Use of the circulatory system in LIDAR systems

Abstract

The LIDAR system includes a circulator that outputs a plurality of different emitted circulatory signals. The circulator receives a plurality of different circulatory return signals, each of which includes light included in one of the emitted circulatory signals and reflected by one or more objects located outside the LIDAR system. The circulator is configured to output a plurality of circulator output signals, each of which includes light from one of the circulator return signals. The LIDAR system also includes electronics that use the circulator output signals to generate one or more LIDAR data results. The LIDAR data results are selected from the group consisting of a distance and a line-of-sight velocity between the LIDAR system and one or more objects.

Description

Related applications

[0001] This application claims the interests of U.S. Provisional Patent Application No. 63 / 160,796, filed on 13 March 2021, entitled “LIDAR System Processing Multiple Channels in a Common Circulatory System.” This application is also a continuation of U.S. Patent Application No. 17 / 221,770, filed on 2 April 2021, entitled “Use of a Circulatory System in a LiDAR System.” Both are incorporated herein by reference as a whole. Field

[0002] This invention relates to an optical device. In particular, this invention relates to a LIDAR system. Background

[0003] The demands on LIDAR system performance are increasing. In particular, many LIDAR system applications require increased resolution and / or field of view. One way to meet these demands is to increase the number of LIDAR signals output by the LIDAR system. However, current LIDAR systems use optical circulators to separate the incident light signal from the outgoing light signal. Increasing the number of LIDAR signals output by a LIDAR system generally requires increasing the number of circulators and / or the number of associated components within them. Undesirably, increasing the number of circulators and their associated components can increase the complexity and / or cost of the LIDAR system. As a result, there is a need for LIDAR systems that can meet the demands for higher performance. Overview

[0004] The LIDAR system has a circulator that outputs a plurality of different outgoing circulator signals. The circulator receives a plurality of different circulator return signals. Each of the circulator return signals includes light reflected by one or more objects located outside the LIDAR system, which is contained in one of the outgoing circulator signals. The circulator is configured to output a plurality of circulator output signals, each containing light from one of the circulator return signals. The LIDAR system also includes electronic equipment that uses the circulator output signals to generate one or more LIDAR data results. The LIDAR data results are selected from the group consisting of distance and line-of-sight velocity between the LIDAR system and one or more objects.

[0005] In some examples, a portion of the circulatory output signal is a first circulatory output signal, and a portion of the circulatory output signal is a second circulatory output signal. The first circulatory output signal mainly consists of light reflected by one or more objects in a first polarization state. The second circulatory output signal mainly consists of light reflected by one or more objects in a second polarization state. Furthermore, the circulatory output signal includes a plurality of pairs. Each pair of circulatory output signals includes one of the first circulatory output signals and one of the second circulatory output signals. The first and second circulatory output signals included in each pair mainly consist of light from the same circulatory return signal.

[0006] Another embodiment of the LIDAR system is configured to direct the system output signal to a plurality of different sample regions within the field of view. The LIDAR system is configured to generate LIDAR data for each sample region. The LIDAR data for each sample region indicates the distance and / or line-of-sight velocity between the LIDAR system and an object in the sample region. The LIDAR system includes a plurality of waveguides, each configured to receive optical signals, including light from the system output signal. The waveguides receiving the optical signals are a function of the distance between the LIDAR system and the object. [Brief explanation of the drawing]

[0007] Figure 1 is a top view of a LiDAR chip applied to a LiDAR adapter.

[0008] Figure 2 is a top view of a LiDAR chip applied to a LiDAR adapter.

[0009] Figure 3A is a partial top view of a LiDAR system having a LiDAR chip and a LiDAR adapter that communicates optically. The path of the optical signal carrying channel C2 is shown, from the LiDAR chip, through the LiDAR adapter, and then out of the LiDAR system.

[0010] Figure 3B shows the LIDAR system of Figure 3A. The path for the optical signal carrying channel C2 is shown, from outside the LIDAR system, through the LIDAR adapter, to the LIDAR chip.

[0011] Figure 3C shows the LIDAR system of Figure 3A. The path through which the optical signal carrying channel C3 travels through the LIDAR system is shown.

[0012] Figure 4 is a top view of a LiDAR system that includes the LiDAR chip and electronic equipment shown in Figure 2 and the LiDAR adapter shown in Figure 3, all mounted on a common support.

[0013] Figure 5A shows an example of processing elements applied to the LIDAR chip in Figure 1.

[0014] Figure 5B provides a schematic diagram of an electronic device applied to a processing element configured according to Figure 5A.

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

[0016] Figure 6A is a top view of the LIDAR chip.

[0017] Figure 6B is a top view of a LiDAR system including the LiDAR chip shown in Figure 6A. The LiDAR system includes a plurality of waveguides, each configured to receive optical signals, and the waveguides receiving the optical signals change in response to changes in the distance between the LiDAR system and objects located outside of it.

[0018] Figure 6C is a top view of a LiDAR system. The LiDAR system includes a plurality of waveguides, each configured to receive optical signals, and the waveguides that receive the optical signals change in response to changes in the distance between the LiDAR system and objects located outside of it.

[0019] Figure 7 shows a cross-section of a portion of a chip constructed from a silicon-on-insulator wafer.

[0020] A LiDAR system can be configured to simultaneously output multiple different system output signals, each carrying a different channel. Light from the system output signals can be reflected by an object placed outside the system and returned to the LiDAR system in the system return signal. The LiDAR system includes a circulator. The light from the system output signals passes through the circulator before the system output signals are emitted from the LiDAR system. Furthermore, the light from the system return signals passes through the circulator after the system return signals have returned to the LiDAR system. Since the light from multiple system output signals and multiple system return signals are processed by the same circulator, it is not necessary to add circulators to increase the number of system output signals transmitted from the LiDAR system.

[0021] Furthermore, the circulator can accommodate changes in the polarization state of light reflected by objects located outside the LiDAR system. For example, a signal carrying light reflected in a first polarization state can be emitted from the circulator through one port, and a signal carrying light reflected in a second polarization state can be emitted from the circulator through another port. As a result, the LiDAR system can accommodate optical signals in different polarization states. A single circulator can handle different polarization states while outputting more system output signals. This capability allows for improved performance without substantially increasing the cost or complexity of the LiDAR system.

[0022] Figure 1 is a top view of a LiDAR chip 8 including chip components 9. The LiDAR chip may include a photonic integrated circuit (PIC) and can be a photonic integrated circuit (PIC) chip. Chip component 9 includes a light source 10 that outputs a light source output signal. The light source output signal is, respectively, a PC j It can be one or more spare channels that can be represented by, where j is the spare channel index from integer values ​​1 to N. The spare channel (PC j Each of these is associated with a different wavelength.

[0023] When the light source output signal carries one spare channel, a suitable light source 10 includes, but is not limited to, a single-channel laser such as a single-channel semiconductor laser. j When transporting a wavelength comb, a suitable light source 10 includes, but is not limited to, a multi-channel laser such as a semiconductor laser that generates a wavelength comb. Alternatively, when the light source output signal transports multiple auxiliary channels, the light source 10 may include multiple different lasers, and the outputs of these lasers may be combined to form the light source output signal.

[0024] The chip component 9 includes an optical source waveguide 11 that receives an optical source output signal from the optical source 10. The optical source waveguide 11 conveys the optical source output signal to a splitter 12. The splitter 12 is configured to split the optical source output signal into a plurality of different output LIDAR signals that are respectively received on different utility waveguides 13. Each of the utility waveguides 13 conveys one of the output LIDAR signals to an output port. Through this, the output LIDAR signal can be emitted from the LIDAR chip and function as a LIDAR output signal. Examples of suitable output ports include, but are not limited to, waveguide facets such as the facets of the utility waveguide 13.

[0025] The splitter 12 can be a wavelength-dependent splitter. For example, the splitter 12 can be configured such that each of the LIDAR output signals conveys a different wavelength selection. For example, examples of suitable wavelength-dependent splitters 12 include, but are not limited to, wavelength division multiplexers such as arrayed waveguide gratings, Etalon gratings, and ring resonator-based devices. Therefore, when the optical source output signal conveys a plurality of preliminary channels (PC j of N > 2), each of the LIDAR output signals can convey different channels represented by C i . Here, i is a channel index with integer values from 1 to M. When the splitter 12 is a wavelength-dependent splitter, the splitter 12 can be configured such that the channel index in channel C   i corresponds to the preliminary channel index in preliminary channel PC j . For example, the splitter 12 can be configured such that the channel index i = the channel index j. As a result, each of the preliminary channels (PC j ) functions as a channel (C i ) conveyed by a different one of the LIDAR output signals.

[0026] The multiple arrows in Figure 1 each represent a LiDAR output signal leaving the utility waveguide 13. For illustrative purposes, the LiDAR system is shown to generate three LiDAR output signals (N=3) denoted as C1 to C3.

[0027] Light from each of the aforementioned LIDAR output signals may be included in the system output signal output from the LIDAR system. The system output signal travels away from the LIDAR system, and each may be reflected by an object in the path of the system output signal. Light from the reflected system output signal may return to the LIDAR system as a system return signal.

[0028] The LIDAR chip includes a plurality of first input waveguides 16. Each of the first input waveguides 16 can receive a first LIDAR input signal which includes or consists of light from one of the system recovery signals. Each of the first LIDAR input signals is channel (C i Transport one of the ) and FLIS i It can be expressed as follows, where i is the channel index. The first LIDAR input signal carrying channel C1 is FLIS C1 It is denoted as and received in one of the first input waveguides 16. The first LIDAR input signal carrying channel C3 is FLIS C3 It is written as such and received by one of the first input waveguides 16.

[0029] Each of the first LIDAR input signals is incident on one of the first input waveguides 16 and functions as a first comparison signal. Each of the first input waveguides 16 carries one of the first comparison signals to the first processing element 34.

[0030] The LIDAR chip includes a plurality of second input waveguides 36. Each of the second input waveguides 36 can receive a second LIDAR input signal which includes, or consists of, light from one of the system return signals. Each of the second LIDAR input signals is channel (C iTransport one of the ) and SLIS i It can be expressed as, where i is the channel index. The second LIDAR input signal carrying channel C1 is denoted as SLISc1 and is received by one of the second input waveguides 36. The second LIDAR input signal carrying channel C3 is SLIS C3 It is written as such and received by one of the second input waveguides 36.

[0031] Each of the second LIDAR input signals is incident on one of the second input waveguides 36 and functions as a second comparison signal. Each of the second input waveguides 36 carries one of the second comparison signals to the second processing element 40.

[0032] The chip component 9 includes a divider 42 configured to move a portion of the light source output signal from the light source waveguide 11 to an intermediate waveguide 44 as an intermediate signal. The divider 42 can be a wavelength-independent divider. As a result, the intermediate signals can have the same or substantially the same wavelength distribution. Suitable dividers 42 include, but are not limited to, evanescent optical couplers, Y junctions, and MMIs.

[0033] The LIDAR chip also includes an intermediate divider 46 configured to receive the intermediate signal and divide it into a first intermediate signal received on a first intermediate waveguide 49 and a second intermediate signal received on a second intermediate waveguide 50. The intermediate divider 46 may be a wavelength-independent divider. As a result, the first and second intermediate signals may have the same or substantially the same wavelength distribution. Suitable intermediate dividers 46 include, but are not limited to, evanescent optical couplers, Y junctions, and MMIs.

[0034] The first intermediate waveguide 49 carries the first intermediate signal to the first channel divider 51. The first channel divider 51 is configured to divide the first intermediate signal into first reference signals received by different first reference waveguides 53.

[0035] The first channel divider 51 may be a wavelength-dependent divider. For example, the first channel divider 51 may be configured so that each of the first reference signals carries a different wavelength selection. Suitable first channel dividers 51 include, but are not limited to, array waveguide gratings, echelle gratings, and ring resonator-based devices. As a result, each of the first reference signals carries the spare channel (PC). j ) can carry one of the different ones, and therefore, channel (C i ) can carry one of the following different signals. For example, the first reference signal is FR i It can be expressed as follows, where i is Channel C i This represents the channel index from which FR has the same channel index. i The first reference signal and channel (C) are represented by the first reference signal and channel (C) i ) carry the same channel. For example, the first reference waveguide 53, denoted as FR1, guides the first reference signal that carries the auxiliary channel PC1, which functions as channel C1. As another example, the first reference waveguide 53, denoted as FR3, guides the first reference signal that carries the auxiliary channel PC3, which functions as channel C3.

[0036] Each of the first reference waveguides 53 guides one of the first reference signals to one of the processing elements 34. The first reference waveguides 53 and the first input waveguide 16 are arranged so that each processing element 34 receives the first reference signal and the first LIDAR input signal carrying the same channel. The LIDAR system is configured to generate LIDAR data using the first reference signal and the first LIDAR input signal received by the processing elements 34.

[0037] The second intermediate waveguide 50 carries the second intermediate signal to the second channel divider 52. The second channel divider 52 is configured to divide the second intermediate signal into second reference signals, each received by a different second reference waveguide 54. The second channel divider 52 may be a wavelength-dependent divider. For example, the second channel divider 52 may be configured so that each of the second reference signals carries a different wavelength selection. Suitable second channel dividers 52 include, but are not limited to, array waveguide gratings, echelle gratings, and ring resonator-based devices. Thus, each of the second reference signals is connected to the spare channel (PC j ) can carry one of the different ones, and therefore, channel (C i ) can carry one of the different ones. For example, the second reference signal is SR i It can be expressed as follows, where i is Channel C i This represents the channel index from. Therefore, SRs with the same channel index i The second reference signal and channel (C) are represented by i ) carry the same channel. For example, the second reference waveguide 54 labeled SR1 guides the second reference signal that carries the auxiliary channel PC1, which functions as channel C1. As another example, the second reference waveguide 54 labeled SR3 guides the second reference signal that carries the auxiliary channel PC3, which functions as channel C3.

[0038] Each of the second reference waveguides 54 guides one of the second reference signals to one of the second processing elements 40. The second reference waveguides 54 and the second input waveguides 36 are arranged so that each second processing element 40 receives the second reference signal and the second LIDAR input signal carrying the spare channel, and therefore the same channel. The LIDAR system is configured to generate LIDAR data using the second reference signal and the second LIDAR input signal received by the second processing elements 40.

[0039] The LIDAR chip may include a control branch 55 for controlling the operation of the light source 10. The control branch 55 includes a directional coupler 56 that moves a portion of the light source output signal from the light source waveguide 11 onto the control waveguide 58. The coupled portion of the light source output signal functions as a tap signal. Figure 1 shows a directional coupler 56 that moves a portion of the light source output signal onto the control waveguide 58, but other signal tap components can be used to move a portion of the light source output signal from the utility waveguide 12 onto the control waveguide 58. Examples of preferred signal tap components include, but are not limited to, Y junctions and MMIs.

[0040] A control waveguide 58 carries tap signals to a control element 60, which can communicate with an electronic device 62. During operation, the electronic device 62 can adjust the frequency of the light source output signal in response to the output from the control element. A preferred example of constructing the control element is described in U.S. Patent Application No. 15 / 977,957, filed on 11 May 2018, and is incorporated herein by reference in whole.

[0041] A suitable electronic device 62 may include, but is not limited to, an analog electrical circuit, a digital electrical circuit, a processor, a microprocessor, a digital signal processor (DSP), a computer, a microcomputer, or a controller comprising a combination thereof suitable for performing the above-described operation, monitoring, and control functions. In some examples, the controller accesses memory containing instructions, control, and monitoring functions performed by the controller during operation. Although the electronic device is illustrated as a single component in a single location, the electronic device may include multiple different components that are independent of each other and / or located in different locations. Also, as described above, all or part of the disclosed electronic device may be included on the chip. This includes electronic devices integrated with the chip.

[0042] Although the light source 10 is shown as being located on the LIDAR chip, all or part of the light source 10 can be located away from the LIDAR chip.

[0043] The light source output signal is transmitted through multiple different spare channels (PC j This is disclosed in the context of a LIDAR system that carries a spare channel. However, the LIDAR system in Figure 1 can be configured to operate with a light source output signal that carries a single spare channel which may be represented by PC1. For example, the LIDAR chip in Figure 1 can be configured such that the divider 12, the first channel divider 51, and the second channel divider 52 are wavelength-independent dividers such as optical couplers, Y junctions, MMIs, cascaded evanescent optical couplers, or cascaded Y junctions, respectively. As a result, the LIDAR output signals can each have the same or nearly identical wavelength distribution, the first LIDAR input signals can each have the same or nearly identical wavelength distribution, and the second LIDAR input signals can each have the same or nearly identical wavelength distribution. As a result, the spare channel PC i This is different channel C i Each of them functions as one of them. Therefore, channel C i Each of them is associated with the same wavelength.

[0044] Figure 2 shows PC i An example of a LIDAR chip configured to operate with a light source output signal carrying a single spare channel which may be represented as shown. Divider 12 is a wavelength-independent divider such as an evanescent optical coupler, a Y junction, an MMI, a cascaded evanescent optical coupler, or a cascaded Y junction. The wavelength-independent divider is the (C i The LIDAR output signal (represented as C) can be provided with the same or nearly identical wavelength distribution as the other, and can also be provided with the same or nearly identical wavelength distribution as the spare channel which can be represented by PC1. As a result, the spare channel PC1 is the same as the (C i (This is written as) Different channel C from the LIDAR output signal i Each of these can function as one of them. Therefore, channel Ci Each of these can be associated with the same wavelength.

[0045] In Figure 2, the intermediate divider 46 is replaced with the intermediate divider 46, first channel divider 51, and second channel divider 52 from Figure 1. In this example, the intermediate divider 46 receives the intermediate signal from the intermediate waveguide 44 and FR the intermediate signal. i The first reference signal and SR represented by i It is configured to split into a second reference signal represented by . The intermediate divider 46 is a wavelength-independent divider such as an optical coupler, Y junction, MMI, cascaded evanescent optical coupler, or cascaded Y junction. The wavelength-independent divider is configured to split into a second reference signal represented by . i ) and second reference signal (SR i ) can provide each other with the same or nearly the same wavelength distribution, and can also provide the same or nearly the same wavelength distribution as the intermediate signal. Since the intermediate signal is a sample of the light source output signal that carries the spare channel represented by PC1, the spare channel PC1 is the first reference signal (FR i ) and second reference signal (SR i It can function as a channel carried by the first reference signal (FR). Therefore, the first reference signal (FR) can function as a channel. i ) and second reference signal (SR i Each channel carried by can be associated with the same wavelength.

[0046] The LIDAR chip can be used in combination with a LIDAR adapter. In some examples, the LIDAR adapter can be optically positioned between the LIDAR chip and one or more reflective objects, and / or in the field of view, through which the optical path for the LIDAR output signal travels from the LIDAR chip to the field of view passes. The LIDAR adapter can also be configured such that the LIDAR output signal, a first LIDAR input signal, and a second LIDAR input signal travel along different optical paths between the LIDAR adapter and the reflective objects.

[0047] Examples of a LiDAR adapter applied to the LiDAR chips shown in Figures 1 and 2 are shown in Figures 3A and 3B. The paths of the optical signal carrying channel C2 are shown in Figures 3A and 3B. The path shown in Figure 3A tracks the light from the LiDAR output signal carrying channel C2 as it travels from the LiDAR chip through the adapter until it is emitted from the LiDAR system as a system output signal. In contrast, the path shown in Figure 3B tracks the light from the system return signal carrying channel C2 as it travels through the adapter until it is incident on the LiDAR chip in the first and second LiDAR input signals.

[0048] The LIDAR adapter 98 includes a plurality of adapter elements 99 arranged on the base 100. The adapter elements 99 include a pre-circulatory element 102 arranged to receive a LIDAR output signal carrying channel C2 from the LIDAR chip and to output a circulatory input signal. As will be described in more detail below, the adapter elements 99 may include a circulatory organ 104, and the pre-circulatory element 102 may be configured to output a plurality of circulatory input signals that move in different non-parallel directions and are incident on the circulatory organ. Furthermore or alternatively, the pre-circulatory element 102 may be configured to focus or sight the circulatory input signals at a desired position. For example, the pre-circulatory element 102 may be configured to focus or sight the circulatory input signals at a desired position on the circulatory organ 104. The illustrated pre-circulatory element 102 is a lens.

[0049] The circulatory unit 104 may include a first polarization beam splitter 106 that receives a circulatory unit input signal. The first polarization beam splitter 106 is configured to split the circulatory unit input signal into an optical signal in a first polarization state and an optical signal in a second polarization state. The first and second polarization states may be linear polarization states, and the second polarization state may be different from the first polarization state. For example, the first polarization state may be TE and the second polarization state may be TM, or the first polarization state may be TM and the second polarization state may be TE.

[0050] Since the light source 10 often includes one or more lasers as the source of the light source output signal, the light source output signal can be linearly polarized. Since the light source output signal is the source of the circulatory input signal, the circulatory input signal received by the first polarization beam splitter 106 can also be linearly polarized. In Figures 3A and 3B, the optical signal in the first polarization state is represented by a vertical bidirectional arrow, and the optical signal in the second polarization state is represented by a black circle. For the purposes of the following explanation, we will assume that the circulatory input signal is in the first polarization state, but a circulatory input signal in the second polarization state is also possible. Since we will assume that the circulatory input signal is in the first polarization state, the circulatory input signal will be represented by a vertical arrow.

[0051] Assuming that the circulatory input signal is in the first polarization state, it has been shown that the first polarization beam splitter 106 outputs a first polarization state signal in the first polarization state. However, it has not been shown that the first polarization beam splitter 106 outputs an optical signal in the second polarization state because the actual mass of the circulatory input signal in the second polarization state is small.

[0052] The circulatory system 104 may include a second polarization beam splitter 108 that receives a first polarization state signal. The second polarization beam splitter 108 splits the first polarization state signal into a first polarization signal and a second polarization signal, where the first polarization signal has a first polarization state but does not have or substantially does not have a second polarization state, and the second polarization signal has a second polarization state but does not have or substantially does not have a first polarization state. Since the first polarization state signal received by the second polarization beam splitter 108 has a first polarization state but does not have or substantially does not have a second polarization state, the second polarization beam splitter 108 outputs a first polarization signal but substantially does not output a second polarization signal. The first polarization beam splitter 106 and the second polarization beam splitter 108 may have a combined effect of filtering out one of the polarization states from the circulatory system input signal.

[0053] The circulator 104 may include a non-reciprocal polarization rotor 110 that receives a first polarization signal and outputs a first rotation signal. In some examples, the non-reciprocal polarization rotor 110 is configured to rotate the polarization state of the first polarization signal by n * 90° + 45°, where n is 0 or an even integer. As a result, the polarization state of the first rotation signal is rotated by 45° from the polarization state of the first polarization signal. Suitable non-reciprocal polarization rotors 110 include, but are not limited to, non-reciprocal polarization rotors such as Faraday rotors.

[0054] The circulator 104 may include a 45° polarizing rotor 112 that receives the first rotation signal and outputs a second rotation signal. In some examples, the 45° polarizing rotor 112 is configured to rotate the polarization state of the first rotation signal by m * 90° + 45°, where m is 0 or an even integer. As a result, the polarization state of the second rotation signal is rotated by 45° from the polarization state of the first rotation signal. As a combined effect of the polarization state rotations provided by the non-reciprocal polarizing rotor 110 and the 45° polarizing rotor 112, the polarization state of the second rotation signal is rotated by 90° with respect to the polarization state of the first polarizing signal. Thus, in the illustrated example, the second rotation signal has a second polarization state. A preferred 45° polarizing rotor 112 includes, but is not limited to, a reciprocal polarizing rotor such as a half-wave plate.

[0055] The circulator 104 may include a third polarization beam splitter 114 that receives a second rotation signal from a 45° polarization rotor 112. The third polarization beam splitter 114 is configured to split the second rotation signal into an optical signal of a first polarization state and an optical signal of a second polarization state. Because the second rotation signal is in the second polarization state, the third polarization beam splitter 108 outputs the second rotation signal but substantially does not output the signal of the first polarization state.

[0056] As is clear from Figure 3A, the first polarization beam splitter 106, the second polarization beam splitter 108, the non-reciprocal polarization rotor 110, and the 45° polarization rotor 112 can be included in a single component assembly 116. The component assembly 116 can be constructed as a unified block, and its components can be joined together within the block. In some examples, the component assembly 116 has the geometric shape of a cube, a cuboid, a square cuboid, or a rectangular cuboid.

[0057] The circulator 104 may include a second component assembly 118. In some examples, the second component assembly 118 has the same configuration as component assembly 116. As a result, component assembly 116 can also function as the second component assembly 118. The second component assembly 118 can receive a second rotation signal from the third polarization beam splitter 108. In particular, a 45° polarization rotor 112 within the second component assembly 118 can receive a second rotation signal from the third polarization beam splitter 108 and output a third rotation signal. In some examples, the 45° polarization rotor 112 is configured to rotate the polarization state of the second rotation signal by m * 90° + 45°, where m is 0 or an even integer. As a result, the polarization state of the third rotation signal is rotated by 45° from the polarization state of the second rotation signal. Preferred 45° polarization rotors 112 include, but are not limited to, reciprocal polarization rotors such as half-wave plates.

[0058] The second component assembly 118 may include a non-reciprocal polarization rotor 110 that receives a third rotation signal and outputs a fourth rotation signal. In some examples, the non-reciprocal polarization rotor 110 is configured to rotate the polarization state of the third polarization signal by n * 90° + 45°, where n is 0 or an even integer. As a result, the polarization state of the fourth rotation signal is rotated by 45° from the polarization state of the third polarization signal. Suitable non-reciprocal polarization rotors 110 include, but are not limited to, non-reciprocal polarization rotors such as Faraday rotors.

[0059] As a combined effect of polarization state rotation provided by the non-reciprocal polarization rotor 110 and the 45° polarization rotor 112 within the second component assembly 118, the polarization state of the fourth rotation signal is rotated by 90° relative to the polarization state of the second polarization signal. Therefore, in the illustrated example, the fourth rotation signal has a first polarization state.

[0060] The non-reciprocal polarized rotor 110 in the first component assembly 116 and the non-reciprocal polarized rotor 110 in the second component assembly 118 are each Faraday rotors. The adapter element 99 may include a magnet 120 arranged to provide a magnetic field that provides a Faraday rotor with the desired functionality.

[0061] The second component assembly 118 may include a 90° polarizing rotor 122 that receives a fourth rotation signal and outputs a fifth rotation signal. In some examples, the 90° polarizing rotor 122 is configured to rotate the polarization state of the first rotation signal by n * 90° + 90°, where n is 0 or an even integer. As a result, the polarization state of the fifth rotation signal is rotated by 90° from the polarization state of the fourth rotation signal. As a combined effect of the polarization state rotations provided by the non-reciprocal polarizing rotor 110, the 45° polarizing rotor 112, and the 90° polarizing rotor 122, the polarization state of the fifth rotation signal is rotated by 0° with respect to the polarization state of the second rotation signal. Thus, in the illustrated example, the fifth rotation signal has a second polarization state. A preferred 90° polarizing rotor 122 includes, but is not limited to, a reciprocal polarizing rotor such as a half-wave plate.

[0062] If the second component assembly 118 has the same configuration as the component assembly 116, the 90° polarizing rotor 122 may also be present in the component assembly 116.

[0063] The first polarization beam splitter 106 within the component assembly 116 receives the fifth rotation signal. The first polarization beam splitter 106 is configured to split the received optical signal into an optical signal in a first polarization state and an optical signal in a second polarization state. Since the fifth rotation signal is in the second polarization state and does not have, or substantially does not have, any components in the first polarization state, the first polarization beam splitter 106 outputs an exit circulator signal in the second polarization state. As shown in Figure 3A, this exit circulator signal exits from the circulator.

[0064] The adapter element 99 includes a beam shaping device 124 positioned to receive the output circulator signal. In some examples, the beam shaping device 124 is configured to widen the output circulator signal. Suitable beam shaping devices 124 include, but are not limited to, concave lenses, convex lenses, piano concave lenses, and piano convex lenses.

[0065] The adapter element 99 includes a sight 126 that receives a shaped ejection circulator signal and outputs a sighted ejection circulator signal. A suitable sight 126 includes, but is not limited to, a convex lens and a grin lens.

[0066] The LIDAR system in Figure 3A may optionally include one or more beam maneuvering elements 128 that receive an exit circulator signal sighted from the sight 126 and output a system output signal that carries channel C2. The direction in which the system output signal carrying channel C2 moves away from the LIDAR system is denoted as d2 in Figure 3A. The electronics can operate one or more beam maneuvering elements 128 to thereby maneuver the system output signal to different sample regions 129. The sample regions can extend away from the LIDAR system to a maximum distance configured such that the LIDAR system provides reliable LIDAR data. The sample regions can be stitched together to define a field of view. For example, the field of view of the LIDAR system includes or is composed of the space occupied by a combination of sample regions.

[0067] Suitable beam steering elements 128 include, but are not limited to, movable mirrors, MEMS mirrors, optical phase arrays (OPA), optical gratings, and working optical gratings.

[0068] Figure 3B shows the path of light from the system return signal carrying channel C2, as it travels through the adapter in Figure 3A and enters the LIDAR chip in the first LIDAR input signal and the second LIDAR input signal.

[0069] The system return signal is received by one or more beam steering elements 128. These one or more beam steering elements 128 output a controlled return signal directed to the beam shaper 124. If the beam shaper 124 is configured to widen the output circulator signal, the beam shaper 124 narrows the width of the controlled return signal.

[0070] The beam shaping unit 124 outputs a circulatory return signal received by the oscillator. In particular, the circulatory return signal is received by the first polarization beam splitter 106 in the second component assembly 118. As described above, a possible result of using one or more lasers is a light source 10 in which the system output signal is linearly polarized. For example, the light carried by the system output signal is all or substantially all in a first polarization state or a second polarization state. Reflection of the system output signal by an object can change the polarization state of all or part of the light in the system output signal. Thus, the system return signal can contain light in different linear polarization states. For example, the system return signal may have a first contribution from light in the first polarization state and a second contribution from light in the second polarization state. The first polarization beam splitter 106 can be configured to separate the first and second contributions. For example, the first polarization beam splitter 106 can be configured to output a first separation signal 128 that carries light in the first polarization state and a second separation signal 130 that carries light in the second polarization state.

[0071] The second polarization beam splitter 108 in the second component assembly 118 receives the first separation signal and reflects the first separation signal. The non-reciprocal polarization rotor 110 in the second component assembly 118 receives the first separation signal and outputs a first FPSS signal. The FPSS represents a first polarization state source, indicating that the light that was in the first polarization state after being reflected by an object was the light source for the first FPSS signal.

[0072] The first separation signal moves in the opposite direction to the third rotation signal through the non-reciprocal polarization rotor 110. As a result, the non-reciprocal polarization rotor 110 is configured to rotate the polarization state of the first separation signal by -n * 90° - 45°. Therefore, the polarization state of the first FPSS signal is rotated by -45° from the polarization state of the first separation signal.

[0073] The 45° polarization rotor 112 within the second component assembly 118 receives the first FPSS signal and outputs the second FPSS signal. Because the 45° polarization rotor 112 is a reciprocal polarization rotor, it is configured to rotate the polarization state of the first FPSS signal by m * 90° + 45°, where m is 0 or an even integer. As a result, the polarization state of the second FPSS signal is rotated by 45° from the polarization state of the first FPSS signal. As a combined effect of the polarization state rotations provided by the non-reciprocal polarization rotor 110 and the 45° polarization rotor 112 within the second component assembly 118, the second FPSS signal is rotated by 0° from the polarization state of the first separated signal. As a result, the second FPSS signal has a first polarization state.

[0074] The second FPSS signal is received by a third polarizing beam splitter 114. The third polarizing beam splitter 114 reflects the second FPSS signal, which then exits the circulator 104. After exiting the circulator 104, the second FPSS signal is received by a first beam steering element 132 configured to change its direction of travel. Preferred first beam steering elements 132 include, but are not limited to, mirrors and right-angle prism reflectors.

[0075] The second FPSS signal travels from the first beam steering element 132 to the second lens 134. The second lens 134 is configured to output a first LIDAR input signal represented by FLIS2. The second lens 134 is also configured to focus or sight the first LIDAR input signal (FLIS2) to a desired position. For example, the second lens 134 can be configured to focus the first LIDAR input signal (FLIS2) to an exit port on one first input waveguide 16. For example, as shown in Figure 3A, the second lens 134 can be configured to focus the first LIDAR input signal (FLIS2) to a facet of one first input waveguide 16.

[0076] As described in relation to Figures 1A and 1B, the first LIDAR input signal (FLIS2) is incident on one first input waveguide 16 and functions as a first comparison signal that is induced in one of the first processing elements 34.

[0077] The 90° polarization rotor 122 within the second component assembly 118 receives the second separation signal 130 and outputs a first SPSS signal. The SPSS represents a second polarization state source, indicating that the light in the second polarization state after reflection by an object was the light source for the first SPSS signal. Because the 90° polarization rotor 122 is a reciprocal polarization rotor, it is configured to rotate the polarization state of the second separation signal 130 by n * 90° + 90°, where n is 0 or an even integer. As a result, the polarization state of the first SPSS signal is rotated by 90° from the polarization state of the second separation signal 130. Thus, in the illustrated example, the first SPSS signal has a first polarization state.

[0078] The non-reciprocal polarization rotor 110 within the second component assembly 118 receives the first SPSS signal and outputs the second SPSS signal. The first SPSS signal moves in the opposite direction to the third rotation signal through the non-reciprocal polarization rotor 110. As a result, the non-reciprocal polarization rotor 110 is configured to rotate the polarization state of the first SPSS signal by -n * 90° - 45°. Therefore, the polarization state of the second SPSS signal is rotated by -45° from the polarization state of the first SPSS signal.

[0079] The 45° polarization rotor 112 within the second component assembly 118 receives the second SPSS signal and outputs a third FPSS signal. Because the 45° polarization rotor 112 is a reciprocal polarization rotor, it is configured to rotate the polarization state of the second SPSS signal by m * 90° + 45°, where m is 0 or an even integer. As a result, the polarization state of the third SPSS signal is rotated by 45° from the polarization state of the second FPSS signal. As a combined effect of the polarization state rotations provided by the non-reciprocal polarization rotor 110 and the 45° polarization rotor 112 within the second component assembly 118, the third SPSS signal is rotated by 0° from the polarization state of the first SPSS signal. Furthermore, as a combined effect of polarization state rotation provided by the non-reciprocal polarization rotor 110, the 45° polarization rotor 112, and the 90° polarization rotor 122 within the second component assembly 118, the third SPSS signal is rotated by 90° from the polarization state of the second separation signal 130. Therefore, in the illustrated example, the third SPSS signal is shown in the first polarization state.

[0080] The third SPSS signal is received by a third polarizing beam splitter 114. The third polarizing beam splitter 114 reflects the third SPSS signal, thereby causing it to exit the circulator 104. After exiting the circulator 104, the third SPSS signal is received by a second beam steering element 136 configured to change its direction of travel. Preferred second beam steering elements 136 include, but are not limited to, mirrors and right-angle prism reflectors.

[0081] The third SPSS signal travels from the first beam steering element 132 to the third lens 138. The third lens 138 is configured to output a second LIDAR input signal, represented by SLIS2. The third lens 138 is also configured to focus or sight the second LIDAR input signal (SLIS2) to a desired position. For example, the third lens 138 can be configured to focus the second LIDAR input signal (SLIS2) to an exit port on one second input waveguide 36. For example, as shown in Figure 3A, the third lens 138 can be configured to focus the second LIDAR input signal (SLIS2) to a facet of one second input waveguide 36.

[0082] As described in relation to Figures 1A and 1B, the second LIDAR input signal (SLIS2) is incident on one second input waveguide 36 and functions as a second comparison signal that is induced in one of the second processing elements 40.

[0083] Figure 3C shows the path that light from the LIDAR output signal carrying channel C3 travels through the LIDAR system. The pre-circulatory element 102 can be configured so that light from different LIDAR output signals travels through the circulator via different paths. For example, the pre-circulatory element 102 can be configured so that light from different circulatory input signals travels through the circulator via non-parallel paths. In some examples, the pre-circulatory element 102 is configured so that different circulatory input signals are incident on the first port of the circulator 104 in different directions. For example, the illustrated pre-circulatory element 102 is a lens that receives the LIDAR output signal. The angles of incidence of different LIDAR output signals to the lens may be different. For example, in Figure 3C, the angle of incidence of the LIDAR output signal carrying channel C3 to the first lens 102 is different from that of the LIDAR output signal carrying channel C2. As a result, the circulatory input signal carrying channel C3 and the circulatory input signal carrying channel C2 travel away from the lens in different directions. Because different circulatory input signals move away from the pre-circulatory element 102 in different directions, the LIDAR output signal is incident on the first port 140 of the circulatory unit 104, which is moving in a different direction.

[0084] Different circulatory input signals are incident on the circulatory system 104, which moves in different directions, but the light from different circulatory input signals is processed in the same order by the same selection of circulatory elements. For example, the light from different circulatory input signals travels through the elements in the order disclosed in the context of Figures 3A and 3B. As a result, the light from different circulatory input signals exits the circulatory system at the second port 142. For example, the path of light from a circulatory input signal carrying channel C3 through the circulatory system represents the exiting circulatory signal that exits the circulatory system at the second port 142. Similarly, the light from a circulatory return signal carrying channel C3 is incident on the circulatory system at the second port 142. Likewise, as described in relation to Figures 3A and 3B, the light from a circulatory input signal carrying channel C2 is incident on and exits the circulatory system at the second port 142.

[0085] A comparison of Figure 3A and Figure 3B shows that the exit circulatory signal approaches the second port 142 from different directions and moves away from the circulatory system in different directions. This difference in the direction of the exit circulatory signal means that the circulatory input signal may enter the circulatory system from different directions.

[0086] Figure 3C shows that light from the output circulator signal carrying channel C3 is emitted from the LIDAR system as a system output signal carrying channel C3. In Figure 3C, the direction in which the system output signal carrying channel C3 moves away from the LIDAR system is denoted as d3. Figure 3C also includes the notation d2 from Figure 3A. This notation d2 indicates the direction in which the system output signal carrying channel C2 moves away from the LIDAR system. A comparison of notations d2 and d3 shows that the system output signals carrying channels C2 and C3 move away from the LIDAR system in different directions. As a result, different system output signals can illuminate different sample regions simultaneously. LIDAR data can be generated for each of the different sample regions that are simultaneously illuminated by the LIDAR system.

[0087] The system recovery signal carrying channel C2 returns to the LIDAR system in the reverse direction of the arrow labeled d2, or substantially in the reverse direction of the arrow labeled d2. Similarly, the system recovery signal carrying channel C3 returns to the LIDAR system in the reverse direction of the arrow labeled d3, or substantially in the reverse direction of the arrow labeled d3. As a result, different system recovery signals return to the LIDAR system from different directions. The light from the different system recovery signals travels through the sequential components of the LIDAR system in the same order disclosed in the context of Figures 3A and 3B.

[0088] Each circulatory system restore signal carries light from one of the system restore signals. Each circulatory system restore signal is incident on a second port 142 that moves in a different direction. Thus, the light from each circulatory system restore signal can travel through the circulatory system along different paths.

[0089] Light from different circulatory return signals that were in a first polarization state after being reflected by an object (first polarization state source, FPSS) is emitted from the circulatory unit 104 at the third port 144. For example, Figure 3C shows a second FPSS signal (including light from the system return signal carrying channel C3) emitted from the circulatory unit at the third port 144. Similarly, as described in relation to Figures 3A and 3B, a second FPSS signal including light from the system return signal carrying channel C2 is also emitted from the circulatory unit at the third port 144.

[0090] Different second FPSS signals travel away from the circulatory system in different directions. As a result, different first input waveguides 16 on the LIDAR chip are arranged to receive different second FPSS signals. For example, light from the second FPSS signal carrying channel C3 is included in the first LIDAR input signal labeled FLIS3, and light from the second FPSS signal carrying channel C2 is included in the first LIDAR input signal labeled FLIS2. The first LIDAR input signals labeled FLIS3 and FLIS2 are received by different first input waveguides 16. Different second FPSS signals traveling away from the circulatory system in different directions may result in the circulatory input signal being incident on the circulatory system from different directions. Thus, the LIDAR system can be configured so that the circulatory input signal is incident on a circulatory system that is moving in a direction that causes the second FPSS signal to travel away from the circulatory system in different non-parallel directions.

[0091] Light in the circulatory return signal that was in the second polarization state after being reflected by an object (first polarization state source, FPSS) is emitted from the circulatory unit 104 at the fourth port 146. For example, Figure 3C shows the third SPSS signal (including light from the system return signal carrying channel C3) emitted from the circulatory unit at the fourth port 146. Similarly, as described in relation to Figures 3A and 3B, the third SPSS signal including light from the system return signal carrying channel C2 is also emitted from the circulatory unit at the fourth port 146.

[0092] Different third SPSS signals travel away from the circulatory system in different directions. As a result, light from different third SPSS signals is received by different second input waveguides 36 on the LIDAR chip. For example, light from the third SPSS signal carrying channel C3 is included in the second LIDAR input signal labeled SLIS3, and light from the third SPSS signal carrying channel C2 is included in the second LIDAR input signal labeled SLIS2. The second LIDAR input signals labeled SLIS3 and SLIS2 are received by different first input waveguides 16. Different third SPSS signals traveling away from the circulatory system in different directions may result in the circulatory input signal being incident on the circulatory system from different directions. Thus, the LIDAR system can be configured so that the circulatory input signal is incident on the circulatory system as it moves in a direction that causes the third SPSS signals to travel away from the circulatory system in different non-parallel directions.

[0093] Second Lidar input signal (SLIS) i Each of the first LIDAR input signals (FLIS) is incident on one of the second input waveguides 36 and functions as a second comparison signal induced in one of the second processing elements 40. Since each of the second LIDAR input signals carries light that was in the second polarization state after being reflected by an object (second polarization state source, SPSS), the data generated from the second processing element 40 is LIDAR data from the light reflected by the object in the second polarization state. In contrast, the first LIDAR input signal (FLIS) i Each of these signals is incident on one of the first input waveguides 16 and functions as a first comparison signal induced in one of the first processing elements 34. Since each of the first LIDAR input signals carries light that was in a first polarization state after being reflected by an object (first polarization state source, FPSS), the data generated by the first processing element 34 is LIDAR data from the light reflected by the object in the first polarization state.

[0094] The second FPSS signal and the third SPSS signal can function as circulatory output signals. These circulatory output signals may include the first and second circulatory output signals. Each of the second FPSS signals can function as one of the first circulatory output signals. As a result, each of the first circulatory output signals may include, primarily include, essentially constitute, and / or constitute light (FPSS) that was in a first polarization state when reflected by an object outside the LIDAR system. Each of the third SPSS signals can function as one of the second circulatory output signals. As a result, each of the second circulatory output signals may include, primarily include, essentially constitute, and / or constitute light (SPSS) that was in a first polarization state when reflected by an object outside the LIDAR system.

[0095] A comparison of Figures 3A and 3C shows that the light from each of the circulatory input signals is operated by the same selection of circulatory elements (first selection) as it moves from the first port 140 to the second port 142. For example, the light from each of the circulatory input signals is operated by the first polarizing beam splitter 106, the second polarizing beam splitter 108, the non-reciprocal polarizing rotor 110, and the 45° polarizing rotor 112 from the component assembly 116, as well as by the third polarizing beam splitter 114, and also by the 45° polarizing rotor 112, the non-reciprocal polarizing rotor 110, the second polarizing beam splitter 108, and the first polarizing beam splitter 106 from the second component assembly 118. However, Figures 3A and 3C also show that the light from each of the circulatory input signals can also travel through the circulatory system via different paths. A comparison of Figures 3B and 3C shows that each light from the first circulatory output signal is operated by the same selection of circulatory elements (second selection) as it travels from the second port 142 to the third port. However, Figures 3B and 3C also show that the light from each of the first circulatory output signals can travel through the circulatory system via different paths. A comparison of Figures 3B and 3C shows that each light from the second circulatory output signal is operated by the same selection of circulatory elements (third selection) as it travels from the second port 142 to the third port. However, Figures 3B and 3C also show that the light from each of the second circulatory output signals can travel through the circulatory system via different paths. As is clear from Figures 3A to 3C, the first selection of components, the second selection of components, and the third selection of components may be different.

[0096] The output circulatory signal may include, primarily include, essentially constitute, and / or constitute, light from one of the circulatory input signals. The return circulatory signal may include, primarily include, essentially constitute, and / or constitute, light from one of the circulatory input signals and one of the output circulatory signals. Furthermore, the circulatory output signal may include, primarily include, essentially constitute, and / or constitute, light from one of the circulatory return signals, one of the output circulatory signals, and one of the circulatory input signals.

[0097] The polarizing beam splitters shown in Figures 3A to 3C may have the structure of a cube beam splitter or a Wollaston prism. As a result, the components described as beam splitters may represent beam splitting elements such as coatings, plates, films, or interfaces between light-transmitting materials 150 such as glass, crystals, birefringent crystals, or prisms. The light-transmitting material 150 may include one or more coatings as desired. Examples of preferred coatings for the light-transmitting material 150 include, but are not limited to, anti-reflective coatings. In some examples, one, two, three, or four ports selected from the group consisting of a first port 140, a second port 142, a third port 144, and a fourth port 146 constitute all or part of the surface of the circulator. For example, as shown in Figures 3A and 3B, one, two, three, or four ports selected from the group consisting of the first port 140, the second port 142, the third port 144, and the fourth port 146 may each be all or part of the surface of the light-transmitting material 150. The surface of the circulatory device or the light-transmitting material 150 that functions as a port may include one or more coatings.

[0098] In some examples, the components of component assembly 116, the second component assembly 118, and / or the circulatory system 104 are fixed to each other using one or more bonding media such as adhesive, epoxy, or solder. In some examples, the components of component assembly 116 and / or the second component assembly 118 are fixed to each other before being incorporated into the circulatory system 104. The fabrication of the circulatory system can be simplified by using the second component assembly 118, which has the same configuration as the component assembly 116 and the components of these component assemblies, before assembling the circulatory system 104.

[0099] The LIDAR system is disclosed as having a component assembly 116 and a second component assembly 118 having the same configuration, however, component assembly 116 and the second component assembly 118 may have different structures. For example, component assembly 116 may include a 90° polarizing rotor 122 that is not used during the operation of the LIDAR system. As a result, component assembly 116 can exclude the 90° polarizing rotor 122. In another example, component assembly 116 may include or be configured with a non-reciprocal polarizing rotor 110 and a 45° polarizing rotor 112. In this example, the non-reciprocal polarizing rotor 110 or the 45° polarizing rotor 112 can receive the circulatory input signal directly from the pre-circulatory element 102. As a result, component assembly 116 can exclude the first polarizing beam splitter 106, the second polarizing beam splitter 108, the associated light-transmitting material 150, and the 90° polarizing rotor 122.

[0100] Furthermore, the adapter element 99 can be rearranged and / or is optional. For example, beam steering components such as the first beam steering element 132 and the second beam steering element 132 can be arbitrarily selected, and beam shaping elements such as the second lens 134 and the third lens 138 can also be arbitrarily selected. As another example, the pre-circulator element 102 can be arbitrarily selected. For example, the LIDAR system can omit the pre-circulator element 102, and the utility waveguide 13 can be arranged and / or configured so that different circulator input signals are incident on the first port 140 and move in a desired direction.

[0101] A LIDAR chip includes one or more waveguides that constrain the optical path of one or more optical signals. A LIDAR adapter may include waveguides, but the optical path through which a signal travels between components on the LIDAR adapter and / or between components on the LIDAR chip and the LIDAR adapter may be empty space. For example, when a signal travels between different components on the LIDAR adapter and / or between components on the LIDAR adapter and the LIDAR chip, it can travel through the space in which the LIDAR chip, LIDAR adapter, and / or base 102 are located. As a result, components on the adapter may be separate optical components attached to the base 102.

[0102] The LIDAR chip, electronics, and LIDAR adapter can be mounted 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 is a top view of a LIDAR assembly including the LIDAR chip and electronics 62 of Figure 2 and the LIDAR adapter of Figure 3C, mounted on a common support 160. Although the electronics 62 are shown mounted on the common support, all or part of the electronics may be mounted off the common support. Suitable approaches for mounting the LIDAR chip, electronics, and / or LIDAR adapter on the common support include, but are not limited to, epoxy, solder, and mechanical clamps. The beamformer 124, sight 126, and one or more steering elements 128 are shown mounted on the common support 160, but one or more components selected from the group consisting of the beamformer 124, sight 126, and one or more steering elements 128 may be mounted off the common support 160.

[0103] Figures 5A and 5B show examples of processing elements applied to the first processing element 34 and / or the second processing element 40. As described in relation to Figure 1, each processing element receives a comparison signal and a reference signal from the second input waveguide 36 and the second reference waveguide 54 or from the first input waveguide 16 and the first reference waveguide. The processing element in Figure 5A includes a first splitter 200 that splits the comparison signal carried in the first input waveguide 16 or the second input waveguide 36 into a first comparison waveguide 204 and a second comparison waveguide 206. The first comparison waveguide 204 carries the first portion of the comparison signal to the optical coupling element 211. The second comparison waveguide 206 carries the second portion of the comparison signal to the second optical coupling element 212.

[0104] The processing element in Figure 5A also includes a second splitter 202 that splits the reference signal carried in the first reference waveguide 53 or the second reference waveguide 54 onto the first reference waveguide 210 and the second reference waveguide 208. The first reference waveguide 210 carries the first portion of the reference signal to the optical coupling element 211. The second reference waveguide 208 carries the second portion of the reference signal to the second optical coupling element 212.

[0105] The second optical coupling element 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 pulsates between the second portion of the comparison signal and the second portion of the reference signal.

[0106] The second optical coupling element 212 also splits the resulting second composite signal into a first auxiliary detector waveguide 214 and a second auxiliary detector waveguide 216. The first auxiliary detector waveguide 214 carries the first portion of the second composite signal to a first auxiliary photosensor 218, which converts the first portion of the second composite signal into a first auxiliary electrical signal. The second auxiliary detector waveguide 216 carries the second portion of the second composite signal to a second auxiliary photosensor 220, which converts the second portion of the second composite signal into a second auxiliary electrical signal. Examples of suitable photosensors include germanium photodiodes (PDs) and avalanche photodiodes (APDs).

[0107] In some examples, the second optical coupling element 212 divides the second composite signal as follows: the portion of the comparison signal contained 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° with respect to the 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), but the portion of the reference signal in the second portion of the second composite signal (i.e., a portion of the second portion of the reference signal) is not phase-shifted with respect to the portion of the reference signal in the first portion of the second composite signal (i.e., a portion of the second portion of the reference signal). Alternatively, the second optical coupling element 212 divides the second composite signal such that: the reference signal portion in the first portion of the second composite signal (i.e., a portion of the second portion of the reference signal) is phase-shifted by 180° with respect to the reference signal portion in the second portion of the second composite signal (i.e., a portion of the second portion of the reference signal), but the comparison signal portion in the first portion of the second composite signal (i.e., a portion of the second portion of the comparison signal) is not phase-shifted with respect to the comparison signal portion in the second portion of the second composite signal (i.e., a portion of the second portion of the comparison signal). Suitable examples of optical sensors include germanium photodiodes (PDs) and avalanche photodiodes (APDs).

[0108] The first optical coupling element 211 combines the first part of the comparison signal and the first part of the reference signal into a first composite signal. Due to the frequency difference between the first part of the comparison signal and the first part of the reference signal, the first composite signal pulsates between the first part of the comparison signal and the first part of the reference signal.

[0109] The optical coupling element 211 also splits the first composite signal into 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 photosensor 223, which converts a 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 auxiliary photosensor 224, which converts a second portion of the second composite signal into a second electrical signal. Examples of suitable photosensors include germanium photodiodes (PDs) and avalanche photodiodes (APDs).

[0110] In some examples, the optical coupling element 211 divides the first composite signal such that: the portion of the comparison signal in the first portion of the composite signal (i.e., a portion of the first portion of the comparison signal) is phase-shifted by 180° relative to the portion of the comparison signal in the second portion of the composite signal (i.e., a portion of the first portion of the comparison signal), but the portion of the reference signal in the first portion of the composite signal (i.e., a portion of the first portion of the reference signal) is not phase-shifted relative to the portion of the reference signal in the second portion of the composite signal (i.e., a portion of the first portion of the reference signal). Alternatively, the optical coupling element 211 divides the composite signal such that: the portion of the reference signal in the first portion of the composite signal (i.e., a portion of the first portion of the reference signal) is phase-shifted by 180° relative to the portion of the reference signal in the second portion of the composite signal (i.e., a portion of the first portion of the reference signal), but the portion of the comparison signal in the first portion of the composite signal (i.e., a portion of the first portion of the comparison signal) is not phase-shifted relative to the portion of the comparison signal in the second portion of the composite signal (i.e., a portion of the first portion of the comparison signal).

[0111] When the second optical coupling element 212 divides the second composite signal such that 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, the optical coupling element 211 also divides the composite signal such that the comparison signal portion in the first part of the composite signal is phase-shifted by 180° relative to the comparison signal portion in the second part of the composite signal. When the second optical coupling element 212 divides the second composite signal such that the reference signal portion in the first part of the second composite signal is phase-shifted by 180° relative to the reference signal portion in the second part of the second composite signal, the optical coupling element 211 also divides the composite signal such that the reference signal portion in the first part of the composite signal is phase-shifted by 180° relative to the reference signal portion in the second part of the composite signal.

[0112] The first reference waveguide 210 and the second reference waveguide 208 are configured to provide a phase shift between the first part of the reference signal and the second part of the reference signal. For example, the first reference waveguide 210 and the second reference waveguide 208 can be configured to provide a 90° phase shift between the first part of the reference signal and the second part of the reference signal. As an example, one part of the reference signal can be an in-phase component and the other part can be an orthogonal component. Thus, one part of the reference signal can be a sine function and the other part can be a cosine function. In an example, the first reference waveguide 210 and the second reference waveguide 208 are constructed such that the first reference signal part is a cosine function and the second reference signal part is a sine function. Thus, the reference signal part in the second composite signal is phase-shifted with respect to the reference signal part in the first composite signal, but the comparison signal part in the first composite signal is not phase-shifted with respect to the comparison signal part in the second composite signal.

[0113] The first photosensor 223 and the second photosensor 224 can be connected as a balance detector, and the first auxiliary photosensor 218 and the second auxiliary photosensor 220 can also be connected as a balance detector. For example, Figure 5B shows an overview of the relationships between the electronic equipment, the first photosensor 223, the second photosensor 224, the first auxiliary photosensor 218, and the second auxiliary photosensor 220. The photodiode symbol is used to represent the first photosensor 223, the second photosensor 224, the first auxiliary photosensor 218, and the second auxiliary photosensor 220, although one or more of these sensors may have other configurations. In some examples, all the components shown in the schematic diagram of Figure 5B are contained on a LIDAR chip. In some examples, the components shown in the schematic diagram of Figure 5B are distributed between the LIDAR chip and electronic equipment detached from the LIDAR chip.

[0114] The electronic device connects a first light sensor 223 and a second light sensor 224 as a first balance detector 225, and connects a first auxiliary light sensor 218 and a second auxiliary light sensor 220 as a second balance detector 226. In particular, the first light sensor 223 and the second light sensor 224 are connected in series. Also, the first auxiliary light sensor 218 and the second auxiliary light sensor 220 are connected in series. The series connection in the first balance detector communicates with a first data line 228 that carries the output from the first balance detector as a first data signal. The series connection in the second balance detector communicates with a second data line 232 that carries the output from the second balance detector as a second data signal. The first data signal is an electrical representation of the first composite signal, and the second data signal is an electrical representation of the second composite signal. Therefore, the first data signal includes contributions from the first and second waveforms, and the second data signal is a composite of the first and second waveforms. The first waveform portion of the first data signal is phase-shifted relative to the first waveform portion of the first data signal, while the second waveform portion of the first data signal is in phase with the second waveform portion of the first data signal. For example, the second data signal includes a portion of the reference signal that is phase-shifted relative to a different portion of the reference signal contained in the first data signal. The second data signal also includes a portion of the comparison signal that is in phase with a different portion of the comparison signal contained in the first data signal. As a result of the pulsation between the comparison signal and the reference signal, i.e., the pulsation in the first and second composite signals, the first and second data signals pulsate.

[0115] The electronic device 62 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 may be a composite Fourier transform with the first data signal and the second data signal as inputs. Since the first data signal is in phase and the second data signal is orthogonal, the first and second data signals together act as a composite data signal, in which the first data signal is the real component and the second data signal is the imaginary component of the input.

[0116] 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 analog-to-digital converter (ADC) 264 converts the first data signal from analog format to digital format and outputs a first digital data signal. The conversion mechanism 238 also includes a second analog-to-digital converter (ADC) 266 that receives a second data signal from a second data line 232. The second analog-to-digital converter (ADC) 266 converts the second data signal from analog format to digital format 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 digital data signal and the second digital data signal both act as a composite data signal, in which the first digital data signal acts as the real component of the composite data signal, and the second digital data signal acts as the imaginary component of the composite data signal.

[0117] The conversion mechanism 238 includes a conversion element 268 that receives the composite data signal. For example, the conversion element 268 receives a first digital data signal as input from a first analog-to-digital converter (ADC) 264 and also receives a second digital data signal from a second analog-to-digital converter (ADC) 266. The conversion element 268 can be configured to perform a mathematical transformation on the composite signal in order to convert it from the time domain to the frequency domain. The mathematical transformation may be a composite transformation such as a composite fast Fourier transform (FFT). Such a composite transformation, such as a composite fast Fourier transform (FFT), provides a clear answer regarding the frequency shift of the comparison signal relative to the system output signal.

[0118] The electronic device includes a LiDAR data generator 270 that receives an output from the conversion element 268 and processes the output from the conversion element 268 to generate LiDAR data (distance between the reflective object and the LiDAR chip or LiDAR system and / or line-of-sight velocity). The LiDAR data generator finds peaks on the output of the conversion element 268 to identify one or more peaks at beat frequencies.

[0119] The electronic device uses one or more frequency peaks for further processing to generate LIDAR data (distance and / or line-of-sight velocity between the reflective object and the LIDAR chip or LIDAR system). The conversion element 268 can perform its assigned function using firmware, hardware, software, or a combination thereof.

[0120] Figure 5C shows an example of the relationship between frequency, time, cycle, and data period of the system output signal. Although Figure 5C shows frequency vs. time for only one channel, the illustrated frequency vs. time pattern can represent frequency vs. time for each channel. The base frequency (f0) of the system output signal can be the frequency of the system output signal at the start of the cycle.

[0121] Figure 5C shows the cycle j and cycle j +1 The frequency-to-time ratio is shown for a sequence of two cycles labeled as such. In some examples, the frequency-to-time ratio is repeated in each cycle, as shown in Figure 5C. The illustrated cycles do not include a relocation period, and / or relocation periods are not placed between cycles. As a result, Figure 5C shows the result of a continuous scan in which the manipulation of the system output signal is continuous.

[0122] Each cycle includes K data periods, each associated with the period index k, and DP K It is represented as follows. In the example in Figure 5C, each cycle is DP KIt includes three data periods denoted as (k=1, 2, and 3). In some examples, the frequency-to-time pattern is the same for data periods corresponding to each other in different cycles, as shown in Figure 5C. Corresponding data periods are data periods with the same periodic exponent. As a result, each data period DP1 can be considered a corresponding data period, and the associated frequency-to-time pattern is the same in Figure 5C. At the end of the cycle, the electronics return the frequency to the same frequency level that started the previous cycle.

[0123] During data periods DP1 and DP2, the electronic device operates the light source such that the frequency of the system output signal changes 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.

[0124] Figure 5C shows that each is associated with the sample region index k, and Rn k The sample region indicated by is shown. Figure 5C shows the sample region Rn k and Rn k+1 This is indicated. Each sample region is illuminated by the system output signal during the data period shown in Figure 5C as being associated with the sample region. For example, during the data periods indicated by DP1 to DP3, the sample region Rn k The sample region is illuminated by the system output signal. The sample region index k can be assigned to time. For example, the sample region can be illuminated by the system output signal in the sequence indicated by index k. As a result, the sample region Rn 10 This is after the sample region Rn9 and Rn 11 It can be irradiated in front of it.

[0125] A LIDAR system is typically configured to provide reliable LIDAR data when an object is within the operating distance range from the LIDAR system. The operating distance range can be extended from a minimum operating distance to a maximum operating distance. The maximum round-trip time may be the time required for the system output signal to leave the LIDAR system, travel the maximum operating distance to the object, and return to the LIDAR system, as shown in Figure 5C, τ M It is written as follows.

[0126] Because there is a delay between the transmission of the system output signal and its return to the LIDAR system, the composite signal does not include the contribution from the LIDAR signal until after the system return signal has returned to the LIDAR system. The composite signal requires the contribution from the system return signal because it has a LIDAR beat frequency. The electronic equipment measures the LIDAR beat frequency, which is caused by the system return signal returning to the LIDAR system during the data window of the data period. In Figure 5C, the data window is denoted as W. The contribution from the LIDAR signal to the composite signal is due to the maximum operating time delay (τ M It exists for a longer time than ). As a result, the data window has a maximum operating time delay (τ M It is indicated that this should be extended from ) until the end of the data period.

[0127] The frequency peak in the output of the composite Fourier transform represents the beat frequency of the composite signal, which includes the pulsation of the comparison signal relative to the reference signal. LIDAR data can be generated by combining beat frequencies from two or more different data periods. For example, LIDAR data can be measured by combining the beat frequency measured from DP1 in Figure 5C with the beat frequency measured from DP2 in Figure 5C. As an example, during a data period in which an electronic device increases the frequency of the emitted LIDAR signal, such as during data period DP1 in Figure 5C, the following equation: f ub = -f d +ατ is applied, where f ub The frequency (f) provided by the conversion element LDP(In this case, it is measured from DP1), and f d is Doppler shift (f d = 2vf c / c) represents, where f d Here, θ represents the optical frequency (f0), c represents the speed of light, v is the line-of-sight velocity between the reflecting object and the LIDAR system (assuming the direction from the reflecting object to the chip is positive), τ is the time (round trip time) for light from the system output signal to travel to the object and return to the LIDAR system, and c is the speed of light. During a data period in which the electronic equipment reduces the frequency of the emitted LIDAR signal, such as that occurring during data period DP2 in Figure 5C, the following equation applies: f db = -f d -ατ is applied, where f db The frequency (f) provided by the conversion element i (In this case, it is measured from DP2). In these two equations, f d and τ are unknowns. The electronic device solves these two equations for these two unknowns. Next, the line of sight velocity of the sample region is given by the Doppler shift (v = c*f d / (2f c The separation distance for the sample region can be measured from c*τ / 2. Since LIDAR data can be generated for each corresponding frequency pair output by the transformation, separate LIDAR data can be generated for each object in the sample region. Thus, an electronic device can measure one or more line-of-sight velocities and / or one or more line-of-sight separation distances from a single sampling of one sample region in the field of view.

[0128] The data period labeled DP3 in FIG. 5C is arbitrary. As described above, there are situations where one or more objects are present in the sample region. For example, in the feedback period at DP1 of cycle 2 and also in the feedback period at DP2 of cycle 2, one or more frequency pairs can be made to match. In these situations, which frequency peak from DP2 corresponds to which frequency peak from DP1 can be ambiguous. As a result, which frequencies need to be used together to generate LIDAR data for the objects within the sample region can be ambiguous. As a result, it is necessary to identify the corresponding frequencies. The identification of the corresponding frequencies can be performed such that the corresponding frequencies are the frequencies from the same reflecting object within the same sample region. The data period labeled DP3 can be used to find the corresponding frequencies. LIDAR data can be generated for each pair of corresponding frequencies and can be considered and / or processed as LIDAR data for different reflecting objects within the sample region.

[0129] In an example of the identification of corresponding frequencies, as shown in FIG. 5C, a LIDAR system in which a cycle includes three data periods (DP1, DP2, and DP3) is used. If there are two objects present within the sample region irradiated by the LIDAR output signal, the conversion element outputs two different frequencies: f ub for f u1 and f u2 during DP1, and outputs two other different frequencies, f db for f d1 and f d2 during DP2. In this example, the possible frequency pairings are (f d1 , f u1 ), (f d1 , f u2 ), (f d2 , f u1 ), and (f<00,00088>, f du2 ). The values of f d and τ can be calculated for each of these possible frequency pairs. The values of each pair of f d and τ are such that f3 = -fd + α3 By substituting into τ0, theoretical f3 can be generated for each possible frequency pairing. The value of α3 is different from the value used in DP1 and DP2. In Figure 5C, the value of α3 is zero. In this case, the transformation element also outputs two values ​​for f3 associated with one of the objects in the sample region. Frequency pairs with theoretical f3 values ​​closest to each actual f3 value are considered corresponding pairs. As described above, LIDAR data can be generated for each corresponding pair and / or considered and / or processed as LIDAR data for one different reflective object in the sample region. Each set of corresponding frequencies can be used in the above equation to generate LIDAR data. The generated LIDAR data will be for one object in the sample region. As a result, multiple different LIDAR data values ​​can be generated for a sample region, each different LIDAR data value corresponding to one different object in the sample region.

[0130] The LIDAR data results described in the context of Figures 5A to 5C are generated by a single processing element. Therefore, the LIDAR data results described in the context of Figures 5A to 5C are generated by processing element 34 or a second processing element 40. However, as is clear from the above discussion, a LIDAR chip can include multiple processing elements, and different processing elements receive comparison signals containing light that was in different polarization states after being reflected by an object located outside the LIDAR system. For example, if the LIDAR adapter is configured as shown in Figures 3A to 3C, the first processing element 34 receives a first comparison signal containing light that was in a first polarization state after being reflected by an object (FPSS). On the other hand, the second processing element 40 receives a second comparison signal containing light that was in a second polarization state after being reflected by an object (SPSS). As a result, the LIDAR results generated by processing element 34 are associated with a different polarization state than the LIDAR results generated by the second processing element 40.

[0131] A processing element 34 that receives a first comparison signal carrying channel i is associated with a second processing element 40 that receives a second comparison signal carrying the same channel i. Since the results of the LIDAR data can be generated from one processing element 34 and its associated second processing element 40, it is possible to generate results for multiple LIDAR data for different channels and, accordingly, different sample regions. The different LIDAR data results generated for channels and / or, accordingly, sample regions, may be identical, substantially identical, or different.

[0132] In some examples, measuring LIDAR data in a sample area involves an electronic device combining LIDAR data from different related processing elements. Combining LIDAR data may include taking the mean, median, or mode of the LIDAR data generated from the related processing elements. For example, the electronic device may average the distance between the LIDAR system and the reflective object measured from the related processing elements, and / or average the line-of-sight velocity between the LIDAR system and the reflective object measured from the related processing elements.

[0133] In some examples, measuring LIDAR data in a sample region involves the electronic device identifying one of the relevant processing elements (i.e., processing element 34 or a relevant second processing element 40) as the source of LIDAR data that best represents reality (LIDAR representative data). The electronic device can then use the LIDAR data from the identified processing element as LIDAR representative data for further processing. For example, the electronic device can identify which of several relevant processing elements produced the composite signal with the maximum amplitude, or which of several relevant processing elements has a transforming element 268 that outputs the frequency peak with the highest amplitude. The electronic device can select the LIDAR data from the identified processing element as having LIDAR representative data, and can also use the LIDAR data from the identified signal for further processing by the LIDAR system. In some examples, the electronic device combines identifying the processing element that provided the LIDAR representative data with combining LIDAR data from different processing elements. For example, an electronic device can identify which of several related processing elements has a composite signal with an amplitude exceeding an amplitude threshold so that it has representative LIDAR data. If three or more composite signals are identified as having representative LIDAR data, the electronic device can combine the LIDAR data from each of the identified processing elements. If one processing element is identified as having representative LIDAR data, the electronic device can use the LIDAR data from that processing element as representative LIDAR data. If no processing element is identified as providing representative LIDAR data, the electronic device can discard the LIDAR data for the sample regions associated with those processing elements.

[0134] There is a growing demand for LIDAR systems that can operate over wider distance ranges. The LIDAR system described above can overcome the challenges of LIDAR systems configured to operate over wide distance ranges. One of the challenges in operating a LIDAR system over wide distance ranges is that one or more beam maneuvering elements 128 continuously maneuver the system output signal while the light from the system output signal travels from the LIDAR system to an object and then returns to the LIDAR system as a system return signal. As described above, one or more beam maneuvering elements 128 receive the system return signal and output a maneuvered return signal. Maneuvering the system output signal also maneuvers the direction of the maneuvered return signal output by one or more beam maneuvering elements 128. As a result, the direction in which the maneuvered return signal travels away from one or more beam maneuvering elements 128 changes in response to the maneuvering of the system output signal that occurs while the light travels to and from the object over round-trip time (τ).

[0135] The amount of time available for one or more beam maneuvering elements 128 to change direction away from them increases with increasing round-trip time (τ). Round-trip time (τ) increases as the distance of the object from the LIDAR system increases. As a result, increasing the distance of the object from the LIDAR system provides one or more beam maneuvering elements 128 with more time to change direction in which the system return signal is maneuvered. Thus, the amount of change that occurs in the direction in which the maneuvered return signal moves away from one or more beam maneuvering elements 128 increases with increasing distance from the object from the LIDAR system. This change in the direction in which the maneuvered return signal moves away from one or more beam maneuvering elements 128 may cause light from the system return signal to partially or completely miss the return waveguide. This change in the direction in which the maneuvered return signal moves away from one or more beam maneuvering elements 128 changes the path of the maneuvered return signal through the circulator. This change in the path through the circulator may be sufficient to cause all or part of the resulting induced first LIDAR input signal to miss the first input waveguide 16. As a result, it may become difficult or impossible to generate LIDAR data for objects that are a certain distance away from the LIDAR system.

[0136] The above-described LIDAR system can be used to reliably generate LIDAR data for objects at different locations with a wide operating distance range. For example, Figure 6A illustrates a modified LIDAR chip from Figure 2, in which the light source waveguide 11 functions as a utility waveguide 13 that carries the outgoing LIDAR signal to the output port. Here, the outgoing LIDAR signal exits the LIDAR chip through the output port and functions as the LIDAR output signal.

[0137] The LIDAR chip includes one or more first input waveguides 16. Each of the first input waveguides 16 can receive a first LIDAR input signal which includes or consists of light from a system return signal derived from the reflection of the LIDAR output signal by an object. The first LIDAR input signal is FLIS DiIt can be expressed as follows, where Di represents the distance with distance index i, and different distance index i results in different values ​​of Di. Therefore, D1, D2, D3, etc., each represent different distances. The notations D1, D2, and D3, etc., can be assigned such that D3 > D2 > D1. When the first LIDAR input signal carries light reflected by an object located at distance Di, the first LIDAR input signal is FLIS Di This is expressed as and received in one of the first input waveguides 16. Thus, the first input signal can be expressed differently in response to objects located at different distances from the LIDAR system. The first LIDAR input signal is incident on one or more of the first input waveguides 16. The one or more first input waveguides 16 that receive the first LIDAR input signal are a function of the distance of the object from the LIDAR system. The portion of the first LIDAR input signal incident on the first input waveguide 16 functions as the first comparison signal. The first input waveguide 16 that receives the first comparison signal carries the first comparison signal to the first processing element 34.

[0138] The LIDAR chip includes one or more second input waveguides 36. Each of the second input waveguides 36 can receive a second LIDAR input signal which includes or constitutes light from a system return signal resulting from the reflection of a system output signal. The second LIDAR input signal is SLIS Di It can be expressed as, where Di represents the distance with distance exponent i. Thus, the second LIDAR input signal can be expressed differently in response to objects located at different distances from the LIDAR system. The second LIDAR input signal is incident on one or more second input waveguides 36. The second input waveguides 36 that receive the second LIDAR input signal are a function of the distance of the object from the LIDAR system. The portion of the second LIDAR input signal incident on the second input waveguides 36 functions as a second comparison signal. The second input waveguides 36 that receive the second comparison signal carry the second comparison signal to the second processing element 40.

[0139] Figures 6B and 6C each show the LIDAR system of FIG. 3A modified for use with the LIDAR chip of FIG. 6A. The LIDAR system is shown with the pre-circulator element 102, but the pre-circulator element 102 is optional. Light from the LIDAR output signal travels from the LIDAR chip through the adapter and exits the LIDAR system as a system output signal on the same or substantially the same path as the path through which the LIDAR output signal carrying channel C2 moves through the adapter of FIG. 3A. As a result, FIGS. 6B and 6C show the path through which light from the system return signal travels through the adapter until it is incident on the LIDAR chip in the first LIDAR input signal and the second LIDAR input signal, respectively. Each shows the path through which it travels until it is incident on the LIDAR chip in the first LIDAR input signal and the second LIDAR input signal.

[0140] Figures 6B and 6C each show a part of the sample area (denoted as Rn i ~Rn i+2 ). The electronic device operates one or more beam steering elements 128 so that the system output signal is scanned in the direction of the arrow denoted as A. As a result, the sample area is scanned in the order of Rn i , Rn i+1 , and Rn i+2 .

[0141] In Figure 6B, the object is located at a distance D1 from the LIDAR system. In contrast, Figure 6C shows the same LIDAR system as in Figure 6B, but with an object located at a distance D3 from the LIDAR system. Distances D1, D2, and D3 are arranged such that D3 > D2 > D1. As a result, the object in Figure 6B is closer to the LIDAR system than the object in Figure 6C. Varying the distance between the object and the LIDAR system changes the amount of time that one or more beam maneuvering elements 128 need to manipulate the system output signal before the system output signal returns to one or more beam maneuvering elements 128. For example, as the object moves further away from the LIDAR system, the beam maneuvering elements 128 have more time to manipulate the system output signal before the system output signal returns to one or more beam maneuvering elements 128. This principle is illustrated by the round-trip delay angle denoted as θ in Figure 6C. The angle denoted as θ represents the amount of movement in one or more beam maneuvering elements 128 during the round-trip time τ (the time between the system output signal output from one or more beam maneuvering elements 128 and the system return signal returning to one or more beam maneuvering elements 128). Since the round-trip time τ increases as the distance between the object and the LIDAR system increases, the value of the round-trip delay angle θ is substantial and is clear in Figure 6C. In contrast, the round-trip delay angle θ is not clear in Figure 6B due to the proximity of the object and the LIDAR system.

[0142] The change in the round-trip delay angle θ due to increasing distance alters the path the controlled return signal takes as it moves away from one or more beam control elements 128. For example, the path the controlled return signal takes when the object is located at distance D1 is denoted as P1 in Figures 6B and 6C. The path the controlled return signal takes when the object is located at distance D3 is denoted as P3 in Figures 6B and 6C. As is evident from the comparison between Figures 6B and 6C, and / or from the description of Figures 3A-3C, the light from the controlled return signal is incident on the second port 142 of the circulator moving in different directions by different paths. Because the light from the controlled return signal is incident on the second port 142 of the circulator moving in different directions, the light from the controlled return signal travels through the circulator on different paths, as disclosed in the context of Figures 3B and 3C. For example, the path the light from the controlled return signal takes through the circulator in Figure 6B can be compared to the path the light from the controlled return signal takes through the circulator in Figure 3B. Furthermore, the path of light from the controlled reset signal through the circulator in Figure 6C can be compared to the path of light from the controlled reset signal through the circulator in Figure 3C. Therefore, when an object is at a different distance from the LIDAR system, the resulting light from the system reset signal travels through the circulator via a different path. Consequently, changing the distance between the object and the LIDAR system changes the path of the resulting light from the system reset signal through the circulator.

[0143] The first input waveguide 16 is configured to receive the first LIDAR input signal originating from an object at a different distance from the LIDAR system. For example, Figure 6C shows one of the first input waveguides 16 (FLIS) configured to receive the first LIDAR input signal originating from an object located at a distance D1 from the LIDAR system. D1 Another first input waveguide 16 (FLIS), which is configured to receive a first LIDAR input signal originating from an object located at a distance D2 from the LIDAR system, is also configured to receive the first LIDAR input signal. D2(as indicated), and another first input waveguide 16 (FLIS) arranged to receive a first LIDAR input signal originating from an object located at a distance D3 from the LIDAR system. D3 This indicates that it is written as follows.

[0144] Objects can be positioned at distances other than Dl, D2, and D3 from the LIDAR system. As a result, at certain distances, the first LIDAR input signal can be received by one or more first input waveguides 16. For example, if an object is positioned between Dl and D2, the resulting first LIDAR input signal can be received by two first input waveguides 16. In some examples, when an object is positioned at or between Dl, D2, and D3 from the LIDAR system, or further away, the first LIDAR input signal is received by one or more first input waveguides 16.

[0145] The second input waveguide 36 can be configured to receive a second LIDAR input signal originating from an object at a different distance from the LIDAR system. For example, Figure 6C shows one of the second input waveguides 36 (SLIS) configured to receive a second LIDAR input signal originating from an object located at a distance D1 from the LIDAR system. D1 Another second input waveguide 36 (SLIS), which is configured to receive a second LIDAR input signal originating from an object located at a distance D2 from the LIDAR system, is also configured to receive this second LIDAR input signal. D2 (as indicated), and another second input waveguide 36 (SLIS) arranged to receive a second LIDAR input signal originating from an object located at a distance D3 from the LIDAR system. D3 This indicates that it is written as follows.

[0146] Objects can be positioned at distances other than Dl, D2, and D3 from the LIDAR system. As a result, at certain distances, the second LIDAR input signal can be received by one or more second input waveguides 36. For example, if an object is positioned between Dl and D2, the resulting second LIDAR input signal can be received by two second input waveguides 36. In some examples, when an object is positioned at or between Dl, D2, and D3 from the LIDAR system, or further away, the second LIDAR input signal is received by one or more second input waveguides 36.

[0147] Each first input waveguide 16 has first ports through which a first LIDAR input signal can pass and be incident into the first input waveguide 16. For example, each first input waveguide 16 can be terminated at facets through which a first LIDAR input signal can pass and be incident into the first input waveguide 16. The distance between the first ports (one example denoted as dl in Figure 6B) is selected so that the first input signal is incident into different ports of the first input waveguide 16 in response to an object located at different positions within the operating distance range of the LIDAR system. Examples of distances between ports (dl) include, but are not limited to, distances longer than 0 μm, 1 μm, 2 μm, or 3 μm, and / or less than 5 μm, 10 μm, 15 μm, or 150 μm.

[0148] Each second input waveguide 36 has ports through which the second LIDAR input signal can pass and be incident into the second input waveguide 36. For example, each second input waveguide 36 can be terminated at facets through which the second LIDAR input signal can pass and be incident into the second input waveguide 36. The distance between the second ports (one example denoted as d2 in Figure 6B) is selected so that the second input signal is incident into different ports of the second input waveguide 36 in response to objects located at different positions within the operating distance range of the LIDAR system. Examples of distances between ports (d2) include, but are not limited to, distances longer than 0 μm, 1 μm, 2 μm, or 3 μm, and / or less than 5 μm, 10 μm, 15 μm, or 150 μm.

[0149] FLIS D1 The first input waveguide 16 and SLIS receive the signal. D1 The second input waveguide 36 that receives the signal is the lowest adjacent waveguide. This is because it receives the LIDAR input signal generated when the object is closest to the LIDAR system and within the operating distance range of the LIDAR system. As the system output signal is scanned in the direction of arrow A and the distance between the object and the LIDAR system increases, the first and second LIDAR input signals move away from the lowest adjacent waveguide in the direction of arrow B in Figure 6C. As a result, additional first input waveguides 16 and / or second input waveguides 36 can be added in the direction of arrow B as the maximum operating distance of the LIDAR system increases.

[0150] Once a sample region within the field of view has been scanned as desired, it is generally desirable to repeat the scanning of that sample region within the field of view. This scanning can be repeated by resetting the system output signal to the first sample region in the order of the sample regions and scanning the sample region in the same order. The system output signal can be reset to the first sample region by manipulating the system output signal sequentially from the last sample region to the first sample region. Alternatively, one or more beam maneuvering elements 128 may be prism mirrors that reset the system output signal in the first sample region. Alternatively, once a sample region within the field of view has been scanned as desired, the scanning of the field of view can be repeated by scanning the sample regions in the reverse order.

[0151] Scanning the sample area can move the system output signal in the direction indicated by the arrow labeled A and / or C in Figure 6C. If scanning the sample area moves the system output signal in the direction indicated by the arrow labeled C, increasing the distance between the object and the LIDAR system will move the first and second LIDAR input signals away from the lowest nearest waveguide in the direction indicated by the arrow labeled D in Figure 6C. As a result, additional first input waveguides 16 and / or second input waveguides 36 can be added that move away from the lowest nearest waveguide in the direction indicated by the arrow labeled D. For example, first input waveguides 16 and second input waveguides 36 shown by dashed lines can be added. As a result, the LIDAR chip can include one or more first input waveguides 16 on one or both sides of the first input waveguide 16 that functions as the lowest nearest waveguide. Furthermore, or alternatively, the LIDAR chip may include one or more second input waveguides 36 on one or both sides of the second input waveguide 36 that acts as the lowest nearby waveguide.

[0152] The presence of multiple first input waveguides 16 allows for the collection of the first LIDAR input signal even when the distance between the LIDAR system and the object increases sufficiently to move away from the nearest waveguide with the lowest first LIDAR input signal. Similarly, the presence of multiple second input waveguides 36 allows for the collection of the second LIDAR input signal even when the distance between the LIDAR system and the object increases sufficiently to move away from the nearest waveguide with the lowest first LIDAR input signal. Because LIDAR input signal collection can continue even at large separation distances, reliable LIDAR data can be generated even with LIDAR systems that have a large operating distance range.

[0153] As described above, one or more first input waveguides 16 receive at least a portion of the first LIDAR input signal. As a result, one or more first processing elements 34 can generate LIDAR data results for the same sample region. The electronic equipment can be configured to identify the first processing element 34 that is the source of the LIDAR data that best represents reality (first LIDAR representative data). For example, the electronic equipment can identify which of several first processing elements 34 generated the composite signal with the maximum amplitude, or which of several first processing elements 34 has a conversion element 268 that outputs the frequency peak with the highest amplitude. The electronic equipment can select the LIDAR data results having the first LIDAR representative data from the identified processing elements, and can also use the first LIDAR representative data for further processing by the LIDAR system.

[0154] Furthermore, one or more second input waveguides 36 receive at least a portion of the second LIDAR input signal. As a result, one or more second processing elements 40 can generate LIDAR data results for the same sample region. The electronic equipment can be configured to identify the second processing element 40 that is the source of the LIDAR data that best represents reality (second LIDAR representative data). For example, the electronic equipment can identify which of several second processing elements 40 generated the composite signal with the maximum amplitude, or which of several second processing elements 40 has a conversion element 268 that outputs the frequency peak with the highest amplitude. The electronic equipment can select the LIDAR data results having the second LIDAR representative data from the identified second processing elements 40, and can also use the second LIDAR representative data for further processing by the LIDAR system.

[0155] As an alternative to identifying the first processing element 34 that generated the first LIDAR representative data, the first processing element 34 can be combined to generate the result of the first LIDAR representative data. For example, the output of the transformation element 268 in the first processing element 34 can be added, and a peak finder can be applied to the result. As described above, the result of the peak finder can be used to generate LIDAR data, and the resulting LIDAR data can serve as the first LIDAR representative data. As another example, the LIDAR data generated by each of the first processing elements 34 can be averaged to generate the first LIDAR representative data.

[0156] As an alternative to identifying the second processing element 40 that generated the second LIDAR representative data, the second processing element 40 can be combined to generate the result of the second LIDAR representative data. For example, the output of the transformation element 268 in the second processing element 34 can be added, and a peak finder can be applied to the result. As described above, the result of the peak finder can be used to generate LIDAR data, and the resulting LIDAR data can serve as the second LIDAR representative data. As another example, the LIDAR data generated by each of the second processing elements 40 can be averaged to generate the second LIDAR representative data.

[0157] If the LIDAR system generates first LIDAR representative data but does not generate second LIDAR representative data, the first LIDAR representative data can function as LIDAR representative data. If the LIDAR system generates second LIDAR representative data but does not generate first LIDAR representative data, the second LIDAR representative data can function as LIDAR representative data.

[0158] When a LIDAR system generates first LIDAR representative data and second LIDAR representative data, an electronic device can identify whether the first LIDAR representative data or the second LIDAR representative data best represents reality (i.e., functions as LIDAR representative data). The electronic device can then use the LIDAR representative data for further processing. For example, the electronic device can identify whether the first processing element 34 or the second processing element 40 has generated a composite signal with the maximum amplitude, or whether the first processing element 34 or the second processing element 34 has a conversion element 268 that outputs a frequency peak with the highest amplitude. The electronic device can select the result of the LIDAR data from the identified processing element as having LIDAR representative data, and the LIDAR data from the identified signal can be used for further processing by the LIDAR system. For example, if the electronic device identifies the first processing element 34, the electronic device can use the first LIDAR representative data as LIDAR representative data. In some cases, electronic devices combine first LIDAR representative data and second LIDAR representative data. For example, the average of the first and second LIDAR representative data can serve as the LIDAR representative data.

[0159] In addition to generating LIDAR data, or as an alternative, a LIDAR system can be used to measure different properties of an object reflecting the system output signal. This is because the relative ratio of the TE polarization state to the TM polarization state can change during reflection, and the amount of this change depends on properties including the material's composition and surface quality. For example, signals associated with different polarization states can indicate the type of material, surface roughness, or the presence of a surface coating or contaminants. Therefore, in some examples, electronic devices can use the ratio of one or more signal features to identify material properties such as surface roughness, or the presence of a surface coating or contaminants. For example, an electronic device can compare the ratio of signal features to one or more criteria, such as a ratio threshold. An electronic device can measure or approximate the value of a material property and determine the presence or absence of the material in response to the result of comparing the presence or absence of the material property and / or the ratio of one or more criteria. Examples of signal feature ratios include, but are not limited to, the ratio of composite signal amplitudes of composite signals that include light from the same sample region but are associated with different polarization states, the ratio of comparison signal amplitudes of comparison signals that include light from the same sample region but are associated with different polarization states, and the ratio of LIDAR input signal amplitudes of LIDAR input signals that include light from the same sample region but are associated with different polarization states.

[0160] The LIDAR systems in Figures 6A and 6B are disclosed as having three first input waveguides 16, but the LIDAR systems may have two or more first input waveguides 16. Furthermore or alternatively, the LIDAR systems in Figures 6A and 6B are disclosed as having three second input waveguides 36, but the LIDAR systems may have two or more second input waveguides 36.

[0161] The LiDAR systems in Figures 6A–6C are illustrated as outputting a single channel for the sake of simplicity in the illustration. However, the LiDAR systems in Figures 6A–6C can be modified for use with multiple channels, as disclosed in the context of Figures 1–5C.

[0162] Suitable platforms for LIDAR chips include, but are not limited to, silica, indium phosphide, and silicon-on-insulator wafers. Figure 7 is a cross-sectional view of a portion of a chip made from a silicon-on-insulator wafer. A silicon-on-insulator (SOI) wafer includes a bridging layer 290 between a substrate 292 and a light-transmitting medium 294. In a silicon-on-insulator wafer, the bridging layer is silica, while the substrate and light-transmitting medium are silicon. The substrate of an optical platform such as an SOI wafer can function as the base of the entire chip. For example, the optical components shown in Figure 1 can be located on the top or upper edge and / or side of the substrate.

[0163] A portion of the chip shown in Figure 7 includes a waveguide structure applied to a chip composed of a silicon-on-insulator wafer. A ridge 296 of the light-transmitting medium extends away from the slab region 298 of the light-transmitting medium. The optical signal is bound between the edge of the ridge and the embedded oxide layer.

[0164] Figure 7 shows the dimensions of a ridge waveguide. For example, the ridge has a width denoted as w and a height denoted as h. The thickness of the slab region is denoted as T. In LIDAR applications, these dimensions may be more important than others because higher levels of optical power than those used in other applications are required. The ridge width (denoted as w) is greater than 1 μm and less than 4 μm, the ridge height (denoted as h) is greater than 1 μm and less than 4 μm, and the thickness of the slab region is greater than 0.5 μm and less than 3 μm. These dimensions can apply to the straight or substantially straight sections of the waveguide, the curved sections of the waveguide, and the tapered sections of the waveguide. Thus, these sections of the waveguide are single-mode. However, in some examples, these dimensions apply to the straight or substantially straight sections of the waveguide. Furthermore, or alternatively, the slab thickness of the curved section of the waveguide can be reduced to reduce optical loss in the curved section of the waveguide. For example, the curved portion of the waveguide may have a ridge extending away from the slab region with a thickness of 0.0 μm or more and less than 0.5 μm. The above dimensions generally provide a straight or substantially straight portion of the waveguide having a single-mode structure, but they can result in a tapered and / or curved portion that is multimode. The coupling of the single-mode geometry and the multimode geometry can be done using a taper that substantially does not excite higher-order modes. Thus, the waveguide can be constructed so that the signal carried in the waveguide is carried in single mode even when the waveguide portion has multimode dimensions. The waveguide structure in Figure 7 is suitable for all or part of the waveguide on a LIDAR chip constructed according to Figures 1-4.

[0165] While the LIDAR system is disclosed as processing optical signals having two different polarization states, in some examples the LIDAR system includes a circulator 104 of the disclosure configured to process optical signals reflected by an object in only one polarization state. As a result, the components that process optical signals containing light reflected by an object in the first polarization state may be arbitrary. Alternatively, the components that process optical signals containing light reflected by an object in the second polarization state may be arbitrary. For example, the LIDAR system can be modified to process optical signals containing light reflected by an object that is in the first polarization state but not in the second polarization state. For example, the LIDAR system can be modified to exclude the second beam steering element 136, the third lens 138, the second input waveguide 36, the second processing element 40, the second intermediate waveguide 50, and the second channel splitter 52. In another example, the LIDAR system is modified to process optical signals containing light reflected by an object that is in the second polarization state but not in the first polarization state.

[0166] The numerical designations such as 1st, 2nd, and 3rd are used to distinguish different features and components and do not indicate the order or presence of those designated by smaller numbers. For example, a 2nd component may be present even if a 1st component is absent, and / or a 3rd step may be performed before a 1st step.

[0167] Those skilled in the art will readily be able to make other embodiments, combinations, and modifications of the present invention in consideration of this teaching. Accordingly, the present invention is limited only to the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings.

Claims

1. A circulator configured to simultaneously output a plurality of different ejection circulator signals input from different directions; The circulatory system is configured to receive a plurality of different circulatory system return signals, each of which includes light reflected by one or more objects located outside the LIDAR system and is included in one of the ejecting circulatory system signals; The circulator is configured to output a plurality of circulatory output signals, each of which includes light from one of the circulatory return signals; and An electronic device configured to use the cardiovascular output signal to generate one or more LIDAR data results selected from the group consisting of distance and line-of-sight velocity between the LIDAR system and one or more objects. A LIDAR system, including a LiDAR system.

2. A portion of the aforementioned circulatory system output signal is the first circulatory system output signal, and a portion of the aforementioned circulatory system output signal is the second circulatory system output signal. The first circulatory output signal mainly includes light reflected by one or more objects in a first polarization state. The second circulatory output signal mainly includes light reflected by one or more objects in a second polarization state. The system according to claim 1.

3. The system according to claim 2, wherein the first polarization state and the second polarization state are linear polarization states.

4. The system according to claim 3, wherein each of the cardiovascular output signals is essentially composed of light in a polarization state selected from the group consisting of the first polarization state and the second polarization state.

5. The circulator is configured to receive a plurality of circulator input signals, The circulator includes a plurality of different optical components, a second port through which the output circulator signal passes and is emitted from the circulator, a third port through which the first circulator output signal passes and is emitted from the circulator, and a fourth port through which the second circulator output signal passes and is emitted from the circulator. As the light from each of the aforementioned circulatory input signals travels along different paths from the second port to the third port, the light from each of the aforementioned circulatory return signals is processed by the first selection of the optical component. As the light from each of the cardiovascular input signals travels along different paths from the second port to the third port, the light from each of the cardiovascular return signals is processed by the second selection of the optical component, and the second selection of the optical component is different from the first selection of the optical component. The system according to claim 2.

6. The circulatory device is configured to receive a circulatory device input signal. Each of the aforementioned output circulator signals is essentially composed of light from one of the different circulator input signals, Each of the cardiovascular input signals is essentially composed of light in a polarization state selected from the group consisting of the first polarization state and the second polarization state. The system according to claim 4.

7. The cardiovascular output signals include a plurality of pairs, and each pair of cardiovascular output signals includes one of the first cardiovascular output signals and one of the second cardiovascular output signals. The first circulatory output signal and the second circulatory output signal in each pair mainly include light from the same circulatory return signal. The system according to claim 2.

8. The system according to claim 1, wherein the LIDAR system is configured to output a plurality of system output signals, each of which is essentially composed of light from one of the output circulator signals.

9. The system according to claim 1, wherein each of the different ejection circulator signals carries a different channel, and each of the different channels has a different wavelength.

10. The system according to claim 1, wherein each of the different ejection circulator signals carries a different channel, and each of the different channels has the same wavelength.

11. The system according to claim 1, wherein the circulator is configured to receive a plurality of circulator input signals, and each of the output circulator signals includes light from one of the different circulator input signals.

12. The system according to claim 11, wherein the plurality of circulatory input signals move in different directions and are incident on the circulatory system.

13. The system according to claim 12, wherein each of the aforementioned different directions is non-parallel.

14. The system according to claim 11, wherein the circulatory device receives the circulatory device input signal from the lens.

15. The system according to claim 14, wherein the cardiovascular input signals move away from the lens in different non-parallel directions.

16. The circulator includes a plurality of different optical components, a first port through which the circulator input signal passes and enters the circulator, and a second port through which the ejection circulator signal passes and exits the circulator; also As the light from each of the aforementioned circulatory input signals travels along different paths from the first port to the second port, the light from each of the aforementioned circulatory input signals is processed by the same selection of optical components. The system according to claim 11.

17. The system according to claim 16, wherein the optical component includes a plurality of polarizing beam splitters and a plurality of polarizing rotors.

18. The optical components are arranged with a polarization beam splitter placed between the first assembly of optical components and the second assembly of optical components. The first assembly and the second assembly each have the same configuration and are interchangeable. The first assembly and the second assembly each include a polarizing beam splitter and a polarizing rotor, The system according to claim 16.

19. The system according to claim 1, wherein each of the ejection circulator signals moves away from the circulator in different non-parallel directions.

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