Optical Coupler for LIDAR Sensors

Abstract

To provide an integrated optical platform that efficiently manipulates light while maintaining a high power processing performance.SOLUTION: A light detection and ranging (LIDAR) device includes a waveguide, cladding, and a scattering array. The waveguide is configured to route an infrared optical field. The cladding is disposed around the waveguide. The scattering array is formed in the cladding. The scattering array is configured to perturb the infrared optical field routed by the waveguide to direct the infrared optical field into an infrared beam propagating toward a surface of the cladding.SELECTED DRAWING: None

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 17 / 531,029, filed November 19, 2021, which claims priority to U.S. Provisional Application No. 63 / 117,316, filed November 23, 2020. U.S. Application Nos. 17 / 531,029 and 63 / 117,316 are incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE This disclosure relates generally to optics, and specifically to Light Detection and Ranging (LIDAR). [Background technology]

[0003] Frequency Modulated Continuous Wave (FMCW) LIDAR directs a frequency modulated collimated beam of light at a target to directly measure the distance and velocity of the object. Target range and velocity information can be derived from the FMCW LIDAR signal. Designs and techniques that increase the accuracy of the LIDAR signal are preferred.

[0004] The automotive industry is currently developing autonomous capabilities to control vehicles in certain situations. According to SAE International Standard J3016, there are six levels of autonomy, from level 0 (no autonomy) to level 5 (vehicles that can operate without driver input in all conditions). Vehicles with autonomous capabilities use sensors to sense the environment in which the vehicle travels. By collecting and processing data from the sensors, the vehicle can explore the environment. An autonomous vehicle may include one or more FMCW LIDAR devices to sense the environment. Traditional LIDAR systems require mechanically moving parts to steer the laser beam used to image the sensed environment. These are considered bulky, expensive, and unreliable for many applications such as automotive and robotics. Summary of the Invention

[0005] An embodiment of the present disclosure includes a light detection and ranging (LIDAR) device including a waveguide, a cladding, and a scattering layer. The waveguide is configured to route an infrared light field. The cladding is disposed about the waveguide. A scattering array is formed within the cladding. The scattering array is configured to disrupt the infrared light field routed by the waveguide and direct the infrared light field into an infrared beam that propagates toward a surface of the cladding.

[0006] In one embodiment, the scattering array is separated from the waveguide by a particular separation distance, and the waveguide is disposed between the scattering array and the surface of the cladding.

[0007] In one embodiment, the LIDAR device further includes a substrate layer in contact with the cladding, the scattering array being disposed between the waveguide and an interface of the substrate layer and the cladding.

[0008] In one embodiment, the LIDAR device further includes a reflector layer formed within the cladding, the waveguide being disposed between the reflector layer and the scattering array, and the reflector layer is configured to direct the infrared beam so that the infrared beam passes through the substrate layer.

[0009] In one embodiment, the thickness between the scattering array and the interface, and the separation between the waveguide and the scattering array, are configured to increase the intensity of the infrared beam by destructively interfering with the downward-scattered portion of the infrared light field.

[0010] In one embodiment, the scattering array is also configured to couple a received infrared beam into the waveguide, the received infrared beam being a reflection of the infrared beam by a target in an environment external to the LIDAR device.

[0011] In one embodiment, the cladding is transparent to infrared light fields.

[0012] In one embodiment, the waveguide has a first refractive index that is higher than the second refractive index of the cladding.

[0013] In one embodiment, the waveguide tapers and flares outward as the waveguide approaches the scattering array, which gradually flares outward.

[0014] In one embodiment, the polarization orientation of the infrared beam coincides with the longitudinal direction of the scatterers in the scattering array.

[0015] In one embodiment, the LIDAR device further includes a second waveguide. The first taper of the waveguide is extended into a second taper of the second waveguide. The scattering array is a two-dimensional combiner configured to scatter the infrared light field into a first polarization orientation and to scatter the second infrared light field into a second polarization orientation. The second infrared light field is routed by the second waveguide.

[0016] In one embodiment, the infrared light field routed in the waveguide propagates orthogonally to a second infrared light field propagating in a second waveguide.

[0017] In one embodiment, the waveguide and the second waveguide are formed in the same layer.

[0018] In one embodiment, the waveguide is silicon nitride.

[0019] An embodiment of the present disclosure includes an autonomous vehicle control system for an autonomous vehicle including a LIDAR device and one or more processors. The LIDAR device includes a waveguide, a cladding, and a scattering layer. The waveguide is configured to route an infrared light field. The cladding is disposed around the waveguide. A scattering array is formed within the cladding. The scattering array is configured to disrupt the infrared light field routed by the waveguide and direct the infrared light field into an infrared beam propagating toward a surface of the cladding. The one or more processors are configured to control the autonomous vehicle in response to an infrared return beam that is a reflection of the infrared transmit beam.

[0020] In one embodiment, the polarization orientation of the infrared transmit beam is aligned with the longitudinal direction of the scatterers in the scattering array.

[0021] In one embodiment, the LIDAR device further includes a second waveguide. The scattering array is a two-dimensional combiner configured to scatter the infrared light field in a first polarization orientation and to scatter a second infrared light field in a second polarization orientation. The second infrared light field is routed by the second waveguide.

[0022] In one embodiment, the scattering array is separated from the waveguide by a particular separation distance.

[0023] An embodiment of the present disclosure includes an autonomous vehicle including a LIDAR sensor and one or more processors. The LIDAR device includes a waveguide, a cladding, and a scattering layer. The waveguide is configured to route an infrared light field. The cladding is disposed around the waveguide. A scattering array is formed within the cladding. The scattering array is configured to disrupt the infrared light field routed by the waveguide and direct the infrared light field into an infrared beam propagating toward a surface of the cladding. The one or more processors are configured to control the autonomous vehicle in response to an infrared return beam that is a reflection of the infrared transmit beam.

[0024] In one embodiment, the polarization orientation of the infrared transmit beam is aligned with the longitudinal direction of the scatterers in the scattering array. [Brief description of the drawings]

[0025] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following drawings, in which, unless otherwise stated, like reference numerals refer to like parts throughout the various drawings. [Figure 1a] 1 illustrates a cross section of an optical coupler emitting a light beam in an upward direction according to an embodiment of the present disclosure. [Figure 1b] 1 illustrates a received beam propagating through a surface and being coupled to an optical mode propagating within a waveguide according to an embodiment of the present disclosure. [Diagram 2] 1 illustrates a cross-section of an optical coupler including a reflector layer configured to direct light through a substrate layer and out of the optical coupler in accordance with an embodiment of the present disclosure. [Figure 3a] 1 illustrates a layers of a three-dimensional view of a single polarization (1D) optical coupler with an optional top metallic reflector according to an embodiment of the present disclosure. [Figure 3b] (same as above) [Figure 3c] (same as above) [Figure 4a] 1 illustrates layers of a three-dimensional view of a dual-polarization (2D) optical coupler without any reflector layer according to an embodiment of the present disclosure. [Figure 4b] (same as above) [Figure 5a] 1 illustrates an autonomous vehicle including an exemplary sensor array according to an embodiment of the present disclosure. [Figure 5b] FIG. 1 illustrates a top view of an autonomous vehicle including an exemplary sensor array according to an embodiment of the present disclosure. [Figure 5c] 1 illustrates an exemplary vehicle control system including a sensor, a drivetrain, and a control system according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] An embodiment of a LIDAR optical coupler is described herein. In the following description, some details are presented to provide a thorough understanding of the embodiment. However, those skilled in the relevant art will recognize that the technology described herein may be practiced without one or more specific details, or with other methods, components, or materials, etc. In other cases, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring certain aspects.

[0027] References throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described with respect to an embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrase "one embodiment" or "an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Also, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0028] Throughout this specification, several technical terms are used. These terms shall take their general meaning in the technical field from which they originate, unless specifically defined herein or the context of use clearly indicates otherwise. For purposes of this disclosure, the term "Autonomous Vehicle" includes vehicles having autonomous capabilities at any autonomy level of SAE International Standard J3016.

[0029] Solid-state LIDAR devices are an improvement over the mechanically moving parts of traditional LIDARs by reducing or eliminating the mechanically moving parts required to steer the light beam for LIDAR operation. A key component of a solid-state LIDAR system is the optical coupler that emits and / or receives the light. Optical efficiency is a key aspect of the optical coupler.

[0030] Frequency Modulated Continuous Wave (FMCW) LIDAR directly measures the distance and velocity of an object by directing a frequency modulated, collimated beam of light at the object. The light reflected from the object / target is combined with a Tapped Version of the beam. The frequency of the resulting beat tone is proportional to the distance of the object from the LIDAR system after being corrected for Doppler shift, necessitating a second measurement for Doppler shift correction. Both measurements, which may or may not be performed simultaneously, provide both distance and velocity information.

[0031] A key consideration in the design of solid-state FMCW LIDAR systems is power handling capability. Improved power handling allows for improved signal-to-noise ratio (SNR) and longer range performance. For high performance FMCW LIDAR systems, it is preferable to develop an integrated optical platform that efficiently steers light while maintaining high power handling performance.

[0032] An embodiment of the present disclosure includes a waveguide, a cladding, and a scattering array that directs an infrared light field to an infrared beam that exits a surface of the cladding or a substrate (e.g., a silicon substrate) that supports the waveguide and the cladding. The LIDAR device may include a reflector layer configured to direct the infrared beam so that the infrared beam exits through the substrate layer. The scattering array may also be configured to couple a received infrared beam into the waveguide when the received infrared beam is a reflection of the infrared beam by a target in the external environment of the LIDAR device. The scattering array may be Quasi-Periodic. In some embodiments, a second waveguide is extended into the waveguide and the scattering array is a two-dimensional coupler configured to scatter the infrared light field into a first polarization orientation and to scatter a second infrared light field (routed by the second waveguide) into a second polarization orientation that is orthogonal to the first polarization orientation. These and other embodiments are described in more detail with respect to FIGS. 1a-5c.

[0033] FIG. 1a illustrates a cross section of an optical coupler 150 emitting a light beam 107 in an upward direction according to an embodiment of the present disclosure. The optical coupler 150 includes a waveguide 102, a cladding 120, a scattering array 104, and a substrate layer 130. In one embodiment, the waveguide 102 can be a Silicon Nitride Slab. In one embodiment, the cladding 120 is an Oxide. In one embodiment, the cladding 120 is a Silicon Dioxide. The cladding 120 can be transparent to infrared radiation. The waveguide 102 can have a first refractive index that is higher than a second refractive index of the cladding 120. The substrate layer 130 can be a silicon wafer substrate. In FIG. 1a, the substrate layer 130 is shown abutting the cladding 120 at an interface 109. If the cladding 120 is silicon dioxide and the substrate layer 130 is silicon, the interface 109 can be considered a silicon-glass interface.

[0034] In FIG. 1a, the scattering array 104 is separated from the waveguide 102 by a separation distance 105 of the cladding 120. The scattering array 104 may be quasi-periodic. The scattering array 104 may include silicon scatterers, which may be formed of silicon. FIG. 1a includes 12 scatterers for illustrative purposes, although more or fewer scatterers may be used. In the embodiment shown in FIG. 1a, the scattering array 104 is disposed between the waveguide 102 and the interface 109.

[0035] In operation, an optical mode 101 propagates through the waveguide 102. The optical mode 101 may be an infrared light field with a narrow linewidth. The optical mode 101 may be generated from laser light coupled into the waveguide 102. A tail 103 of the optical mode 101 extends outside the waveguide 102. The waveguide 102 is configured to route the optical mode 101. As the optical mode 101 propagates, the tail 103 interacts with a scattering array of silicon scatterers 104 (e.g., silicon nitride slabs) that scatter the light out of the waveguide 102. Although FIG. 1a shows the scatterers 104 with a single thickness, width, and spacing, these scatterers may have various thicknesses, widths, and spacings to shape the generated light beam 107 into a particular shape. The intensity of such scattering can be controlled depending on the separation 105 of the scatterers 104 (which may be the thickness of the oxide spacer) and the duty factor. In one embodiment, the scattering array 104 is configured to disrupt the infrared light field 101 routed by the silicon nitride waveguide 102 so as to direct the infrared light field 101 into an infrared beam 107 propagating towards the surface 121 of the cladding 120 .

[0036] Light is scattered in both downward (e.g., downward-scattered light 106) and upward (e.g., beam 107) directions. The downward scattered light propagates through separation 105, scatterers 104, and oxide thickness 108, and is eventually partially reflected from silicon-glass interface 109 as light 110. The thicknesses of 102, 104, 105, and 108 may be configured to cause destructive interference in the optical waves propagating through interface 109, thereby increasing the optical power propagating upward as beam 107. The net effect is an upward-propagating optical beam 107 that contains a majority of the optical power contained in optical mode 101. In one embodiment, separation 105 and thickness 108 of cladding 120 are configured to increase the intensity of beam 107 by destructively interfering with the downward-scattered portion 106 of optical field 101. Because the beam 107 exits through the surface 121 of the cladding 120, the optical structure 150 can be considered a vertical optical coupler that is surface emitting rather than edge emitting. Surface emitting optical couplers can be advantageous for LIDAR systems and devices.

[0037] In addition to being a transmitting optical coupler that transmits beam 107, optical structure 150 may also function as a receiving optical coupler that receives incident light and couples the light to waveguide 102. FIG. 1b shows received beam 157 propagating through surface 121 and coupled to optical mode 151 propagating in waveguide 102 in the opposite direction to optical mode 101. Thus, scattering array 104 (and separation distance 105 and thickness 108) may also be configured to couple received beam 157 with waveguide 102. Received beam 157 may be a received infrared beam that is a reflection of infrared beam 107 reflecting a target in an external environment of optical structure 150 when optical structure 150 is included in a LIDAR device. Optical mode 151 may therefore be converted to a received electrical signal in a LIDAR context.

[0038] FIG. 2 illustrates a cross-section of an optical coupler 250 including a reflector layer 212 configured to direct light through the substrate layer 130 and out of the optical coupler 250 according to an embodiment of the present disclosure. In this embodiment, the substrate layer 130 is transparent to infrared light. The reflector layer 212 can be a metallic reflector layer, such as copper. The reflector layer 212 can also be a diffractive structure configured to reflect the line width of the beam 207. The reflector layer 212 is formed in the cladding 120. The waveguide 202 is disposed between the reflector layer 212 and the scattering array 204. The scattering array 204 can be quasi-periodic. In operation, an optical mode 201 propagates through the waveguide 202. The optical mode 201 can include characteristics associated with the optical mode 101. In some embodiments, the waveguide 202 can have characteristics associated with the waveguide 102. A tail 203 of the optical mode 201 extends outside the waveguide material. The tail 203 interacts with a scattering array of scatterers 204 that scatters the light outside the waveguide 202 as a beam 207. Depending on the separation distance of the cladding 120 and the duty factor of the scatterers 204, the intensity of such scattering can be controlled and designed.

[0039] In FIG. 2, light is scattered in both downward 206 and upward 207 directions. The downward scattered light propagates through separation dimension 205, scatterers 204, and thickness 208, and is eventually partially reflected at interface 109 as beam 210. The upward scattered light passes through separation dimension 211 as beam 207 and encounters reflector layer 212, which reflects most of the light downward as beam 213. By controlling the thicknesses of 202, 204, 205, 208, and 211, the light waves (including beam 213) transmitted through interface 209 can be made to cause constructive interference and form downward-propagating ray 214 that contains most of the power in input mode 201. Because beam 214 exits through the bottom surface of substrate layer 130, optical structure 250 can be considered a vertical optical coupler that is surface emitting rather than edge emitting.

[0040] 3a-3c show layers of a three-dimensional view of a single polarization (1D) optical coupler 350 with an optional top metal reflector 312 according to an embodiment of the present disclosure. The optical coupler 350 may be a hybrid silicon-silicon nitride optical coupler. FIG. 3a shows a scattering array 304 disposed on a substrate layer 130. The scattering array 304 may be quasi-periodic. FIG. 3a-3c does not specifically show the cladding 120 so as not to obscure other components of the optical coupler 350. However, the thickness of the cladding 120 (e.g., thickness 108) would support the scattering array 304, for example. The cladding 120 may also support the waveguide 301 and the reflector layer 312.

[0041] FIG. 3b shows a waveguide 301 that connects to a tapered silicon nitride slab 302 that expands the input optical mode 101 to a desired size. In the illustrated embodiment, the waveguide 301 is tapered and flares outward as the waveguide approaches the scattering array 304. The waveguide 301 and tapered nitride slab 302 can be a continuous material of silicon nitride. The waveguide 301 and slab 302 are disposed above the scattering array 304, which controls the scattering of light out of the silicon nitride slab 302. The polarization state of the emitted light (e.g., beam 214) and the polarization state of the light that is effectively received by the expansion are aligned with the longitudinal direction 391 of the scatterers of the scattering array 304. In one embodiment, the polarization orientation of the infrared beam (generated by the scattering array 304) is aligned with the longitudinal direction of the scatterers of the scattering array 304.

[0042] FIG. 3c shows a selective reflector layer 312 disposed on the slab 302. The reflector layer 312 extends over an area similar to or larger than the area occupied by the scatterers of the scattering array 304. The substrate layer 130 may act as an additional reflective interface that can be used to control the coupling of light into and out of the input waveguide 301. Other waveguide designs may be used in the optical coupler 350 in addition to the tapered slab shown at 302. In one embodiment, a straight slab without a taper may be used with the same effect. Additionally, the transition between the input waveguide 301 and the slab 302 may be tailored.

[0043] 4a and 4b show layers of a three-dimensional view of a dual-polarization (2D) optical coupler 450 without a selective reflector layer according to an embodiment of the present disclosure. The optical coupler 450 may be a hybrid silicon-silicon nitride optical coupler. FIG. 4a shows a scattering array 404 disposed on a substrate layer 130. The scattering array 404 may be quasi-periodic. FIGS. 4a and 4b do not specifically show the cladding 120 so as not to hide other components of the optical coupler 450. However, the thickness of the cladding 120 (e.g., thickness 108) would support the scattering array 404, for example. The cladding 120 may also support the waveguides 401 and 402.

[0044] FIG. 4b shows two input waveguides 401 and 402 connecting to a slab 403 that expands the optical mode from either input waveguide 401 or 402 to a desired size. Waveguide 401 receives optical mode 481 and waveguide 402 receives optical mode 482. In some embodiments, slab 403 can be likened to two 1D coupler slabs 302 (FIG. 3b) rotated 90 degrees and merged. In one embodiment, the first taper of waveguide 401 is extended to the second taper of waveguide 402. Depending on whether the light enters from waveguide 401 or 402, the light is scattered by scattering array 404 into one of two orthogonal polarization states. In one embodiment, optical mode 481 is scattered by scattering array 404 into a first polarization orientation and optical mode 482 is scattered by scattering array 404 into a second polarization orientation that is orthogonal to the first polarization orientation.

[0045] In the example of FIG. 4b, the light field 481 routed by waveguide 401 propagates perpendicular to the light field 482 propagating from waveguide 402. The polarization state of the incident light on optical coupler 450 (e.g., reflection of the transmit beam emitted by optical coupler 450) can affect which waveguide the light is routed to. In some embodiments, scattering array 404 is configured to direct a first polarization orientation of the incident light to waveguide 401 and a second polarization orientation of the incident light to waveguide 402. Thus, in a dual-polarization configuration, the optical couplers of the present disclosure can transmit and receive light in two orthogonal polarization states.

[0046] The optical structures 150, 250, 350 and 450 can be considered integrated vertical optical couplers because they can transmit and / or receive light through the top or bottom surfaces of the cladding or substrate layers. That is, the optical structures 150, 250, 350, 450 can be surface emitting rather than edge emitting. These vertically propagating beams can be projected into the environment to perform LIDAR measurements.

[0047] FIG. 5a illustrates an example autonomous vehicle 500 that may include the optical structures of FIGS. 1a-4b of a LIDAR device according to an embodiment of the present disclosure. The illustrated autonomous vehicle 500 includes a sensor array configured to capture one or more objects of an external environment of the autonomous vehicle and generate sensor data related to the captured one or more objects for the purpose of controlling the operation of the autonomous vehicle 500. FIG. 5a illustrates sensors 533A, 533B, 533C, 533D, and 533E. FIG. 5b illustrates a top view of the autonomous vehicle 500 that includes sensors 533F, 533G, 533H, and 533I in addition to sensors 533A, 533B, 533C, 533D, and 533E. Any of the sensors 533A, 533B, 533C, 533D, 533E, 533F, 533G, 533H, and / or 533I may include a LIDAR device that includes the design of FIGS. 1a-4b. 5c illustrates a block diagram of an example system 599 for an autonomous vehicle 500. For example, the autonomous vehicle 500 may include a powertrain 502 including a prime mover 504 that may be powered by an energy source 506 and provide power to a drivetrain 508. The autonomous vehicle 500 may further include a control system 510 including directional control 512, powertrain control 514, and brake control 516. The autonomous vehicle 500 may be embodied as many different vehicles, including vehicles that may transport people and / or cargo and may operate in a variety of different environments. It will be appreciated that the components 502-516 described above may vary widely depending on the type of vehicle in which these components are used.

[0048] For example, the embodiments described below focus on wheeled land vehicles such as cars, vans, trucks, or buses. In such embodiments, the prime mover 504 may include one or more electric motors and / or an internal combustion engine (among others). The energy source may include, for example, a fuel system (e.g., providing gasoline, diesel, hydrogen), a battery system, solar panels or other renewable energy sources and / or a fuel cell system. The drivetrain 508 may include wheels and / or tires along with a transmission and / or any other mechanical drive components suitable for converting the power output of the prime mover 504 into vehicle motion, as well as one or more brakes configured to controllably stop or slow the autonomous vehicle 500 and a steering or steering component suitable for controlling the trajectory of the autonomous vehicle 500 (e.g., a rack and pinion steering connection that allows one or more wheels of the autonomous vehicle 500 to pivot about a generally vertical axis to change the angle of the wheel's rotational plane relative to the vehicle's longitudinal axis). In some embodiments, a combination of powertrain and energy source may be used (e.g., in the case of an electric / gas hybrid vehicle). In some embodiments, multiple electric motors (eg, dedicated to individual wheels or axles) can be used as prime movers.

[0049] Directional control 512 may include one or more actuators and / or sensors for controlling and receiving feedback from directional or steering components so that autonomous vehicle 500 can follow a desired trajectory. Powertrain control 514 may be configured to control the output of powertrain 502, such as by controlling the output power of prime mover 504 and controlling the transmission gears of drivetrain 508, thereby controlling the speed and / or direction of autonomous vehicle 500. Brake control 516 may be configured to control one or more brakes, such as disc or drum brakes coupled to the wheels of the vehicle, to slow or stop autonomous vehicle 500.

[0050] Other vehicle types, including, but not limited to, off-road vehicles, all-terrain or track vehicles, or construction equipment, will necessarily utilize other powertrains, drivetrains, energy sources, directional control, powertrain control, and braking control as would be understood by one of ordinary skill in the art having the benefit of this disclosure. Also, in some embodiments, some components may be combined, although for example, directional control of the vehicle may be handled primarily by modifying the output of one or more prime movers. Thus, the embodiments disclosed herein are not limited to the specific application of the technology described herein in wheeled land autonomous vehicles.

[0051] In the illustrated embodiment, autonomous control for autonomous vehicle 500 is embodied in vehicle control system 520, which may include one or more processors and one or more memories 524 within processing logic 522, which is configured to execute program code (e.g., instructions 526) stored in memory 524. Processing logic 522 may include, for example, a graphics processing unit (GPU) and / or a central processing unit (CPU). Vehicle control system 520 may be configured to control powertrain 502 of autonomous vehicle 500 in response to an infrared return beam that is a reflection of an infrared transmit beam emitted by light structures 150, 250, 350 and / or 450 into an environment external to autonomous vehicle 500 and reflected back to light structures 150, 250, 350 and / or 450.

[0052] The sensors 533A-533I may include various sensors suitable for collecting data from the autonomous vehicle's surrounding environment for use in controlling the operation of the autonomous vehicle. For example, the sensors 533A-533I may include a RADAR unit 534, a LIDAR unit 536, a 3D positioning sensor 538, a satellite navigation system such as GPS, GLONASS, BeiDou, Galileo, or Compass. The optical coupler design of FIGS. 1a-4b may be included in the LIDAR unit 536. The LIDAR unit 536 may include, for example, multiple LIDAR sensors distributed around the autonomous vehicle 500. In some embodiments, the 3D positioning sensor 538 may use satellite signals to determine the vehicle's position on Earth. The sensors 533A-533I may optionally include one or more ultrasonic sensors, one or more cameras 540, and / or an inertial measurement unit (IMU) 542. In some embodiments, the camera 540 may be a monographic or stereographic camera capable of recording still and / or video images. The camera 540 may include a complementary metal-oxide-semiconductor (CMOS) image sensor configured to capture images of one or more objects in the external environment of the autonomous vehicle 500. The IMU 542 may include a multi-gyroscope and accelerometer capable of detecting linear and rotational motion of the autonomous vehicle 500 in three directions. One or more encoders (not shown), such as wheel encoders, may be used to monitor the rotation of one or more wheels of the autonomous vehicle 500.

[0053] The output of the sensors 533A-533I may be provided to a control subsystem 550, which includes a localization subsystem 552, a trajectory subsystem 556, a perception subsystem 554, and a control system interface 558. The localization subsystem 552 may be configured to determine the position and orientation (also sometimes referred to as "attitude") of the autonomous vehicle 500 within the surrounding environment, and generally within a particular geographic region. The autonomous vehicle's position may be compared to the positions of additional vehicles in the same environment as part of the labeled autonomous vehicle data generation. The perception subsystem 554 may be configured to detect, track, classify, and / or determine objects within the environment surrounding the autonomous vehicle 500. The trajectory subsystem 556 may be configured to generate trajectories for stationary and moving objects in the environment, as well as trajectories for the autonomous vehicle 500 given a desired destination over a particular time frame. Machine learning models according to some embodiments may be utilized to generate the vehicle trajectory. The control system interface 558 is configured to communicate with the control system 510 to implement the trajectory of the autonomous vehicle 500. In some embodiments, machine learning models can be leveraged to control an autonomous vehicle to execute a planned trajectory.

[0054] It will be understood that the collection of components for vehicle control system 520 shown in FIG. 5c is merely exemplary in nature. Individual sensors may be omitted in some embodiments. In some embodiments, the different types of sensors shown in FIG. 5c may be used redundantly and / or to cover different areas in the environment surrounding the autonomous vehicle. In some embodiments, different types and / or combinations of control subsystems may be used. Also, although subsystems 552-558 are shown as separate from processing logic 522 and memory 524, it will be understood that in some embodiments, some or all of the functionality of subsystems 552-558 may be embodied in program code, such as instructions 526 resident in memory 524 and performed by processing logic 522, and that these subsystems 552-558 may be embodied using the same processor and / or memory, in some cases. In some embodiments, the subsystems may be embodied as various dedicated circuit logic, various processors, various Field Programmable Gate Arrays (FPGAs), various Application-Specific Integrated Circuits (ASICs), various real-time controllers, etc., and as previously described, multiple subsystems may utilize circuits, processors, sensors, and / or other components. Additionally, the various components of vehicle control system 520 may be networked in various ways.

[0055] In some embodiments, different architectures including various combinations of software, hardware, circuit logic, sensors, and networks can be used to embody the various components shown in FIG. 5c. Each processor can be embodied, for example, as a microprocessor, and each memory can refer to main storage as well as any auxiliary levels of memory, for example, random access memory (RAM), including cache memory, non-volatile or backup memory (e.g., programmable or flash memory), or read-only memory. Each memory can also be considered to include memory storage physically located elsewhere in the autonomous vehicle 500, for example, any cache memory of the processor, as well as any storage capacity used as virtual memory, for example, as stored in a mass storage device or other computer controller. The processing logic 522 shown in FIG. 5c, or entirely separate processing logic, can be used to perform additional functions in the autonomous vehicle 500 other than for autonomous control purposes, for example, to control an entertainment system or operate doors, lights, or convenience functions.

[0056] For additional storage, autonomous vehicle 500 may also include one or more mass storage devices, such as a removable disk drive, a hard disk drive, a direct access storage device ("DASD"), an optical drive (e.g., CD drive, DVD drive), a solid state storage drive (SSD), a network attached storage, a storage area network, and / or a tape drive. Autonomous vehicle 500 may also include a user interface 564, such as one or more displays, touch screens, voice and / or gesture interfaces, buttons, and other tactile controls, through which autonomous vehicle 500 receives inputs from and generates outputs for the passenger. In some embodiments, inputs from the passenger may be received via other computers or electronic devices, such as via an app on a mobile device or via a web interface.

[0057] In some embodiments, autonomous vehicle 500 may include one or more network interfaces, e.g., network interface 562, suitable for communicating with one or more networks 570 (e.g., a local area network ("LAN"), a wide area network ("WAN"), a wireless network, and / or the Internet, etc.), which may enable communication of information with other computers and electronic devices, including, for example, a central service, such as a cloud service, for autonomous vehicle 500 to receive environmental and other data for use in autonomous control. In some embodiments, data collected by one or more sensors 533A-533I may be uploaded via network 570 to computing system 572 for additional processing. In such embodiments, a timestamp may be associated with each instance of vehicle data prior to uploading.

[0058] The processing logic 522 shown in Figure 5c, as well as the various additional controllers and subsystems disclosed herein, generally operate and execute under the control of an operating system or otherwise rely on various computer software applications, components, programs, objects, modules, or data structures, which are described in detail below. Also, the various applications, components, programs, objects, or modules may execute on one or more processors of other computers coupled to the autonomous vehicle 500 via a network 570, for example in a distributed, cloud-based, or client-server computing environment, whereby the processing required to carry out the functions of a computer program is allocated across multiple computers and / or services via the network.

[0059] The routines executed to embody the various embodiments described herein are referred to herein as "program code" whether embodied as part of an operating system or as part of a particular application, component, program, object, module, or instruction sequence, or a subset thereof. Program code generally includes one or more instructions resident in various memory and storage devices, which, when read and executed by one or more processors, perform the steps necessary to execute the steps or elements embodying the various aspects of the present disclosure. Also, while the embodiments are and will be described in the context of fully functional computers and systems, it will be understood that the various embodiments described herein can be distributed as program products in various forms, and can be embodied regardless of the particular type of computer readable medium used to actually effect the distribution. Examples of computer readable media include non-transitory media types such as volatile and non-volatile memory devices, floppy and other removable disks, solid state drives, hard disk drives, magnetic tape, and optical disks (e.g., CD-ROM, DVD).

[0060] Additionally, various program codes described below may be identified based on the application for which they are embodied in a particular embodiment. However, it should be understood that any particular program nomenclature below is used merely for convenience, and thus the present invention should not be limited to use only with any particular application identified and / or implied by such nomenclature. It should also be understood that the present disclosure is not limited to the particular organization and allocation of program functions described herein, given the generally infinite number of ways in which computer programs can be organized into routines, procedures, methods, modules, objects, etc., and the various ways in which program functions are allocated among the various software layers resident within a typical computer (e.g., operating system, libraries, APIs, applications, applets).

[0061] Those skilled in the art having the benefit of this disclosure will recognize that the exemplary environment illustrated in Figure 5c is not intended to limit the embodiments disclosed herein, and indeed, those skilled in the art will recognize that other alternative hardware and / or software environments may be used without departing from the scope of the embodiments disclosed herein.

[0062] In an embodiment of the present disclosure, visible light can be defined as having a wavelength range of about 380 nm to 700 nm. Invisible light can be defined as light having a wavelength outside the visible light range, such as ultraviolet light and infrared light. Infrared light having a wavelength range of about 700 nm to 1 mm includes near infrared light. In an embodiment of the present disclosure, near infrared light can be defined as having a wavelength range of about 700 nm to 1.6 μm.

[0063] In aspects of the present disclosure, the term "transparent" can be defined as having greater than 90% light transmittance. In some embodiments, the term "transparent" can be defined as a material that has greater than 90% transmittance of visible light.

[0064] As used herein, the term "processing logic" may include one or more processors, microprocessors, multi-core processors, application specific integrated circuits (ASICs), and / or field programmable gate arrays (FPGAs) for performing the operations disclosed herein. In some embodiments, memory (not shown) is integrated into the processing logic for storing instructions for performing operations and / or storing data. Additionally, the processing logic may include analog or digital circuitry for performing operations according to embodiments of the present disclosure.

[0065] A "memory" or "memories" as described herein may include one or more volatile or non-volatile memory architectures. A "memory" or "memories" may be removable and non-removable media embodied in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data. Examples of memory technologies may include RAM, ROM, EEPROM, flash memory, CD-ROM, DVD, high definition multimedia / data storage disks or other optical storage devices, magnetic cassettes, magnetic tapes, magnetic disk storage devices, or other non-transmitting media that can be used to store information to enable access by a computing device.

[0066] The network includes any network or network system, such as, but not limited to, a peer-to-peer network, a local area network (LAN), a wide area network (WAN), a public network such as the Internet, a private network, a cellular network, a wireless network, a wired network, a combined wired and wireless network, and a satellite network.

[0067] The communications channel may include or be routed by one or more wired or wireless communications using IEEE 802.11 protocols, Serial Peripheral Interface (SPI), Inter-Integrated Circuit (I2C), Universal Serial Port (USB), Controller Area Network (CAN), cellular data protocols (e.g., 3G, 4G, LTE, 5G), optical communications networks, Internet Service Providers (ISPs), peer-to-peer networks, LANs, WANs, public networks (e.g., the “Internet”), private networks, satellite networks, or others.

[0068] The computing devices may include desktop computers, laptop computers, tablets, phablets, smartphones, feature phones, server computers, etc. The server computers may be located remotely in a data center or stored locally.

[0069] The processes described above are described in terms of computer software and hardware. The techniques described may constitute machine-executable instructions embodied in a tangible or non-transitory machine (e.g., computer) readable storage medium that, when executed by a machine, causes the machine to perform the described operations. The processes may also be embodied in hardware, such as an application specific integrated circuit ("ASIC").

[0070] A tangible, non-transitory, machine-readable storage medium may include any mechanism for providing (e.g., storing) information in a form accessible by a machine (e.g., a computer, a network device, a PDA, a manufacturing tool, any device having one or more processor sets, etc.). For example, machine-readable storage media include recordable / non-recordable media (e.g., Read Only Memory (ROM), Random Access Memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, etc.).

[0071] The foregoing description of illustrated embodiments of the disclosure, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Although specific embodiments and examples of the invention have been described herein for illustrative purposes, various modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.

[0072] Such modifications of the invention can be made in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.

Claims

1. 1. A light detection and ranging (LIDAR) device for a vehicle, the LIDAR device comprising: a cladding having a first surface and a second surface; a waveguide formed within the cladding, the waveguide configured to route a light field generated from light coupled into the waveguide; a scattering array including a plurality of scatterers formed in the cladding between the waveguide and the second surface, the scattering array configured to disrupt the light field and scatter the light field into a first beam that propagates towards the first surface of the cladding; and A LIDAR device comprising:

2. 10. The LIDAR device of claim 1, wherein the first beam propagating toward the first surface of the cladding comprises a majority of the optical power contained in the light field.

3. 2. The LIDAR device of claim 1, wherein each of the plurality of scatterers has a substantially uniform parameter, the parameter including a thickness, a width, or a spacing of the plurality of scatterers.

4. 2. The LIDAR device of claim 1, wherein each of the plurality of scatterers has a parameter that varies across the plurality of scatterers to form the first beam into a particular shape, the parameter including a thickness, a width, or a spacing of the plurality of scatterers.

5. 10. The LIDAR device of claim 1, wherein the scattering array is spaced from the waveguide by a specific spacing distance.

6. 6. The LIDAR device of claim 5, wherein an intensity of scattering provided by the scattering array is controlled as a function of the particular spacing distance and duty factor of the plurality of scatterers.

7. the scattering array is quasi-periodic; the plurality of scatterers include silicon scatterers; 2. The LIDAR device of claim 1.

8. 8. The LIDAR device of claim 7, wherein the quasi-periodic scattering array is configured such that the spacing between each of the plurality of scatterers varies.

9. 10. The LIDAR device of claim 1 , wherein the waveguide comprises silicon nitride.

10. 10. The LIDAR device of claim 1, wherein the cladding comprises an oxide that is transparent to infrared light.

11. The LIDAR device of claim 10 , wherein the cladding comprises silicon dioxide.

12. a substrate disposed against the second surface of the cladding to form an interface, wherein light scattered toward the interface is at least partially reflected from the interface and propagates toward the first surface of the cladding.

2. The LIDAR device of claim 1.

13. 13. The LIDAR device of claim 12, wherein the substrate comprises silicon and the interface comprises a silicon-glass interface.

14. a reflector layer disposed within the cladding between the waveguide and the first surface of the cladding, the reflector layer configured to reflect the first beam toward the second surface of the cladding.

2. The LIDAR device of claim 1.

15. 1. An autonomous vehicle control system, comprising: The LIDAR device includes: a cladding having a first surface and a second surface; a waveguide formed within the cladding, the waveguide configured to route a light field generated from light coupled into the waveguide; a scattering array including a plurality of scatterers formed in the cladding between the waveguide and the second surface, the scattering array configured to disrupt the light field and scatter the light field into a first beam that propagates towards the first surface of the cladding; and An autonomous vehicle control system comprising:

16. 16. The autonomous vehicle control system of claim 15, wherein the first beam propagating toward the first surface of the cladding comprises a majority of the optical power contained in the optical field.

17. 16. The autonomous vehicle control system of claim 15, wherein the scattering array is spaced from the waveguide by a particular spacing distance, and a strength of scattering provided by the scattering array is controlled by the particular spacing distance.

18. 1. An autonomous vehicle, comprising: The LIDAR device includes: a cladding having a first surface and a second surface; a waveguide formed within the cladding, the waveguide configured to route a light field generated from light coupled into the waveguide; a scattering array including a plurality of scatterers formed in the cladding between the waveguide and the second surface, the scattering array configured to disrupt the light field and scatter the light field into a first beam that propagates towards the first surface of the cladding; and An autonomous vehicle comprising:

19. 20. The autonomous vehicle of claim 18, wherein the first beam propagating toward the first surface of the cladding comprises a majority of the optical power contained in the optical field.

20. 20. The autonomous vehicle of claim 18, wherein the LIDAR device is configured to receive a return beam that is a reflection of the first beam from a target in an external environment.

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