Transmitting Unit and Solid-State LiDAR

Abstract

The present invention provides a transmitting unit and a solid-state lidar. The transmitting unit includes a VCSEL laser; the VCSEL laser is provided with a high-contrast sub-wavelength grating structure; the operating mode of the VCSEL laser is a single TM mode; the period of the high-contrast sub-wavelength grating is less than the wavelength of the detection light emitted by the VCSEL laser. By selecting an HCG grating with a period less than this wavelength according to the wavelength of the detection light of the VCSEL laser, it is ensured that the emitted light from the laser is always the zero-order diffracted light of single TM mode lasing, so that the VCSEL laser 11 always maintains the smallest divergence angle.

Description

Technical Field

[0001] This application belongs to the technical field of semiconductor lasers, and particularly relates to a transmitting unit and a solid-state lidar. Background Art

[0002] FLASH solid-state lidar has developed rapidly in recent years due to its advantages such as no mechanical rotating parts, high reliability, strong environmental adaptability, low price, and easy mass production.

[0003] Conventional lasers used in solid-state lidar have disadvantages such as low electro-optical conversion efficiency per unit area, high internal resistance, and large divergence angle. They not only require a large driving current but also greatly reduce the collimation efficiency, increasing the driving difficulty and cost. Therefore, the ranging ability of solid-state lidar in the prior art is low, which in turn affects the development of solid-state lidar. Summary of the Invention

[0004] In view of this, the present invention provides a transmitting unit and a solid-state lidar, aiming to solve the problem of low ranging ability of solid-state lidar caused by large divergence angle of the laser in the prior art.

[0005] The first aspect of the embodiment of the present invention provides a transmitting unit; the transmitting unit includes a VCSEL laser; the VCSEL laser is provided with a high-contrast sub-wavelength grating structure; the working mode of the VCSEL laser is a single TM mode; the period of the high-contrast sub-wavelength grating is less than the wavelength of the detection light emitted by the VCSEL laser.

[0006] The first aspect of the embodiment of the present invention provides a solid-state lidar, including a receiving unit, a power supply unit, a control unit, and the solid-state lidar provided in the first aspect above;

[0007] The power supply unit supplies power to the transmitting unit, the receiving unit, and the control unit respectively; the control unit is connected to the transmitting unit and the receiving unit;

[0008] The transmitting unit further includes a multi-channel laser driver and a collimation optical system;

[0009] The control unit is used to control the multi-channel laser driver to drive the VCSEL laser to emit detection light; the collimation optical system is used to make the emitted detection light form a preset divergence angle;

[0010] The receiving unit includes an optical filtering system, a light condensing optical system, and a multi-channel area array detector;

[0011] The optical filtering system is used to remove background noise in the detection light reflected by the object;

[0012] The condensing optical system is used to condense the detection light after removing background noise onto the multi-channel area array detector;

[0013] The multi-channel area array detector is used to convert the received detection light into an electrical signal and send it to the control unit.

[0014] In some possible implementation manners, the optical filtering system includes a narrowband filter unit and a polarization unit;

[0015] The narrowband filter unit is used to remove background noise in the detection light reflected by the object that has a different wavelength or mode from the detection light;

[0016] The polarization unit is used to remove background noise in the detection light reflected by the object that has the same wavelength as the detection light but a different polarization angle.

[0017] In some possible implementation manners, the narrowband filter unit satisfies the following conditions:

[0018]

[0019]

[0020]

[0021]

[0022] where Δτ is the passband width of the narrowband filter unit, is the central wavelength drift of the narrowband filter unit corresponding to different incident angles, is the central wavelength drift of the narrowband filter unit corresponding to different temperatures, is the deviation of the central wavelength and bandwidth of the narrowband filter unit due to manufacturing errors, is the deviation of the central wavelength and bandwidth of the VCSEL laser; λ f is the minimum wavelength that the multi-channel area array detector can detect, λ c is the theoretical central wavelength of the passband width of the narrowband filter unit, λ e is the maximum wavelength that the multi-channel area array detector can detect, OD n is the required cut-off depth of the narrowband filter unit, and r is the wavelength transmittance of the transmission region.

[0023] In some possible implementation manners, the theoretical central wavelength of the passband width of the narrowband filter unit is the same as the theoretical central wavelength of the VCSEL laser; the theoretical central wavelength of the passband width is the central wavelength of the narrowband filter unit within its transmissible wavelength range.

[0024] In some possible implementation manners, the polarization unit is configured to transmit light in the TM mode and block light in the TE mode.

[0025] In some possible implementation manners, the VCSEL laser includes a first strobe and a plurality of light-emitting units arranged in a matrix; the first strobe is configured to strobe a corresponding light-emitting unit according to a control signal of a control unit; the multi-channel area array detector includes at least one second strobe and a matrix-arranged photoelectric conversion element, and the light-emitting unit corresponds to the photoelectric conversion element; the second strobe is configured to strobe the photoelectric conversion element of a corresponding channel according to a control signal of the control unit; the solid-state lidar further includes a first timer and at least one second timer, the first timer is configured to record the light-emitting time of each light-emitting unit; each second strobe corresponds to a second timer; each second timer is configured to record the signal reception time when the second strobe strobes the photoelectric conversion element of the corresponding channel.

[0026] In some possible implementation manners, the control unit is configured to perform the following steps:

[0027] Determine the trigger time of each light-emitting unit according to the preset light-emitting sequence of each light-emitting unit;

[0028] Send a control signal to the first strobe according to the trigger time of each light-emitting unit to enable the first strobe to strobe the corresponding light-emitting unit; when a certain light-emitting unit is strobed, send a control signal to the second strobe to enable the second strobe to strobe the target photoelectric conversion element corresponding to the light-emitting unit, and at the same time send a control signal to the power supply unit to enable the supply voltage of the target photoelectric conversion element to change periodically, and determine that the scanning of the detection area corresponding to the light-emitting unit is completed after the supply voltage of the target photoelectric conversion element changes at least one cycle;

[0029] After the scanning of the detection areas corresponding to all the light-emitting units is completed, determine the detection result of the solid-state lidar according to the light-emitting time obtained by the first timer and the signal reception time obtained by the second timer during the detection area scanning.

[0030] In some possible implementation manners, the control unit is further configured to perform the following steps:

[0031] Divide the plurality of light-emitting units arranged in a matrix in a row division / column division / two-dimensional addressing manner, and use the light-emitting area of each selected light-emitting unit as a detection area.

[0032] In some possible implementations, it further includes a housing; the transmitting unit, the receiving unit, the power supply unit, and the control unit are all disposed within the housing; an outgoing optical window corresponding to the transmitting unit and a detection optical window corresponding to the receiving unit are provided on the housing; there is light isolation between the outgoing optical window and the detection optical window.

[0033] The transmitting unit provided by the embodiment of the present invention; the transmitting unit includes a VCSEL laser; the VCSEL laser is provided with a high-contrast sub-wavelength grating structure; the operating mode of the VCSEL laser is a single TM mode; the period of the high-contrast sub-wavelength grating is less than the wavelength of the detection light emitted by the VCSEL laser. By selecting an HCG grating with a period less than this wavelength according to the wavelength of the detection light of the VCSEL laser, it is ensured that the outgoing light emitted by the laser is always the zero-order diffracted light of single TM mode lasing, so that the VCSEL laser always maintains the smallest divergence angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 It is a schematic structural diagram of a solid-state lidar provided by an embodiment of the present invention;

[0036] Figure 2 It is a cross-sectional view of a high-contrast sub-wavelength grating provided by an embodiment of the present invention;

[0037] Figure 3 It is a schematic structural diagram of a VCSEL provided by an embodiment of the present invention;

[0038] Figure 4 It is a divergence angle-power curve graph of a VCSEL provided by an embodiment of the present invention;

[0039] Figure 5 It is a schematic structural diagram of an HCG-VCSEL provided by an embodiment of the present invention;

[0040] Figure 6 It is a divergence angle-power curve graph of an HCG-VCSEL provided by an embodiment of the present invention;

[0041] Figure 7 It is a schematic structural diagram of a solid-state lidar provided by another embodiment of the present invention;

[0042] Figure 8It is a schematic diagram of the operation of the narrowband filter unit provided by an embodiment of the present invention;

[0043] Figure 9 It is a schematic diagram of the operation of the polarization unit provided by an embodiment of the present invention;

[0044] Figure 10 It is a schematic diagram of the light-emitting area of the emission unit and the corresponding photosensitive pixels on the receiving unit provided by an embodiment of the present invention;

[0045] Figure 11 It is a schematic diagram of the logic circuit provided by an embodiment of the present invention. Detailed implementation manners

[0046] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present invention. However, those skilled in the art should clearly understand that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present invention.

[0047] Figure 1 It is a schematic diagram of the structure of the emission unit provided by an embodiment of the present invention. As Figure 1 shown, in this embodiment, the emission unit 1 includes a VCSEL laser 11; the VCSEL laser 11 is provided with a high-contrast subwavelength grating structure; the operating mode of the VCSEL laser 11 is a single TM mode; the period of the high-contrast subwavelength grating is less than the wavelength of the detection light emitted by the VCSEL laser 11.

[0048] In this embodiment, the VCSEL (Vertical-Cavity Surface-Emitting Laser) laser 11 can be driven to emit light in zones.

[0049] Figure 2 It is a cross-sectional view of the high-contrast subwavelength grating provided by an embodiment of the present invention. As Figure 2 shown, the high-contrast subwavelength grating (HCG) has a thickness of d, a frequency of f, a refractive index of n a , and a period of Λ. It has low loss, high reflectivity, and strong phase matching and focusing capabilities, and has a simple structure.

[0050] When the detection light with a wavelength of λ0 emitted by the VCSEL laser 11 is incident on Figure 2When the grating shown is considered, since the period of the high-contrast sub-wavelength grating is less than the wavelength of the detection light emitted by the VCSEL laser 11, that is, Λ < λ0, the outgoing beam of the high-contrast sub-wavelength grating at this time is the 0th-order diffracted beam, which can effectively reduce the beam emission angle, thereby improving the ranging ability of the radar.

[0051] In this embodiment, lasers with different wavelengths correspond to different grating periods. The TM mode is mainly realized through the grating distribution. By adjusting parameters such as the grating period, grating depth, and grating duty cycle, the resonance intensity of the TM mode after passing through the grating can be increased, and at the same time, the intensity of the TE mode can be suppressed to achieve single-TM mode lasing. And by adjusting the period of the grating to be less than the wavelength of the laser, it is ensured that the outgoing light emitted by the laser is always the 0th-order diffracted light of single-TM mode lasing, so that the VCSEL laser 11 always maintains the smallest divergence angle.

[0052] Figure 3 is a schematic structural diagram of a VCSEL laser in the prior art, as Figure 3 shown. In the prior art, the VCSEL is provided with multiple layers of P-type DBR (distributed Bragg reflector), and the VCSEL laser has a relatively high thickness and a relatively large internal resistance. Figure 4 is Figure 3 the divergence angle-power curve of the VCSEL laser in Figure 4 shown. The horizontal axis is the divergence angle of the VCSEL laser, and the vertical axis is the power of the VCSEL laser.

[0053] Figure 5 is a schematic structural diagram of the HCG-VCSEL provided by the embodiment of the present invention. As Figure 5 shown, after using HCG to replace the multiple layers of P-type DBR, the thickness of the VCSEL can be effectively reduced, and then the internal resistance can be reduced. And the parameters of the HCG grating in the HCG-VCSEL of the present invention need to be adjusted according to the outgoing wavelength of the VCSEL laser 11, so as to ensure that the outgoing light emitted by the laser is always the 0th-order diffracted light of single-TM mode lasing, so that the VCSEL laser 11 always maintains the smallest divergence angle.

[0054] Figure 6 is the divergence angle-power curve of the HCG-VCSEL provided by the embodiment of the present invention. As Figure 6 shown, the horizontal axis is the divergence angle of the laser, and the vertical axis is the power of the laser. Compared with Figure 4 the divergence angle-power curve of the laser shown in

[0055] In some embodiments, the period of the high-contrast sub-wavelength grating is 1 / m of the wavelength of the detection light, that is, the following relationship is satisfied between the period Λ of the high-contrast sub-wavelength grating and the wavelength λ0 of the detection light:

[0056]

[0057] where m is a natural number greater than 1.

[0058] Figure 7 is a schematic structural diagram of a solid-state lidar provided by another embodiment of the present invention. As Figure 7 shown, in some embodiments, the solid-state lidar includes a transmitting unit 1, a receiving unit 2, a power supply unit 3, and a control unit 4.

[0059] The power supply unit 3 supplies power to the transmitting unit 1, the receiving unit 2, and the control unit 4 respectively.

[0060] The control unit 4 is connected to the transmitting unit 1 and the receiving unit 2;

[0061] The transmitting unit 1 further includes a multi-channel laser driver 12 and a collimating optical system 13;

[0062] The control unit 4 is configured to control the multi-channel laser driver 12 to drive the vertical cavity surface emitting laser 11 to emit detection light;

[0063] The collimating optical system 13 is configured to make the emitted detection light form a preset divergence angle;

[0064] The receiving unit 2 includes an optical filtering system 21, a condensing optical system 22, and a multi-channel area array detector 23;

[0065] The optical filtering system 21 is configured to remove background noise in the detection light reflected by the object;

[0066] The condensing optical system 22 is configured to converge the detection light after removing the background noise to the multi-channel area array detector 23;

[0067] The multi-channel area array detector 23 is configured to convert the received detection light into an electrical signal and send it to the control unit 4.

[0068] In this embodiment, the VCSEL laser 11 can emit light in zones, and each light-emitting area is separately controlled as a light-emitting unit. The collimation optical axis of the VCSEL laser 11 of the present invention is perpendicular to the light-emitting surface or the plane of the vertical-cavity surface-emitting laser driving circuit board. Each channel of the multi-channel area array detector 23 can be a single pixel, such as a SPAD (single-photon avalanche diode), or can be a multi-pixel, such as an MPPC (silicon photomultiplier tube), SiPM (silicon photon multiplier tube), etc., and no movement is required during the detection process. The electrical signals include digital signals and / or analog signals. The control unit 4 is used to control and process the digital signals and / or analog signals of the transmitting unit 1 and the receiving unit 2.

[0069] In some embodiments, the optical filtering system 21 includes a narrowband filtering unit 211 and a polarization unit 212; Figure 8 It is a working schematic diagram of the narrowband filtering unit provided by the embodiment of the present invention, Figure 9 It is a working schematic diagram of the polarization unit provided by the embodiment of the present invention. As Figure 8 and Figure 9 shown, the horizontal axis is the spatial position of the light, and the vertical axis is the light wave energy.

[0070] The narrowband filtering unit 211 is used to remove the background noise in the detection light reflected by the object that has a different wavelength or mode from the detection light;

[0071] The polarization unit 212 is used to remove the background noise in the detection light reflected by the object that has the same wavelength as the detection light but a different polarization angle.

[0072] In this embodiment, the light beam reflected back by the object contains light of different wavelengths and different modes. As Figure 8 shown, after passing through the narrowband filtering unit 211, only the light beam containing the detection wavelength can be obtained, which can effectively reduce the background noise. However, the light beam with the same wavelength as the VCSEL laser 11 in the background cannot be filtered out. As Figure 9 shown, after the detection light and the light beam with the same wavelength as the detection light pass through the polarization unit 212, only the light beam with the same wavelength as the background light and the same polarization direction remains. Therefore, by setting the narrowband filtering unit 211 and the polarization unit 212, the background light energy received by the multi-channel area array detector 23 can be effectively reduced, and the signal-to-noise ratio of the light can be improved.

[0073] In some embodiments, the narrowband filtering unit 211 satisfies the following conditions:

[0074]

[0075]

[0076]

[0077]

[0078] Among them, Δτ is the passband width of the narrowband filter unit, is the central wavelength drift of the narrowband filter unit corresponding to different incident angles, is the central wavelength drift of the narrowband filter unit corresponding to different temperatures, is the deviation of the central wavelength and bandwidth of the narrowband filter unit due to manufacturing errors, is the deviation of the central wavelength and bandwidth of the VCSEL laser 11; λ f is the minimum wavelength that the multi-channel area array detector 23 can detect, λ c is the theoretical central wavelength of the transmission bandwidth of the narrowband filter unit 211, λ e is the maximum wavelength that the multi-channel area array detector 23 can detect, OD n is the required cut-off depth of the narrowband filter unit, and r is the wavelength transmittance of the transmission region.

[0079] In this embodiment, OD n = 10 -n , that is, the wavelength transmittance of the cut-off region is less than 10 -n , where n is a positive integer.

[0080] In some embodiments, the theoretical central wavelength of the transmission bandwidth of the narrowband filter unit 211 is the same as the theoretical central wavelength of the VCSEL laser 11; the theoretical central wavelength of the transmission bandwidth is the central wavelength of the narrowband filter unit within its transmissible wavelength range.

[0081] In this embodiment, the narrowband filter unit can be a filter. Bandwidth central wavelength: The central wavelength of the wavelength range that the filter can transmit. For example, if the wavelength range that the filter can transmit is 880 nm to 920 nm, then the transmission wavelength bandwidth of the filter is 920 - 880 = 40 nm, and the theoretical central wavelength of the bandwidth is 900 nm.

[0082] In some embodiments, the polarization unit 212 is used to transmit light in the TM mode and block light in the TE mode.

[0083] In this embodiment, based on the HCG-VCSEL, by setting the polarization unit to transmit light in the TM mode, the emission unit can generate single TM mode 0th order diffracted light, effectively reducing the beam exit angle.

[0084] Figure 10 is a schematic diagram of the light-emitting area of the emission unit and the corresponding photosensitive pixels on the receiving unit provided by the embodiment of the present invention. Figure 11It is a schematic diagram of a logic circuit provided by an embodiment of the present invention. In some embodiments, the VCSEL laser 11 includes a first gater and a plurality of light-emitting units arranged in a matrix; the first gater is used to gate the corresponding light-emitting unit according to the control signal of the control unit 4; the multi-channel area array detector 23 includes at least one second gater and a matrix of photoelectric conversion elements, and the light-emitting units and the photoelectric conversion elements are in one-to-one correspondence; the second gater is used to gate the photoelectric conversion elements of the corresponding channel according to the control signal of the control unit 4; the solid-state lidar further includes a first timer and at least one second timer, the first timer is used to record the light-emitting time of each light-emitting unit; each second gater corresponds to a second timer; each second timer is used to record the signal reception time when the second gater gates the photoelectric conversion elements of the corresponding channel.

[0085] In this embodiment, the first timer and the second timer can identify and calculate the time information of the signals of this channel, or can identify and calculate the time information of external trigger signals. The number of the first gatings is 1, and the number of the second gatings can be 1 or multiple, which is not limited here.

[0086] In some embodiments, the control unit 4 is used to perform the following steps:

[0087] Determine the trigger time of each light-emitting unit according to the preset light-emitting sequence of each light-emitting unit;

[0088] Send a control signal to the first gater according to the trigger time of each light-emitting unit so that the first gater gates the corresponding light-emitting unit; when a certain light-emitting unit is gated, send a control signal to the second gater so that the second gater gates the target photoelectric conversion element corresponding to the light-emitting unit, and at the same time send a control signal to the power supply unit 3 so that the supply voltage of the target photoelectric conversion element changes periodically, and determine that the scanning of the detection area corresponding to the light-emitting unit is completed after the supply voltage of the target photoelectric conversion element changes at least 1 cycle;

[0089] After the scanning of the detection areas corresponding to all the light-emitting units is completed, determine the detection result of the solid-state lidar according to the light-emitting time obtained by the first timer and the signal reception time obtained by the second timer during the detection area scanning.

[0090] In this embodiment, each gating path of the first gater is respectively connected to a light-emitting unit. After the first gater receives the control signal of the control unit 4, it gates the light-emitting unit indicated by the control signal. At this time, the first timer records the light-emitting time. Then the control unit 4 instructs the multi-channel area array detector 23 to scan the corresponding photoelectric conversion elements for the detection area, and the second timer records the signal reception time. The above process is continuously cycled to detect the entire field of view.

[0091] In this embodiment, the detection area of the solid-state lidar is a rectangular area. The detection range (i.e., the width of the rectangle) is determined by the light-emitting unit, and the detection distance (i.e., the length of the rectangle) is determined by the supply voltage of the receiving unit. The higher the supply voltage, the farther the detection distance. To adapt to different detection distances, the control unit 4 makes the supply voltage of the receiving unit 2 continuously change through the power supply unit 3. The change in the supply voltage can be an irregular change or a periodic change, which is not limited herein. When generating the control signal, the control unit 4 can generate the control signal in real time according to the selected light-emitting area during the scanning of the light-emitting area, or can generate all the control signals after determining the selection order of each light-emitting area, and sequentially send the control signals during the scanning, which is not limited herein.

[0092] In this embodiment, through the second gater correspondingly set according to the scanning area, n gating channels in each second gater correspond one-to-one with n photoelectric conversion elements; one second timer is correspondingly set for each second gater, so that one second timer serves multiple photosensitive channels corresponding to the scanning area in the multi-channel area array detector 23, thereby completing the field of view detection through the above corresponding scanning method, which can effectively reduce the number of amplifiers and timers required to be set in the solid-state lidar, reduce the complexity of the lidar. At the same time, through the zonal control of the light emission, the requirement for the circuit driving ability of the light emission can be reduced, the output light power density can be increased, and thus the ranging ability can be improved.

[0093] In some embodiments, the control unit is further configured to perform the following steps:

[0094] Divide the multiple light-emitting units arranged in a matrix layout row by row / column by column / in the way of two-dimensional addressing, and use the light-emitting area of each selected light-emitting unit as a detection area.

[0095] In this embodiment, when scanning the detection area row by row, the VCSEL laser 11 includes light-emitting units arranged row by row and a first gater Ch0. The first gater Ch0 has a total of n channels corresponding to the P 01 ~P 0n rows. The multi-channel area array detector 23 includes n rows and m columns of channel photoelectric conversion elements, m second gatings (i.e., Ch1~Chm), a transimpedance amplifier unit, and a timing unit. Each second gating contains at least n channels. The transimpedance amplifier unit includes at least m TIA transimpedance amplifiers that can work in parallel, and the timing unit includes at least m + 1 TDC timers working in parallel (i.e., m second timers and 1 first timer).

[0096] During operation, it can be from P 01 ~P 0nDrive the light emission in sequence. At the same time, the corresponding channels of the selectors Ch0 to Chm are selected. The light beam is reflected by the object to be measured, and the optical signal is converted into an electrical signal by the photoelectric conversion element, and the received time information is obtained through TIA amplification and TDC timing. The time information received by the 1 to m channels of the TDC timer is respectively compared with the time information received by the 0 channel of the TDC timer to obtain the detection results corresponding to each photoelectric conversion element in the corresponding row of the detector.

[0097] In this embodiment, when scanning the detection area column by column, the VCSEL laser 11 includes a light-emitting unit arranged in columns and a first selector Ch0. The first selector Ch0 has a total of n channels, which respectively correspond to the P 01 ~P 0n columns. The multi-channel area array detector includes m rows and n columns of channel photoelectric conversion elements, m second selectors (i.e., Ch1 to Chm), a transimpedance amplifier unit, and a timing unit. Each second selector includes at least n channels. The transimpedance amplifier unit includes at least m TIA transimpedance amplifiers that can work in parallel. The timing unit includes at least m + 1 TDC timers that work in parallel (i.e., m second timers and 1 first timer).

[0098] During operation, it is possible to drive the light emission in sequence from P 01 ~P 0n Drive the light emission in sequence. At the same time, the corresponding channels of the selectors Ch0 to Chm are selected. The light beam is reflected by the object to be measured, and the optical signal is converted into an electrical signal by the photoelectric conversion element, and the received time information is obtained through TIA amplification and TDC timing. The time information received by the 1 to m channels of the TDC timer is respectively compared with the time information received by the 0 channel of the TDC timer to obtain the detection results corresponding to each photoelectric conversion element in the corresponding column of the detector.

[0099] In this embodiment, the VCSEL laser 11 includes a two-dimensional addressable array laser and a selector Ch0. The first selector Ch0 has a total of m×n channels, which respectively correspond to each light-emitting unit; the detector 23 includes m rows and n columns of channel photoelectric conversion elements, a second selector Ch1, a transimpedance amplifier, and a timer. The second selector Ch1 includes at least m×n channels; a plurality of light-emitting units are arranged in a matrix of m rows and n columns, and n*m light-emitting units correspond one-to-one with m rows and n columns of photoelectric conversion elements. The n*m selection channels in the second selector correspond one-to-one with m rows and n columns of photoelectric conversion elements;

[0100] When working, each light-emitting unit is driven to emit light in sequence. At the same time, the corresponding channels of the first gater Ch0 and the second gater Ch1 are gated. The light beam is reflected by the object to be measured, and the optical signal is converted into an electrical signal by the photoelectric conversion element, and the received time information is obtained through TIA amplification and TDC timing. The time information received by the 1-channel of the TDC timer is respectively compared with the time information received by the 0-channel of the TDC timer to obtain the distance information of each field of view corresponding to each photoelectric conversion element in the corresponding row of the detector.

[0101] In some embodiments, the solid-state lidar further includes a housing 5; the transmitting unit 1, the receiving unit 2, the power supply unit 3, and the control unit 4 are all arranged in the housing 5; an outgoing optical window 51 corresponding to the transmitting unit and a detection optical window 52 corresponding to the receiving unit are arranged on the housing 5; there is light isolation between the outgoing optical window 51 and the detection optical window 52.

[0102] In this embodiment, there is light isolation between the outgoing optical window 51 and the detection optical window 52, without optical crosstalk, and the two windows are at a specific angle.

[0103] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0104] Those skilled in the art can clearly understand that for the convenience and brevity of description, only the above division of each functional unit and module is used for illustration. In actual applications, the above functions can be allocated to different functional units and modules as needed, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of mutual distinction and do not limit the protection scope of the present application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0105] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0106] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0107] In the embodiments provided by the present invention, it should be understood that the disclosed device / terminal and method can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0108] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or they can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0109] In addition, the functional units in various embodiments of the present invention can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0110] When an integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, to implement all or part of the processes in the above-described embodiment methods of the present invention, it can also be completed by a computer program instructing relevant hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-described various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0111] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention and should all be included in the protection scope of the present invention.

Claims

1. A solid-state lidar, characterized in that, It includes a receiving unit, a power supply unit, a control unit and a transmitting unit; the transmitting unit includes a VCSEL laser; a high-contrast sub-wavelength grating structure is arranged on the light-emitting surface of the VCSEL laser; the working mode of the VCSEL laser is a single TM mode; the period of the high-contrast sub-wavelength grating is less than the wavelength of the detection light emitted by the VCSEL laser; The power supply unit supplies power to the transmitting unit, the receiving unit and the control unit respectively; the control unit is connected to the transmitting unit and the receiving unit; The transmitting unit further includes a multi-channel laser driver and a collimating optical system; The control unit is used to control the multi-channel laser driver to drive the VCSEL laser to emit detection light; the collimating optical system is used to make the emitted detection light form a preset divergence angle; The receiving unit includes an optical filtering system, a light condensing optical system and a multi-channel area array detector; The optical filtering system is used to remove the background noise in the detection light reflected by the object; The light condensing optical system is used to converge the detection light after removing the background noise to the multi-channel area array detector; The multi-channel area array detector is used to convert the received detection light into an electrical signal and send it to the control unit; The optical filtering system includes a narrow-band filtering unit and a polarization unit; The narrow-band filtering unit is used to remove the background noise in the detection light reflected by the object that has a different wavelength or mode from the detection light; The polarization unit is used to remove the background noise in the detection light reflected by the object that has the same wavelength as the detection light but a different polarization angle; The narrow-band filtering unit satisfies the following conditions: where, Δτ is the passband width of the narrowband filter unit, is the center wavelength drift of the narrowband filter unit corresponding to different incident angles, is the center wavelength drift of the narrowband filter unit corresponding to different temperatures, is the center wavelength and bandwidth deviation of the narrowband filter unit due to manufacturing errors, is the center wavelength and bandwidth deviation of the VCSEL laser; λ f is the minimum wavelength that the multi-channel area array detector can detect, λ c is the theoretical center wavelength of the transmission bandwidth of the narrowband filter unit, λ e is the maximum wavelength that the multi-channel area array detector can detect, OD n is the required cut-off depth of the narrowband filter unit, and r is the wavelength transmittance of the transmission region.

2. The solid-state lidar according to claim 1, wherein, The theoretical center wavelength of the transmission bandwidth of the narrow-band filtering unit is the same as the theoretical center wavelength of the VCSEL laser; the theoretical center wavelength of the transmission bandwidth is the center wavelength of the narrow-band filtering unit within its transmissible wavelength range.

3. The solid-state lidar according to claim 1, characterized in that, The polarization unit is used to transmit the TM-mode light and cut off the TE-mode light.

4. The solid-state lidar according to claim 1, characterized in that, The VCSEL laser includes a first gater and a plurality of light-emitting units arranged in a matrix; the first gater is used to gate the corresponding light-emitting unit according to the control signal of the control unit; the multi-channel area array detector includes at least one second gater and a matrix-arranged photoelectric conversion element, and the light-emitting unit corresponds to the photoelectric conversion element; the second gater is used to gate the photoelectric conversion element of the corresponding channel according to the control signal of the control unit; the solid-state lidar further includes a first timer and at least one second timer, the first timer is used to record the light-emitting moment of each light-emitting unit; each second gater corresponds to a second timer; each second timer is used to record the signal reception moment when the second gater gates the photoelectric conversion element of the corresponding channel.

5. The solid-state lidar according to claim 4, wherein The control unit is used to perform the following steps: Determine the trigger time of each light-emitting unit according to the preset light-emitting sequence of each light-emitting unit; Send a control signal to the first strobe according to the triggering time of each light-emitting unit so that the first strobe gates the corresponding light-emitting unit; when a certain light-emitting unit is gated, send a control signal to the second strobe so that the second strobe gates the target photoelectric conversion element corresponding to the light-emitting unit, and at the same time send a control signal to the power supply unit so that the supply voltage of the target photoelectric conversion element changes periodically, and determine that the scanning of the detection area corresponding to the light-emitting unit is completed after the supply voltage of the target photoelectric conversion element changes at least one cycle; After completing the scanning of the detection areas corresponding to all the light-emitting units, determine the detection result of the solid-state lidar according to the light-emitting time obtained by the first timer and the signal reception time obtained by the second timer during the detection area scanning.

6. The solid-state lidar according to claim 5, characterized in that, The control unit is further configured to perform the following steps: Divide the multiple light-emitting units arranged in a matrix by row / by column / by two-dimensional addressing, and use the light-emitting area of each selected light-emitting unit as a detection area.

7. The solid-state lidar according to any one of claims 1-6, characterized in that, It further includes a housing; the transmitting unit, the receiving unit, the power supply unit, and the control unit are all arranged in the housing; an outgoing optical window corresponding to the transmitting unit and a detection optical window corresponding to the receiving unit are arranged on the housing; there is light isolation between the outgoing optical window and the detection optical window.

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