converter 820. A grating structure 900 is formed on them. The optical signals in two oppositely arranged waveguide sections in the same interlayer converter can realize interlayer conversion through the grating structure 900 .

Specifically, the above-mentioned grating structure 900 can be manufactured on a corresponding waveguide segment by using an etching process. The arrangement of the grating structure 900 destroys the original waveguide structure, so that light can be emitted or received along a certain direction. During manufacture, the upward or downward emission angle θ of the grating structure 900 can be changed by changing the grating period and duty cycle. Similarly, the angle θ received by the grating structure 900 from below or from above can be changed by changing the grating period and duty cycle of the grating structure 900 . The above-mentioned angle θ can be calculated by simulation software before preparing the grating structure 900, so as to ensure that the prepared grating structure 900 meets the requirements, so that the optical signal can pass through the two oppositely arranged grating structures 900 to realize the gap between the two waveguide segments. transition between layers. In this way, the light entering the second waveguide layer 500 through the coupler 700 can be transmitted to the grating structure 900 on the third waveguide section 310 through the optical splitter 710 and then received by the grating structure 900 on the first waveguide section 511. , and then enter another grating structure 900 on it through the third waveguide section 310, and transmit through the grating structure 900 to the grating structure 900 on the second waveguide section 521, and after being received by it, transmit through the second waveguide section 521 to the transmitting antenna 721, and finally transmitted to free space through the transmitting antenna 721.

The above-mentioned grating structure 900 is arranged in a fan shape to achieve a wider range of signal reception and transmission, ensuring that no signal loss occurs when the optical signal is converted from one waveguide segment to another waveguide segment, or the signal loss is minimized.

During the above optical signal transmission process, the light emitting angle or the light receiving angle of the grating structure 900 is 0-90°. The specific angle can be determined according to the material and manufacturing process of the first waveguide layer 300 , the second waveguide layer 500 , and the corresponding interlayer converters, and there is no unique limitation here.

In some embodiments, the light emitting angle or the light receiving angle of the grating structure 900 is 0-60°. With this angle range, the range of optional materials is wider.

Please refer to FIG. 1. In another embodiment of the present application, a laser radar is provided, including a laser radar transmitting system, a receiving system, and a signal processing system. The laser radar transmitting system includes a laser 910 and any of the above-mentioned embodiments. Optical Phased Array Chip. Specifically, the laser 910 adopts an external laser 910 module. The laser 910 is used to generate the light source signal of the optical phased array chip, and the output end is connected with the input end of the coupler 700 .

The lidar provided in the embodiments of the present application includes the optical phased array chip provided in the above embodiments. The optical phased array chip has the same structural features and functions as the optical phased array chip in the above embodiments, and details are not described here.

The above are only optional embodiments of the application, and are not intended to limit the application. For those skilled in the art, various modifications and changes may occur in this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of the claims of the present application.

Claims

The optical phased array chip is characterized in that it includes a substrate layer, a buried oxide layer, a first waveguide layer, an oxide layer, a second waveguide layer, and an upper cladding layer arranged in sequence; wherein, the thermo-optic coefficient of the second waveguide layer lower than the thermo-optic coefficient of the first waveguide layer;

A coupler, an optical splitter, and a transmitting antenna assembly are formed on the second waveguide layer; a phase shifter assembly is formed on the first waveguide layer; a two interlayer converter assemblies; wherein the coupler is in signal communication with the optical splitter through the second waveguide layer, and the optical splitter is in signal communication with the phase shifter assembly through one of the interlayer converter assemblies signal communication, and the phase shifter component is in signal communication with the transmitting antenna component through another interlayer converter component.
The optical phased array chip according to claim 1, wherein the second waveguide layer is divided into a first part and a second part arranged at intervals, and the coupler and the optical splitter are formed in the first part On, the transmitting antenna assembly is formed on the second part.
The optical phased array chip according to claim 2, wherein the first waveguide layer is located between the first part and the second part, and one end of the first waveguide layer passes through one of the The interlayer transducer assembly is in signal communication with a corresponding end of the first portion, and the other end of the first waveguide layer is in signal communication with a corresponding end of the second portion through another of the interlayer transducer assemblies .
The optical phased array chip according to claim 3, wherein the two ends of the first waveguide layer are respectively stacked with the corresponding ends of the two parts in the second waveguide layer.
The optical phased array chip according to any one of claims 2-4, wherein the optical splitter has a plurality of signal output terminals;

The phase shifter assembly includes a plurality of phase shifters communicated with a plurality of signal output ends of the optical splitter in one-to-one correspondence;

The transmitting antenna assembly includes a plurality of transmitting antennas in one-to-one communication with the plurality of phase shifters.
The optical phased array chip according to claim 5, wherein the signal output end of the first part has a plurality of first waveguide sections corresponding one-to-one to the plurality of signal output ends of the optical splitter;

The second part includes a plurality of second waveguide sections arranged in sequence, and the plurality of second waveguide sections are set in one-to-one correspondence with the plurality of first waveguide sections; each of the second waveguide sections is provided with a said transmit antenna;

The first waveguide layer includes a plurality of third waveguide sections arranged in sequence, and the plurality of third waveguide sections are set in one-to-one correspondence with the plurality of first waveguide sections; each of the third waveguide sections is provided with a said phase shifter;

One of the interlayer converter assemblies includes a plurality of first interlayer converters disposed between the plurality of third waveguide segments and the plurality of first waveguide segments in one-to-one correspondence;

Another interlayer converter assembly includes a plurality of second interlayer converters disposed between the plurality of third waveguide segments and the plurality of first waveguide segments in one-to-one correspondence.
The optical phased array chip according to claim 6, wherein when the vertical distance between the second waveguide layer and the first waveguide layer is greater than 50nm and less than 400nm, the switches located in the same interlayer Optical signals in the two waveguide layers can be converted between layers through evanescent wave coupling.
The optical phased array chip according to claim 7, wherein the first waveguide section and the third waveguide section are located in the first interlayer converter, and the second waveguide section Both the portion of the third waveguide segment and the third waveguide segment located in the second interlayer converter are tapered; the first interlayer converter and the second interlayer converter are both tapered waveguide mode converters.
The optical phased array chip according to claim 6, wherein when the vertical distance between the second waveguide layer and the first waveguide layer is greater than 1 μm and less than 4 μm, the first waveguide section and the A grating structure is formed on the part of the third waveguide segment located in the first interlayer converter, and the part of the second waveguide segment and the third waveguide segment located in the second interlayer converter ; Optical signals in two opposite waveguide segments located in the same interlayer converter can realize interlayer conversion through the grating structure.
The optical phased array chip according to claim 9, wherein the grating structure is fan-shaped.
The optical phased array chip according to claim 9, wherein the light emitting angle or the light receiving angle of the grating structure is 0-90°.
The optical phased array chip according to claim 9, wherein the light emitting angle or the light receiving angle of the grating structure is 0-60°.
The optical phased array chip according to any one of claims 1-4, wherein the first waveguide layer is a silicon waveguide layer, and the second waveguide layer is a silicon nitride waveguide layer.
The laser radar includes a laser radar transmitting system, a receiving system and a signal processing system, wherein the laser radar transmitting system comprises a laser and the optical phased array chip according to any one of claims 1-13.