Using common chirp periods in generating lidar data

Abstract

A LIDAR system is configured to output a system output signal that travels away from the LIDAR system and is reflectable by objects located outside the LIDAR system. The system output signal has a frequency versus time pattern of a repetition period. Each cycle of the frequency versus time pattern includes a plurality of data segments configured such that the system output signal is chirped differently in different data segments. The LIDAR system also includes electronics configured to generate a plurality of different LIDAR data sets. Each LIDAR data set is indicative of a radial velocity and / or separation between the LIDAR system and one or more of the objects located outside the LIDAR system. Each LIDAR data set is generated from light included in the system output signal during a group of the plurality of data segments. The group of data segments includes one or more common data segments that are each included in two or more different groups of data segments.

Description

[0001] Related applications This application is a continuation-into-file of U.S. Patent Application No. 16 / 867,537, filed May 5, 2020, entitled “Using Public Chirped Periods in Generating LiDAR Data,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to optical devices. In particular, this invention relates to LIDAR systems. Background Technology

[0003] The performance requirements for LiDAR systems are constantly increasing as these systems support an increasing number of applications. A LiDAR system typically generates LiDAR data for a series of sampling zones, each illuminated sequentially by the system's output signal. The LiDAR data for each sampling zone indicates the radial velocity and / or distance between the LiDAR system and one or more objects located within that zone. A LiDAR system can scan the system's output signals from multiple different sampling zones. These sampling zones can be stitched together to form the LiDAR system's field of view. As a result, LiDAR data from different sampling zones provides LiDAR data for objects within that field of view.

[0004] Increasing the rate at which LiDAR data can be generated for different sampling areas can increase the frequency at which the field of view can be scanned and / or increase the resolution of the field of view. Consequently, increasing the LiDAR data generation rate increases the number of situations in which the LiDAR system can be successfully applied. However, increasing the LiDAR data generation rate typically increases the complexity and / or cost of the LiDAR system. Therefore, improved LiDAR systems are needed. Summary of the Invention

[0005] A LiDAR system includes one or more optical components configured to output a system output signal that travels away from the LiDAR system and can be reflected by objects located outside the LiDAR system. The system output signal has a repetitive frequency-to-time pattern. Each period of the frequency-to-time pattern includes multiple data segments configured such that the system output signal is chirped differently during the different data segments. The LiDAR system also includes electronics configured to generate multiple different LiDAR datasets. Each LiDAR dataset indicates the radial velocity and / or separation between the LiDAR system and one or more objects located outside the LiDAR system. Each LiDAR dataset is generated during a set of multiple data segments based on light included in the system output signal. All or part of the data segment group includes one or more common data segments, which are all included in two or more different data segment groups.

[0006] A method of operating a LiDAR system includes outputting a system output signal from the LiDAR system such that the system output signal travels away from the LiDAR system and can be reflected by an object located outside the LiDAR system. The system output signal has a repetitive frequency-to-time pattern. Each period of the frequency-to-time pattern comprises multiple data segments configured to chirp the system output signal differently during the different data segments. The method also includes generating multiple different LiDAR datasets. Each LiDAR dataset indicates the radial velocity and / or separation between the LiDAR system and one or more objects located outside the LiDAR system. Each LiDAR dataset is generated based on light included in the system output signal during a set of multiple data segments. The data segment group includes one or more common data segments, each of which is included in two or more different data segment groups. Attached Figure Description

[0007] Figure 1A It is a schematic top view of a LIDAR system including or composed of LIDAR chips, wherein the LIDAR chips output LIDAR output signals and receive LIDAR input signals on a common waveguide.

[0008] Figure 1B It is a schematic top view of a LIDAR system including or composed of LIDAR chips, wherein the LIDAR chips output LIDAR output signals and receive LIDAR input signals on different waveguides.

[0009] Figure 1C This is a schematic top view of another embodiment of a LIDAR system, which includes or is composed of LIDAR chips, the LIDAR chips outputting LIDAR output signals on different waveguides and receiving multiple LIDAR input signals.

[0010] Figure 2 It is suitable for and Figure 1B A top view of an example of a LiDAR adapter used with a LiDAR chip.

[0011] Figure 3 It is suitable for and Figure 1C A top view of an example of a LiDAR adapter used with a LiDAR chip.

[0012] Figure 4 Included in public support components Figure 1A LIDAR chip and Figure 2A top view of an example of a LiDAR system with a LiDAR adapter.

[0013] Figure 5A An example of a processing component suitable for use with a LIDAR system is shown.

[0014] Figure 5B Provide suitable and according to Figure 5A A schematic diagram of an electronic device used in conjunction with the constructed processing components.

[0015] Figure 5C It is a graph of the frequency of the system output signal versus time.

[0016] Figure 5D It is another graph of the frequency of the system output signal versus time.

[0017] Figure 5E It is another graph of the frequency of the system output signal versus time.

[0018] Figure 5F It is another graph of the frequency of the system output signal versus time.

[0019] Figure 6 This is a cross-sectional view of a portion of a LiDAR chip that includes a waveguide on a silicon-on-insulator platform. Detailed Implementation

[0020] A LIDAR system outputs a system output signal that sequentially illuminates a series of sampling areas. During the illumination of the sampling areas, the system output signal can be reflected by one or more objects located within the sampling areas. The system is configured to receive at least a portion of the reflected light. The system includes electronics that use the reflected light to generate multiple LIDAR datasets, each indicating the radial velocity and / or distance between the LIDAR system and an object located within the illuminated sampling area.

[0021] The system output signal has a frequency-to-time pattern with repetitive periods. Each period comprises multiple data segments configured to chirp the system output signal differently during the different data segments. Each LIDAR dataset is generated based on light included in the system output signal over a set of multiple data segments. Different data segment groups may include common data segments, all of which are contained within two or more different data segment groups. Therefore, a single data segment can be used to generate LIDAR data for two or more different sampling areas.

[0022] The ability to use a single data period to generate LiDAR data for two or more different sampling areas reduces the total time required to generate LiDAR for these sampling areas. Therefore, the LiDAR data generation rate is increased. Furthermore, using a single data period to generate LiDAR data for multiple sampling areas can be accomplished with fundamental modifications to existing electronics. Thus, an increased LiDAR generation rate can be achieved without a substantial increase in the cost or complexity of a LiDAR-less system.

[0023] Figure 1A This is a schematic top view of a LIDAR chip, which may serve as a LIDAR system or may be included in a LIDAR system that includes components other than the LIDAR chip. The LIDAR chip may include a photonic integrated circuit (PIC) and may be a photonic integrated circuit chip. The LIDAR chip includes a light source 4 that outputs a primary LIDAR signal. Suitable light sources 4 include, but are not limited to, semiconductor lasers, such as external cavity lasers (ECLs), distributed feedback lasers (DFBs), discrete mode (DM) lasers, and distributed Bragg reflector lasers (DBRs).

[0024] The LIDAR chip includes a utility waveguide 12 that receives the output LIDAR signal from the light source 4. The utility waveguide 12 terminates in a facet 14 and carries the output LIDAR signal to the facet 14. The facet 14 can be positioned such that the output LIDAR signal traveling through the facet 14 leaves the LIDAR chip and is used as a LIDAR output signal. For example, the facet 14 can be located at the edge of the chip, such that the output LIDAR signal traveling through the facet 14 leaves the chip and is used as a LIDAR output signal. In some cases, the portion of the LIDAR output signal that has left the LIDAR chip can also be considered the system output signal. As an example, when the LIDAR output signal leaving the LIDAR chip also means the LIDAR output signal leaving the LIDAR system, the LIDAR output signal can also be considered the system output signal.

[0025] The LIDAR output signal travels away from the LIDAR system through free space in the atmosphere. The LIDAR output signal can be reflected by one or more objects in its path. When the LIDAR output signal is reflected, at least a portion of the reflected light travels back towards the LIDAR chip as the LIDAR input signal. In some cases, the LIDAR input signal can also be considered the system echo signal. As an example, when the LIDAR output signal leaves the LIDAR chip (which is also when the LIDAR output signal leaves the LIDAR system), the LIDAR input signal can also be considered the system echo signal.

[0026] The LIDAR input signal can enter the practical waveguide 12 through the facet 14. The portion of the LIDAR input signal entering the practical waveguide 12 serves as the incoming LIDAR signal. The practical waveguide 12 carries the incoming LIDAR signal to the splitter 16, which moves a portion of the outgoing LIDAR signal from the practical waveguide 12 as a comparison signal to the comparison waveguide 18. The comparison waveguide 18 carries the comparison signal to the processing component 22 for further processing. Although... Figure 1A A directional coupler operating as splitter 16 is shown, but other signal tapping components can be used as splitter 16. Suitable splitters 16 include, but are not limited to, directional couplers, optical couplers, Y-junctions, tapered couplers, and multimode interference (MMI) devices.

[0027] The utility waveguide 12 also carries the output LIDAR signal to the splitter 16. The splitter 16 moves a portion of the output LIDAR signal from the utility waveguide 12 to the reference waveguide 20 as a reference signal. The reference waveguide 20 carries the reference signal to the processing component 22 for further processing.

[0028] The percentage of light transmitted from the practical waveguide 12 by the splitter 16 can be fixed or substantially fixed. For example, the splitter 16 can be configured such that the power of the reference signal transmitted to the reference waveguide 20 is an outgoing percentage of the power of the outgoing LIDAR signal, or that the power of the comparison signal transmitted to the comparison waveguide 18 is an incoming percentage of the power of the incoming LIDAR signal. In many splitters 16, such as directional couplers and multimode interferometers (MMIs), the outgoing percentage is equal to or substantially equal to the incoming percentage. In some cases, the outgoing percentage is greater than 30%, 40%, or 49% and / or less than 51%, 60%, or 70% and / or the incoming percentage is greater than 30%, 40%, or 49% and / or less than 51%, 60%, or 70%. Splitters 16 such as multimode interferometers (MMIs) typically provide 50% or approximately 50% outgoing and incoming percentages. However, multimode interferometers (MMIs) can be more easily fabricated in platforms such as silicon-on-insulator platforms than some alternatives. In one example, the separator 16 is a multimode interferometer (MMI), and the outgoing and incoming percentages are 50% or substantially 50%. As will be described in more detail below, the processing component 22 combines the comparison signal with the reference signal to form a composite signal carrying the LIDAR data of the sampled area in the field of view. This composite signal can then be processed to extract the LIDAR data of the sampled area (radial velocity and / or distance between the LIDAR system and objects outside the LIDAR system).

[0029] The LIDAR chip may include a control branch for controlling the operation of the light source 4. This control branch includes a splitter 26 that moves a portion of the outgoing LIDAR signal from the utility waveguide 12 to the control waveguide 28. The coupled portion of the outgoing LIDAR signal serves as a tap signal. Although Figure 1A A directional coupler operating as splitter 26 is shown, but other signal tapping components can be used as splitter 26. Suitable splitters 26 include, but are not limited to, directional couplers, optical couplers, Y-junctions, tapered couplers, and multimode interference (MMI) devices.

[0030] Control waveguide 28 carries the tap signal to control assembly 30. The control assembly can be electrically communicated with electronics 32. All or part of the control assembly may be included in electronics 32. During operation, the electronics can utilize the output from control assembly 30 in a control loop configured to control process variables of one, two, or three loop-controlled optical signals selected from the group consisting of tap signals, system output signals, and outgoing LIDAR signals. Examples of suitable process variables include the frequency and / or phase of the loop-controlled optical signals.

[0031] A LIDAR system can be modified so that the incoming and outgoing LIDAR signals can be carried on different waveguides. For example, Figure 1B yes Figure 1A A top view of the LIDAR chip, modified to carry incoming and outgoing LIDAR signals on different waveguides. The outgoing LIDAR signal leaves the LIDAR chip via facet 14 and is used as the LIDAR output signal. When light from the LIDAR output signal is reflected by an object outside the LIDAR system, at least a portion of the reflected light returns to the LIDAR chip as a first LIDAR input signal. The first LIDAR input signal enters the comparison waveguide 18 via facet 35 and is used as a comparison signal. The comparison waveguide 18 carries the comparison signal to the processing component 22 for further processing. Figure 1A As described in the context, reference waveguide 20 carries a reference signal to processing component 22 for further processing. As will be described in more detail below, processing component 22 combines the comparison signal with the reference signal to form a composite signal carrying LIDAR data from the sampled area of ​​the field of view.

[0032] A LIDAR chip can be modified to receive multiple LIDAR input signals. For example, Figure 1C The diagram shows a device modified to receive two LiDAR input signals. Figure 1BThe splitter 40 is configured to place a portion of the reference signal carried on the reference waveguide 20 onto a first reference waveguide 42 and another portion of the reference signal onto a second reference waveguide 44. Thus, the first reference waveguide 42 carries the first reference signal, and the second reference waveguide 44 carries the second reference signal. The first reference waveguide 42 carries the first reference signal to a first processing component 46, and the second reference waveguide 44 carries the second reference signal to a second processing component 48. Examples of suitable splitters 40 include, but are not limited to, Y-junctions, optical couplers, and multimode interference couplers (MMIs).

[0033] The emitted LIDAR signal leaves the LIDAR chip via facet 14 and is used as the LIDAR output signal. When light from the LIDAR output signal is reflected by one or more objects located outside the LIDAR system, at least a portion of the reflected light returns to the LIDAR chip as a first LIDAR input signal. The first LIDAR input signal enters the comparison waveguide 18 via facet 35 and is used as a first comparison signal. The comparison waveguide 18 carries the first comparison signal to the first processing component 46 for further processing.

[0034] Additionally, when light from the LIDAR output signal is reflected by one or more objects located outside the LIDAR system, at least a portion of the reflected signal returns to the LIDAR chip as a second LIDAR input signal. This second LIDAR input signal enters the second comparison waveguide 50 via the facet 52 and is used as a second comparison signal carried by the second comparison waveguide 50. The second comparison waveguide 50 then carries the second comparison signal to the second processing component 48 for further processing.

[0035] Although the light source 4 is shown as being located on the LIDAR chip, it can be located outside the LIDAR chip. For example, the utility waveguide 12 can terminate at a second small plane through which the emitted LIDAR signal can enter the utility waveguide 12 from the light source 4 located outside the LIDAR chip.

[0036] In some cases, according to Figure 1B or Figure 1CThe constructed LIDAR chip is used in conjunction with a LIDAR adapter. In some cases, the LIDAR adapter may be physically and optically positioned between the LIDAR chip and one or more reflective objects and / or the field of view, wherein the optical path of(multiple) first LIDAR input signals and / or LIDAR output signals from the LIDAR chip to the field of view passes through the LIDAR adapter. Alternatively, the LIDAR adapter may be configured to operate the first LIDAR input signals and LIDAR output signals such that they travel on different optical paths between the LIDAR adapter and the LIDAR chip, but on the same optical path between the LIDAR adapter and a reflective object in the field of view.

[0037] Figure 2 The text shows what is suitable for use with... Figure 1B An example of a LIDAR adapter used with a LIDAR chip. The LIDAR adapter includes multiple components located on a base. For example, the LIDAR adapter includes a circulator 100 located on base 102. The illustrated optical circulator 100 includes three ports and is configured to allow light entering one port to exit from the next port. For example, the illustrated optical circulator includes a first port 104, a second port 106, and a third port 108. The LIDAR output signal enters from the utility waveguide 12 of the LIDAR chip at the first port 104 and exits at the second port 106.

[0038] The LIDAR adapter can be configured such that the output of the LIDAR output signal from the second port 106 can also be used as the output of the LIDAR output signal from the LIDAR adapter and therefore from the LIDAR system. As a result, the LIDAR output signal can be output from the LIDAR adapter, allowing the LIDAR output signal to travel towards the sampling area in the field of view. Therefore, in some cases, the portion of the LIDAR output signal that has left the LIDAR adapter can also be considered the system output signal. As an example, when the departure of the LIDAR output signal from the LIDAR adapter is also the departure of the LIDAR output signal from the LIDAR system, the LIDAR output signal can also be considered the system output signal.

[0039] The LIDAR output signal from the LIDAR adapter includes light from the LIDAR output signal received from the LIDAR chip, light composed of light from the LIDAR output signal received from the LIDAR chip, or light substantially composed of light from the LIDAR output signal received from the LIDAR chip. Therefore, the LIDAR output signal from the LIDAR adapter can be the same as or substantially the same as the LIDAR output signal received from the LIDAR chip. However, there may be differences between the LIDAR output signal from the LIDAR adapter and the LIDAR output signal received from the LIDAR chip. For example, the LIDAR output signal may experience optical loss as it travels through the LIDAR adapter, and / or the LIDAR adapter may optionally include an amplifier configured to amplify the LIDAR output signal as it travels through the LIDAR adapter.

[0040] When one or more objects in the sampling area reflect the LIDAR output signal, at least a portion of the reflected light travels back to the circulator 100 as a system echo signal. The system echo signal enters the circulator 100 through the second port 106. Figure 2 The image shows the LIDAR output signal and the system echo signal traveling along the same optical path between the LIDAR adapter and the sampling area.

[0041] The system echo signal leaves the circulator 100 through the third port 108 and is guided to the comparison waveguide 18 on the LIDAR chip. Therefore, all or part of the system echo signal can serve as the first LIDAR input signal, and the first LIDAR input signal includes light from the system echo signal or is composed of light from the system echo signal. Thus, the LIDAR output signal and the first LIDAR input signal travel along different optical paths between the LIDAR adapter and the LIDAR chip.

[0042] from Figure 2 It is clear that, in addition to the circulator 100, the LIDAR adapter may also include optical components. For example, the LIDAR adapter may include components for guiding and controlling the optical path of the LIDAR output signal and the system echo signal. As an example, Figure 2 The adapter includes an optional amplifier 110, which is positioned to receive and amplify the LIDAR output signal before it enters the circulator 100. The amplifier 110 can be operated by the electronics 32, thereby allowing the electronics 32 to control the power of the LIDAR output signal.

[0043] Figure 2A LiDAR adapter including an optional first lens 112 and an optional second lens 114 is also shown. The first lens 112 can be configured to couple the LiDAR output signal to a desired location. In some cases, the first lens 112 is configured to focus or collimate the LiDAR output signal at the desired location. In one example, the first lens 112 is configured to couple the LiDAR output signal to a first port 104 when the LiDAR adapter does not include amplifier 110. As another example, when the LiDAR adapter includes amplifier 110, the first lens 112 can be configured to couple the LiDAR output signal at the input port to amplifier 110. The second lens 114 can be configured to couple the LiDAR output signal to a desired location. In some cases, the second lens 114 is configured to focus or collimate the LiDAR output signal at the desired location. For example, the second lens 114 can be configured to couple the LiDAR output signal to a small plane 35 of the comparison waveguide 18.

[0044] A LIDAR adapter may also include one or more reversing components, such as a reflector. Figure 2 A LiDAR adapter is shown, which includes a mirror as a reversing component 116 that redirects the system echo signal from the circulator 100 to a small plane 20 of the comparison waveguide 18.

[0045] The LIDAR chip includes one or more waveguides that constrain the optical path of one or more optical signals. While the LIDAR adapter may include waveguides, the optical paths of the system echo signal and LIDAR output signal traveling between components on the LIDAR adapter and / or between the LIDAR chip and components on the LIDAR adapter can be in free space. For example, when traveling between different components on the LIDAR adapter and / or between components on the LIDAR adapter and the LIDAR chip, the system echo signal and / or LIDAR output signal can travel through the atmosphere in which the LIDAR chip, LIDAR adapter, and / or base 102 are located. As a result, optical components such as lenses and reversing components can be used to control the characteristics of the optical paths of the system echo signal and LIDAR output signal traveling on, to, and from the LIDAR adapter.

[0046] Suitable base 102 for a LIDAR adapter includes, but is not limited to, substrates, platforms, and boards. Suitable substrates include, but are not limited to, glass, silicon, and ceramic. These components may be discrete components attached to the substrate. Suitable techniques for attaching discrete components to base 102 include, but are not limited to, epoxy resins, solders, and mechanical clamping. In one example, one or more components are integrated components, and the remaining components are discrete components. In another example, the LIDAR adapter includes one or more integrated amplifiers, and the remaining components are discrete components.

[0047] LiDAR systems can be configured to compensate for polarization. Light from a laser source is typically linearly polarized, and therefore the LiDAR output signal is also typically linearly polarized. Reflection from an object can alter the polarization angle of the returning light. Therefore, the system echo signal can include light in different linear polarization states. For example, a first portion of the system echo signal may include light in a first linear polarization state, and a second portion may include light in a second linear polarization state. The intensity of the resulting composite signal is proportional to the square of the cosine of the angle between the polarization fields of the comparison and reference signals. If the angle is 90 degrees, LiDAR data may be lost in the resulting composite signal. However, LiDAR systems can be modified to compensate for changes in the polarization state of the LiDAR output signal.

[0048] Figure 3 It shows Figure 3 The LIDAR system was modified to adapt the LIDAR adapter to... Figure 1C It is used in conjunction with a LIDAR chip. The LIDAR adapter includes a beamsplitter 120 that receives the system echo signal from the circulator 100. The beamsplitter 120 splits the system echo signal into a first part and a second part of the system echo signal. Suitable beamsplitters include, but are not limited to, Wollaston prisms and MEMS-based beamsplitters.

[0049] The first portion of the system echo signal is guided to the comparison waveguide 18 on the LIDAR chip and used as a reference for... Figure 1C The first LIDAR input signal is described in the context of the above. A second portion of the system echo signal is directed to polarization rotator 122. Polarization rotator 122 outputs a second LIDAR input signal, which is directed to a second input waveguide 76 on the LIDAR chip and used as a second LIDAR input signal.

[0050] Beam splitter 120 can be a polarization beam splitter. An example of a polarization beam splitter is configured such that a first portion of the system echo signal has a first polarization state but does not have, or substantially does not have, a second polarization state, and a second portion of the system echo signal has a second polarization state but does not have, or substantially does not have, the first polarization state. The first and second polarization states can be linear polarization states, and the second polarization state is different from the first polarization state. For example, the first polarization state can be TE and the second polarization state can be TM, or the first polarization state can be TM and the second polarization state can be TE. In some cases, the laser source can be linearly polarized, such that the LIDAR output signal has a first polarization state. Suitable beam splitters include, but are not limited to, Wollaston prisms and MEM-based polarization beam splitters.

[0051] A polarization rotator can be configured to change the polarization state of a first portion and / or a second portion of the system echo signal. For example, Figure 3 The polarization rotator 122 shown can be configured to change the polarization state of a second portion of the system echo signal from a second polarization state to a first polarization state. As a result, the second LIDAR input signal has the first polarization state but does not have, or substantially does not have, the second polarization state. Therefore, both the first and second LIDAR input signals have the same polarization state (the first polarization state in this example). Although carrying light with the same polarization state, the first and second LIDAR input signals are associated with different polarization states due to the use of a polarization beamsplitter. For example, the first LIDAR input signal carries light reflected in the first polarization state, and the second LIDAR input signal carries light reflected in the second polarization state. As a result, the first LIDAR input signal is associated with the first polarization state, and the second LIDAR input signal is associated with the second polarization state.

[0052] Since the first LIDAR input signal and the second LIDAR carry light with the same polarization state, the comparison signal obtained from the first LIDAR input signal has the same polarization angle as the comparison signal obtained from the second LIDAR input signal.

[0053] Suitable polarization rotators include, but are not limited to, polarization-preserving fiber rotation, Faraday rotators, half-wave plates, MEM-based polarization rotators and integrated optical polarization rotators using asymmetric y-branching, Mach-Zehnder interferometers and multimode interference couplers.

[0054] Because the transmitted LIDAR signal is linearly polarized, the first reference signal can have the same linear polarization state as the second reference signal. Furthermore, components on the LIDAR adapter can be selected to ensure that the first reference signal, the second reference signal, the comparison signal, and the second comparison signal all have the same polarization state. Figure 3In the examples disclosed in the context, the first comparison signal, the second comparison signal, the first reference signal, and the second reference signal can all be light with a first polarization state.

[0055] As a result of the above configuration, both the first composite signal generated by the first processing component 46 and the second composite signal generated by the second processing component 48 are obtained by combining a reference signal and a comparison signal with the same polarization state, and will correspondingly provide the desired beating between the reference signal and the comparison signal. For example, the composite signal is generated by combining a first comparison signal and a first reference signal with the first polarization state and excludes or substantially excludes light with the second polarization state, or the composite signal is generated by combining a first comparison signal and a first reference signal with the second polarization state and excludes or substantially excludes light with the first polarization state. Similarly, the second composite signal includes a second reference signal, and the second comparison signal with the same polarization state will correspondingly provide the desired beating between the reference signal and the comparison signal. For example, the second composite signal is generated by combining a second comparison signal and a second reference signal with the first polarization state and excludes or substantially excludes light with the second polarization state, or the second composite signal is generated by combining a second comparison signal and a second reference signal with the second polarization state and excludes or substantially excludes light with the first polarization state.

[0056] The above configuration results in the generation of LiDAR data for a single sampled area in the field of view from multiple different composite signals (i.e., a first composite signal and a second composite signal) from the sampled area. In some cases, determining the LiDAR data for the sampled area involves electronic devices combining LiDAR data from different composite signals (i.e., a first composite signal and a second composite signal). Combining LiDAR data may include averaging, medianing, or mode of the LiDAR data generated from the different composite signals. For example, the electronic devices may average the distance between a reflecting object and the LiDAR system determined from the composite signal with the distance determined from the second composite signal, and / or the electronic devices may average the radial velocity between a reflecting object and the LiDAR system determined from the composite signal with the radial velocity determined from the second composite signal.

[0057] In some cases, determining the LiDAR data for the sampling area involves the electronic device identifying one or more composite signals (i.e., a composite signal and / or a second composite signal) as the source of LiDAR data (representative LiDAR data) that best represents reality. The electronic device can then use the LiDAR data from the identified composite signals as representative LiDAR data for additional processing. For example, the electronic device can identify signals with larger amplitudes (composite signals or second composite signals) as representative LiDAR data and can use the LiDAR data from the identified signals for further processing by the LiDAR system. In some cases, the electronic device combines composite signals identified as representative LiDAR data with LiDAR data from different LiDAR signals. For example, the electronic device can identify each of composite signals with amplitudes above an amplitude threshold as representative LiDAR data, and when more than two composite signals are identified as representative LiDAR data, the electronic device can combine the LiDAR data from each of the identified composite signals. When a composite signal is identified as representative LiDAR data, the electronic device can use the LiDAR data from that composite signal as representative LiDAR data. When no composite signal is identified as representative LiDAR data, the electronic device can discard the LiDAR data of the sampling areas associated with those composite signals.

[0058] Although described in the context that the components are arranged such that the first comparison signal, the second comparison signal, the first reference signal, and the second reference signal all have a first polarization state. Figure 3 ,but Figure 3 Other configurations of the components can be arranged such that the composite signal is generated by combining a reference signal and a comparison signal with the same linear polarization state, and the second composite signal is generated by combining a reference signal and a comparison signal with the same linear polarization state. For example, beam splitter 120 can be configured such that a second portion of the system echo signal has a first polarization state, and a first portion of the system echo signal has a second polarization state, a polarization rotator receives the first portion of the system echo signal, and the output LIDAR signal can have a second polarization state. In this example, both the first and second LIDAR input signals have a second polarization state.

[0059] The above system configuration causes the first and second portions of the system echo signal to be guided into different composite signals. As a result, since both the first and second portions of the system echo signal are associated with different polarization states, but the electronics can process each of the composite signals, the LIDAR system responds to the reflection of the LIDAR output signal to compensate for the change in the polarization state of the LIDAR output signal.

[0060] Figure 3 The LIDAR adapter may include additional optical components, including passive optical components. For example, the LIDAR adapter may include an optional third lens 126. The third lens 126 may be configured to couple a second LIDAR output signal at a desired location. In some cases, the third lens 126 focuses or collimates the second LIDAR output signal at a desired location. For example, the third lens 126 may be configured to focus or collimate the second LIDAR output signal onto a small plane 52 of the second comparison waveguide 50. The LIDAR adapter also includes one or more reversing components 124, such as mirrors and prisms. Figure 3 A LiDAR adapter is shown that includes a mirror as a reversing component 124, which redirects a second portion of the system echo signal from the circulator 100 to a small plane 52 of a second comparison waveguide 50 and / or to a third lens 126.

[0061] When a LiDAR system includes a LiDAR chip and a LiDAR adapter, the LiDAR chip, electronics, and LiDAR adapter can be located on a common mount. Suitable common mounts include, but are not limited to, glass plates, metal plates, silicon plates, and ceramic plates. As an example, Figure 4 Included on the common support 140 Figure 1A LIDAR chip and electronic device 32 and Figure 2 A top view of the LIDAR system with the LIDAR adapter. Although the electronics 32 is shown as being located on the common support, all or part of the electronics may be located outside the common support. When the light source 4 is located outside the LIDAR chip, the light source may be located on or outside the common support 140. Suitable methods for mounting the LIDAR chip, electronics, and / or LIDAR adapter on the common support include, but are not limited to, epoxy resin, solder, and mechanical clamping.

[0062] A LIDAR system may include components containing additional passive and / or active optical elements. For example, a LIDAR system may include one or more components that receive LIDAR output signals from a LIDAR chip or a LIDAR adapter. A portion of the LIDAR output signal exiting from one or more of these components may be used as the system output signal. As an example, a LIDAR system may include one or more beam steering components that receive LIDAR output signals from a LIDAR chip or a LIDAR adapter and output all or a portion of the LIDAR output signal as the system output signal. For example, Figure 4 A beam steering assembly 142 is shown that receives the LIDAR output signal from the LIDAR adapter. Although Figure 4A beam steering assembly positioned on a common support 140 is shown, but the beam steering assembly may be positioned on the LIDAR chip, on the LIDAR adapter, outside the LIDAR chip, or outside the common support 140. Suitable beam steering assemblies include, but are not limited to, movable mirrors, MEMS mirrors, optical phased arrays (OPAs), and actuators for moving the LIDAR chip, LIDAR adapter, and / or common support.

[0063] Electronic devices can operate one or more beam steering components 142 to direct the system output signal to different sampling areas 144. The sampling areas can extend away from the LIDAR system to the maximum distance the LIDAR system is configured to provide reliable LIDAR data. The sampling areas can be stitched together to define the field of view. For example, the field of view of the LIDAR system includes or is constituted by the combination of the sampling areas.

[0064] Figures 5A to 5C An example of a suitable processing component is shown, which may be used as all or a small portion of the processing components selected from the group consisting of processing component 22, first processing component 46, and second processing component 48. The processing component receives a comparison signal from comparison waveguide 196 and a reference signal from reference waveguide 198. Figure 1A and Figure 1B The comparison waveguide 18 and reference waveguide 20 shown can be used as comparison waveguide 196 and reference waveguide 198, Figure 1C The comparison waveguide 18 and the first reference waveguide 42 shown can be used as comparison waveguide 196 and reference waveguide 198, or Figure 1C The second comparison waveguide 50 and the second reference waveguide 44 shown can be used as comparison waveguide 196 and reference waveguide 198.

[0065] The processing components include a second splitter 200, which splits the comparison signal carried on comparison waveguide 196 onto a first comparison waveguide 204 and a second comparison waveguide 206. The first comparison waveguide 204 carries a first portion of the comparison signal onto an optical combination assembly 211. The second comparison waveguide 208 carries a second portion of the comparison signal onto a second optical combination assembly 212.

[0066] The processing components include a first splitter 202, which splits the reference signal carried on reference waveguide 198 onto a first reference waveguide 204 and a second reference waveguide 206. The first reference waveguide 204 carries a first portion of the reference signal onto an optical combining assembly 211. The second reference waveguide 208 carries a second portion of the reference signal onto a second optical combining assembly 212.

[0067] The second optical combining component 212 combines the second portion of the comparison signal and the second portion of the reference signal into a second composite signal. Due to the frequency difference between the second portion of the comparison signal and the second portion of the reference signal, the second composite signal beats between the second portion of the comparison signal and the second portion of the reference signal.

[0068] The second optical combining assembly 212 further splits the resulting second composite signal onto a first auxiliary detector waveguide 214 and a second auxiliary detector waveguide 216. The first auxiliary detector waveguide 214 carries a first portion of the second composite signal to a first auxiliary optical sensor 218, which converts the first portion of the second composite signal into a first auxiliary electrical signal. The second auxiliary detector waveguide 216 carries a second portion of the second composite signal to a second auxiliary optical sensor 220, which converts the second portion of the second composite signal into a second auxiliary electrical signal. Examples of suitable optical sensors include germanium photodiodes (PDs) and avalanche photodiodes (APDs).

[0069] In some cases, the second optical combining component 212 splits the second composite signal such that a portion of the comparison signal included in the first portion of the second composite signal (i.e., a portion of the second portion of the comparison signal) is phase-shifted by 180° relative to a portion of the comparison signal in the second portion of the second composite signal (i.e., a portion of the second portion of the comparison signal). 0 However, the portion of the reference signal in the second part of the second composite signal (i.e., the portion of the second part of the reference signal) is not phase-shifted relative to the portion of the reference signal in the first part of the second composite signal (i.e., the portion of the second part of the reference signal). Instead, the second optical combining component 212 splits the second composite signal such that the portion of the reference signal in the first part of the second composite signal (i.e., the portion of the second part of the reference signal) is phase-shifted by 180° relative to the portion of the reference signal in the second part of the second composite signal (i.e., the portion of the second part of the reference signal). 0 However, the portion of the comparison signal in the first part of the second composite signal (i.e., the portion of the second part of the comparison signal) has no phase shift relative to the portion of the comparison signal in the second part of the second composite signal (i.e., the portion of the second part of the comparison signal). Examples of suitable optical sensors include germanium photodiodes (PDs) and avalanche photodiodes (APDs).

[0070] The first optical combining component 211 combines a first portion of the comparison signal and a first portion of the reference signal into a first composite signal. Due to the frequency difference between the first portion of the comparison signal and the first portion of the reference signal, the first composite signal beats between the first portion of the comparison signal and the first portion of the reference signal.

[0071] The first optical combining assembly 211 further splits the first composite signal onto a first detector waveguide 221 and a second detector waveguide 222. The first detector waveguide 221 carries a first portion of the first composite signal to a first optical sensor 223, which converts the first portion of the second composite signal into a first electrical signal. The second detector waveguide 222 carries a second portion of the second composite signal to a second optical sensor 224, which converts the second portion of the second composite signal into a second electrical signal. Examples of suitable optical sensors include germanium photodiodes (PDs) and avalanche photodiodes (APDs).

[0072] In some cases, the optical combining component 211 splits the first composite signal such that a portion of the comparison signal included in the first part of the composite signal (i.e., a portion of the first part of the comparison signal) is phase-shifted by 180° relative to a portion of the comparison signal in the second part of the composite signal (i.e., a portion of the first part of the comparison signal), but the portion of the reference signal in the first part of the composite signal (i.e., a portion of the first part of the reference signal) is not phase-shifted relative to a portion of the reference signal in the second part of the composite signal (i.e., a portion of the first part of the reference signal). Alternatively, the optical combining component 211 splits the composite signal such that a portion of the reference signal in the first part of the composite signal (i.e., a portion of the first part of the reference signal) is phase-shifted by 180° relative to a portion of the reference signal in the second part of the composite signal (i.e., a portion of the first part of the reference signal). 0 However, the portion of the comparison signal in the first part of the composite signal (i.e., the portion of the first part of the comparison signal) is not phase-shifted relative to the portion of the comparison signal in the second part of the composite signal (i.e., the portion of the first part of the comparison signal).

[0073] When the second optical combining component 212 splits the second composite signal, the comparison signal portion in the first part of the second composite signal is phase-shifted by 180° relative to the comparison signal portion in the second part of the second composite signal. 0 At the same time, the optical combining component 211 also splits the composite signal, causing the comparison signal portion in the first part of the composite signal to be phase-shifted by 180° relative to the comparison signal portion in the second part of the composite signal. 0 When the second optical combining component 212 splits the second composite signal such that a portion of the reference signal in the first part of the second composite signal is phase-shifted by 180° relative to a portion of the reference signal in the second part of the second composite signal, the optical combining component 211 also splits the composite signal such that a portion of the reference signal in the first part of the composite signal is phase-shifted by 180° relative to a portion of the reference signal in the second part of the composite signal.

[0074] The first reference waveguide 210 and the second reference waveguide 208 are configured to provide a phase shift between a first portion and a second portion of the reference signal. For example, the first reference waveguide 210 and the second reference waveguide 208 may be configured to provide a 90-degree phase shift between the first portion and the second portion of the reference signal. As an example, one reference signal portion may be an in-phase component, while the other is a quadrature component. Therefore, one of the reference signal portions may be a sine function, and the other reference signal portion may be a cosine function. In one example, the first reference waveguide 210 and the second reference waveguide 208 are configured such that the first reference signal portion is a cosine function and the second reference signal portion is a sine function. Therefore, the reference signal portion in the second composite signal is phase-shifted relative to the reference signal portion in the first composite signal; however, the comparison signal portion in the first composite signal is not phase-shifted relative to the comparison signal portion in the second composite signal.

[0075] The first optical sensor 223 and the second optical sensor 224 can be connected as a balanced detector, and the first auxiliary optical sensor 218 and the second auxiliary optical sensor 220 can also be connected as a balanced detector. For example, Figure 5B A schematic diagram illustrating the relationship between the electronic device, the first light sensor 223, the second light sensor 224, the first auxiliary light sensor 218, and the second auxiliary light sensor 220 is provided. The symbol for a photodiode is used to represent the first light sensor 223, the second light sensor 224, the first auxiliary light sensor 218, and the second auxiliary light sensor 220; however, one or more of these sensors may have other structures. In some cases, Figure 5B All components shown in the schematic diagram are included on the LIDAR chip. In some cases, Figure 5B The components shown in the diagram are distributed between the LIDAR chip and the electronic devices located outside the LIDAR chip.

[0076] An electronic device connects a first optical sensor 223 and a second optical sensor 224 as a first balanced detector 225, and a first auxiliary optical sensor 218 and a second auxiliary optical sensor 220 as a second balanced detector 226. Specifically, the first optical sensor 223 and the second optical sensor 224 are connected in series. Additionally, the first auxiliary optical sensor 218 and the second auxiliary optical sensor 220 are connected in series. The serial connection in the first balanced detector communicates with a first data line 228, which carries the output from the first balanced detector as a first data signal. The serial connection in the second balanced detector communicates with a second data line 232, which carries the output from the second balanced detector as a second data signal. The first data signal is an electrical representation of a first composite signal, and the second data signal is an electrical representation of a second composite signal. Therefore, the first data signal includes contributions from a first waveform and a second waveform, and the second data signal is a composite of the first and second waveforms. The portion of the first waveform in the first data signal is phase-shifted relative to the portion of the first waveform in the first data signal, but the portion of the second waveform in the first data signal is in phase relative to the portion of the second waveform in the first data signal. For example, the second data signal includes a portion of a reference signal that is phase-shifted relative to a different portion of the reference signal included in the first data signal. Additionally, the second data signal includes a portion of a comparison signal that is in phase with a different portion of the comparison signal included in the first data signal. The first and second data signals are beat differences resulting from a beat difference between the comparison signal and the reference signal, i.e., beat differences in the first composite signal and the second composite signal.

[0077] Electronic device 32 includes a transformation mechanism 238 configured to perform a mathematical transformation on a first data signal and a second data signal. For example, the mathematical transformation could be a complex Fourier transform with the first and second data signals as inputs. Since the first data signal is an in-phase component and the second data signal is its quadrature component, the first and second data signals together act as a complex data signal, where the first data signal is the real component of the input and the second data signal is the imaginary component of the input.

[0078] The conversion mechanism 238 includes a first analog-to-digital converter (ADC) 264 that receives a first data signal from a first data line 228. The first ADC 264 converts the first data signal from analog to digital form and outputs a first digital data signal. The conversion mechanism 238 also includes a second ADC 266 that receives a second data signal from a second data line 232. The second ADC 266 converts the second data signal from analog to digital form and outputs a second digital data signal. The first digital data signal is a digital representation of the first data signal, and the second digital data signal is a digital representation of the second data signal. Therefore, the first and second digital data signals together are used as a complex signal, wherein the first digital data signal is used as the real component of the complex signal, and the second digital data signal is used as the imaginary component of the complex signal.

[0079] Transformation mechanism 238 includes a transformation component 268 that receives complex data signals. For example, transformation component 268 receives a first digital data signal from a first analog-to-digital converter (ADC) 264 as input and also receives a second digital data signal from a second analog-to-digital converter (ADC) 266 as input. Transformation component 268 can be configured to perform mathematical transformations on the complex signals to convert them from the time domain to the frequency domain. The mathematical transformation can be a complex transformation, such as the complex fast Fourier transform (FFT). Complex transformations such as the complex fast Fourier transform (FFT) provide a definitive solution for the frequency offset of the LIDAR input signal relative to the LIDAR output signal caused by the radial velocity between the reflecting object and the LIDAR chip. Electronic devices use one or more frequency peaks output from transformation component 268 for further processing to generate LIDAR data (distance and / or radial velocity between the reflecting object and the LIDAR chip or LIDAR system). Transformation component 268 can perform its assigned functions using firmware, hardware, or software, or a combination thereof.

[0080] although Figure 5A An optical combining component is shown that combines a portion of a reference signal with a portion of a comparison signal; however, a processing component may include a single optical combining component that combines the reference signal with the comparison signal to form a composite signal. As a result, at least a portion of the reference signal and at least a portion of the comparison signal can be combined to form a composite signal. The combined portion of the reference signal may be the entire reference signal or a small portion of the reference signal, and the combined portion of the comparison signal may be the entire comparison signal or a small portion of the comparison signal.

[0081] An electronic device tunes the frequency of its system output signal over time. The system output signal has a frequency-time pattern with repetitive periods. Figure 5C An example of a suitable frequency-time pattern for the system output signal is shown. Figure 5C The frequency of the system output signal for a sequence of two periods labeled j and j+1 is shown. The system output signal (f) o The fundamental frequency can be the frequency of the system output signal at the beginning of the period. The periods shown do not include repositioning periods and / or repositioning periods that are not located between periods. As a result, Figure 5C The results of continuous scanning are shown.

[0082] Each period in the cycle comprises M data time periods, each of which is associated with a time period index m and is labeled DP. m .exist Figure 5C In the example, each cycle includes a label DP m Two data periods, where m=1 and m=2. In some cases, such as... Figure 5C As shown, the frequency-time pattern is the same for data periods that correspond to each other in different periods. Corresponding data periods are those with the same period index. Therefore, each data period DP1 can be considered a corresponding data period, and... Figure 5C The associated frequencies are the same for the time pattern. At the end of the cycle, the electronics return the frequency to the same level as the previous cycle.

[0083] LiDAR data is generated from a series of sampled areas illuminated by the system's LiDAR signal. The field of view of a LiDAR system includes or is constituted by the space occupied by a combination of sampled areas. For example, sampled areas can be stitched together to define the field of view.

[0084] Figure 5C All are associated with the sampling region index k and are marked as SR k The sampling area. Figure 5C The sampling area SR was marked. k-1 To SR k+3 .exist Figure 5C The diagram illustrates how the system output signal illuminates each sampling area during a data period associated with that area. For example, during the data period marked DP2 within period j and the data period marked DP1 within period j+1, the system output signal illuminates the sampling area SR. k+1 Therefore, it is labeled as SR. k+1 The sampling area is associated with the data period marked as DP2 within period j and the data period marked as DP1 within period j+1.

[0085] As from Figure 5C It is clear from this that a data period can be associated with more than one sampling area. For example, within period j, the data period labeled DP2 is associated with the data period labeled SR. k+1 The sampling area and the label SRk The sampling areas are associated. Therefore, different data time period groups can share a common data time period. However, each group sharing a common data time period can include one or more data time periods that are not shared by that group. Since the sampling area is illuminated by the system output signal during the associated data time period, and different sampling areas can be associated with the same data time period, different sampling areas can overlap with each other.

[0086] The system output signal can be chirped for at least a portion of the data periods within the same cycle. The chirp can be constant and continuous throughout the duration of the data periods. For example, during data periods labeled DP1 and DP2, the electronic device operates a light source, causing the frequency of the system output signal to change at a linear rate α. The direction of frequency change during data period DP1 is opposite to the direction of frequency change during data period DP2. Therefore, the chirp of the system output signal can be different for different data periods within the same cycle.

[0087] The frequency output from the complex Fourier transform represents the beat frequency of the composite signal, which includes a comparison signal with respect to the beat frequency relative to the reference signal. The beat frequency (f) can be determined from the data time period group associated with the sampling area. LDP This generates LiDAR data for the sampled area. Therefore, the electronic device generates a LiDAR dataset of the sampled area from the light included in the system output signal during a set of multiple data periods. For example, the beat frequency determined from DP1 in period j can be combined with the beat frequency determined from DP2 in period j to determine the denoted SR. k The sampling area is LIDAR data. Therefore, the electronic device generates the sampling area SR from a set of data periods including data periods marked DP1 and DP2 in period j. k The LIDAR dataset.

[0088] As an example of how to determine a sampling area of ​​LiDAR data from a set of data periods, the following equation applies to data periods during which the electronic device increases the frequency of the emitted LiDAR signal, such as during... Figure 5C What happens in data period DP1 within period j: f ub = -f d +ατ, where f ub The frequency is provided by the conversion component 268 (in this case, f is determined by DP1). LDP ), f d Indicates Doppler frequency shift (f d = 2νf c / c), where f c Represents optical frequency (f) o), where c represents the speed of light, ν is the radial velocity between the reflecting object and the LIDAR system, and the direction from the reflecting object toward the LIDAR system is assumed to be positive, and c is the speed of light. The following equation applies during data periods when the electronic device reduces the frequency of the emitted LIDAR signal, such as in Figure 5C The following occurs in the data period DP2 within period j: f db = -f d -ατ, where f db The frequency is provided by the conversion component 268 (in this case, f determined from DP2). i，LDP In these two equations, f d τ and τ are unknown. An electronic device solves these two equations to obtain the two unknowns f. d And τ. Then, it is possible to determine the Doppler frequency shift (ν = c*f) d / (2f c To quantize the radial velocity of the sampling region, and / or to be able to quantize it based on c*f d / 2 is used to quantify the separation distance of the sampling area.

[0089] The above example discloses the process of falling within the same cycle. j A set of data time periods within a sampling area (SR) k The generation of LiDAR data. However, LiDAR data for a sampling area can be generated for a set of data periods that include data periods from different periods. For example, associated data periods can be used for LiDAR data labeled SR. k+1 The sampling area generates LiDAR data. For example, labeled SR k+1 The LiDAR data of the sampling area can be obtained by using f from the data period labeled DP2 within period j, as described above. db The value and f from the data period marked DP1 within period j+1 ub The value is used to generate it.

[0090] In some cases, there may be more than one object in the sampling region. These different objects do not need to be physically different and can be different surfaces of the same object. In some cases where there are more than one object in the sampling region, the transform can output more than one frequency, where each frequency is associated with a different object. Frequencies generated by the same object in different data periods within the same period can be considered corresponding frequency pairs. LiDAR data can be generated for each corresponding frequency pair output by the transform. As a result, separate LiDAR data can be generated for each object in the sampling region.

[0091] Figure 5C The period in the data can include more than two data periods. For example, Figure 5D An example is shown illustrating the relationship between the frequency, time, period, and data segments of the system output signal, where each period includes more than two data segments. Figure 5C The data period marked DP3 allows frequency matching belonging to the same corresponding frequency pairs. For example, more than one frequency pair can be matched during the feedback period in DP1 of cycle 2 and during the feedback period in DP2 of cycle 2. In these cases, it may be unclear which frequency peaks from DP2 correspond to which frequency peaks from DP1. As a result, it may be unclear which frequencies need to be used together to generate LiDAR data for objects in the sampling area. Consequently, it may be necessary to identify corresponding frequencies. Corresponding frequency identification can be performed such that the corresponding frequencies are frequencies from the same reflecting object within the sampling area. The data period marked DP3 can be used to find corresponding frequencies. LiDAR data can be generated for each pair of corresponding frequencies and considered and / or processed as LiDAR data for different reflecting objects in the sampling area.

[0092] like Figure 5D As shown, the example of identifying the corresponding frequency uses a LiDAR system, where the period includes three data segments (DP1, DP2, and DP3). When two objects are present in the sampling area illuminated by the system output signal, the transformation component 268 targets f. ub Output two different frequencies: f during DP1 u1 and f u2 and for f db Two other distinct frequencies: f during DP2 d1 and f d2 In this case, the possible frequency pairings are: (f d1 f u1 );(f d1 f u2 );(f d2 f u1 ); and (f d2 f u2 f can be calculated for each possible frequency pair. d And the value of τ. f d Each pair of values ​​for τ can be substituted into f 3=− f d +α3τ0 is used to generate the theoretical f3 for each possible frequency pairing. The value of α3 differs from the value of α used in DP1 and DP2. Figure 5DIn this case, the value of α3 is zero. The transformation component 268 also outputs two values ​​of f3, each associated with one of the objects in the sampling area. The frequency pair with the theoretical f3 value closest to each actual f3 value is considered the corresponding pair. LiDAR data can be generated for each pair as described above and considered and / or processed as LiDAR data for different reflecting objects in the sampling area. Each corresponding frequency set can be used in the above equations to generate LiDAR data. The generated LiDAR data will be used for one of the objects in the sampling area. As a result, multiple different LiDAR data values ​​can be generated for the sampling area, where each of the different LiDAR data values ​​corresponds to a different object in the sampling area.

[0093] Figure 5D The frequency-to-time pattern shown illustrates three sampling zones associated with a single data period. Additionally, Figure 5D Three data periods are shown that are associated with each sampling region. However, the number of data periods that can be associated with each sampling region may vary compared to the number of sampling regions associated with each data period. For example, Figure 5E It shows Figure 5D The frequency-to-time pattern is configured to associate three data periods with each sampling area, but only two sampling areas are associated with each data period.

[0094] although Figures 5C to 5E The duration of each data period is shown to be the same, but the duration of different data periods can also be different. For example, Figure 5D The duration of the data period marked DP3 may differ from that of the data period marked DP2. Figures 5C to 5E It also shows at least two data periods with the same rate of change (α) within the same period; however, different data periods within the same period can have different rates of change. For example, Figure 5F An example is shown illustrating the relationship between the frequency, time, period, and data segments of a system output signal, where different data segments within the same period have different rates of frequency change. When different data segments within the same period have different rates of frequency change and / or different durations, suitable methods for generating LiDAR data include, but are not limited to, the method disclosed in U.S. Patent Application Serial No. 16 / 848,829, filed April 14, 2020, entitled Reducing the Sampling Rate in a LiDAR System, the entire contents of which are incorporated herein; and also in U.S. Patent Application Serial No. 16 / 848,818, filed April 14, 2020, entitled Parallel LiDAR Measurements of a Region in a Field of View, the entire contents of which are incorporated herein.

[0095] Suitable platforms for LIDAR chips include, but are not limited to, silicon dioxide, indium phosphide, and silicon-on-insulator wafers. Figure 6 This is a cross-sectional view of a portion of a chip constructed from a silicon-on-insulator (SOI) wafer. The SOI wafer includes a buried layer 310 between a substrate 312 and a light transmission medium 314. In the SOI wafer, the buried layer 310 is silicon dioxide, while the substrate 312 and the light transmission medium 314 are silicon. The substrate 312 of an optical platform, such as an SOI wafer, can be used as the substrate for the entire LIDAR chip. For example, Figures 1A to 1C The optical components shown on the LIDAR chip can be positioned on the top and / or lateral side or above the substrate 312.

[0096] Figure 6 This is a cross-sectional view of a portion of a LiDAR chip including a waveguide structure suitable for LiDAR chips constructed from silicon-on-insulator wafers. A ridge 316 of the optical transmission medium extends from a plate-shaped region 318 of the optical transmission medium. The optical signal is confined between the top of the ridge 316 and the buried oxide layer 310.

[0097] exist Figure 6 The dimensions of the ridge waveguide are marked in the figure. For example, the ridge has a width marked w and a height marked h. The thickness of the plate-shaped region is marked T. These dimensions may be more important than other dimensions for LiDAR applications because higher optical power levels are required than in other applications. The ridge width (marked w) is greater than 1 μm and less than 4 μm, the ridge height (marked h) is greater than 1 μm and less than 4 μm, and the plate-shaped region thickness is greater than 0.5 μm and less than 3 μm. These dimensions can be applied to the straight or substantially straight portions of the waveguide, the curved portions of the waveguide, and the tapered portions of the waveguide(s). Therefore, these portions of the waveguide will be single-mode. However, in some cases, these dimensions are suitable for the straight or substantially straight portions of the waveguide. Alternatively or additionally, the curved portions of the waveguide can have a reduced plate-shaped thickness to reduce optical losses in the curved portions of the waveguide. For example, the curved portions of the waveguide can have ridges extending away from the plate-shaped region with a thickness greater than or equal to 0.0 μm and less than 0.5 μm. While the dimensions described above typically provide straight or substantially straight sections of waveguides with a single-mode configuration, they can result in multimode (multiple) tapered sections and / or (multiple) bent sections. Coupling between multimode and single-mode geometries can be achieved using tapered sections that generally do not excite higher-order modes. Therefore, waveguides can be constructed such that even when carried in waveguide segments with multimode dimensions, the signal carried in the waveguide is carried in single-mode mode. Figure 6 The waveguide construction disclosed in the context is suitable for use according to Figures 1A to 1C All or part of the waveguide on the constructed LIDAR chip.

[0098] The optical sensor that interfaces with the waveguide on the LIDAR chip can be a component that is separate from the chip and then attached to it. For example, the optical sensor can be a photodiode or an avalanche photodiode. Examples of suitable optical sensor components include (but are not limited to) InGaAs PIN photodiodes manufactured by Hamamatsu Corporation in Hamamatsu, Japan, or InGaAs APDs (avalanche photodiodes) manufactured by Hamamatsu Corporation in Hamamatsu, Japan. These optical sensors can be located at the center of the LIDAR chip. Alternatively, all or part of the waveguide terminating at the optical sensor can terminate on a small plane located at the edge of the chip, and the optical sensor can be attached above the small plane to the edge of the chip such that the optical sensor receives light passing through the small plane. The use of an optical sensor as a component separate from the chip is suitable for all or part of an optical sensor selected from the group consisting of a first auxiliary optical sensor 218, a second auxiliary optical sensor 220, a first optical sensor 223, and a second optical sensor 224.

[0099] As an alternative to a standalone optical sensor, all or part of the optical sensor can be integrated with a chip. Examples of optical sensors that interface with a ridge waveguide on a chip constructed from silicon-on-insulator can be found in Optics Express Vol. 15, No. 21, 13965-13971 (2007); U.S. Patent No. 8,093,080, issued January 10, 2012; U.S. Patent No. 8,242,432, issued August 14, 2012; and U.S. Patent No. 6,108,472, issued August 22, 2000, each of which is incorporated herein by reference. The use of a chip-integrated optical sensor is suitable for all or part of an optical sensor selected from the group consisting of an auxiliary optical sensor 218, a second auxiliary optical sensor 220, a first optical sensor 223, and a second optical sensor 224.

[0100] The light source 4, which is mated to the utility waveguide 12, can be a laser chip that is separate from and then attached to the LIDAR chip. For example, the light source 4 can be a laser chip attached to the chip using a flip-chip arrangement. A flip-chip arrangement is suitable when the light source 4 is to be mated to a ridge waveguide on a chip constructed of silicon on insulator. Alternatively, the utility waveguide 12 may include an optical grating (not shown), such as a Bragg grating, which serves as a reflector for an external cavity laser. In these cases, the light source 4 may include a gain element that is separate from the LIDAR chip and then attached to the LIDAR chip in a flip-chip arrangement. Examples of suitable mating between a flip-chip gain element and a ridge waveguide on a chip constructed of silicon on insulator can be found in U.S. Patent No. 9,705,278, granted July 11, 2017, and U.S. Patent No. 5,991,484, granted November 23, 1999; each of which is incorporated herein by reference. When the light source 4 is a gain element or a laser chip, the electronic device 32 can change the frequency of the output LIDAR signal by changing the level of the current applied through the gain element or the laser cavity.

[0101] Suitable electronic devices 32 may include, but are not limited to, controllers, which include analog circuitry, digital circuitry, processors, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), computers, microcomputers, or combinations thereof suitable for performing the aforementioned operation, monitoring, and control functions. In some cases, the controller may access memory containing instructions executed by the controller during the performance of the operation, control, and monitoring functions. Although the electronic device is shown as a single component in a single location, the electronic device may also comprise multiple different components that are independent of each other and / or placed in different locations. Additionally, as described above, all or part of the disclosed electronic device may be included on a chip including electronic devices integrated with the chip.

[0102] The aforementioned LIDAR system includes multiple optical components, such as a LIDAR chip, LIDAR adapter, light source, optical sensor, waveguide, and amplifier. In some cases, in addition to or as alternatives to the optical components shown, the LIDAR system also includes one or more passive optical components. Passive optical components can be solid-state components excluding moving parts. Suitable passive optical components include, but are not limited to, lenses, mirrors, optical gratings, reflective surfaces, splitters, demultiplexers, multiplexers, polarizers, polarization beam splitters, and polarization rotators. In some cases, in addition to or as alternatives to the optical components shown, the LIDAR system also includes one or more active optical components. Suitable active optical components include, but are not limited to, optical switches, phase tuners, attenuators, maneuverable mirrors, maneuverable lenses, tunable demultiplexers, and tunable multiplexers.

[0103] In view of these teachings, those skilled in the art should readily conceive of other embodiments, combinations, and modifications of the invention. Therefore, the invention is defined solely by the appended claims, which encompass all such embodiments and modifications when considered in conjunction with the foregoing description and drawings.

Claims

1. A system for using common chirped periods in generating LiDAR data, comprising: A LIDAR system is configured to output a system output signal that travels away from the LIDAR system to illuminate multiple different sampling areas and is reflectible by objects located outside the LIDAR system. The system outputs an optical signal with a repetitive frequency-to-time pattern. Each cycle of the frequency-to-time pattern includes multiple data periods, which are configured such that the system output signal is chirped differently in different data periods; as well as The LIDAR system includes electronic devices configured to generate multiple different LIDAR datasets. Each LIDAR dataset is associated with one of the sampling regions and indicates the radial velocity and / or separation between the LIDAR system and one or more of the objects in the associated sampling region. Each LIDAR dataset is generated over a set of multiple data periods based on the light included in the system's output signal. A data time period group includes one or more public data time periods, and Each of the one or more public data periods is included in two or more different data period groups.

2. The system according to claim 1, wherein, The data time period group includes a shared group, each of which includes a first data time period group and a second data time period group, wherein the first data time period group and the second data time period group share at least one common data time period and also include at least one data time period that is not shared by the first data time period group and the second data time period group.

3. The system according to claim 2, wherein, Each of the data time periods included in at least a portion of the shared group is shared with one of the data time period groups that is neither the first data time period group nor the second data time period group.

4. The system according to claim 1, wherein, Each of the data periods included in each data period group is one of the common data periods.

5. The system according to claim 1, wherein, This includes each data period in each group occurring sequentially in time.

6. The system according to claim 1, wherein, Each of the data time period groups includes at least one data time period, wherein the frequency of the system output signal increases linearly with time during the duration of the data time period in which the frequency of the system output signal increases linearly with time.

7. The system according to claim 6, wherein, Each of the data time period groups includes at least one data time period, wherein the frequency of the system output signal decreases linearly with time over the duration of the data time period.

8. The system according to claim 1, wherein, Each of the data time periods is associated with a sampling area illuminated by the system output signal during the data time period.

9. The system according to claim 1, wherein, The LIDAR chip is configured to output a LIDAR output signal, and the system output signal includes light from the LIDAR output signal, the LIDAR chip including a photonic integrated circuit (PIC).

10. The system according to claim 9, wherein, The LIDAR chip is constructed on a silicon-on-insulator wafer.

11. A method for using common chirped periods in generating LiDAR data, comprising: The system output signal is output from the LIDAR system in a manner that allows the signal to travel away from the LIDAR system, illuminating multiple different sampling areas and enabling reflection from objects located outside the LIDAR system. The system outputs an optical signal with a repetitive frequency-to-time pattern. Each cycle of the frequency-to-time pattern includes multiple data periods, which are configured such that the system output signal is chirped differently in different data periods; as well as Generate multiple different LIDAR datasets. Each LIDAR dataset is associated with one of the sampling regions and indicates the radial velocity and / or separation between the LIDAR system and one or more of the objects in the associated sampling region. Each LIDAR dataset is generated over a set of multiple data periods based on the light included in the system's output signal. Data time period groups include one or more common data time periods. The one or more public data periods are included in two or more different data period groups.

12. The method according to claim 11, wherein, The data time period group includes a shared group, each of which includes a first data time period group and a second data time period group, wherein the first data time period group and the second data time period group share at least one common data time period and also include at least one data time period that is not shared by the first data time period group and the second data time period group.

13. The method according to claim 12, wherein, Each of the data time periods included in at least a portion of the shared group is shared with one of the data time period groups that is neither the first data time period group nor the second data time period group.

14. The method according to claim 11, wherein, Each of the data periods included in each data period group is one of the common data periods.

15. The method according to claim 11, wherein, Each of the data periods in each data period group occurs sequentially in time.

16. The method according to claim 11, wherein, Each of the data time period groups includes at least one data time period, wherein the frequency of the system output signal increases linearly with time over the duration of the at least one data time period.

17. The method according to claim 16, wherein, Each of the data time period groups includes at least one data time period, wherein the frequency of the system output signal decreases linearly with time during the duration of the at least one data time period in which the frequency of the system output signal decreases linearly with time.

18. The method according to claim 11, wherein, Each of the data time periods is associated with a sampling area illuminated by the system output signal during the data time period.

19. The method according to claim 11, wherein, The system output signal includes light from the LIDAR output signal, and the LIDAR output signal is output from a LIDAR chip including a photonic integrated circuit (PIC).

20. The method according to claim 19, wherein, The LIDAR chip is constructed on a silicon-on-insulator wafer.

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