A reflective optical phased array chip and manufacturing method and laser scanning device

Abstract

The present invention discloses a reflective optical phased array chip, a manufacturing method and a laser scanning device, comprising: a substrate, a high reflective layer, a piezoelectric layer, an antenna array and a transducer unit; wherein the high reflective layer is arranged between the substrate and the piezoelectric layer; the antenna array comprises a plurality of nano-antenna elements, and the plurality of nano-antenna elements are arranged on the piezoelectric layer in a periodic pattern; the height of the nano-antenna element is adjustable to change the phase of the antenna array; the transducer unit is arranged on the piezoelectric layer and arranged around the antenna array. The phased array chip of the present invention is provided with a piezoelectric layer, and an antenna array formed by arranging a plurality of nano-antenna elements on the piezoelectric layer is provided. The emission phase of the antenna array is adjusted by adjusting the height of the nano-antenna element. When the light beam is directly incident on the antenna array, the light beam can be controlled, and the structure is simple and the flexibility is good.

Description

Technical Field

[0001] The present invention relates to the field of light beam scanning technology, and in particular to a reflective optical phased array chip and a manufacturing method thereof, and a laser scanning device. Background Art

[0002] As an important technology, beam scanning has been widely used in the fields of communication, laser radar, 3D imaging, hyperspectral imaging and optical sensing. At present, beam scanning is mainly achieved by using slow and expensive mechanical beam scanning devices, such as rotating prisms, micro-electromechanical systems (MEMS) galvanometers, traditional mechanical galvanometers and other devices; however, these mechanical devices are usually complex and expensive, with limited response speed and poor stability.

[0003] Optical phased array (OPA) technology is a flexible, fast and accurate non-mechanical beam directional scanning technology, which has the characteristics of high resolution, strong anti-interference and high confidentiality. Optical phased array provides a pure solid-state beam control device for beam scanning. When the laser beam is irradiated on the OPA device, the OPA device can change the beam direction and thus realize beam scanning by adjusting the phase of each structural unit. If the optical phased array is integrated on a chip, the beam scanning no longer requires mechanical drive devices such as motors. Applying it to the measurement system can simplify the structure of the measurement system, and it has good flexibility and low power consumption. This makes the optical phased array very attractive in the fields of light detection and ranging, image projection, lidar and optical storage. Therefore, it is necessary to research and develop optical phased array chips.

[0004] The disclosure of the above-mentioned background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above-mentioned content has been disclosed on the filing date of this patent application, the above-mentioned background technology should not be used to evaluate the novelty and creativity of this application. Summary of the invention

[0005] The object of the present invention is to provide a reflective optical phased array chip and a manufacturing method and a laser scanning device to solve at least one of the above-mentioned background technical problems.

[0006] To achieve the above object, the technical solution of the embodiment of the present invention is implemented as follows:

[0007] A reflective optical phased array chip comprises: a substrate, a high reflective layer, a piezoelectric layer, an antenna array and a transducer unit; wherein:

[0008] The high reflective layer is arranged between the substrate and the piezoelectric layer;

[0009] The antenna array comprises a plurality of nano-antenna elements, which are arranged on the piezoelectric layer in a periodic pattern; the height of the nano-antenna elements is adjustable to change the phase of the antenna array;

[0010] The energy conversion unit is disposed on the piezoelectric layer and arranged around the antenna array.

[0011] In some embodiments, the transducer unit is used to convert the phase control signal into a surface wave, and the height of the nano-antenna element is driven to change periodically by the surface wave.

[0012] In some embodiments, the antenna array is a one-dimensional array or a two-dimensional array, and the interval between two adjacent nano-antenna elements is smaller than the wavelength of the incident light.

[0013] In some embodiments, the transducer unit includes at least one group of IDTs, each group of IDTs includes at least one input IDT, and the input phase control signal is converted into a surface wave through the input IDT.

[0014] In some embodiments, the phase control signal is an electrical signal, and the corresponding surface wave is generated by adjusting the size, frequency and fluctuation curve of the electrical signal to drive the height of the nano-antenna element to change accordingly.

[0015] In some embodiments, a support wall and a transparent protective cover are also included; wherein the support arm is arranged on the base and located around the base to support the transparent protective cover; the transparent protective cover, the support wall and the base form a closed space to enclose the high reflective layer, the piezoelectric layer, the antenna array and the transducer unit in the space.

[0016] In some embodiments, a dielectric layer is further included, and the dielectric layer is disposed between the high reflective layer and the piezoelectric layer.

[0017] Another technical solution of the embodiment of the present invention is:

[0018] A method for manufacturing a reflective optical phased array chip comprises the following steps:

[0019] S10, providing a substrate, and disposing a high reflective layer on the surface of the substrate;

[0020] S20, disposing a piezoelectric layer on the surface of the high reflective layer;

[0021] S30, arranging a plurality of nano-antenna elements in a periodic pattern on the piezoelectric layer to form an antenna array, and arranging a transducer unit around the antenna array; wherein the height of the nano-antenna element is adjustable to change the phase of the antenna array.

[0022] In some embodiments, the method further includes the step of providing a dielectric layer between the high reflective layer and the piezoelectric layer.

[0023] Another technical solution of the embodiment of the present invention is:

[0024] A laser scanning device includes a transmitter, a collector, and a control and processing circuit; wherein:

[0025] A transmitter, comprising a light source and a phased array chip as described in any of the above embodiments; the light beam emitted by the light source is phase-modulated by the phased array chip and then emitted toward a target area, and at least part of the emitted light beam is reflected by the target area to form a reflected light beam;

[0026] A collector, used for receiving the reflected light beam to obtain an electrical signal;

[0027] The control and processing circuit is connected to the transmitter and the collector, and is used to control the transmitter and the collector, and calculate the time required for the light beam to be received after being emitted and reflected.

[0028] The beneficial effects of the technical solution of the present invention are:

[0029] Compared with the prior art, the phased array chip of the present invention is provided with a piezoelectric layer, and an antenna array formed by arranging multiple nano-antenna elements on the piezoelectric layer. The output phase of the antenna array is adjusted by adjusting the height of the nano-antenna elements. When the light beam is directly incident on the antenna array, the light beam can be controlled, and the structure is simple and flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 Schematic diagram of the structure of a reflective optical phased array chip according to an embodiment of the present invention.

[0032] Figure 2 Schematic diagram of the arrangement of the antenna array of a reflective optical phased array chip according to an embodiment of the present invention.

[0033] Figure 31 is a structural diagram of an interdigital transducer of a reflective optical phased array chip according to an embodiment of the present invention.

[0034] Figure 4 FIG. 4 is a top view of a reflective optical phased array chip according to an embodiment of the present invention.

[0035] Figure 5 is a schematic structural diagram of a reflective optical phased array chip according to another embodiment of the present invention.

[0036] Figure 6 4 is a schematic structural diagram of a reflective optical phased array chip according to yet another embodiment of the present invention.

[0037] Figure 7 1 is a flow chart of a method for manufacturing a reflective optical phased array chip according to an embodiment of the present invention.

[0038] Figure 8 Schematic diagram of the structure of a laser scanning device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the technical problems, technical solutions and beneficial effects to be solved by the embodiments of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing or for circuit connection.

[0041] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0043] Figure 1 The figure shows a schematic diagram of the structure of a reflective optical phased array chip according to an embodiment of the present invention. The chip comprises: a substrate 101, a high reflective layer 102, a piezoelectric layer 103, an antenna array 106 and a transducer unit 104; wherein the high reflective layer 102 is arranged between the substrate 101 and the piezoelectric layer 103; the antenna array 106 comprises a plurality of nano-antenna elements 105, and the plurality of nano-antenna elements 105 are arranged on the piezoelectric layer 103 in a periodic pattern; the height of the nano-antenna elements 105 is adjustable to change the phase of the antenna array 106; the transducer unit 104 is arranged on the piezoelectric layer 103 and around the antenna array 106. The material of the substrate 101 is any one of silicon, gallium arsenide, quartz, sapphire, gallium nitride and silicon carbide.

[0044] Specifically, the antenna array 106 includes a plurality of height-adjustable nano-antenna elements 105, and the structures of the plurality of nano-antenna elements 105 are the same. The plurality of nano-antenna elements 105 are periodically arranged to form the antenna array 106, and the antenna array 106 can be a one-dimensional array or a two-dimensional array, and the interval between two adjacent nano-antenna elements 105 is less than the wavelength of the incident light.

[0045] In some embodiments, multiple nano-antenna elements 105 are arranged in one dimension to form an antenna array 106, such as Figure 2 In the illustrated embodiment, the nano-antenna element 105 is in a long strip structure, and the length of the nano-antenna element is designed and configured according to the parameters of the specific device, and is not specifically limited in the present invention.

[0046] In some embodiments, a plurality of nano-antenna elements are arranged in two dimensions to form an antenna array, and the nano-antenna elements are in at least one of a cylindrical shape, a square cylindrical shape, a circular hole shape, a square hole shape, an elliptical cylindrical shape, an elliptical hole shape, a cross cylindrical shape, a cross hole shape, a V-shaped cylindrical shape, a V-shaped hole, etc. In the present invention, the number of nano-antenna elements is configured according to the parameter design of the specific device.

[0047] The transducer unit 104 adjusts the height of the nano-antenna element 105 to change periodically according to the phase control signal input externally, and modulates the phase response of the nano-antenna element according to the change in the height of the nano-antenna element 105, while the amplitude response of the nano-antenna element remains basically unchanged. Among them, the phase response variation interval is [0, 2π], and as the height of the nano-antenna element increases, the phase response gradually approaches 2π. When the light beam (indicated by a solid arrow in the figure) is incident on the antenna array 106, the phase of each light beam is adjusted by adjusting the phase response of each nano-antenna element 105, so that the emitted light beam is scanned in the field of view. Among them, the nano-antenna element is a piezoelectric material with a high refractive index.

[0048] The transducer unit 104 is used to convert the external input phase control signal into a surface wave. The surface wave propagates along the surface of the piezoelectric layer 103. When the surface wave passes through the antenna array 106, the piezoelectric layer 103 will vibrate, so that the height of the nano-antenna element arranged on the piezoelectric layer 103 changes periodically with the vibration, so that the height of each nano-antenna element 105 is adjusted to show periodic elongation or shortening under the drive of the surface wave, and the height of each nano-antenna element 105 is different from each other, so that the phase response profile of the antenna array 106 can be adjusted. When the light beam is directly incident on the antenna array, the light beam can be controlled according to the phase control signal. Among them, the piezoelectric layer 103 is composed of a piezoelectric material that supports the excitation and propagation of surface waves. The material of the piezoelectric layer can be the same as the material of the nano-antenna element, or it can be different from the material of the nano-antenna element; in some embodiments, the piezoelectric material can be one of gallium arsenide, lithium niobate, zinc oxide, aluminum nitride, etc. The phase control signal may be an electrical signal, and the corresponding surface wave is generated by adjusting the size, frequency and fluctuation curve of the electrical signal to drive the height of the nano-antenna element to change accordingly, thereby adjusting the output phase of the antenna array. The surface wave is a mechanical wave, preferably an acoustic surface wave.

[0049] When a part of the incident light beam passes through the piezoelectric layer 103, the high reflective layer 102 can reflect the light beam that passes through the piezoelectric layer 103 back to the piezoelectric layer 103 and then emit it through the antenna array 106. The incident light beam is modulated twice by the antenna array 106; specifically, the incident light beam is modulated for the first time by the nano-antenna element, and then is modulated for the second time by the antenna array after being reflected by the high reflective layer. Such a design not only improves the energy utilization rate but also enhances the modulation ability of the antenna array to the light beam. Among them, the material of the high reflective layer 102 can be made of high-reflectivity metals such as gold, silver, and aluminum, or it can be a multilayer dielectric film formed by overlapping high-refractive index and low-refractive index materials.

[0050] In some embodiments, the transducer unit 104 includes at least one group of interdigital transducers, each group of interdigital transducers includes at least one input interdigital transducer, and the input interdigital transducer uses the inverse piezoelectric effect to convert the external input phase control signal into a surface wave. In one embodiment, each group of interdigital transducers also includes at least one output interdigital transducer opposite to the input interdigital transducer, which is used to convert the surface acoustic wave into an electrical signal output as a feedback signal. According to the feedback signal, the working state of the antenna array driven by the phase control signal can be monitored, and feedback control can be performed when necessary. Among them, the antenna array is arranged between the input and output interdigital transducers. In some embodiments, the interdigital transducer is composed of two bus bars and a plurality of metal electrodes alternately connected to the two bus bars. In some embodiments, the structure of the interdigital transducer is at least one of a chirped structure, a tilted structure, and a toe-cut structure. Figure 3 The structure diagram of the interdigital transducer is shown in FIG. Figure 3 a shows the chirped structure. Figure 3 b shows an inclined structure. Figure 3 c shows the apodized structure.

[0051] like Figure 4 The figure shows a top view of an optical phased array chip according to an embodiment of the present invention. In some embodiments, the transducer unit 104 is configured to include two groups of interdigital transducer arrays 1041 and 1042, each group of interdigital transducer arrays is respectively arranged on both sides of the antenna array 106, and each group of interdigital transducer arrays includes a plurality of input interdigital transducers, and there is a phase difference between the input electrical signals of each input interdigital transducer, so as to control the light beam to achieve two-dimensional scanning. In some embodiments, each group of interdigital transducer arrays also includes a plurality of output interdigital transducers. Furthermore, each output interdigital transducer is arranged corresponding to each input interdigital transducer.

[0052] like Figure 5 The schematic diagram of the structure of the optical phased array chip of another embodiment of the present invention. The chip includes: a substrate 101, a high reflective layer 102, a piezoelectric layer 103, an antenna array 106, a transducer unit 104, a support wall 107 and a transparent protective cover 108. The high reflective layer 102 is arranged between the substrate 101 and the piezoelectric layer 103; the antenna array 106 and the transducer unit 104 are arranged on the piezoelectric layer 103; the support arm 107 is arranged on the substrate 101 and is located around the substrate 101, and is used to support the transparent protective cover 108; the transparent protective cover 108, the support wall 107 and the substrate 101 form a closed space to enclose the high reflective layer 102, the piezoelectric layer 103, the antenna array 106 and the transducer unit 104 in the space.

[0053] like Figure 6The figure shows a schematic diagram of the structure of an optical phased array chip according to another embodiment of the present invention. The chip includes: a substrate 101, a high reflective layer 102, a piezoelectric layer 103, an antenna array 106, a transducer unit 104 and a dielectric layer 109. The high reflective layer 102 is arranged on the substrate 101, the dielectric layer 109 is arranged between the high reflective layer 102 and the piezoelectric layer 103, and the antenna array 106 and the transducer unit 104 are arranged on the piezoelectric layer 103. The dielectric layer 109 is made of a transparent, low refractive index material, such as silicon dioxide. By providing a dielectric layer with a low refractive index, the interference caused by the amplitude change when the height of the antenna element presents a periodic change is effectively reduced.

[0054] Reference Figure 7 As shown, the present invention also proposes a method for manufacturing a reflective optical phased array chip, the method comprising the following steps:

[0055] S10, providing a substrate, and setting a high reflective layer on the surface of the substrate;

[0056] Specifically, in some embodiments, the material of the substrate is any one of silicon, gallium arsenide, quartz, sapphire, gallium nitride and silicon carbide, and a high-reflection layer is formed by depositing a high-reflectivity metal material on the substrate, or a high-reflection film is evaporated on the substrate to form a high-reflection layer; wherein the high-reflectivity metal material is one of gold, silver, aluminum, etc.; in some embodiments, a high-reflection layer having a multi-layer dielectric film structure can also be formed by overlapping deposition of materials including high refractive index and low refractive index.

[0057] S20, setting a piezoelectric layer on the surface of the high reflective layer;

[0058] Specifically, the piezoelectric material is deposited on the high reflective layer to form a piezoelectric layer with a certain thickness.

[0059] S30, arranging a plurality of nano-antenna elements in a periodic pattern on the piezoelectric layer to form an antenna array, and arranging a transducer unit around the antenna array; wherein the height of the nano-antenna element is adjustable to change the phase of the antenna array.

[0060] Specifically, multiple nano-antenna elements are arranged in a certain pattern on the piezoelectric layer to form an antenna array. Preferably, multiple nano-antenna elements are arranged at the center of the piezoelectric layer; wherein the arrangement of the nano-antenna elements can be a one-dimensional array or a two-dimensional array, and the interval between two adjacent nano-antenna elements is less than the wavelength of the incident light. The transducer unit is arranged around the antenna array and is set on the piezoelectric layer. In some embodiments, metal can be deposited on the piezoelectric layer to form a metal electrode to serve as the transducer unit.

[0061] It is understandable that the above manufacturing method is only one embodiment of the present invention and does not specifically limit the chip manufacturing method of the present invention. In some other possible embodiments, each part can be manufactured separately and then coupled together to form the optical phased array chip involved in the embodiment of the present invention.

[0062] Reference Figure 8 As shown, as an embodiment of the present invention, a laser scanning device 200 is also provided, including a transmitter 20, a collector 21 and a control and processing circuit 22; wherein, the transmitter 20 includes a light source 201 and a phased array chip 202 as described in any of the above-mentioned embodiments, the light beam emitted by the light source 201 passes through the phased array chip 202, and is emitted toward the target area 300 after being phase-modulated by the phased array chip 202, and the light beam 400 is emitted into the target area space to illuminate the target object in the space, at least part of the emitted light beam is reflected by the target area to form a reflected light beam 400, and at least part of the reflected light beam 400 is received by the collector 21; the collector 21 is used to receive the reflected light beam 400 to obtain an electrical signal; the control and processing circuit 22 is connected to the transmitter 20 and the collector 21, and is used to control the transmitter 20 and the collector 21, and calculate the time required for the light beam to be received from the emission to the reflection back.

[0063] It is to be understood that the above content is a further detailed description of the present invention in conjunction with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be deemed to belong to the protection scope of the present invention. In the description of this specification, the description of reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention.

[0064] In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples without contradicting each other. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope defined by the appended claims.

[0065] Furthermore, the scope of the present invention is not intended to be limited to the particular embodiments of the processes, machines, manufactures, compositions of matter, means, methods, and steps described in the specification. One of ordinary skill in the art will readily appreciate that the above disclosures, processes, machines, manufactures, compositions of matter, means, methods, or steps, currently existing or to be developed, may be utilized to perform substantially the same functions as the corresponding embodiments described herein or to obtain substantially the same results as the embodiments described herein. Therefore, the appended claims are intended to include within their scope such processes, machines, manufactures, compositions of matter, means, methods, or steps.

Claims

1. A reflective optical phased array chip, characterized in that: It includes a substrate, a high reflective layer, a dielectric layer, a piezoelectric layer, an antenna array and a transducer unit; wherein, The high reflective layer is arranged between the substrate and the piezoelectric layer, and reflects the light beam passing through the piezoelectric layer back to the piezoelectric layer, and then emits it through the antenna array; The antenna array includes a plurality of nano-antenna elements, which are arranged on the piezoelectric layer in a periodic pattern; the transducer unit is used to convert an externally input phase control signal into a surface wave, and the surface wave propagates along the surface of the piezoelectric layer. When the surface wave passes through the antenna array, it causes the piezoelectric layer to vibrate, so that the height of the nano-antenna elements arranged on the piezoelectric layer shows a periodic change with the vibration. Under the drive of the surface wave, the height of each of the nano-antenna elements shows a periodic extension or shortening, and the heights of each nano-antenna element are different from each other, so as to change the phase of the antenna array; The energy conversion unit is disposed on the piezoelectric layer and arranged around the antenna array; The dielectric layer is arranged between the high reflective layer and the piezoelectric layer, and the dielectric layer is made of a transparent material with a low refractive index; The incident light beam is modulated twice by the antenna array; specifically, the incident light beam is modulated for the first time by the nano-antenna element, and is modulated for the second time by the antenna array after being reflected by the high-reflection layer; The phase control signal is an electrical signal.

2. The reflective optical phased array chip according to claim 1, wherein: The antenna array is a one-dimensional array or a two-dimensional array, and the interval between two adjacent nano-antenna elements is smaller than the wavelength of the incident light.

3. The reflective optical phased array chip according to claim 1, wherein: The transducer unit comprises at least one group of IDTs, each group of IDTs comprises at least one input IDT, and the input phase control signal is converted into a surface wave through the input IDT.

4. The reflective optical phased array chip according to claim 1, wherein: The corresponding surface wave is generated by adjusting the size, frequency and fluctuation curve of the electrical signal to drive the height of the nano-antenna element to change accordingly.

5. A method for manufacturing a reflective optical phased array chip, characterized in that: The steps include: S10, providing a substrate, and disposing a high reflective layer on the surface of the substrate; S20, disposing a piezoelectric layer on the surface of the high reflective layer; S30, arranging a plurality of nano-antenna elements in a periodic pattern on the piezoelectric layer to form an antenna array, wherein the high reflective layer reflects the light beam passing through the piezoelectric layer back to the piezoelectric layer, and then emits it through the antenna array, and arranging a transducer unit around the antenna array; wherein the transducer unit is used to convert an externally input phase control signal into a surface wave, and the surface wave propagates along the surface of the piezoelectric layer. When the surface wave passes through the antenna array, it causes the piezoelectric layer to vibrate, so that the height of the nano-antenna elements arranged on the piezoelectric layer shows periodic changes with the vibration, and the height of each of the nano-antenna elements shows periodic extension or shortening under the drive of the surface wave, and the height of each nano-antenna element is different from each other, so as to change the phase of the antenna array; A dielectric layer is provided between the high reflective layer and the piezoelectric layer, wherein the dielectric layer is made of a transparent material with a low refractive index; The incident light beam is modulated twice by the antenna array; specifically, the incident light beam is modulated for the first time by the nano-antenna element, and is modulated for the second time by the antenna array after being reflected by the high-reflection layer; The phase control signal is an electrical signal.

6. A laser scanning device, characterized in that: It includes a transmitter, a collector, and a control and processing circuit; wherein, A transmitter, comprising a light source and the phased array chip according to any one of claims 1 to 5; the light beam emitted by the light source is phase-modulated by the phased array chip and then emitted toward a target area, and at least part of the emitted light beam is reflected by the target area to form a reflected light beam; A collector, used for receiving the reflected light beam to obtain an electrical signal; The control and processing circuit is connected to the transmitter and the collector, and is used to control the transmitter and the collector, and calculate the time required for the light beam to be received after being emitted and reflected.

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