Transmission-type optical phased array light beam scanning chip and combination

Abstract

The invention discloses a transmission-type optical phased array light beam scanning chip and combination. The chip comprises a transparent substrate, a dielectric wrapping layer, a transparent electrode, an electrically adjustable filling material, a metal electrode and a top capping dielectric layer. The dielectric wrapping layer, the transparent electrode and the electrically-adjustable filling material jointly form a dynamic grating structure, and the transparent electrode and the metal electrode are used for applying an electric field to the electrically-adjustable filling material to change the refractive index of the electrically-adjustable filling material, so that the phase retardation of incident light in each nano antenna unit is adjusted, and light beam scanning output is realized. The depth-to-width ratio of the nano antenna unit is larger than 10, and the grating period is smaller than the wavelength of working light waves, so that an enough phase modulation range is guaranteed to be obtained. The device can realize high-speed phase modulation of incident light, has low insertion loss and high response speed, overcomes the defects of slow response and large loss of traditional mechanical scanning and a liquid crystal phased array, and is suitable for application scenes needing rapid light beam scanning, such as laser radar, optical communication, micro projection and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical phased array beam control technology, and particularly relates to a transmissive optical phased array beam scanning chip and combination. BACKGROUND

[0002] High-efficiency, high-speed, low-cost and semiconductorized beam steering has a wide range of applications in many fields. In the field of laser radar, beam steering can realize solid-state and long-distance imaging of laser radar, replacing traditional mechanical motors to obtain higher reliability and lower cost. In the field of micro projection, high-efficiency beam steering devices can realize high-efficiency micro projection. In the field of optical communication, solid-state light scanners can replace MEMS micro mirrors to realize high-speed optical switching. In addition, in the field of consumer electronics, this technology has the potential to be applied to AR (augmented reality) glasses, mobile phone cameras and other scenarios.

[0003] Traditional beam scanning methods include mechanical scanning and MEMS micro mirror scanning; solid-state beam scanning technologies include acousto-optic deflectors (AOD) and liquid crystal phased arrays. However, both mechanical scanning and existing solid-state scanning technologies have problems such as insufficiently fast response speed, insufficiently high reliability and insufficiently low cost. For example, the reliability of MEMS micro mirrors is not high and the scanning speed is usually in the kHz (kilohertz) level; AOD devices have high power consumption, high prices and are temperature sensitive; liquid crystal phased arrays have the defect of slow response speed (typical response time is in the millisecond level). These shortcomings limit the large-scale application of the above technologies.

[0004] Therefore, the prior art has defects and needs to be improved. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art and provide a transmissive optical phased array beam scanning chip.

[0006] In order to achieve the above object, the present application is implemented by the following technical scheme: the present application provides a transmission type optical phased array beam scanning chip, comprising a transparent substrate, a transparent electrode, an electrically adjustable filling material and a metal electrode, the transparent electrode and the electrically adjustable filling material together constitute a dynamic grating structure, thereby forming an optical phased array composed of a plurality of parallel arranged high aspect ratio nano antenna units; the transparent substrate is used for supporting the dynamic grating structure, one end of each transparent electrode is connected with the metal electrode, and the remaining part is provided with the electrically adjustable filling material on the periphery; the ratio of the vertical depth D of the electrically adjustable filling material to the lateral width W is greater than 10, and the vertical depth of the nano antenna unit is 5-10 times of the wavelength of the working light wave; the transparent electrode and the metal electrode are configured to apply an electric field to the electrically adjustable filling material to change the refractive index thereof and thereby adjust the phase of the outgoing light of different nano antenna units, so as to realize the phase control and scanning of the light beam.

[0007] Further, the ratio of the vertical depth D of the electrically adjustable filling material to the lateral width W is between 10 and 50.

[0008] Further, the period of the nano antenna unit is less than the wavelength of the working light wave.

[0009] Further, the period of the nano antenna unit is less than one half of the wavelength of the working light wave.

[0010] Further, the electrically adjustable filling material is a material with electro-optic effect, and the electrically adjustable filling material is one of liquid crystal, piezoelectric electro-optic crystal, electro-optic polymer or electro-optic glass.

[0011] Further, the dynamic grating structure further comprises a medium wrapping layer arranged between the transparent electrode and the electrically adjustable filling material, and the medium wrapping layer, the transparent electrode and the electrically adjustable filling material together constitute the dynamic grating structure.

[0012] Further, a top sealing medium layer is further included, the top sealing medium layer is a transparent medium, and is used for sealing the filling material when the filling material is in a liquid state. The transparent electrode adopts a transparent conductive oxide material, and the material is indium tin oxide or aluminum-doped zinc oxide.

[0013] Further, in the case of the same depth of the dynamic grating structure, the phase difference value between the nano antenna units is in a linear positive proportional relationship with the medium refractive index, and the phase difference expression is as follows: Wherein, λ is the wavelength of the working light wave, n1 and n2 are the equivalent refractive indexes of different channels of medium, and L is the depth of the nano antenna unit.

[0014] Further, the incident surface and / or the exit surface of the transmissive optical phased array beam scanning chip is provided with at least one layer of optical anti-reflection film.

[0015] Further, the transparent electrode and / or the metal electrode are divided into odd-numbered electrode and even-numbered electrode according to the positions of the nano-antenna units, and the difference in voltage applied to the two groups of electrodes forms an asymmetric phase distribution of the optical phased array to realize one-sided directional beam deflection scanning.

[0016] The application also provides a beam scanning chip combination, which comprises: at least two beam scanning chips and a half-wave plate arranged between adjacent two beam scanning chips, and the plurality of beam scanning chips are arranged at a certain angle with each other, the beam scanning chip is the transmissive optical phased array beam scanning chip described above, and the half-wave plate is used to realize rotation of the polarization of the light beam.

[0017] By using the above scheme, the application provides a transmissive optical phased array beam scanning chip and combination, which comprises: a transparent substrate, a dielectric cladding layer, a transparent electrode, an electrically adjustable filling material, a metal electrode and a top sealing dielectric layer. The dielectric cladding layer, the transparent electrode and the electrically adjustable filling material together constitute a dynamic grating structure, i.e. an optical phased array composed of a plurality of nano-antenna units with a high aspect ratio. The transparent substrate is used to support the grating structure; the transparent electrode and the metal electrode are used to apply an electric field to the electrically adjustable filling material to change the refractive index thereof, so as to adjust the phase delay of the incident light in each nano-antenna unit and realize beam scanning output. The nano-antenna unit has a vertical depth-width ratio (aspect ratio) greater than 10, and the grating period is less than the wavelength of the working light wave, so as to ensure that a sufficient phase modulation range is obtained. Through the above structure, the chip of the application can realize high-speed phase modulation of the incident light, has low insertion loss and high response speed, overcomes the shortcomings of slow response and large loss of traditional mechanical scanning and liquid crystal phased array, and is suitable for application scenarios such as laser radar, optical communication, micro projection and the like which require fast beam scanning. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 FIG. 1 is a structural schematic diagram of the transmissive optical phased array beam scanning chip of the application.

[0019] Figure 2 FIG. 2 is a sectional view of the transmissive optical phased array beam scanning chip of the application.

[0020] Figure 3 FIG. 3 is a schematic diagram of the aspect ratio of the electrically adjustable filling material in the application.

[0021] Figure 4 FIG. 4 is a schematic diagram of the driving voltage grouping of the first embodiment of the application.

[0022] Figure 5Fig. 1 is a schematic diagram of the phase distribution corresponding to the driving voltage of the first embodiment of the present application.

[0023] Figure 6 Fig. 2 is a schematic diagram of the light beam deflection of the first embodiment of the present application.

[0024] Figure 7 Fig. 3 is a schematic diagram of the structure of the second embodiment of the present application.

[0025] Figure 8 Fig. 4 is a schematic diagram of the structure of the third embodiment of the present application.

[0026] Figure 9 Fig. 5 is a schematic diagram of the structure of the fourth embodiment of the present application.

[0027] Figure 10 Fig. 6 is a schematic diagram of the structure of the light beam scanning chip combination of the present application.

[0028] Figure 11 Fig. 7 is a schematic diagram of the optical path of the light beam scanning chip combination of the present application. DETAILED DESCRIPTION

[0029] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Referring to Figures 1-3 The present application provides a transmissive optical phased array light beam scanning chip, which comprises a transparent substrate 2, a transparent electrode 4, an electrically adjustable filling material 6 and a metal electrode 10. The transparent electrode 4 and the electrically adjustable filling material 6 together form a dynamic grating structure, thereby forming an optical phased array composed of a plurality of high-aspect-ratio nano antenna units arranged side by side. The transparent substrate 2 is used to support the dynamic grating structure and is made of a material with high transmittance and low absorption in the working waveband (for example, quartz glass is often used in the visible and near-infrared waveband). One end of each transparent electrode 4 is connected to the metal electrode 10, and the remaining part is surrounded by the electrically adjustable filling material 6. The metal electrode 10 and the metal lead are connected to the external driving circuit, which is used to apply a voltage field to the electrically adjustable filling material 6. A dielectric wrapping layer 8 (such as an aluminum oxide or silicon oxide film) is usually arranged between the transparent electrode 4 and the electrically adjustable filling material 6. The main function of the dielectric wrapping layer 8 is to isolate the electric field to prevent leakage, and the material with hydrophilic or hydrophobic surface can be selected according to the need to improve the interface characteristics with the filling medium.

[0031] The electrically tunable filling material 6 is an electro-optic material whose refractive index changes under the action of an applied electric field. Examples include liquid crystals, piezoelectric electro-optic crystals (such as lithium niobate, lithium tantalate, PZT, etc.), electro-optic polymers, and glasses with electro-optic properties (such as chalcogenide glasses). The ratio of the vertical depth D to the horizontal width W of the electrically tunable filling material 6 is greater than 10, and the vertical depth of the nano-antenna unit is 5-10 times the wavelength of the working light wave. The transparent electrode 4 and the metal electrode 10 are configured to apply an electric field to the electrically tunable filling material 6 to change its refractive index and thereby adjust the phase of the emitted light from different nano-antenna units, thus achieving phase control and scanning of the beam. Preferably, the ratio of the vertical depth D to the horizontal width W of the electrically tunable filling material 6 is between 10 and 50. This high aspect ratio, combined with the refractive index modulation capability of the electro-optic medium, ensures that the chip of this invention can achieve phase modulation on the order of 0-2π within a small antenna size.

[0032] The working principle of the transmissive optical phased array beam scanning chip provided by this invention is as follows: By applying a voltage to the transparent electrode 4 to change the refractive index of the electrically tunable filling material 6, the optical path phase delay of the incident light in different nano-antenna units is adjusted, thereby causing the outgoing beam to deflect in space. The outgoing phase of the dynamic grating structure is jointly determined by the electric field applied to the electrically tunable filling material 6 and the depth of the dynamic grating structure (i.e., the vertical depth D of the electrically tunable filling material). Under the same dynamic grating structure depth, the phase difference between the nano-antenna units is linearly proportional to the refractive index of the medium, and its phase difference expression is as follows: (1) Where λ is the wavelength of the working light wave, n1 and n2 are the equivalent refractive indices of the medium filling different channels, and L is the depth of the nanoantenna unit.

[0033] According to formula (1) above, assuming the working light wavelength is 905 nm, if a phase modulation range of 0 to 2π is desired, and the refractive index of the electrically tunable filling material 6 is tunable to approximately 0.2 (e.g., the refractive index change of liquid crystal material), then the required depth of the nano-antenna unit is L≈λ / Δn=905nm / 0.2≈4.525µm. This depth can be achieved under existing semiconductor micro-nano process conditions. Typically, the depth of the nano-antenna unit designed in this invention is approximately 5 to 10 times the working light wavelength. This high aspect ratio structural parameter is one of the core differences between this invention and other spatial light modulation phased array schemes. In other words, in the dynamic grating structure of this invention, the aspect ratio D / W of the electrically tunable filling material 6 is generally greater than 10. To obtain a sufficiently large beam deflection angle and high antenna array efficiency, this invention preferably adopts a deep subwavelength nano-antenna unit period (i.e., grating period (Pitch)) design to achieve a higher aspect ratio. Preferably, the period of the nanoantenna element is selected to be smaller than the operating light wavelength (i.e., subwavelength), or even smaller than half the operating light wavelength (i.e., deep subwavelength). For example, when the duty cycle is 1:1 (duty cycle is the ratio of the thickness of the filled material region to the thickness of the unfilled region in the high aspect ratio nanoantenna element, such as...), Figure 3 (The ratio of S to W in the grating). If the grating period is at the deep subwavelength level, the unit width W = Pitch / 2 of the electrically tunable filler material will be significantly smaller than the working wavelength, thus achieving a high aspect ratio of D / W > 10 while meeting the required phase delay.

[0034] Furthermore, the dynamic grating structure also includes a dielectric encapsulation layer 8 disposed between the transparent electrode 4 and the electrically tunable filling material 6. The dielectric encapsulation layer 8, together with the transparent electrode 4 and the electrically tunable filling material 6, constitutes the dynamic grating structure. The main function of the dielectric encapsulation layer 8 is to reduce leakage current, and a dielectric material with interface matching (e.g., hydrophilic or hydrophobic properties) to the electrically tunable filling material 6 can be selected. Optionally, the transmissive optical phased array beam scanning chip may also include a top sealing dielectric layer 12, which is a transparent dielectric layer used to seal the electrically tunable filling material 6 when it is in a liquid state. The top sealing dielectric layer 12 is a transparent material (e.g., a silicon dioxide thin film) covering the top of the dynamic grating structure. It is used to encapsulate and seal the electrically tunable filler material 6 when it is in a liquid state, and can also serve as an optical antireflection layer. The top sealing dielectric layer 12 can be a deposited dielectric thin film (prepared by electron beam evaporation, magnetron sputtering, PECVD, etc.) or a relatively thick transparent substrate (e.g., a quartz sheet about 500µm thick) bonded to the top of the structure. When the filler material is solid, the top sealing dielectric layer 12 may not be provided, or only an antireflection film may be deposited at the interface.

[0035] In this embodiment of the invention, the period of the nanoantenna unit can be selected according to the operating wavelength: for shorter wavelengths (such as visible light), a period on the order of hundreds of nanometers can be used; for longer wavelengths (such as mid-infrared), the period scale can be enlarged accordingly, but both are preferably kept on the order of the operating light wavelength or smaller, so as to ensure that the grating diffraction is mainly in the zero order and ±1 order, thereby achieving pure phase modulation beam deflection. The material of the transparent substrate 2 can be selected as a low-absorption optical material according to the operating wavelength. For example, quartz glass is commonly used in the visible and near-infrared bands, while silicon, germanium, and other materials can be selected in the mid-infrared band. The transparent electrode 4 is made of a transparent conductive oxide material, preferably an indium tin oxide (ITO) or aluminum-doped zinc oxide (AZO) transparent conductive film, and its thickness is preferably tens to hundreds of nanometers, which ensures sufficient conductivity while minimizing light absorption. The pattern of the transparent electrode 4 can be to cover the entire nanoantenna unit array area, or it can be divided into multiple electrode segments to drive different areas respectively, with corresponding lead-out metal lines connected to the peripheral driving circuit. The dielectric coating layer 8 is typically a thin dielectric film, such as silicon oxide (SiO2) or aluminum oxide (Al2O3) about 50–200 nm thick, which covers the surface of the transparent electrode 4 or the sidewall of the electrically tunable filler material 6 for electrical isolation and surface property adjustment. The electrically tunable filler material 6 has an initial refractive index n0 when no electric field is applied, and the refractive index becomes n0 + Δn after a voltage is applied (Δn can be positive or negative, depending on the material properties). By controlling the refractive index of the electrically tunable filler material 6 corresponding to different nanoantenna elements (e.g., by applying different voltages), different phase delays can be generated according to formula (1), thereby forming a phase gradient in the emitted beam and causing the far-field beam to deflect.

[0036] Please see Figures 4-5 As an alternative first embodiment, in this embodiment, the transparent electrodes and / or the metal electrodes of the transmissive optical phased array beam scanning chip are divided into odd-numbered electrodes and even-numbered electrodes according to the position of the nanoantenna units (e.g., alternating between odd-numbered and even-numbered paths based on the position of the nanoantenna units). The difference in the voltage applied to the two sets of electrodes forms an asymmetric phase distribution of the optical phased array to achieve beam deflection scanning in a unilateral direction. Specifically, adjacent nanoantenna units are controlled by different sets of electrodes, and the voltages applied to the odd-numbered electrodes and even-numbered electrodes differ. For example... Figure 4 As shown, the driving electrodes can be divided into two groups: odd-numbered groups (e.g., V1, V3, V5, V7, V9) and even-numbered groups (e.g., V2, V4, V6, V8, V10). By controlling the voltage difference between the odd-numbered and even-numbered electrodes (e.g., V1 relative to V2, V3 relative to V4, etc., sequentially forming several different driving voltages), multiple different phase delay values ​​can be formed between adjacent nanoantenna elements, thereby producing an asymmetric phase distribution. This asymmetric phase distribution causes the emitted beam to deflect in one direction, such as...Figure 6 As indicated by the arrows, adjusting the voltage amplitude of the odd and even sets of electrodes changes the magnitude and direction of the phase gradient, thereby controlling the angle and direction of the beam scanning. This driving scheme utilizes the periodicity of the chip array structure of this invention, simplifying driving control and achieving high-speed beam deflection.

[0037] As an alternative second embodiment, please refer to Figure 7 To improve the light transmission efficiency of this transmissive optical phased array beam scanning chip, one or more layers of optical antireflection coatings 14 can be applied to the incident light surface (outside the transparent substrate) and the exit light surface (the interface between the top capping dielectric layer or filling material and air). The optical antireflection coating 14 is designed according to the principle of optical interference, selecting dielectric films (such as MgF2, SiO2, etc.) of appropriate thickness and refractive index to reduce interface reflection loss and increase the light intensity entering and emitting from the chip.

[0038] As an alternative third embodiment, please refer to Figure 8 In this embodiment, the top sealing dielectric layer is not a deposited thin film, but rather a transparent sealing substrate is bonded to the top of the dynamic grating structure via a bonding process. This transparent sealing substrate can be made of the same or similar material as the bottom transparent substrate (e.g., quartz glass), and is typically quite thick (several hundred micrometers) to provide mechanical protection and environmental isolation. Before bonding, an antireflective coating can be deposited on both the upper surface of the dynamic grating structure and the lower surface of the transparent sealing substrate to be bonded, to reduce reflection at the interface. The bonded encapsulation structure provides a more robust device package while offering thickness support for applications requiring longer optical paths (e.g., integration with other optical devices).

[0039] As an alternative fourth embodiment, please refer to Figure 9 In this embodiment, when the electrically tunable filler material is a solid-state electro-optic material (e.g., lithium niobate crystal, piezoelectric ceramic PZT, or cured electro-optic polymer), the material itself has a fixed shape and mechanical strength, and does not require an additional sealing liquid, thus eliminating the need for a top sealing dielectric layer. In this case, the top of the chip is directly at the interface between the electrically tunable filler material and air, and an anti-reflection coating is typically deposited on its surface to reduce interface reflection. Removing the top sealing dielectric layer reduces the types of media in the light transmission path, which is beneficial for reducing losses, but at the same time, it is necessary to ensure good isolation between the electrically tunable filler material and the external environment to maintain stable performance.

[0040] As a fifth alternative embodiment, a transmissive optical phased array beam scanning chip was designed for near-infrared applications at a wavelength of 905 nm. This chip uses a 550µm thick quartz glass as a transparent substrate; the dynamic grating structure has a pitch of 600nm and a duty cycle of 1:1 (with a gap of 300nm); the transparent electrodes are made of aluminum-doped zinc oxide (AZO) thin films with a thickness of approximately 150nm; the dielectric layer is a silicon dioxide (SiO2) thin film with a thickness of approximately 75nm on each side (approximately 150nm total on both sides); the material filling the space between adjacent transparent electrodes is a positive liquid crystal material with an adjustable refractive index range Δn≈0.2; the vertical depth D of the electrically adjustable filling material is designed to be 6µm to ensure 2π phase modulation; a silicon dioxide layer of approximately 2µm thickness is placed on top as a top sealing dielectric layer; and metal leads of approximately 200nm thickness made of aluminum are used to connect the transparent electrodes to the external drive. Tests showed that the device can achieve rapid beam scanning after voltage is applied and obtain a relatively uniform light intensity distribution within a range of ±30°, verifying the feasibility and superior performance of the present invention.

[0041] As a sixth alternative implementation, a transmissive phased array beam scanning chip was designed for communication band applications at a wavelength of 1550nm. The chip uses a 550µm thick quartz glass as a transparent substrate; the dynamic grating structure has a pitch of 1000nm and a duty cycle of 1:1 (with a gap of 300nm); the transparent electrodes are made of aluminum-doped zinc oxide (AZO) thin films with a thickness of approximately 200nm; the dielectric layer is a silicon dioxide (SiO2) thin film with a thickness of approximately 150nm on each side (approximately 150nm total on both sides); the material filling the space between adjacent transparent electrodes is a positive liquid crystal material with an adjustable refractive index range Δn≈0.2; the vertical depth D of the electrically adjustable filling material is designed to be 7.2µm to ensure 2π phase modulation; a silicon dioxide layer of approximately 2µm thickness is placed on top as a top sealing dielectric layer; and aluminum leads of approximately 200nm thickness are used to connect the transparent electrodes to the external drive. Tests showed that the device can achieve rapid beam scanning after voltage is applied and obtain a relatively uniform light intensity distribution within a range of ±30°.

[0042] This invention also provides a beam scanning chip assembly capable of achieving axial scanning in the same dimension. Since current single-chip solutions only provide single-axis scanning capability, this embodiment achieves multi-axis scanning through a combination of multiple chips. Specifically, it includes at least two beam scanning chips and a half-wave plate disposed between adjacent beam scanning chips. The beam scanning chips are arranged at a certain angle to each other. The beam scanning chips are the aforementioned transmissive optical phased array beam scanning chips, and the half-wave plate is used to rotate the beam polarization. Please refer to [link to relevant documentation]. Figure 10 and Figure 11This embodiment achieves dual-axis scanning, specifically including two transmissive optical phased array beam scanning chips #1 and #2, and a half-wave plate placed between them. Transmissive optical phased array beam scanning chip #1 performs scanning along one axis, such as the X-axis; transmissive optical phased array beam scanning chip #2, placed perpendicularly and orthogonally to transmissive optical phased array beam scanning chip #1, performs scanning along the other axis, such as the Y-axis; a half-wave plate (1 / 2 wave plate) is added between them to achieve beam polarization rotation. The advantage of the transmissive chip combination is that it is easy to stack arbitrarily. In addition to the expansion of X-axis and Y-axis scanning in this embodiment, by stacking multiple chips, it is also very convenient to achieve angular expansion scanning in the same dimension.

[0043] In summary, this invention provides a transmissive optical phased array beam scanning chip and assembly. The beam scanning chip includes: a transparent substrate, a dielectric cladding layer, transparent electrodes, an electrically tunable filler material, metal electrodes, and a top-sealing dielectric layer. The dielectric cladding layer, transparent electrodes, and electrically tunable filler material together constitute a dynamic grating structure, i.e., an optical phased array composed of multiple high aspect ratio nanoantenna units. The transparent substrate supports the grating structure; the transparent electrodes and metal electrodes apply an electric field to the electrically tunable filler material to change its refractive index, thereby adjusting the phase delay of the incident light in each nanoantenna unit and achieving beam scanning output. The nanoantenna unit has a depth-to-width ratio (Aspect Ratio) greater than 10, and the grating period is smaller than the wavelength of the working light wave to ensure a sufficient phase modulation range. Through this structure, the chip of this invention can achieve high-speed phase modulation of incident light, exhibiting low insertion loss and high response speed, overcoming the shortcomings of slow response and high loss in traditional mechanical scanning and liquid crystal phased arrays. It is suitable for applications requiring rapid beam scanning, such as lidar, optical communication, and micro-projection.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A transmissive optical phased array beam scanning chip, comprising a transparent substrate, transparent electrodes, an electrically tunable filling material, and metal electrodes, characterized in that, The transparent electrode and the electrically tunable filling material together constitute a dynamic grating structure, thereby forming an optical phased array composed of multiple parallel-arranged, high aspect ratio nanoantenna units. The transparent substrate supports the dynamic grating structure. One end of each transparent electrode is connected to the metal electrode, and the remaining portion is surrounded by the electrically tunable filling material. The ratio of the vertical depth D to the horizontal width W of the electrically tunable filling material is greater than 10, and the vertical depth of the nanoantenna unit is 5-10 times the wavelength of the working light wave. The transparent electrode and the metal electrode are configured to apply an electric field to the electrically tunable filling material to change its refractive index and thereby adjust the phase of the emitted light from different nanoantenna units, thereby achieving phase control and scanning of the light beam.

2. The transmissive optical phased array beam scanning chip according to claim 1, characterized in that, The ratio of the vertical depth D to the horizontal width W of the electrically adjustable filler material is between 10 and 50.

3. The transmissive optical phased array beam scanning chip according to claim 1, characterized in that, The period of the nanoantenna unit is less than the wavelength of its operating light wave; The period of the nanoantenna unit is less than half the wavelength of its operating light wave.

4. The transmissive optical phased array beam scanning chip according to claim 1, characterized in that, The electrically tunable filler material is a material with an electro-optic effect; The electrically tunable filler material is one of liquid crystal, piezoelectric electro-optic crystal, electro-optic polymer, or electro-optic glass.

5. The transmissive optical phased array beam scanning chip according to claim 1, characterized in that, The dynamic grating structure further includes a dielectric coating layer disposed between the transparent electrode and the electrically adjustable filling material, wherein the dielectric coating layer, the transparent electrode, and the electrically adjustable filling material together constitute the dynamic grating structure.

6. The transmissive optical phased array beam scanning chip according to claim 1, characterized in that, It also includes a top sealing medium layer, which is a transparent medium, used to seal the filling material when it is in a liquid state; The transparent electrode is made of a transparent conductive oxide material, which is indium tin oxide or aluminum-doped zinc oxide.

7. The transmissive optical phased array beam scanning chip according to claim 1, characterized in that, Under the same dynamic grating structure depth, the phase difference between the nanoantenna elements is linearly proportional to the refractive index of the medium, and its phase difference expression is as follows: Where λ is the wavelength of the working light wave, n1 and n2 are the equivalent refractive indices of the medium in different channels, and L is the depth of the nanoantenna unit.

8. The transmissive optical phased array beam scanning chip according to any one of claims 1-7, characterized in that, The incident surface and / or exit surface of the transmissive optical phased array beam scanning chip are provided with at least one layer of optical antireflection film.

9. The transmissive optical phased array beam scanning chip according to any one of claims 1-7, characterized in that, The transparent electrode and / or the metal electrode are divided into odd-numbered and even-numbered electrodes according to the position of the nanoantenna unit. The difference in voltage applied to the two groups of electrodes forms the asymmetric phase distribution of the optical phased array to achieve beam deflection scanning in one direction.

10. A beam scanning chip assembly, characterized in that, include: The device comprises at least two beam scanning chips and a half-wave plate disposed between two adjacent beam scanning chips. The multiple beam scanning chips are arranged at a certain angle to each other. The beam scanning chip is a transmissive optical phased array beam scanning chip as described in any one of claims 1-9. The half-wave plate is used to realize the rotation of beam polarization.

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