Lidar with phase light modulator

Abstract

An apparatus (400) has a first light source (404) configured to direct a first light beam (410) to a phase light modulator (414) and a second light source (406) configured to direct a second light beam (420) to the phase light modulator (414). The phase light modulator (414) is configured to provide a first modulated light beam (416) directed to a first field of view (418) and a second modulated light beam (426) directed to a second field of view (428). The apparatus (400) also has a first light detector configured to detect the first modulated light beam as reflected from the first field of view and a second light detector configured to detect the second modulated light beam as reflected from the second field of view.

Description

Technical Field

[0001] This application relates generally to ranging devices, and more specifically to ranging and imaging devices using light. Background Technology

[0002] A LiDAR (Light Detection and Ranging) system detects and determines the location of an object. In one example, a light beam is projected onto a known location within the field of view. A photodetector focuses on that location and detects any reflections of light from an object that might be within the field of view. The time it takes for the light to travel is used to help determine the distance to the object. By scanning the beam across the field, the location of objects in the field and an image of the objects can be determined.

[0003] One challenge of scanning LiDAR systems is scanning quickly and accurately enough to capture the motion of objects within the field. For example, in automotive applications, LiDAR systems must determine the motion of pedestrians, vehicles, and other objects rapidly and accurately. Mirrors have been used to scan the beam. Other examples use gimbals to move the entire light projection and detection system as a single unit. However, operating these mechanical systems with sufficient precision is difficult. Furthermore, such systems are typically bulky, have high power requirements, and require frequent maintenance and calibration to maintain accuracy. Summary of the Invention

[0004] According to the described example, an apparatus includes a phase light modulator. The apparatus also includes a first light source optically coupled to the phase light modulator, the first light source being configured to generate a first light beam and positioned to guide the first light beam to the phase light modulator at a first incident angle, the phase light modulator being configured to modulate the first light beam to provide a first modulated beam and, in response to the first light beam, guide the first modulated beam to a first field of view; and a second light source optically coupled to the phase light modulator, the second light source being configured to generate a second light beam and positioned to guide the second light beam to the phase light modulator at a second incident angle, the phase light modulator being configured to modulate the second light beam to provide a second modulated beam and, in response to the second light beam, guide the second modulated beam to a second field of view. The apparatus also includes a first photodetector optically coupled to the first field of view and configured to detect, for example, the first modulated beam reflected from the first field of view, and a second photodetector optically coupled to the second field of view and configured to detect, for example, the second modulated beam reflected from the second field of view. Attached Figure Description

[0005] Figure 1A and Figure 1B (Collectively referred to as “Figure 1”) is a diagram showing the light redirection using a phase optical modulator (PLM).

[0006] Figure 2 This is a side view of an example micromirror.

[0007] Figure 3 This is a top view of the example LIDAR device.

[0008] Figures 4A to 4D (Collectively referred to as “Figure 4”) is a view of the transmitter section of an example LIDAR device and the scanning mode used with the LIDAR device.

[0009] Figure 5A and Figure 5B (Collectively referred to as “Figure 5”) is a view of the receiver section of the LIDAR device in Figure 4.

[0010] Figure 6 This is a diagram of another example LIDAR device.

[0011] Figure 7 This is a flowchart of the example method.

[0012] Figure 8 This is a flowchart of another example method. Detailed Implementation

[0013] In the accompanying drawings, unless otherwise specified, the corresponding numbers and symbols generally refer to the corresponding parts. The accompanying drawings are not necessarily drawn to scale.

[0014] In this specification, the term "coupled" can include a connection formed with an intermediate element, and additional elements and various connections can exist between any elements "coupled". An element referred to herein as "optical coupling" is an element that includes a connection between elements involving optical transmission. Similarly, as used herein, a "phase optical modulator" (PLM) is a device having multiple pixels, wherein the PLM can modify the phase of light applied to each pixel. The PLM can reflect or transmit the applied light. The applied light is modulated by interference from the light from the phase-modified pixels and / or the unmodified pixels.

[0015] In the example arrangement, the slow scan rate and narrow field of view (FOV) problems of the phase light modulator (PLM) directing the light source are addressed by providing the PLM with at least two light sources such that light from each source simultaneously scans different FOVs. In at least one example, the LIDAR device has a single PLM unit for at least two light sources. The light sources have different angular orientations relative to the PLM. Due to the different angular orientations, each laser illuminates a point in its corresponding field of view (FOV), and all FOVs are scanned simultaneously and tiled together. According to the example, one device includes a phase light modulator. The device also includes a first light source optically coupled to a phase light modulator, the first light source being configured to generate a first beam and positioned to guide the first beam to the phase light modulator at a first incident angle, the phase light modulator being configured to modulate the first beam to provide a first modulated beam and, in response to the first beam, guide the first modulated beam to a first field of view; and a second light source optically coupled to the phase light modulator, the second light source being configured to generate a second beam and positioned to guide the second beam to the phase light modulator at a second incident angle, the phase light modulator being configured to modulate the second beam to provide a second modulated beam and, in response to the second beam, guide the second modulated beam to a second field of view. The device also includes a first photodetector optically coupled to the first field of view and configured to detect, for example, the first modulated beam reflected from the first field of view, and a second photodetector optically coupled to the second field of view and configured to detect, for example, the second modulated beam reflected from the second field of view.

[0016] The example PLM is a digital micromirror-based PLM. This type of PLM device includes numerous digital micromirrors on a substrate surface. In this example, this type of PLM may include hundreds of thousands or more than a million micromirrors. Each micromirror is designed such that its vertical position above the substrate can be precisely positioned by driving circuitry in the substrate using an electrostatic force applied to the micromirror. The phase of the light reflected from a particular micromirror is determined by the vertical position of the micromirror (vertical relative to the substrate, which is horizontal in this discussion). For example, if the first micromirror is positioned at the full height above the substrate, and an adjacent second micromirror is positioned a quarter wavelength lower, the light reflected from the second micromirror will travel half a wavelength relative to the light reflected from the first micromirror (a downward quarter wavelength plus an upward quarter wavelength). The light reflected from the first and second micromirrors will then interfere in a predictable manner. The phase change mode on the PLM can be selected to provide desired diffraction-like effects, such as redirecting or focusing the light. See, for example, McManamon et al., “Optical Phased Array Technology” (Proceedings of the IEEE, Vol. 84, No. 2, pp. 269-298 (February 1996), which is incorporated herein by reference in its entirety. Arbitrary patterns, such as spots or beams, can be created at desired distances within the field of view. Another example PLM is a liquid crystal phase light modulator. Using this type of PLM, a voltage applied to each pixel alters the liquid crystal at that pixel, resulting in a phase shift of light. Liquid crystal PLMs can be transmissive or reflective.

[0017] Figure 1A and Figure 1B (Collectively referred to as "Figure 1") is a diagram illustrating light steering using a PLM. In this example, PLM 102 is a digital micromirror-based PLM. Figure 1A In the PLM 102, the micromirror 104 has a steering mode selected to guide the light 106 in direction 108. Figure 1B In this configuration, the micromirror 104 has a mode selected to guide light 106 in direction 110. Therefore, the PLM 102 can redirect the light in the desired direction. In addition to redirecting the light, the PLM 102 can also focus the light at a spot (focal point) at a desired distance.

[0018] Figure 2 This is a side view of an example micromirror similar to micromirror 104 (Figure 1). Platform 204 is connected to two platform electrodes 212 via platform posts 214. Posts 208 support the mirror 210 above platform 204. Figure 2As shown, when a voltage is applied to the drive electrode 206 and a reference voltage (e.g., ground) is applied to the platform electrode 212, an electrostatic force pulls the platform 204 down, and thus the mirror 210 down. The amount of movement is determined by the applied voltage. In other examples, the pixel 202 uses two or more drive electrodes 206 that can be individually addressed by drive circuitry (not shown). The applied electrostatic force is proportional to the area of ​​the drive electrodes 206 and the platform 204. Thus, by using multiple electrodes, the magnitude of the force, and therefore the vertical position of the mirror 210, can be precisely controlled by selecting either the drive electrodes 206 or a combination of drive electrodes 206, while applying the same voltage to each selected drive electrode 206. The phase shift provided by the pixel 202 is determined by the vertical positioning of the mirror 210. For example, if the pixel is reduced by a quarter wavelength (1 / 4λ), the light reflected from that pixel will propagate an additional half wavelength (1 / 4λ downwards to the mirror and 1 / 4λ back) relative to a pixel that is not reduced. In another example, if a pixel is reduced by one-eighth of a wavelength (1 / 8λ), then the light reflected from that pixel will travel an additional quarter wavelength (1 / 8λ down to the mirror and 1 / 8λ back) relative to a pixel that is not reduced.

[0019] Figure 3 This is a top view of an example LIDAR device 300. In this example, the light source 302 is a laser. In this example, the light source 302 provides near-infrared laser light. The light source 302 provides light through a collimating lens 304 to an emitting PLM 306. The emitting PLM 306 provides a configurable phase mode to the light, which guides the light to a target 308. Figure 3 In this example, target 308 is on the surface of object 310, which is a car. Light reflected from object 310 is focused by receiving PLM 312 through lens 316 onto detector 314. Because the point where the light is guided by emitting PLM 306 is known, the detection of reflected light by detector 314 indicates the presence of an object at that point. In this example, detector 314 is an avalanche photodiode. Emitting PLM 306 scans the field of view, while receiving PLM 312 scans the field of view seen by the APD to match the target 308 being scanned by the emitting PLM. This allows the example LIDAR device 300 to determine the distance and outline of object 310.

[0020] The LIDAR device 300 has limitations. For example, each mode on the PLM corresponds to directing the beam in a specific direction. Changing from one mode to another via the transmitting PLM 306 and receiving PLM 312 takes a significant amount of time. For instance, if the data loading time for the new mode is 50 μs and the frame time is 100 ms, only 2000 points can be captured, resulting in a resolution of only about 65x30. Higher resolution is preferred. Furthermore, large field-of-view (FOV) LIDAR scanning is challenging. Scanning an area greater than 60x20 degrees with a 0.1-degree beamwidth and a 10 Hz frame rate requires a PLM update rate of more than 1 million samples per second. However, the size of the mirrors in the PLM limits the FOV, and the wavelength of the light limits the FOV. For a pixel size of approximately 10 μ square pixels using near-infrared light, the FOV of current PLM devices is limited to a few degrees. The receiving PLM 312 allows for the rejection of ambient light by directing light to the detector from a narrow angle. However, scanning a large FOV requires wide-angle optics. Wide-angle optics require a small aperture size to limit the signal strength received at detector 314.

[0021] Figures 4A to 4D (Collectively referred to as “Figure 4”) is a view of the transmitter section 402 of an example LIDAR device 400. Figure 4AThis is a top view of the emitting section 402. As used herein, the terms "top view" and "side view" indicate relative orientation of the views and do not imply any other relationship. For example, the "top" or "side" of the LIDAR device 400 may be in any of several orientations in a particular installation of the example LIDAR device 400. The example LIDAR device 400 includes three light sources: a first light source 404, a second light source 406, and a third light source 408. A controller 401 controls the light output of the first light source 404, the second light source 406, and the third light source 408. The example LIDAR device 400 includes three light sources in this example, but may include two, four, or more light sources, which may be arranged in a one-dimensional or two-dimensional array. Furthermore, in this example, the first light source 404, the second light source 406, and the third light source 408 are near-infrared laser diodes, but may also be other types of light sources, such as ultraviolet light sources. The first light source 404 provides a first beam 410 through a first collimating lens 412 at a first incident angle relative to the emitting PLM 414. In this example, the transmitting PLM 414 is a digital micromirror-based PLM. In other examples, the transmitting PLM 414 is a reflective or transmissive liquid crystal phase light modulator. Based on the steering mode applied to the transmitting PLM 414 by the controller 401, the first output of the transmitting PLM 414 in response to the first beam 410 is a first modulated beam 416 having a first output reflection angle. The first incident angle of the first light source 404 and the steering mode on the transmitting PLM 414 determine the output angle reflected to the first focal point 411. In this example, the first incident angle guides the first modulated beam 416 to the first focal point 411 on the object 450 in the first field of view (FOV) 418.

[0022] The second light source 406 provides a second beam 420 through the second collimating lens 422 at a second incident angle relative to the transmitting PLM 414. Based on the steering mode applied to the transmitting PLM 414 by the controller 401, the output of the transmitting PLM 414 in response to the second beam 420 is a second modulated beam 426 with a second reflection angle. At any given time, the steering mode on the transmitting PLM 414 is constant. Therefore, the difference between the second reflection angle and the first reflection angle is determined by the difference between the second incident angle and the first incident angle. Similar to the first reflection angle, the second reflection angle of the second light source 406 and the mode on the transmitting PLM 414 determine the second reflection angle. In this example, the second reflection angle guides the second modulated beam 426 to a second focal point 421 on the object 450 in the second FOV 428.

[0023] The third light source 408 provides a third beam 430 through the third collimating lens 432 at a third incident angle relative to the transmitting PLM 414. Based on the steering mode applied to the transmitting PLM 414 by the controller 401, the output of the transmitting PLM 414 in response to the third beam 430 is a third modulated beam 436 with a third reflection angle. At any given time, the steering mode on the transmitting PLM 414 is constant. Therefore, the difference between the third reflection angle and the first and second reflection angles is determined by the difference between the third incident angle and the first and second incident angles. Similar to the first and second reflection angles, the third incident angle of the third light source 408 and the mode on the transmitting PLM 414 determine the third reflection angle. In this example, the third reflection angle guides the third modulated beam 436 to a third focal point 431 on the object 450 in the third FOV 438. In summary, the PLM 414 simultaneously guides the light from the first light source 404, the second light source 406, and the third light source 408 to points in the first FOV 418, the second FOV 428, and the third FOV 438, respectively.

[0024] Figure 4B It is by Figure 4A The view shown in line of sight 4B-4B is a view of the field of view. Figure 4B This is a view from the angle of the transmitter PLM 414 facing the first FOV 418, the second FOV 428, and the third FOV 438. For a given azimuth pattern on the transmitter PLM 414, the first light source 404, the second light source 406, and the third light source 408 illuminate a point in each of the first FOV 418, the second FOV 428, and the third FOV 438, respectively. By changing the azimuth pattern of the transmitter PLM 414, the transmitter section 402 scans each FOV. In this example, as... Figure 4B As shown, the first scan point 442, the second scan point 452, and the third scan point 462 are scanned using a raster scan method. However, other scanning methods, such as random scanning, can be used. Figure 4B As shown, in this example, the sizes of the first FOV 418, the second FOV 428, and the third FOV 438 are chosen such that they avoid irrelevant diffraction orders produced by light diffracted from the steering mode on the emitting PLM 414. In other examples, FOVs overlap to provide a more accurate but slower scan. In these examples, any irrelevant diffraction orders must be corrected after detection.

[0025] Figure 4C This is a side view of the transmitter section 402 of the example LIDAR device 400. Figure 4C This is a view taken from the direction of the third light source 408 across the surface emitting PLM 414. Figure 4A Viewed from 4C-4C. From this angle, the third light source 408 obstructs the view of the first light source 404 and the second light source 406. Furthermore, the third collimating lens 432 obstructs the view of the first collimating lens 412 and the second collimating lens 422. For simplicity, Figure 4C Only the third beam 430 and the third modulated beam 436 are shown in the image. From... Figure 4C As can be seen, the third beam 430 and the third modulated beam 436 are not in the same plane. In this example, this avoids interference between the third light source 408 and the third modulated beam 436. This example shows a specific configuration of the light source relative to the emitting PLM 414. Other examples may use different configurations. Furthermore, other examples may use two, four, or more light sources.

[0026] Figure 4D This is a top view of another example transmitter section 405 of another example LIDAR device 403. In this example device, a light source 407 generates a first modulated beam 416, a second modulated beam 426, and a third modulated beam 436. The light source 407 provides beam 423 through a collimating lens 425. The transmitter PLM 414 in this example does not use a single steering mode, but rather three steering modes. In this example, three different steering modes will be applied to three different sections of the transmitter PLM 414. Three steering modes are used in this example. However, two, four, or more steering modes can be used. Furthermore, Figure 4D Examples include a single light source with one angle of incidence. However, by using multiple light sources with multiple angles of incidence and multiple directional modes applied to the transmitting PLM414, the number of fields of view that can be illuminated simultaneously can be increased exponentially. For example, three light sources applied to a transmitting PLM with three directional modes can simultaneously illuminate nine fields of view.

[0027] exist Figure 4D In the example, the three steering modes applied to the emitting PLM 414 generate a first modulated beam 416, a second modulated beam 426, and a third modulated beam 436, which respectively illuminate the object 450 at a first focal point 411, a second focal point 421, and a third focal point 431 in a first field of view 418, a second field of view 428, and a third field of view 438. (As mentioned above...) Figure 4A and Figure 4B The described steering pattern scans the field of view. Because each steering pattern is applied to one-third or less of the area where the PLM 414 is emitted, Figure 4D The example will limit the amount of light provided to each focal point to one-third or less of the brightness provided by the light source 407.

[0028] Figure 5A and Figure 5B(Collectively referred to as “Figure 5”) is a view of the receiving portion 502 of the example LIDAR device 400 (Figure 4). Figure 5A A top view of the receiving section 502 is shown. The controller 501 is similar to the controller 401 (FIG. 4). A first detector 504, a second detector 506, and a third detector 508 detect light reflected from objects in the first field of view (FOV) 518, the second FOV 528, and the third FOV 538, respectively. The first FOV 518, the second FOV 528, and the third FOV 538 correspond to the first FOV 418, the second FOV 428, and the third FOV 438 (FIG. 4). A first focal point 511, a second focal point 521, and a third focal point 531 correspond to the first focal point 411, the second focal point 421, and the third focal point 431 (FIG. 4), respectively. The first detector 504 detects the first focal point 511 in the first FOV 518 illuminated by the first light source 404 (FIG. 4). The second detector 506 detects the second focal point 521 in the second FOV 528 illuminated by the second light source 406 (FIG. 4). The third detector 508 detects the third focal point 531 in the third field of view 538 illuminated by the third light source 408 (Fig. 4). Object 550 corresponds to object 450 (Fig. 4).

[0029] The receiving PLM 514 focuses a first reflected beam 516, reflected from the object 550 at a first focal point 511 in the first FOV 518, as a first received beam 510 onto the first detector 504 via a first receiving lens 512. In this example, the receiving PLM 514 is a digital micromirror-based PLM. In other examples, the receiving PLM 514 is a reflective or transmissive liquid crystal phase light modulator. The controller 501 receives the output of the first detector 504 for further processing. The first focal point 511 in the first FOV 518 corresponds to the first focal point 411 in the first FOV 418 (FIG. 4). The fourth reflection angle of the first detector 504 and the steering and focusing modes on the receiving PLM 514 provided by the controller 501 determine the fourth angle of incidence of the first focal point 511 relative to the receiving PLM 514. In this example, the fourth reflection angle is different from the first angle of incidence to allow the first detector 504 to be positioned in a manner that does not interfere with the first light source 404 (FIG. 4) and the first detector 504. The steering and focusing mode provided by controller 501 on the receiving PLM 514 is selected to direct the focus of the first reflected beam 516 to the first focus 511 on the object 550. The first focus 511 of the first reflected beam 516 is the same as the first focus 411 pointed to by the first modulated beam 416 (FIG. 4). As the first modulated light 416 (FIG. 4) scans the first FOV 418 (FIG. 4), the focus of the first reflected beam 516 scans the same point pointed to by the first modulated light 416 (FIG. 4). In this example, the first detector 504 is an avalanche photodiode. If the first detector 504 detects light reflected from the first focus 511 of the first reflected beam 516 from the first light source 404 (FIG. 4), the detected light indicates that the object 550 is at that point. Scanning all of the first FOV 518 determines the shape and position of the object 550 that may be in the first FOV 518. In this example, the transmitting PLM 414 (FIG. 4) and the receiving PLM 514 are the same PLM. However, since the mode on the PLM414 / 514 in this example must simultaneously focus the transmitted and received light, using a combined PLM in this example requires positioning the light source and detector in a configuration that may be impractical in some cases. As in the examples of Figures 4 and 5, using separate PLMs for the receiving and transmitting sections allows for greater flexibility in positioning the components of the LIDAR device.

[0030] The receiving PLM 514 and the second receiving lens 522 focus the second reflected beam 526, reflected from the object 550 at the second focal point 521 in the second FOV 528, as the second received beam 520 onto the second detector 506. The controller 501 receives the output of the second detector 506 for further processing. The second focal point 521 in the second FOV 528 corresponds to the second focal point 421 in the second FOV 428 (FIG. 4). The fifth reflection angle of the second detector 506 relative to the receiving PLM 514 and the focusing mode on the receiving PLM 514 determine the fifth angle of incidence of the second focal point 521 relative to the receiving PLM 514. In this example, the fifth reflection angle is different from the second angle of incidence to allow the first detector 506 to be positioned in a manner that does not interfere with the first light source 406 (FIG. 4) and the first detector 506. The second focal point 521 of the second reflected beam 526 is the second focal point 421 of the second FOV 428 to which the second modulated beam 426 (FIG. 4) is directed. At any given time, the steering pattern on the receiving PLM 514 is constant. Therefore, the difference between the fifth and fourth incident angles is determined by the difference between the fifth and fourth reflection angles. Similar to the fourth reflection angle, the fifth reflection angle of the second detector 506 and the pattern on the receiving PLM 514 determine the fifth incident angle. As the second modulated beam 426 (FIG. 4) scans the second FOV 428, the second focus 521 of the second reflected beam 526 scans the same second focus 421 pointed to by the second modulated beam 426 (FIG. 4). In this example, the second detector 506 is an avalanche photodiode. If the second detector 506 detects light reflected from the second light source 406 (FIG. 4) at the second focus 521 of the object 550, the detected light indicates that the object 550 is at that point. Scanning all second FOVs 528 determines the shape and position of objects that may be within the second FOVs 528.

[0031] The receiving PLM 514 and the third receiving lens 532 focus the third reflected beam 536, reflected from the object 550 at the third focal point 531 in the third FOV 538, as the third received beam 530 onto the third detector 508. The controller 501 receives the output of the third detector 508 for further processing. The third focal point 531 in the third FOV 538 corresponds to the third focal point 431 in the third FOV 438 (FIG. 4). The sixth angle of incidence of the third detector 508 and the steering and focusing mode on the receiving PLM 514 provided by the controller 501 determine the sixth reflection angle of the third focal point 531 relative to the receiving PLM 514. In this example, the sixth reflection angle is different from the third angle of incidence to allow the third detector 508 to be positioned in a manner that does not interfere with the third light source 408 (FIG. 4) and the third detector 508. At any given time, the steering mode on the receiving PLM 514 is constant. Therefore, the difference between the sixth angle of incidence and the fourth and fifth angles of incidence is determined by the difference between the sixth reflection angle and the fourth and fifth reflection angles. Similar to the fourth and fifth incident angles, the reflection angle of the third detector 508 and the pattern on the receiving PLM 514 determine the sixth incident angle. The third focal point 531 of the third reflected beam 536 is the third focal point 431 of the third field of view 438 pointed to by the third modulated beam 436 (FIG. 4). As the third modulated beam 436 (FIG. 4) scans the third field of view 438, the third focal point 531 of the first reflected beam 516 scans the same third focal point 431 (FIG. 4) pointed to by the third modulated beam 436 (FIG. 4). In this example, the third detector 508 is an avalanche photodiode. If the third detector 508 detects light reflected from the third light source 408 (FIG. 4) from the object 550 at the third focal point 531, the detected light indicates that the object 550 is at that point. Scanning all third field of view 538 determines the shape and position of objects that may be in the third field of view 538. In summary, the example LIDAR device 400 (FIG. 4) scans three fields of view simultaneously. In other words, the data rate of PLM decreases due to the number of tiled FOVs. Therefore, for a given PLM steering mode load rate, the example LiDAR device 400 (Figure 4) scans the same area three times faster than a LiDAR device using a single light source / detector pair. Furthermore, since each scanned field of view is a smaller portion of the entire field of view, the field-of-view size limitation caused by the steering angle limitation of PLM is overcome. In another example, the tiled FOVs can overlap to provide multiple data points for each point, thus providing better coverage. In yet another example, the FOVs can be tiled in two dimensions. That is, the field of view can be on one plane or on multiple planes relative to a LiDAR device.

[0032] Figure 5BThis is a side view of the receiver section 502 of the example LIDAR device 400. Figure 5B This is viewed from the direction of the third detector 508 across the surface of the receiving PLM 514. Figure 5A The view Figure 5B-5B From this angle, the third detector 508 obstructs the view of the first detector 504 and the second detector 506. Furthermore, the third receiving lens 532 obstructs the view of the first receiving lens 512 and the second receiving lens 522. For simplicity, Figure 5B Only the third receiving beam 530 and the third reflecting beam 536 are shown. (See image.) Figure 5B As shown, the third receiving beam 530 and the third reflecting beam 536 are not in the same plane. In this example, this avoids interference between the third detector 508 and the third reflecting beam 536. This example illustrates a specific configuration of the light source relative to the receiving PLM 514. Other examples may use different configurations. Furthermore, other examples may use two, four, or more detectors. In another example, the FOV or tiled FOV in the examples of Figures 4 and 5 can be extended by illuminating with a diverging laser beam. Examples of using diverging beams are described in Makowski et al., “Simple Holographic Projection in Color,” (Opt. Express 20, 22 (2012.02)) and Maimone et al., “Holographic Near-Eye Displays for Virtual and Augmented Reality,” (ACM Transactions on Graphics, Vol. 36, No. 4, Article 85 (2017.07)), the entire contents of which are incorporated herein by reference.

[0033] Figure 6 This is a diagram of another example LIDAR device 600. In this example, the light source 602 is a laser. In this example, the light source 602 provides near-infrared laser light. The light source 602 provides a diverging beam 603 to an emitting PLM 606, which provides a modulated beam 605 in response to the diverging beam 603 output from the light source 602. (Not using...) Figure 3 In the example, the collimating lens, emitting PLM 606, provides a configurable phase mode to the light, which guides the modulated beam 605 to the target 608 and provides optical power or curvature to focus the diverging beam 603 from the light source 602 onto a focal point 611. Therefore, by using a phase mode with optical power to focus the diverging light from the light source 602, the example LIDAR device 600 eliminates the additional cost and manufacturing complexity of using a collimating lens. Figure 6In this example, focus 611 is on the surface of object 610, which is a car. Receiving PLM 612 includes a mode that focuses light reflected from object 610 at focus 611 onto detector 614. In this example, the mode on receiving PLM 612 includes a steering function and the power or curvature of the light directly focused onto detector 614. Therefore, no additional lens is needed to focus and "decollimate" the light from focus 611 onto detector 614. In this example, transmitting PLM 606 and receiving PLM 612 are digital micromirror-based PLMs. In other examples, one or both of transmitting PLM 606 and receiving PLM 612 are reflective or transmissive liquid crystal phase light modulators. Controller 601 controls the modes on transmitting PLM 606 and receiving PLM 612 and controls the light provided by light source 602 and receives detected light signals from detector 614. Because the controller 601 knows the point where the transmitting PLM 606 directs the light from the light source 602, the detector 614 detects the reflected light to indicate that the object is at that point. In this example, the detector 614 is an avalanche photodiode. The transmitting PLM 606 scans the field of view, while the receiving PLM 612 is adjusted to focus on the focal point 611 that the transmitting PLM 606 is scanning. This allows the example LIDAR device 600 to determine the distance and outline of the object 610. In another example, a configuration using multiple light sources and detectors is employed, as shown in Figures 4 and 5, where the light sources can provide divergent light and the PLMs can provide optical power, and... Figure 6 Similar to the example, this eliminates the need for lens collimation at the light source output and lens focusing at the detector input.

[0034] Figure 7This is a flowchart of example method 700. Step 702 guides a first beam from a first light source to a first input of a phase light modulator. A light source such as first light source 404 (Figure 4) provides the first beam. The phase light modulator is similar to emitting PLM 414 (Figure 4). Step 704 modulates the first beam using the phase light modulator to provide a first modulated beam guided to a first field of view. The first modulated beam is similar to modulated first modulated beam 416 (Figure 4). The first field of view is similar to a first FOV 418 (Figure 4). Step 706 guides a second beam from a second light source to the phase light modulator. A light source such as second light source 406 (Figure 4) provides the second beam. Step 708 modulates the second beam using the phase light modulator to provide a second modulated beam guided to a second field of view. The second modulated beam is similar to second modulated beam 426 (Figure 4). The second field of view is similar to a second FOV 428 (Figure 4). Step 710 detects the first beam reflected from the first field of view using a first photodetector. The first photodetector is similar to first detector 504 (Figure 5). Step 712 involves using a second photodetector to detect the second beam reflected from the second field of view. The second photodetector is a second photodetector 506 (Figure 5).

[0035] Figure 8 This is a flowchart of another example method 800. Step 802 is to guide the diverging beam from the light source to the phase light modulator. The diverging light source is similar to light source 602 ( Figure 6 The phase light modulator is similar to the transmitting PLM 606. Step 804 is to use the phase light modulator to modulate the diverging beam to provide a modulated output beam guided into the field of view. The field of view is similar to target 608. Figure 6 Step 806 involves using a photodetector to detect the light modulation output, such as light reflected from the field of view. The photodetector is similar to detector 614. Figure 6 ).

[0036] Within the scope of the claims, modifications to the described examples are possible, and other examples are also possible.

Claims

1. A light detection and ranging LIDAR device, comprising: Phase light modulator; A first light source, optically coupled to the phase light modulator, is configured to generate a first light beam and is positioned to guide the first light beam to the phase light modulator at a first incident angle. The phase light modulator is configured to modulate the first light beam to provide a first modulated light beam having a first reflection angle and to guide the first modulated light beam to a first field of view in response to the first light beam. A second light source, optically coupled to the phase light modulator, is configured to generate a second light beam and be positioned to guide the second light beam to the phase light modulator at a second incident angle. The phase light modulator is configured to: modulate the first light beam to provide the first modulated light beam and guide the first modulated light beam to the first field of view, while simultaneously modulating the second light beam to provide a second modulated light beam having a second reflection angle and guiding the second modulated light beam to the second field of view in response to the second light beam, wherein the difference between the first reflection angle and the second reflection angle is determined by the difference between the first incident angle and the second incident angle. A first photodetector, optically coupled to the first field of view and configured to detect the first modulated beam reflected from the first field of view; as well as A second photodetector is optically coupled to the second field of view and configured to detect the second modulated beam reflected from the second field of view.

2. The LIDAR device according to claim 1, wherein, The phase light modulator is a first phase light modulator, and the device further includes a second phase light modulator configured to guide the first modulated beam reflected from the first field of view to the first photodetector and configured to guide the second modulated beam reflected from the second field of view to the second photodetector.

3. The LIDAR device according to claim 2, wherein, The third reflection angle from the second phase light modulator to the first photodetector is different from the first incident angle, and wherein the fourth reflection angle from the second phase light modulator to the second photodetector is different from the second incident angle.

4. The LIDAR device according to claim 1, wherein, The phase light modulator modulates the first beam in a steering mode to provide the first modulated beam, and the phase light modulator modulates the second beam in the steering mode to provide the second modulated beam.

5. The LIDAR device of claim 4, further comprising a controller configured to control the steering mode on the phase light modulator such that the first modulated beam scans the first field of view and the second modulated beam scans the second field of view.

6. The LIDAR device according to claim 1, wherein, The phase light modulator includes one of the following: an array of digital micromirrors, wherein the phase light modulator modulates the first beam and the second beam by setting the height of the digital micromirrors above the substrate of the phase light modulator; or a liquid crystal phase light modulator, wherein the phase light modulator modulates the first beam and the second beam by applying a voltage to the liquid crystal at each pixel.

7. The LIDAR device of claim 1, further comprising a first collimating lens between the first light source and the phase light modulator, and a second collimating lens between the second light source and the phase light modulator.

8. A light detection and ranging LIDAR device, comprising: Phase light modulator; A first light source, optically coupled to the phase light modulator, is configured to guide a first light beam toward the phase light modulator at a first incident angle. A second light source, optically coupled to the phase light modulator, is configured to guide a second light beam toward the phase light modulator at a second incident angle, wherein the phase light modulator is configured to set pixel elements simultaneously: Modulate the first beam to generate a first scanning beam with a first reflection angle in a first field of view; and The second beam is modulated to generate a second scanning beam with a second reflection angle in a second field of view, wherein the difference between the first reflection angle and the second reflection angle is determined by the difference between the first incident angle and the second incident angle; as well as A photodetector, optically coupled to the first field of view and configured to detect the reflection of the first light beam from the first field of view.

9. The LIDAR device according to claim 8, wherein, The phase light modulator is a first phase light modulator, and the device further includes a second phase light modulator configured to guide a modulated beam reflected from the field of view to the photodetector.

10. The LIDAR device according to claim 8, wherein, The phase light modulator modulates the diverging beam in a steering mode to provide a modulated beam.

11. The LIDAR device of claim 10, further comprising a controller configured to control the steering mode on the phase light modulator such that the modulated beam scans the field of view.

12. The LIDAR device according to claim 8, wherein, The phase light modulator includes one of the following: an array of digital micromirrors, wherein the phase light modulator modulates a diverging light beam by setting the height of the digital micromirrors above the substrate of the phase light modulator; or a liquid crystal phase light modulator, wherein the phase light modulator modulates the diverging light beam by applying a voltage to the liquid crystal at each pixel.

13. A method for a light detection and ranging LIDAR device, comprising: The first beam from the first light source is directed to the phase light modulator at the first incident angle; The first beam is modulated using the phase light modulator to provide a first modulated beam with a first reflection angle guided to a first field of view; The second beam from the second light source is guided to the phase light modulator at a second incident angle; While the phase light modulator modulates the first beam to provide the first modulated beam directed toward the first field of view, the phase light modulator is used to modulate the second beam to provide a second modulated beam with a second reflection angle directed to the second field of view, wherein the difference between the first reflection angle and the second reflection angle is determined by the difference between the first incident angle and the second incident angle. The first modulated beam reflected from the first field of view is detected using a first photodetector; as well as The second modulated beam reflected from the second field of view is detected using a second photodetector.

14. The method according to claim 13, wherein, The phase light modulator modulates the first beam in a steering mode to provide the first modulated beam, and the phase light modulator modulates the second beam in the steering mode to provide the second modulated beam.

15. The method of claim 14, further comprising controlling the steering mode on the phase light modulator such that the first modulated beam scans the first field of view and the second modulated beam scans the second field of view.

16. The method of claim 13, wherein, The phase light modulator includes one of the following: an array of digital micromirrors, wherein the phase light modulator modulates the first beam and the second beam by setting the height of the digital micromirrors above the substrate of the phase light modulator; or a liquid crystal phase light modulator, wherein the phase light modulator modulates the first beam and the second beam by applying a voltage to the liquid crystal at each pixel.

17. A light detection and ranging LIDAR device, comprising: Phase light modulator; A first light source, optically coupled to the phase light modulator and configured to guide a first light beam to the phase light modulator at a first incident angle; A second light source, optically coupled to the phase light modulator, is configured to guide a second light beam toward the phase light modulator at a second incident angle, wherein the phase light modulator is configured to set pixel elements simultaneously: Modulate the first beam to generate a first scanning beam with a first reflection angle in a first field of view; and The second beam is modulated to generate a second scanning beam with a second reflection angle in a second field of view, wherein the difference between the first reflection angle and the second reflection angle is determined by the difference between the first incident angle and the second incident angle; A first photodetector, optically coupled to the first field of view and configured to detect a first modulated beam reflected from the first field of view; as well as A second photodetector is optically coupled to the second field of view and configured to detect a second modulated beam reflected from the second field of view.

18. The LIDAR device according to claim 17, wherein, The phase light modulator is a first phase light modulator, and the device further includes a second phase light modulator configured to guide the first modulated beam reflected from the first field of view to the first photodetector and configured to guide the second modulated beam reflected from the second field of view to the second photodetector.

19. The LIDAR device according to claim 17, wherein, The phase light modulator modulates the beam in a steering mode to provide the first modulated beam and the second modulated beam.

20. The LIDAR device of claim 19, further comprising a controller configured to control the steering mode on the phase light modulator such that the first modulated beam scans the first field of view and the second modulated beam scans the second field of view.

21. The LIDAR device according to claim 17, wherein, The phase light modulator includes one of the following: an array of digital micromirrors, wherein the phase light modulator modulates the light beam by setting the height of the digital micromirrors above the substrate of the phase light modulator; or a liquid crystal phase light modulator, wherein the phase light modulator modulates the light beam by applying a voltage to the liquid crystal at each pixel.

22. The LIDAR device of claim 17, further comprising a first collimating lens between the light source and the phase modulator.

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