Semi-solid state laser radar

Abstract

This application provides a semi-solid-state lidar, comprising: a light source for providing a laser signal, the laser signal including a local oscillator beam and a probe beam; at least one OPA module connected to the light source for receiving the probe beam and emitting the probe beam; a reflection scanning module for receiving the probe beam emitted by the OPA module and reflecting the probe beam to a detection area; receiving an echo signal and reflecting it back to the OPA module so that the echo signal is received through the OPA module; a detection module for receiving the echo signal provided by the OPA module and the local oscillator beam provided by the light source, performing frequency matching between the echo signal and the local oscillator beam to form a frequency matching signal, and converting the frequency matching signal into a detection electrical signal; and a signal processing module connected to the detection module for receiving the detection electrical signal and determining information about the object to be detected within the detection area based on the detection electrical signal. This application solves the problem in related technologies that arbitrary trajectory scanning detection cannot be achieved.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and more specifically, to a semi-solid-state lidar. Background Technology

[0002] With the rapid development of lidar technology, the application market and scale of lidar equipment are also expanding. A lidar system is a radar system that detects the speed, position, and other characteristics of a target by emitting a laser beam. A lidar system includes a transmitting unit, a receiving unit, and a signal processing and main control unit. In a traditional lidar system, the transmitting unit generally includes a light source driver, a single-pixel light source or an array light source, and a transmitting shaping mirror group; the receiving unit generally includes an amplification circuit, a single-pixel or array detector, and a receiving mirror group; under the control of the signal processing and main control unit, the transmitting unit emits pulsed light, which scans and detects the space being measured. The receiving unit converts the reflected light signal from the object to be detected into an electrical signal, and the signal processing and main control unit calculates the distance information based on this electrical signal to complete the detection.

[0003] Traditional lidar systems use geometric optics principles to emit and converge beams, which cannot be separated from the transceiver lens assembly. Furthermore, they are limited by the geometric arrangement of the light source and detector, making it impossible to achieve scanning and detection of arbitrary trajectories. Summary of the Invention

[0004] This application provides a semi-solid-state lidar to at least solve the problem in related technologies that it is impossible to achieve scanning and detection of arbitrary trajectories.

[0005] According to one aspect of the embodiments of this application, a semi-solid-state lidar is provided, comprising: a light source for providing a laser signal, the laser signal including a local oscillator beam and a probe beam; at least one OPA module connected to the light source for receiving the probe beam and emitting the probe beam; a reflection scanning module for receiving the probe beam emitted by the OPA module and reflecting the probe beam to a detection area; and receiving an echo signal and reflecting it to the OPA module so that the echo signal is received through the OPA module; a detection module for receiving the echo signal provided by the OPA module and the local oscillator beam provided by the light source, performing a beat frequency conversion between the echo signal and the local oscillator beam to form a beat frequency signal, and converting the beat frequency signal into a detection electrical signal; and a signal processing module connected to the detection module for receiving the detection electrical signal and determining information of a target object within the detection area based on the detection electrical signal.

[0006] This application introduces an OPA module. When the probe beam enters the OPA module, the OPA module changes the propagation direction of the probe beam, achieving scanning detection without mechanical movement in at least one dimension. Furthermore, the OPA module can dynamically adjust the direction and shape of the probe beam, enabling scanning detection along arbitrary trajectories. Based on the OPA module, a reflection scanning module is further introduced. This module reflects the probe beam to the detection area and receives the echo signal, reflecting it back to the OPA module. In other words, the reflection scanning module changes the scanning angle of the probe beam emitted from the OPA module in another dimension, expanding the scanning range and achieving a large field-of-view two-dimensional scan in conjunction with the OPA module. In summary, the combination of the OPA module and the reflection scanning module forms a new type of semi-solid-state lidar, which, compared to traditional lidar, eliminates the need for optical mirror groups and can achieve large field-of-view two-dimensional scanning along arbitrary trajectories. Attached Figure Description

[0007] Figure 1 This is a structural diagram of an optional semi-solid-state lidar according to an embodiment of this application;

[0008] Figure 2 This is a schematic diagram of the output of an optional OPA module according to an embodiment of this application;

[0009] Figure 3 This is a schematic diagram of an optional semi-solid-state lidar according to an embodiment of this application;

[0010] Figure 4 This is a schematic diagram of another optional semi-solid-state lidar according to an embodiment of this application;

[0011] Figure 5 This is a schematic diagram illustrating an optional sinusoidal function relationship between light intensity and phase voltage according to an embodiment of this application;

[0012] Figure 6 This is a schematic flowchart of an optional lidar detection method according to an embodiment of this application. Detailed Implementation

[0013] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0014] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0015] According to one aspect of the embodiments of this application, a semi-solid-state lidar is provided. Figure 1 This is a structural diagram of an optional semi-solid-state lidar according to an embodiment of this application. See also... Figure 1 A semi-solid-state lidar includes a light source, at least one OPA (Optical Phased Array) module, a reflection scanning module, a detection module, and a signal processing module.

[0016] The light source provides the laser signal, which includes a local oscillator beam and a probe beam. The light source is a core component of the semi-solid-state lidar system. The laser signal it generates is guided to the detection area via a reflection scanning module. When the laser signal encounters an object to be detected, a portion of the signal is reflected from the object's surface, forming an echo signal. The laser signal can be either a frequency-modulated (FM) continuous wave or a non-FM continuous wave. The local oscillator beam serves as a reference signal; its frequency variation over time is known. It is used to beat the echo signal to obtain frequency difference information, which allows for the calculation of the distance, velocity, and direction of motion of the object to be detected. The probe beam is emitted and scanned via the OPA module to achieve rapid detection of the area to be detected.

[0017] At least one OPA module, connected to a light source, is used to receive and emit a probe beam. An OPA module is an optical device that achieves beam deflection, focusing, and scanning by controlling the phase difference of the beam. Utilizing the principle of phased arrays, it precisely controls the phase of the beam corresponding to each transmitting antenna, causing the beam to form a probe spot in space. By controlling the phase of the corresponding receiving antenna, it receives the beam spot, thus achieving beam manipulation and spatial detection. The OPA module can achieve precise control of the beam direction and deflection. Compared to traditional mechanical scanning, the OPA module requires no moving mechanical parts, thus offering higher reliability and stability. Furthermore, based on the principle of coherent and constructive light waves in physical optics, the OPA module can integrate beam transmission and reception functions without the need for transceiver optical mirror assemblies.

[0018] A reflection scanning module is used to receive the detection beam emitted by the OPA module and reflect the detection beam to the detection area; and to receive the echo signal and reflect it back to the OPA module so that the echo signal can be received through the OPA module. In this embodiment, although the OPA module has fast and high-precision scanning capabilities, its scanning angle range in the wavelength direction is limited. Therefore, by introducing a reflection scanning module, this embodiment can further expand the scanning angle range in the wavelength direction, realizing a large field of view two-dimensional scanning. For example, in scenarios where the OPA module cannot directly detect certain targets or areas, the reflection scanning module can reflect the detection beam to these areas that are difficult to detect directly, thereby improving the overall detection capability of the lidar. Figure 2 This is a schematic diagram of the output of an optional semi-solid-state lidar according to an embodiment of this application, as shown below. Figure 2 As shown, the detection beam emitted from the OPA module changes its scanning path after being reflected by the reflection scanning module, and then enters the detection area after being reflected by the reflection scanning module. Part of the detection beam is reflected when it encounters the object to be detected, forming an echo signal. This echo signal is reflected by the reflection scanning module and then enters the OPA module, allowing the OPA module to receive the echo signal.

[0019] The detection module receives the echo signal from the OPA module and the local oscillator beam from the light source. It beats the echo signal and the local oscillator beam to form a beat frequency signal, which is then converted into a detection electrical signal. The beat frequency signal is typically caused by the frequency difference between the echo signal (the detection beam reflected back from the object being detected) and the local oscillator beam generated by the light source. When the echo signal and the local oscillator beam meet, they coherently cancel each other out, forming a new signal. The frequency of this new signal is equal to the difference between the frequencies of the two original signals, i.e., the beat frequency signal. The echo signal is the beam received by the OPA module after being reflected again by the reflection scanning module from the object being detected.

[0020] The signal processing module, connected to the detection module, receives the detection electrical signals and determines information about the object to be detected within the detection area based on these signals. For example... Figure 1 As shown, taking the laser signal as an example of a frequency-modulated continuous wave (FM-CWHW) signal, the working principle of a semi-solid-state lidar is as follows: The light source generates the FM-CWHW signal, which includes a local oscillator beam and a probe beam. The probe beam generated by the light source is sent to the OPA module. The OPA module controls the deflection of the probe beam by precisely controlling the phase of the beam corresponding to each transmitting antenna. After phase adjustment, the probe beam exits from the OPA module and enters the reflection scanning module. The reflection scanning module receives the probe beam from the OPA module and reflects it to the detection area. When the probe beam encounters the object to be detected, part of the beam is reflected back, forming an echo signal. The reflected echo signal is received again by the reflection scanning module and reflected back to the OPA module. The OPA module is responsible not only for transmitting the probe beam but also for receiving the reflected echo signal and transmitting it to the detection module. The detection module receives the echo signal from the OPA module and the local oscillator beam provided by the light source. The echo signal and the local oscillator beam beat within the detection module, generating a beat signal. The detection module converts the beat signal into a detection electrical signal and transmits it to the signal processing module. The signal processing module receives the detection electrical signal from the detection module. Based on the frequency (i.e., beat frequency) of the detection electrical signal and the known frequency modulation slope, the signal processing module can calculate the time required for the detection beam to travel to and from the object to be detected. Using this time, the distance between the object to be detected and the semi-solid-state lidar can be further calculated.

[0021] This embodiment introduces an OPA module. When the probe beam enters the OPA module, the OPA module changes the propagation direction of the probe beam, achieving at least one form of scanning detection without mechanical movement. Furthermore, the OPA module can dynamically adjust the direction and shape of the probe beam, enabling scanning detection along arbitrary trajectories. Based on the OPA module, a reflection scanning module is further introduced. This module reflects the probe beam to the detection area and receives the echo signal, reflecting it back to the OPA module. In other words, the reflection scanning module changes the scanning angle of the probe beam emitted from the OPA module in another dimension, expanding the scanning range. Combined with the OPA module, this achieves a large field-of-view two-dimensional scanning. In summary, the combination of the OPA module and the reflection scanning module forms a new type of semi-solid-state lidar. Compared to traditional lidar, it eliminates the need for optical mirror groups and can achieve large field-of-view two-dimensional scanning along arbitrary trajectories.

[0022] In one exemplary embodiment, the OPA module emits a laser signal to achieve one-dimensional scanning; and / or, the OPA module emits a laser signal to achieve two-dimensional scanning.

[0023] One-dimensional scanning refers to the scanning of a laser signal in a single dimension (such as the horizontal or vertical direction). For example... Figure 2 As shown, the OPA module achieves scanning in the vertical direction (i.e., the phase direction) by adjusting the phase of the beams corresponding to each optical antenna, and reflects the beams to the detection space through the reflection scanning module; or, the OPA module controls the beams to achieve scanning in the horizontal direction (i.e., the wavelength direction) by adjusting the wavelength of each optical antenna, and reflects the beams to the detection space through the reflection scanning module.

[0024] Two-dimensional scanning refers to the scanning of a laser signal on a two-dimensional plane (such as horizontal and vertical directions). Two-dimensional scanning can also be achieved by adjusting the phase and wavelength of the OPA module itself. As mentioned above, one-dimensional scanning can be achieved in the phase direction by adjusting the phase of the beams corresponding to each optical antenna, and scanning in the wavelength direction can be achieved by laser wavelength modulation. However, large-angle scanning is difficult to achieve based on wavelength modulation. Currently, there are two schemes to achieve large-angle scanning in the wavelength direction: one is to use a single laser for wavelength modulation (100nm wavelength modulation range); the other is to use multiple lasers with different center wavelengths to achieve a 100nm wavelength modulation range. Both schemes have corresponding problems. For example, it is difficult to achieve 100nm wavelength modulation with a single laser while ensuring other parameters; the method using multiple lasers has problems of high power consumption and high cost. Therefore, to solve the problem of the difficulty in achieving large-angle scanning in the wavelength direction in the existing technology, this application proposes a combination of an OPA module and a reflection scanning module to achieve two-dimensional scanning. Figure 2 As shown, by rotating the reflection scanning module, the emission angle of the detection beam emitted by the OPA module in the wavelength direction can be changed, thereby expanding the scanning angle range in the wavelength direction. This reduces power consumption and cost while achieving two-dimensional scanning. Furthermore, it enables large-angle scanning in the wavelength direction without wavelength modulation, thus overcoming the limitations of the OPA module in the scanning angle in the wavelength direction. This allows the semi-solid-state lidar to perform high-efficiency and high-precision detection in a two-dimensional plane.

[0025] This embodiment introduces a reflection scanning module, which changes the scanning angle of the detection beam emitted by the OPA module. This expands the scanning angle in the wavelength direction, thereby enabling the detection of the measured space over a wide angle range. This overcomes the limitations of the OPA module in terms of scanning angle, allowing the OPA module to perform high-efficiency and high-precision detection on a complete two-dimensional plane.

[0026] In one exemplary embodiment, Figure 3This is a schematic diagram of an optional semi-solid-state lidar according to an embodiment of this application, as shown below. Figure 3 As shown, the signal processing module generates a first control signal and transmits it to the light source; it also generates a second control signal and transmits it to the reflection scanning module. The first control signal controls the light source to generate a laser signal. The second control signal controls the deflection of the reflection scanning module.

[0027] like Figure 3 As shown, the reflection scanning module includes a driving component and a scanning mirror. The driving component, based on a second control signal, rotates the scanning mirror to deflect the propagation direction of multiple probe beams, which are then used to probe the measured space. The driving component is electrically connected to the signal processing module and generates corresponding driving forces (such as voltage and current) according to the received second control signal to control the deflection of the scanning mirror.

[0028] The scanning mirror is a key mechanical component in the reflective scanning module. It can be a rotating prism, a mechanical mirror, a galvanometer, or a MEMS (Micro-Electro-Mechanical Systems) micromirror. The scanning mirror is located in the emission direction of the OPA module. When the drive component controls the scanning mirror to perform regular deflection or scanning motion, the probe beam emitted from the OPA module is incident on the scanning mirror. The deflection of the scanning mirror changes the propagation path of the beam, achieving scanning of the beam along the wavelength direction. Thus, the reflective scanning module combined with the OPA module can perform two-dimensional spatial detection.

[0029] In this embodiment, the reflection scanning module includes a driving component and a scanning mirror. The driving component controls the deflection angle of the scanning mirror to achieve mechanical scanning of the emitted beam along any trajectory in the wavelength direction, thereby detecting the measured space within a large angle range.

[0030] In an exemplary embodiment, when the reflection scanning module is a rotating prism or a mechanical rotating mirror, the reflection scanning module includes multiple reflecting surfaces and a rotating axis, and the angle between each reflecting surface and the rotating axis is different.

[0031] The reflection scanning module includes multiple reflective surfaces, meaning that the rotating prism or mechanical mirror is not just a single plane mirror, but rather composed of multiple different reflective surfaces. Each reflective surface can independently reflect light, thus enabling more complex beam manipulation.

[0032] The axis of rotation is the center of rotation for the rotating prism or mechanical mirror. The reflecting surfaces rotate around this axis, thus changing the direction of the probe beam emitted by the OPA module. Each reflecting surface makes a different angle with the axis of rotation, meaning that as the rotating prism or mechanical mirror rotates, the probe beam reflected by each surface will move along a different path. Therefore, the direction of the probe beam emitted by the OPA module can be precisely controlled by adjusting the rotation angle of the rotating prism or mechanical mirror.

[0033] In this embodiment, when the reflection scanning module is a rotating prism or a mechanical rotating mirror, the detection beam can be scanned by rotating the prism or mechanical rotating mirror. In addition, the reflection scanning module includes multiple reflecting surfaces and rotating axes, and the angle between each reflecting surface and the rotating axis is different. The direction of the reflected light can be adjusted as needed to achieve omnidirectional scanning of the detection beam, thereby covering a wider detection area.

[0034] In one exemplary embodiment, such as Figure 3 As shown, the OPA module includes a first beam splitter, a phase shifter, a transmitting antenna, and a receiving antenna. The first beam splitter splits the detection beam output from the light source into a detection sub-beam and provides it to the phase shifter. The phase shifter shifts the phase of the detection sub-beam and provides the phase-shifted detection sub-beam to the transmitting antenna, which then emits it into the detection space. The receiving antenna receives the echo signal and provides it to the detection module after passing through the phase shifter and the first beam splitter in sequence.

[0035] The first beam splitter, a component of the OPA module, is used to split the input probe beam into multiple probe sub-beams. These probe sub-beams are then phase-adjusted by phase shifters before being emitted into the probe space via the transmitting antenna.

[0036] The phase shifter is another key component in the OPA module, used for phase adjustment of the probe sub-beams. By changing the phase of the probe sub-beams, the direction of the laser beam and the scanning path can be controlled. In this embodiment, the OPA module includes multiple optical channels, one of which includes a phase shifter and an optical antenna. The multiple probe sub-beams formed by beam splitting in the OPA module correspond one-to-one with the multiple optical channels. The probe sub-beams from these multiple beams are input into the phase shifters of their respective optical channels, and the phase of the probe sub-beam in each optical channel is adjusted by the phase shifters to control the emission direction of the probe sub-beam input into each optical channel. Thus, the traditional transceiver assembly is no longer needed to control the detection direction of the probe beam.

[0037] The transmitting antenna is the component in the OPA module used to project the phase-shifted probe sub-beam into the probe space. The receiving antenna is the component in the OPA module used to receive the echo signals. When the laser beam illuminates the target and reflects back, the receiving antenna captures these echo signals and transmits them to the subsequent probe module for processing. Both the transmitting and receiving antennas can be two-dimensional antenna arrays. The transmitting and receiving antennas can also be fabricated using CMOS technology, which can significantly reduce costs; for example, the OPA module can be formed on an SOI substrate using CMOS technology, the specific fabrication process of which will not be detailed here.

[0038] like Figure 3 As shown, after the probe beam output from the light source is coupled into the OPA module, it first enters the first beam splitter of the OPA module, which splits the probe beam into multiple probe sub-beams. Each probe sub-beam enters a corresponding phase shifter. The phase shifter adjusts the phase of each probe sub-beam according to a preset phase adjustment strategy. The phase-shifted probe sub-beams enter the transmitting antenna, which efficiently radiates them to the reflection scanning module and then exits into the detection space. When the probe beam reaches the target and is reflected, it forms an echo signal. This echo signal reaches the reflection scanning module and is reflected back to the OPA module. The receiving antenna in the OPA module captures these echo signals. Then, the echo signals pass through the phase shifter and the first beam splitter in sequence before finally entering the detection module.

[0039] In this embodiment, the OPA module splits the injected probe beam, and the resulting multiple probe sub-beams correspond one-to-one with multiple optical channels within the OPA module. By adjusting the phase in each optical channel through a phase shifter, the propagation direction of the probe sub-beams can be flexibly controlled, thereby achieving electronic scanning in the wavelength direction. The direction of each beam can be dynamically controlled, thus enabling scanning detection of arbitrary trajectories.

[0040] In one exemplary embodiment, the scanning angle switching time of the OPA module corresponds one-to-one with the unit scanning cycle subdivision of the reflection scanning module, or is a multiple relationship.

[0041] The scan angle switching time refers to the time required for the OPA module to switch from one scan angle to another. The scan angle switching time depends on the performance and design of the OPA module, as well as the required range of scan angle changes.

[0042] Subdivision of the unit scan cycle refers to the process by which a reflective scanning module divides the scan cycle into smaller scanning units or time periods during a single full scan. For example, if the reflective scanning module uses a code disk, the unit scan cycle is subdivided into the number of code disk scribes; if the reflective scanning module uses MEMS scanning, the unit scan cycle is subdivided into the time division of the drive signal cycle. A code disk is a precision element used to measure rotational angles or displacements. It typically has a series of equally spaced scribes or marks, each scribe recording the increment of rotational angle or displacement. The number of code disk scribes refers to the number of scribes on the code disk, which determines the code disk's resolution, i.e., the smallest increment of angle or displacement that can be measured. More scribes result in higher resolution and more accurate measurements. MEMS (Micro-Electro-Mechanical Systems) is a miniature system integrating mechanical, electronic, and optical technologies. In scanning devices such as lidar, MEMS is often used as the driving mechanism for scanning mirrors, achieving beam scanning by precisely controlling the vibration or rotation of the MEMS. The drive signal cycle refers to the time period of the signal used to drive the MEMS. The driving signal period determines the vibration or rotation frequency of the MEMS, which in turn affects the scanning speed and accuracy. By adjusting the time division of the driving signal period, the scanning step size of the MEMS can be controlled, i.e., the angle or distance the beam moves during each scan.

[0043] The scanning angle switching time of the OPA module corresponds one-to-one with the unit scan cycle subdivision of the reflective scanning module, meaning that each time the OPA module switches scanning angles, the reflective scanning module completes exactly one subdivision scan cycle. The scanning angle switching time of the OPA module is a multiple of the unit scan cycle subdivision of the reflective scanning module, meaning that the OPA module switches scanning angles relatively slowly, while the reflective scanning module completes scanning multiple times within each subdivision scan cycle.

[0044] In this embodiment, the scanning angle switching time of the OPA module corresponds one-to-one with the unit scanning cycle of the reflective scanning module, enabling precise synchronization between the two operations. Alternatively, the scanning angle switching time of the OPA module can be a multiple of the unit scanning cycle of the reflective scanning module, allowing the OPA module to complete the switching of multiple scanning angles in a shorter time, thereby improving scanning efficiency and shortening the scanning cycle.

[0045] In one exemplary embodiment, the light source, OPA module, and detection module are integrated on the optical chip or disposed separately.

[0046] Among them, an optical chip is a technology that integrates optical elements onto a single chip to realize the processes of light emission, light transmission, and light detection.

[0047] In this embodiment, the light source, OPA module, and detection module are set up separately, and are all discrete components, allowing each component to work independently. Different performance levels of light sources, OPA modules, and detection modules can be selected and combined as needed to meet the requirements of specific application scenarios. Integrating the light source, OPA module, and detection module onto a single optical chip can significantly improve the system integration and reduce optical loss and packaging costs between components.

[0048] In one exemplary embodiment, Figure 4 This is a schematic diagram of another optional semi-solid-state lidar according to an embodiment of this application, such as... Figure 4 As shown, the light source includes a second beam splitter and a laser; wherein, the laser is used to generate a laser signal and provide it to the second beam splitter, which splits the laser signal into a local oscillator beam and a probe beam.

[0049] Depending on the actual design requirements, the second beam splitter can be an end-face coupler, a directional coupler, or a grating coupler, etc. Its function is to split the input laser signal into two beams: the local oscillator beam and the probe beam.

[0050] The laser can be any of the DBR, DFB, and external cavity lasers, and can generate narrow linewidth continuous waves.

[0051] Among them, the DBR laser is a type of laser that utilizes a distributed Bragg reflector (DBR) as a feedback mechanism. It has a periodic structure and reflects light of a specific wavelength back into the laser through the Bragg diffraction effect, thereby achieving optical feedback and laser output. The DBR laser has a tunable wavelength characteristic; the output wavelength of the laser can be adjusted by changing the reflection wavelength of the DBR.

[0052] A DFB laser is a type of laser that utilizes the distributed feedback (DFB) effect to achieve optical feedback. Unlike a DBR laser, the grating structure in a DFB laser is continuously variable. The Bragg diffraction effect is generated through periodic modulation of the grating, feeding back light of a specific wavelength into the laser. DFB lasers typically exhibit single-mode output characteristics and are suitable for applications requiring stable wavelengths and narrow linewidths.

[0053] An external cavity laser is an optical device in which part or all of the laser's resonant cavity is located outside the laser itself. It typically consists of a gain medium (such as a semiconductor chip) and an external mirror. By adjusting the position and angle of the external mirror, the output wavelength and linewidth of the laser can be precisely controlled. External cavity lasers offer advantages such as a wide tunable wavelength range, narrow linewidth, and high output power, making them suitable for applications requiring high-precision wavelength control and stable output.

[0054] like Figure 4As shown, the light source also includes a laser driver; wherein the laser driver is electrically connected to the signal processing module, and the laser driver generates a modulation signal under the first control signal of the signal processing module, modulates the continuous wave generated by the laser to form a frequency-modulated continuous wave (i.e., laser signal) through the modulation signal, and splits the laser signal into a local oscillator beam and a probe beam through a second beam splitter.

[0055] In some embodiments, such as Figure 4 As shown, the light source also includes an optical amplifier and an optical amplifier driver. The optical amplifier driver is electrically connected to the signal processing module and generates a control signal based on the control of the signal processing module. This control signal is used to adjust the operating state of the optical amplifier, ensuring that the laser signal generated by the laser achieves a stable and adjustable gain after amplification. The laser and the optical amplifier are optically connected. The optical amplifier receives the laser signal output from the laser, amplifies its power, and ensures that the emitted laser signal has sufficient energy to achieve long-distance detection. The optical amplifier can be an SOA (semiconductor optical amplifier) ​​or an EDFA (erbium-doped fiber amplifier).

[0056] In one exemplary embodiment, such as Figure 4 As shown, the detection module includes a beam combiner and a balancing detector.

[0057] A beam combiner is an optical element used to combine two or more optical signals into one. In this embodiment, the beam combiner is connected to the OPA module and the light source respectively, and is used to receive the echo signal and the local oscillator beam. The echo signal and the local oscillator beam beat within the beam combiner to form a beat frequency signal.

[0058] A balanced detector, connected to a beam combiner, receives beat frequency signals, converts them into detection electrical signals, and provides these signals to a signal processing module. The signal processing module then uses these signals to determine information such as the distance, velocity, and direction of motion of the object being detected. A balanced detector is a photoelectric detector used to detect weak light signals. Examples of balanced detectors include PIN diodes and APDs.

[0059] In some embodiments, such as Figure 4 As shown, the detection module also includes an analog front-end. The analog front-end performs analog signal processing on the beat frequency signal, such as filtering and amplification. The balanced detector converts the beat frequency signal into a detection electrical signal, which is then amplified by the analog front-end and output to the signal processing module.

[0060] In some embodiments, such as Figure 4As shown, the signal processing module also includes an analog-to-digital converter and a logic unit. The analog-to-digital converter is connected to the balanced detector of the detection module. After receiving the detection electrical signal output by the detection module, it converts the detection electrical signal into a digital signal. The logic unit calculates information such as the distance and speed of the object to be detected through the digital signal.

[0061] In this embodiment, the beam combiner can accurately align and merge the echo signal with the local oscillator beam to accurately reflect the frequency difference between the two, and also improve the stability of the beat frequency signal; the balanced detector further converts the beat frequency signal into a high-precision detection electrical signal, enabling the subsequent signal processing module to extract target information more accurately, thereby improving measurement accuracy and resolution.

[0062] In one exemplary embodiment, such as Figure 3 and Figure 4 As shown, the semi-solid-state lidar also includes a digital-to-analog converter (DAC). The signal processing module further generates multiple third control signals and transmits these signals to the DAC. These third control signals are digital control signals. Each third control signal includes detailed information about the required phase of an optical channel. This detailed information is converted into an analog voltage or analog current signal and output through the DAC to the phase shifter corresponding to each optical channel in the OPA module. The phase shifter changes the phase of each optical channel based on the received analog signal, thereby changing the propagation direction of each probe sub-beam.

[0063] A digital-to-analog converter (DAC) is used to convert multiple received third control signals into analog signals, each corresponding to a specific optical channel. Each analog signal controls a phase shifter to adjust the phase of its corresponding optical channel. Each analog signal is input to the phase shifter. In essence, the phase of each optical channel in the OPA module is adjusted by the phase shifter based on the analog signal input to each optical channel. For example... Figure 3 and Figure 4 As shown, the digital-to-analog converter (DAC) module is electrically connected to the signal processing module. The DAC can be separate from the OPA module or encapsulated with it using advanced packaging technology. The DAC is responsible for converting the third control signal generated by the signal processing module into an analog signal (analog voltage or current signal). The analog signal is used to control the phase shifters of each channel in the OPA module. By changing the analog signal, the phase change of the corresponding phase shifter can be adjusted, thereby adjusting the phase of each channel of the OPA module's transmit and receive antennas to change the transmit and receive scanning angles.

[0064] The OPA module is also used to adjust the phase of each optical channel according to the analog signal input to each optical channel, so as to deflect the propagation direction of the probe sub-beam input to each optical channel and obtain multiple probe beams.

[0065] Optionally, the phase shifter in the OPA module receives the analog signal input to each optical channel and adjusts the phase of each optical channel according to the analog signal to deflect the propagation direction of the probe sub-beam input to each optical channel, change the position of the probe (spot), and achieve a full scan of the detection space.

[0066] In this embodiment, the digital-to-analog converter converts the third control signal generated by the signal processing module into an analog signal. The analog signal controls the phase shifters of each channel in the OPA module to adjust the phase of the beam in each channel. By changing the phase, the deflection of the detection beam can be achieved. Furthermore, by precisely adjusting the output signal of the digital-to-analog converter, the phase change of each channel in the OPA module can be set, thereby generating complex or arbitrary scanning trajectories. That is, the target area can be scanned according to a specific pattern without the need for mechanical scanning mirror rotation, thus achieving faster and more accurate spatial detection.

[0067] In an exemplary embodiment, the signal processing module is further configured to: determine the light intensity of the probe sub-beam input to each optical channel; determine the analog voltage value required to adjust the phase of each optical channel according to a preset relationship and the light intensity of the probe sub-beam of each optical channel, wherein the preset relationship is used to characterize the correlation between the light intensity of the probe sub-beam of each optical channel and the analog voltage value required to adjust the phase of each optical channel; and generate a third control signal corresponding to each optical channel according to the analog voltage value required to adjust the phase of each optical channel, thereby obtaining a plurality of third control signals.

[0068] The preset relationship refers to a pre-determined mathematical formula or function that describes the quantitative relationship between the light intensity of the probe sub-beam in the OPA module and the analog voltage value required to adjust the phase. It can be understood that the third control signal is generated based on the preset relationship and the light intensity of the probe sub-beam.

[0069] Analog voltage refers to a continuously adjustable voltage signal converted from a digital signal by a digital-to-analog converter (DAC). The analog voltage value is used to control the phase shifter in the OPA module to change the phase and direction of the probe beam.

[0070] Optionally, the signal processing module measures or presets the light intensity of the probe sub-beam in each optical channel. Based on the light intensity of the probe sub-beam in each optical channel, the signal processing module uses a preset formula to calculate the analog voltage value required to adjust the phase. The signal processing module generates a third control signal corresponding to each optical channel according to the analog voltage value required to adjust the phase of each optical channel.

[0071] In this embodiment, a third control signal corresponding to each optical channel is generated based on a preset relationship and the light intensity of the probe sub-beam of each optical channel. The preset relationship characterizes the relationship between the light intensity of the probe sub-beam and the analog voltage value required to adjust the phase. Through the preset relationship, the corresponding phase adjustment voltage value can be accurately calculated based on the actual light intensity of each optical channel, thereby controlling the emission and reception of the probe beam more flexibly and accurately. This achieves independent control of the phase of each optical channel, and the beam can be flexibly deflected according to a preset trajectory and pattern without relying on the fixed arrangement of the light source or probe module.

[0072] In an exemplary embodiment, the signal processing module is further configured to determine a preset relation based on a first relation and a second relation, wherein the first relation characterizes the correlation between the light intensity of the probe sub-beam input to each optical channel and the phase of each optical channel, and the second relation characterizes the correlation between the analog voltage value in each optical channel and the phase of each optical channel.

[0073] in, Figure 5 This is a schematic diagram illustrating an optional sinusoidal function relationship between light intensity and phase voltage according to an embodiment of this application, such as... Figure 5 As shown, there is a sinusoidal relationship between the intensity and phase of the emitted light from the channel. Therefore, the first relationship can be expressed as:

[0074] I=sin[w(V)·V+φ0](1)

[0075] In formula (1), I represents light intensity; V represents simulated voltage value; w represents the angular velocity and phase (V) of simulated voltage value V; and φ0 refers to the initial phase.

[0076] Due to inconsistencies in the OPA modules, calibration is necessary. After calibration, it is found that the analog voltage value in each optical channel output by the digital-to-analog converter is linearly related to the phase of each optical channel. Therefore, the second relationship can be expressed as:

[0077] φ=aV+b(2)

[0078] In formula (2), φ represents the phase of each optical channel; a and b represent constants, which are usually measured experimentally.

[0079] Based on the first and second relations, the relationship between the light intensity and the analog voltage value in each optical channel can be derived, thus obtaining the preset relation, which can be expressed as:

[0080] I = sin[aV + b](3)

[0081] In this embodiment, the first relation describes the relationship between the sub-beam intensity and the optical channel phase, while the second relation establishes the correlation between the simulated voltage value and the optical channel phase. By combining these two relations, the specific simulated voltage value required to achieve a specific phase change can be accurately calculated, thereby achieving high-precision control of the beam direction. In the OPA module, inconsistency in light intensity and nonlinearity in phase modulation are common problems. Establishing a preset relation based on the first and second relations can maintain the accuracy and consistency of phase modulation under different light intensities. In addition, by combining the first and second relations, the signal processing module can directly calculate the required voltage value from the light intensity data without repeatedly converting between light intensity and phase, which not only reduces the amount of calculation but also improves the system's response speed and control efficiency.

[0082] Figure 6 This is a schematic flowchart of an optional lidar detection method according to an embodiment of this application, as shown below. Figure 6 As shown, the process of this method may include the following steps:

[0083] In step S602, the light source is controlled by the signal processing module to generate a laser signal; the laser signal includes a local oscillator beam and a probe beam.

[0084] Step S604: Receive the probe beam through the OPA module and then emit the probe beam.

[0085] Step S606: Receive the detection beam emitted by the OPA module through the reflection scanning module and reflect the detection beam to the detection area; and receive the echo signal through the reflection scanning module and reflect it back to the OPA module, so that the echo signal is received through the OPA module.

[0086] Step S608: The detection module receives the echo signal provided by the OPA module and the local oscillator beam provided by the light source, beats the echo signal and the local oscillator beam to form a beat frequency signal, and converts the beat frequency signal into a detection electrical signal.

[0087] Step S610: Receive the detection electrical signal through the signal processing module, and determine the information of the object to be detected within the detection area based on the detection electrical signal.

[0088] It should be noted that: the light source in this embodiment can be used to perform the above step S602, the OPA module in this embodiment can be used to perform the above step S604, the reflection scanning module in this embodiment can be used to perform the above step S606, the detection module in this embodiment can be used to perform the above step S608, and the signal processing module in this embodiment can be used to perform the above step S610.

[0089] Through steps S602 to S610, an OPA module is introduced. When the probe beam enters the OPA module, the OPA module changes the propagation direction of the probe beam, achieving scanning detection without mechanical movement in at least one dimension. Furthermore, the OPA module can dynamically adjust the direction and shape of the probe beam, enabling scanning detection along arbitrary trajectories. Based on the OPA module, a reflection scanning module is further introduced. This module reflects the probe beam to the detection area and receives the echo signal, reflecting it back to the OPA module. In other words, the reflection scanning module changes the scanning angle of the probe beam emitted from the OPA module in another dimension, expanding the scanning range and achieving a large field-of-view two-dimensional scan in conjunction with the OPA module. In summary, by combining the OPA module and the reflection scanning module, a new type of semi-solid-state lidar is formed. Compared to traditional lidar, it eliminates the need for optical mirror groups and can achieve large field-of-view two-dimensional scanning along arbitrary trajectories.

[0090] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0091] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM (Read-Only Memory) / RAM (Random Access Memory), magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0092] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a computer-readable storage medium, which may include: flash drive, ROM, RAM, disk or optical disk, etc.

[0093] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0094] If the integrated units in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in the aforementioned computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause one or more computer devices (which may be personal computers, servers, or network devices, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0095] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0096] In the several embodiments provided in this application, it should be understood that the disclosed client can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection between units or modules, and may be electrical or other forms.

[0097] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the solution provided in this embodiment, depending on actual needs.

[0098] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or at least two units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0099] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A semi-solid-state lidar, characterized in that, include: A light source for providing a laser signal, the laser signal including a local oscillator beam and a probe beam; At least one OPA module, the OPA module being connected to the light source, is used to receive the probe beam and emit the probe beam; A reflection scanning module is used to receive the detection beam emitted by the OPA module and reflect the detection beam to the detection area; and to receive the echo signal and reflect it to the OPA module so that the echo signal can be received through the OPA module. The detection module receives the echo signal provided by the OPA module and the local oscillator beam provided by the light source, beats the echo signal and the local oscillator beam to form a beat frequency signal, and converts the beat frequency signal into a detection electrical signal. A signal processing module, connected to the detection module, is used to receive the detection electrical signal and determine the information of the object to be detected within the detection area based on the detection electrical signal.

2. The semi-solid-state lidar according to claim 1, characterized in that, The OPA module emits the laser signal to achieve one-dimensional scanning; and / or, the OPA module emits the laser signal to achieve two-dimensional scanning.

3. The semi-solid-state lidar according to claim 1, characterized in that, The reflection scanning module includes a rotating prism, a mechanical rotating mirror, a galvanometer, or a MEMS micromirror.

4. The semi-solid-state lidar according to claim 3, characterized in that, When the reflection scanning module is the rotating prism or the mechanical rotating mirror, the reflection scanning module includes multiple reflecting surfaces and a rotating axis, and the included angle between each reflecting surface and the rotating axis is different.

5. The semi-solid-state lidar according to claim 1, characterized in that, The OPA module includes: a first beam splitter, a phase shifter, a transmitting antenna, and a receiving antenna; the first beam splitter is used to split the detection beam into detection sub-beams and provide them to the phase shifter; the phase shifter shifts the phase of the detection sub-beams and provides the phase-shifted detection sub-beams to the transmitting antenna, which then emits them into the detection space; and the receiving antenna receives the echo signal and provides it to the detection module after passing through the phase shifter and the first beam splitter in sequence.

6. The semi-solid-state lidar according to claim 1, characterized in that, The scanning angle switching time of the OPA module corresponds one-to-one with the unit scanning cycle of the reflection scanning module, or is a multiple of each other.

7. The semi-solid-state lidar according to claim 1, characterized in that, The light source, the OPA module, and the detection module are either integrated on the optical chip or disposed separately.

8. The semi-solid-state lidar according to claim 1, characterized in that, The light source includes a second beam splitter and a laser; wherein the laser is used to generate the laser signal and provide it to the second beam splitter, which splits the laser signal into the local oscillator beam and the probe beam.

9. The semi-solid-state lidar according to claim 8, characterized in that, The laser is any one of DBR, DFB, and external cavity laser.

10. The semi-solid-state lidar according to claim 1, characterized in that, The detection module includes: A beam combiner, connected to the OPA module and the light source respectively, is used to receive the echo signal and the local oscillator beam, and the echo signal and the local oscillator beam beat in the beam combiner to form the beat frequency signal; A balanced detector, connected to the beam combiner, is used to receive the beat frequency signal, convert the beat frequency signal into the detection electrical signal, and provide it to the signal processing module.

Images