Optical tweezer system, single atom trapping method, and metasurface device

Abstract

The present disclosure provides an optical tweezer system, a single atom trapping method, a metasurface device, a single atom trapping apparatus, an electronic device, a non-transitory computer-readable storage medium, and a computer program product. The single atom trapping method comprises: applying a first modulation to a light beam output by a light source to obtain a modulated light beam; causing the modulated light beam to be incident on a phase-type metasurface, the phase-type metasurface applying a second modulation to the modulated light beam to generate and focus an array of optical tweezers at a focal plane of the phase-type metasurface; and loading an atomic cloud into the array of optical tweezers such that a single atom in the atomic cloud is trapped by a single optical tweezer in the array of optical tweezers.

Description

Technical Field

[0001] This disclosure relates to the fields of quantum computing, quantum simulation and optical trapping technology, and in particular to an optical tweezers system, a single-atom trapping method, a metasurface device, a million-level optical tweezers chip, a single-atom trapping device, an electronic device, a non-transient computer-readable storage medium and a computer program product. Background Technology

[0002] In related technologies, optical devices such as spatial light modulators and acousto-optic deflectors are commonly used to construct optical path systems, thereby preparing optical tweezer arrays with different arrangements to achieve the binding and fixed-point capture of ultracold atoms. At the same time, imaging components are used to complete atomic state detection, which is widely used in research scenarios such as quantum simulation and quantum precision measurement.

[0003] The methods described in this section are not necessarily methods that had been previously conceived or adopted. Unless otherwise specified, no method described in this section should be assumed to be prior art simply because it is included in this section. Similarly, unless otherwise specified, the issues mentioned in this section should not be considered to be accepted in any prior art. Summary of the Invention

[0004] This disclosure provides an optical tweezers system, a single-atom trapping method, a metasurface device, a million-level optical tweezers chip, a single-atom trapping device, an electronic device, a non-transient computer-readable storage medium, and a computer program product.

[0005] According to a first aspect of this disclosure, an optical tweezers system is provided, including a modulation device disposed between a light source and a phase-type metasurface for applying a first modulation to a light beam output from the light source so that the first-modulated light beam is incident on the phase-type metasurface; a substrate; and a phase-type metasurface formed on the substrate and composed of a subwavelength pixel array configured to apply a second modulation to the incident first-modulated light beam to generate and focus an optical tweezers array.

[0006] According to a second aspect of this disclosure, a single-atom trapping method is provided, comprising applying a first modulation to a light beam output from a light source to obtain a modulated light beam; incident the modulated light beam onto a phase-type metasurface, wherein the phase-type metasurface applies a second modulation to the modulated light beam to generate and focus an optical tweezers array at the focal plane of the phase-type metasurface; and loading an atomic cloud into the optical tweezers array such that individual atoms in the atomic cloud are trapped by individual optical tweezers in the optical tweezers array.

[0007] According to a third aspect of this disclosure, a metasurface device is provided, including a substrate; and a phase-type metasurface layer formed on the substrate, the phase-type metasurface layer being composed of a subwavelength pixel array; wherein the phase-type metasurface layer is encoded with a phase pattern, and the subwavelength pixel array is configured to apply a second modulation to an incident first modulated light beam to generate and focus an optical tweezers array.

[0008] According to a fourth aspect of this disclosure, a million-scale optical tweezers chip is provided, comprising a substrate and a phase-type metasurface formed on the substrate. The phase-type metasurface is composed of a subwavelength pixel array and is configured to generate an optical tweezers array in the hundreds of thousands to millions scale by increasing the chip area, the number of pixels, and the available incident light power. The million-scale optical tweezers chip can employ a high-power-tolerant dielectric material and form a highly uniform, micrometer-pitch optical trap array on the focal plane through a large-area phase-type metasurface.

[0009] According to a fifth aspect of this disclosure, a single-atom trapping device is provided, comprising: a first means for applying a first modulation to a light beam output from a light source to obtain a modulated light beam; a second means for incidenting the modulated light beam onto a phase-type metasurface, causing the phase-type metasurface to apply a second modulation to the modulated light beam to generate and focus an array of optical tweezers at a focal plane of the phase-type metasurface; and a third means for loading an atomic cloud into the optical tweezers array so that individual atoms in the atomic cloud are trapped by individual optical tweezers in the optical tweezers array.

[0010] According to a sixth aspect of this disclosure, an electronic device is provided, comprising: at least one processor; and at least one memory communicatively connected to said at least one processor, said at least one memory storing instructions that, when executed individually or jointly by said at least one processor, cause said at least one processor to perform a method according to this disclosure.

[0011] According to a seventh aspect of this disclosure, a non-transitory computer-readable storage medium is provided storing computer instructions, wherein the computer instructions, when executed individually or jointly by one or more processors of a computer, cause the computer to perform a method according to this disclosure.

[0012] According to an eighth aspect of this disclosure, a computer program product is provided, comprising a computer program whose computer instructions, when executed individually or jointly by one or more processors of a computer, cause the computer to perform a method according to this disclosure.

[0013] According to one or more embodiments of this disclosure, the generation and focusing of optical tweezers arrays are achieved in one piece using a phase-type metasurface, overcoming the limitations of traditional architectures. This results in strong array expansion capabilities, a simplified and compact optical path, stable and reliable operation, high optical utilization, and ease of integration and large-scale fabrication. Furthermore, the phase-type metasurface can form millions of optical tweezers chips, and hundreds of thousands to millions of optical tweezers arrays can be generated through a large-area subwavelength pixel array.

[0014] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0015] The accompanying drawings exemplify embodiments and form part of the specification, serving together with the textual description to explain exemplary implementations of the embodiments. The illustrated embodiments are for illustrative purposes only and do not limit the scope of this disclosure. Throughout the drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0016] Figure 1 A schematic block diagram of an optical tweezers system 100 according to some embodiments of the present disclosure is shown.

[0017] Figure 2 A schematic block diagram of a variation of an optical tweezers system 100 according to some embodiments of the present disclosure is shown.

[0018] Figure 3 A schematic block diagram of a variation of an optical tweezers system 100 according to some embodiments of the present disclosure is shown.

[0019] Figure 4 A schematic block diagram of a variation of an optical tweezers system 100 according to some embodiments of the present disclosure is shown.

[0020] Figure 5 A schematic flowchart of a single-atom trapping method 500 according to some embodiments of the present disclosure is shown.

[0021] Figure 6A A schematic structural diagram of an optical tweezers device 600 for capturing and imaging atoms according to some embodiments of the present disclosure is shown.

[0022] Figure 6B A schematic structural diagram of an optical tweezers device 600 for capturing and imaging atoms according to some embodiments of the present disclosure is shown.

[0023] Figure 7 A schematic structural diagram of a multi-metasurface integrated device 700 according to some embodiments of the present disclosure is shown.

[0024] Figure 8 A schematic block diagram of a single-atom trapping device 800 according to some embodiments of the present disclosure is shown.

[0025] Figure 9 A structural block diagram of an electronic device 900 according to some embodiments of the present disclosure is shown.

[0026] Figure 10 A schematic flowchart of a phase pattern design process 1000 according to some embodiments of the present disclosure is shown.

[0027] Figure 11 A schematic diagram of a meta-atom / subwavelength pixel structure 1100 according to some embodiments of the present disclosure is shown. Detailed Implementation

[0028] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0029] In this disclosure, unless otherwise stated, the use of terms such as "first," "second," etc., to describe various elements is not intended to limit the positional, temporal, or importance relationships of these elements; such terms are merely used to distinguish one element from another. In some examples, the first element and the second element may refer to the same instance of that element, while in other cases, based on the context, they may refer to different instances.

[0030] The terminology used in the description of the various examples described in this disclosure is for the purpose of describing particular examples only and is not intended to be limiting. Unless the context explicitly indicates otherwise, an element may be one or more unless the number of elements is specifically limited. As used herein, the term "multiple" means two or more, and the term "based on" should be interpreted as "at least partially based on". Furthermore, the terms "and / or" and "at least one of..." cover any one of the listed items and all possible combinations thereof.

[0031] As shown above, in related technologies, optical devices such as spatial light modulators and acousto-optic deflectors are commonly used to construct optical path systems, thereby preparing optical tweezer arrays with different arrangements to achieve the binding and fixed-point capture of ultracold atoms. At the same time, imaging components are used to complete atomic state detection, which is widely used in research scenarios such as quantum simulation and quantum precision measurement.

[0032] However, traditional optical tweezers array generation schemes, such as spatial light modulators and acousto-optic deflectors, typically require relay optical paths, high numerical aperture objectives, and precise alignment structures, resulting in complex system structures. Furthermore, as the array size expands to the hundreds of thousands or millions, it becomes easily limited by factors such as pixel size, aperture, optical efficiency, power tolerance, and field of view. Moreover, when the number of optical traps increases to the millions, a single device must simultaneously meet requirements for large-area phase encoding, high pixel count, high power tolerance, low background scattering, and high uniformity.

[0033] Traditional solutions based on spatial light modulators or acousto-optic deflectors often struggle to achieve a balance among the aforementioned performance metrics simultaneously. Therefore, a phase-type metasurface device capable of fabricating ultra-large-scale optical tweezer arrays on a chip-based basis is needed.

[0034] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0035] Figure 1 A schematic block diagram of an optical tweezers system 100 according to some embodiments of the present disclosure is shown. The optical tweezers system 100 may include a modulation device 110, a substrate 120, and a phase-type metasurface 130 formed on the substrate 120.

[0036] In some embodiments, the modulation device 110 may be disposed between a light source (not shown) and a phase-type metasurface 130 to apply a first modulation to the light beam output from the light source, so that the first-modulated light beam is incident on the phase-type metasurface 130. In some embodiments, the first modulation may include intensity modulation and switching state modulation of the light beam. By way of example and not limitation, the modulation device 110 may employ an acousto-optic modulator (AOM), which enables rapid switching of the laser beam and precise control of the trap depth.

[0037] In some embodiments, substrate 120 may provide physical support for phase-type metasurface 130. In some embodiments, substrate 120 may be made of an optically transparent material to allow light beams to pass through and be incident on phase-type metasurface 130. It is understood that the material and size of substrate 120 may be selected according to actual application requirements, and this disclosure does not impose specific limitations in this regard.

[0038] In some embodiments, the phase-type metasurface 130 may be composed of a subwavelength pixel array configured to apply a second modulation to an incident, first-modulated beam of light to generate and focus an optical tweezers array. As used herein, "subwavelength pixel" may refer to a pixel whose feature size is smaller than the wavelength of the incident beam. In some embodiments, the phase-type metasurface 130 is capable of imprinting a pre-designed phase pattern onto the incident beam, thereby simultaneously generating and focusing the optical tweezers array at its focal plane without the need for additional separate focusing optics.

[0039] The optical tweezers system 100 provided in this disclosure achieves both the generation and focusing of an optical tweezers array simultaneously by employing a phase-type metasurface 130, fundamentally overcoming the principle limitations of traditional optical tweezers array systems. Compared to traditional optical tweezers systems that rely on acousto-optic deflectors, spatial light modulators, or digital micromirror devices, the optical tweezers system 100 of this disclosure has stronger scalability, enabling direct expansion of the array size by increasing the area of ​​the metasurface; simultaneously, the system's optical path is simpler, its size is smaller, its stability and robustness are significantly improved, its optical efficiency is higher, and it is easy to achieve chip-level integration and wafer-level large-scale manufacturing.

[0040] Figure 2 A schematic block diagram of a variation of an optical tweezers system 100 according to some embodiments of the present disclosure is shown. As shown, in some embodiments, the optical tweezers system 100 may further include a translation device 140 connected to a substrate 120 for translating the substrate 120 to switch the optical tweezers array. By providing the translation device 140, optical tweezers arrays with different geometries can be quickly switched without changing the position and state of other optical elements, improving the system's flexibility and experimental efficiency.

[0041] In some embodiments, a plurality of phase-type metasurfaces 130 may be integrated on the substrate 120, each phase-type metasurface 130 being encoded with a different phase pattern, corresponding to optical tweezer arrays of different geometries. By integrating multiple metasurfaces on a single substrate, the array switching operation can be further simplified, and different arrays can be quickly switched simply by translating the substrate, without replacing the metasurface devices or realigning the optical path.

[0042] In some embodiments, the phase-type metasurface 130 may be encoded with a phase pattern calculated by an iterative phase retrieval algorithm. The iterative phase retrieval algorithm can accurately calculate the phase shift that needs to be applied to each subwavelength pixel of the metasurface based on the light intensity distribution of the target optical tweezers array, thereby generating a high-quality, highly uniform optical tweezers array.

[0043] In some implementations, the iterative phase retrieval algorithm may employ the weighted Gerchberg-Saxton algorithm. This algorithm applies a pure phase constraint to the metasurface plane, a target intensity constraint to the focal plane, and updates the weights based on the deviation between the intensity of each optical trap and the target intensity, thereby improving the intensity uniformity of the large-scale optical tweezers array and suppressing sidelobes or speckle background. It is understood that other suitable iterative phase retrieval algorithms may also be used, and this disclosure does not impose specific limitations on them. Reference will be made below. Figure 10 The phase pattern design process according to some embodiments of this disclosure is described in further detail.

[0044] In some implementations, after generating the phase pattern, a phase response library of subwavelength pixels can be established based on rigorous coupled-wave analysis, finite-time difference method, finite element method or neural network surrogate model, and the geometric parameters of subwavelength pixels (i.e., elementary atoms) can be corrected according to the local neighborhood environment to compensate for elementary coupling errors in regions with high numerical aperture, large phase gradient or complex pattern.

[0045] Figure 3 A schematic block diagram of a variation of an optical tweezers system 100 according to some embodiments of the present disclosure is shown. As shown, in some embodiments, the optical tweezers system 100 may further include a detection device 150 configured to receive and detect signals emitted by particles trapped by the optical tweezers array. By providing the detection device 150, real-time monitoring and imaging of the trapped particles can be achieved, for example, detecting the trapping state and position of single atoms. In some embodiments, the detection device 150 may include a single-photon sensitive imaging device, such as an electron multiplier charge-coupled device (EMCCD) camera.

[0046] Figure 4 A schematic block diagram of a variation of an optical tweezers system 100 according to some embodiments of the present disclosure is shown. As shown, in some embodiments, the optical tweezers system 100 may further include an optical projection device 160 configured to receive an optical tweezers array output from the focal plane of a phase-type metasurface 130 and project the received optical tweezers array onto a particle trapping region. By providing the optical projection device 160, the optical tweezers array generated by the metasurface can be precisely projected onto a designated particle trapping region, such as an ultra-high vacuum glass cavity, facilitating atomic trapping experiments.

[0047] In some embodiments, the phase-type metasurface 130 can be made of silicon-rich silicon nitride (SRN) or titanium dioxide (TiO2). Silicon-rich silicon nitride has the advantage of compatibility with complementary metal-oxide-semiconductor (CMOS) processes, enabling rapid, low-cost wafer-level mass production; while titanium dioxide has superior power handling capability and is compatible with shorter optical wavelengths, making it suitable for higher power and shorter wavelength applications.

[0048] In some embodiments, the phase-type metasurface 130 can be configured to generate optical tweezer arrays with periodic, aperiodic, quasicrystalline, or custom patterns. This flexible pattern generation capability enables the optical tweezer system 100 of this disclosure to meet the diverse needs of various quantum computing, quantum simulation, and precision measurement experiments, such as generating atomic arrays of arbitrary shapes to simulate different quantum systems.

[0049] Figure 5 A schematic flowchart of a single-atom trapping method 500 according to some embodiments of the present disclosure is shown. It will be understood that method 500 can be implemented using the optical tweezers system 100 described above, or using other systems capable of performing the same function.

[0050] As shown in the figure, the single-atom trapping method 500 may include the following steps S510 to S530.

[0051] Step S510: Apply a first modulation to the beam output from the light source to obtain a modulated beam. In some embodiments, the first modulation may include intensity modulation and switching state modulation of the beam. By way of example and not limitation, the first modulation may be performed by an acousto-optic modulator (AOM), which enables nanosecond-level rapid switching of the laser beam and allows for precise control of the laser beam intensity by adjusting the power of the radio frequency signal, thereby enabling dynamic adjustment of the optical tweezers depth.

[0052] In step S520, the modulated beam is incident on a phase-type metasurface, which applies a second modulation to the modulated beam to generate and focus an optical tweezers array at its focal plane. As used herein, "second modulation" may refer to phase modulation. In some embodiments, the phase-type metasurface is composed of a subwavelength pixel array, each subwavelength pixel applying a specific phase shift to the incident beam. By pre-designing the phase shift of each pixel, the phase-type metasurface can imprint arbitrary phase patterns onto the incident modulated beam, thereby simultaneously generating and focusing the optical tweezers array at its focal plane without the need for additional independent focusing optics.

[0053] Step S530 involves loading the atomic cloud into the optical tweezers array so that individual atoms in the atomic cloud are captured by individual optical tweezers in the array. In some embodiments, the atomic cloud may be a pre-cooled ultracold atomic cloud, with its temperature reduced to the micro-Kelvin level, to reduce the thermal motion of atoms and improve the fidelity of single-atom capture. It is understood that each optical tweezer in the array can independently capture one atom, thereby forming a large-scale single-atom array.

[0054] The single-atom trapping method 500 provided in this disclosure simplifies the optical path structure of traditional single-atom trapping methods and reduces system complexity and alignment difficulty by simultaneously generating and focusing an optical tweezers array using a phase-type metasurface. Compared with traditional methods, method 500 has stronger scalability, enabling direct expansion of the single-atom array size by increasing the area of ​​the metasurface; simultaneously, the generated optical tweezers array exhibits higher uniformity and stability, higher optical efficiency, and is easily integrated at the chip level and manufactured on a wafer-level scale, providing a technological foundation for building large-scale neutral atom quantum computing and quantum simulation platforms.

[0055] In some embodiments, the single-atom trapping method 500 may further include: translating the substrate supporting the phase-type metasurface so that another phase-type metasurface encoded with different phase patterns is aligned with the incident modulated beam, thereby switching the optical tweezers array. This step allows for rapid switching of optical tweezers arrays with different geometries without changing the position and state of other optical elements, thus enabling the rapid fabrication of single-atom arrays with different structures and improving experimental flexibility and efficiency.

[0056] In some embodiments, the phase-type metasurface may be encoded with a phase pattern calculated by an iterative phase retrieval algorithm. The iterative phase retrieval algorithm can accurately determine the phase shift required for each subwavelength pixel of the metasurface through iterative calculations in both forward and backward propagation, based on the light intensity distribution of the target optical tweezers array, thereby generating a high-quality, highly uniform optical tweezers array. By way of example and not limitation, the iterative phase retrieval algorithm may employ the Gerchberg-Saxton algorithm.

[0057] In some embodiments, after the modulated beam is incident on the phase-type metasurface, method 500 may further include: projecting an optical tweezers array output from the focal plane of the phase-type metasurface onto a particle trapping region using an optical projection device. This step allows the optical tweezers array generated by the metasurface to be precisely projected onto a designated particle trapping region, such as an ultra-high vacuum glass cavity, facilitating single-atom trapping experiments in a controlled vacuum environment.

[0058] In some embodiments, after a single atom in the atomic cloud is captured by a single optical tweezer in the optical tweezer array, method 500 may further include: receiving and detecting a signal emitted by the captured atom. This step enables real-time monitoring and imaging of the single-atom capture state, for example, by detecting the fluorescence signal of the atom to determine whether an atom is captured in each optical tweezer and the atom's position information. In some embodiments, a single-photon sensitive imaging device, such as an electron multiplier charge-coupled device (EMCCD) camera, can be used to receive and detect the fluorescence signal of the atom.

[0059] In some embodiments, loading the atomic cloud into the optical tweezers array may include loading a metal atomic cloud cooled to a micro Kelvin temperature into the optical tweezers array. As an example, and not a limitation, the metal atoms may be strontium (Sr). 88 Sr atoms possess a unique energy level structure, making them suitable for high-precision quantum computing and quantum simulation experiments. It is understood that the type of atom can be selected based on the specific application requirements, and this disclosure does not impose any specific limitations in this regard.

[0060] In some embodiments, the phase-type metasurface can be placed inside or near the particle trapping region to trap atoms at the focal plane of the phase-type metasurface. In this way, an optical projection device can be eliminated, further simplifying the system structure, reducing optical losses, and improving the strength and trapping efficiency of the optical tweezers.

[0061] Figure 6A A schematic structural diagram of an optical tweezers device 600 for capturing and imaging atoms according to some embodiments of the present disclosure is shown. This device 600 is a specific implementation of the aforementioned optical tweezers system 100 and can be used to implement the aforementioned single-atom trapping method 500.

[0062] In some implementations, an optimized simplified optical path representation may be used, such as... Figure 6B As shown. Figure 6B The main optical paths related to optical tweezers generation, light field projection, and atomic imaging in the optical tweezers device 600 are shown, but not in... Figure 6B The relay, reflection, or detection elements shown one by one can be referenced. Figure 6A Configure and / or adjust the described functional relationships.

[0063] Now for reference Figure 6AAs an example and not a limitation, the optical tweezers device 600 may include a laser 610, an acousto-optic modulator (AOM) 620, a metasurface 630, a first high numerical aperture (NA) lens 640, multiple mirrors 651-653, a 1:1 relay telescope 660, a dichroic mirror 670, a second high NA lens 680, a high vacuum glass cavity 690, and an electron multiplier charge-coupled device (EMCCD) camera 695. Figure 6A The lower right corner also shows the average atomic signal 696 obtained by the device 600 (e.g., an imaging plot).

[0064] In some examples, laser 610 can be used to output an incident beam for generating an optical tweezers array. In some embodiments, laser 610 can output a laser with a wavelength of 520 nm. By way of example and not limitation, this laser can be used to trap strontium ( 88 Sr atoms.

[0065] In some examples, an acousto-optic modulator 620 may be positioned between the laser 610 and the metasurface 630 to apply a first modulation to the beam output from the laser 610. In some embodiments, the first modulation may include intensity modulation and switching state modulation of the beam. The acousto-optic modulator 620 enables rapid switching of the laser beam and precise control of the trap depth.

[0066] In some examples, metasurface 630 may be composed of a subwavelength pixel array for applying a second modulation to the incident, first-modulated beam to generate and focus an optical tweezers array. In some embodiments, metasurface 630 may be made of silicon-rich silicon nitride (SRN) or titanium dioxide (TiO2) material. By way of example and not limitation, the effective numerical aperture (NA) of metasurface 630 may be greater than 0.6, the diffraction efficiency may be approximately 60%, and the diameter may range from 1.2 mm to 3.5 mm.

[0067] In a specific example, metasurface 630 is used to trap light at 520 nm with a focal length of approximately 0.7 mm, a period of approximately 290 nm for the elementary atoms, and a lateral dimension of approximately 100 nm to 190 nm for the elementary atoms. For silicon-rich silicon nitride materials, the height of the elementary atoms can be approximately 750 nm; for titanium dioxide materials, the height of the elementary atoms can be approximately 600 nm. Silicon-rich silicon nitride metasurfaces can withstand at least 25 W / mm². 2 The titanium dioxide metasurface can withstand light intensity of at least 2000 W / mm². 2 Light intensity.

[0068] In some implementations, metasurface 630 can also serve as the core optical layer of a million-scale optical tweezers chip. This chip can support a large-area subwavelength pixel array on a millimeter- to centimeter-scale substrate, and increase the number of available pixels while maintaining high phase modulation accuracy, thereby providing a basis for light field generation for million-scale optical tweezers arrays.

[0069] In some examples, a first high NA lens 640 may be disposed on the exit side of the metasurface 630 to convert the optical tweezers array generated by the focal plane of the metasurface 630 into optical momentum space. In some embodiments, the NA of the first high NA lens 640 may be 0.6.

[0070] In some examples, multiple mirrors 651, 652, and 653 can be used to change the propagation direction of the light beam, guiding the optical tweezers array into the high-vacuum glass cavity 690. It is understood that the number and position of the mirrors can be adjusted according to the actual optical path design, and this disclosure does not impose specific limitations in this regard.

[0071] In some examples, the 1:1 relay telescope 660 may include a first relay lens 661 and a second relay lens 662 for relaying the optical tweezers array while maintaining the geometry and optical properties of the optical tweezers array unchanged.

[0072] In some examples, the dichroic mirror 670 can be used to separate optical tweezers laser signals and atomic fluorescence signals. In some embodiments, the dichroic mirror 670 can transmit the optical tweezers laser while reflecting the fluorescence signals emitted by atoms.

[0073] In some examples, a second high-NA lens 680 may be disposed between the dichroic mirror 670 and the high-vacuum glass cavity 690 to focus the optical tweezers array onto the atom-trapping region within the high-vacuum glass cavity 690. In some embodiments, the NA of the second high-NA lens 680 may be 0.5.

[0074] In some examples, the high-vacuum glass cavity 690 can provide an ultra-high vacuum environment for containing ultracold atomic clouds and conducting single-atom trapping experiments. In some embodiments, the vacuum level within the high-vacuum glass cavity 690 can reach 10⁻⁶. -9 Torr and above.

[0075] In some examples, the electron multiplier charge-coupled device (EMCCD) camera 695 can be used to receive and detect fluorescence signals emitted by trapped atoms, generating atomic images. In some implementations, the EMCCD camera 695 is a single-photon sensitive imaging device capable of high-fidelity single-atom detection.

[0076] During operation, the laser output from laser 610 is first modulated in intensity and switching state by acousto-optic modulator 620, and the modulated laser is then incident on metasurface 630. Metasurface 630 applies phase modulation to the incident laser, generating and focusing an optical tweezers array on its focal plane. This optical tweezers array is converted to optical momentum space by a first high-NA lens 640, then relayed via a 1:1 relay telescope 660, and finally focused into a high-vacuum glass cavity 690 by a dichroic mirror 670 and a second high-NA lens 680. An ultracold atom cloud cooled to micro Kelvin is loaded into the optical tweezers array, allowing individual atoms to be captured by individual optical tweezers. The fluorescence signal emitted by the captured atoms is collected by the second high-NA lens 680 and reflected by the dichroic mirror 670 to an EMCCD camera 695, thereby obtaining an average atomic signal (e.g., an image) 696.

[0077] The optical tweezers device 600 provided in this embodiment significantly simplifies the optical path structure of traditional optical tweezers devices by simultaneously generating and focusing an optical tweezers array using a metasurface, reducing the number of optical components and alignment complexity. Compared to traditional devices, this device 600 exhibits higher stability and robustness, higher optical efficiency, and the ability to generate larger-scale optical tweezers arrays with arbitrary geometric configurations. By way of example and not limitation, this device 600 can generate an array containing at least 360,000 optical tweezer traps with a tweezers strength uniformity of up to 92%. By further increasing the metasurface diameter, the number of subwavelength pixels, and the available trapped light power, it can be scalable to form millions of optical tweezers chips and can generate periodic, aperiodic, quasi-crystalline, and custom-patterned optical tweezers arrays.

[0078] Now for reference Figure 6B The simplified optical path shown has the metasurface 630 located at the core of the optical tweezers array generation path. After the first modulated beam is incident on the metasurface 630, the array optical field is directly generated and focused by the metasurface 630, and then acts on the atomic trapping region within the high-vacuum glass cavity 690 through subsequent projection and imaging paths. Figure 6B The simplified representation shown highlights the role of phase-type metasurfaces in replacing traditional multi-stage wavefront modulation and focusing structures.

[0079] In one embodiment where the single-atom array size is 16×16, a 16×16 two-dimensional optical tweezers array can be generated using a silicon-rich silicon nitride phase-type metasurface with a diameter of approximately 1.16 mm, and the spacing between adjacent optical traps in the array is approximately 4 μm. This is achieved by cooling the array to the micro-Kelvin level. 88 After the Sr atomic cloud is loaded onto the optical tweezers array, the optical correlation loss process near the 689 nm atomic resonance can induce paired atom loss, achieving odd-even projection, so that each optical trap ultimately retains zero or one atom. In the experiment, after odd-even projection, an average of about 41% of the optical traps contained single atoms, corresponding to about 106 single atoms occupying the optical trap.

[0080] In the aforementioned 16×16 single-atom array implementation, while maintaining the 520 nm optical tweezers on, 461 nm imaging light can be used to cause the trapped atoms to scatter fluorescence, and 689 nm cooling light can be used to reduce scattering heating. By counting the photons at each optical trap position using an EMCCD camera and setting a threshold, it can be determined whether a single atom exists in the corresponding optical trap; the imaging fidelity of single atoms in the 16×16 array can be greater than 95%, and the imaging fidelity can reach approximately 99.8% in smaller arrays.

[0081] In one embodiment, the trapped single atoms can be used as optical trap probes to measure the trap depth, radial oscillation frequency, axial oscillation frequency, and spatial position of each optical trap. For a 16×16 optical tweezers array, the standard deviation of the optical trap depth can be approximately 7.5%, the standard deviation of the radial optical trap frequency can be approximately 5%, the standard deviation of the axial optical trap frequency can be approximately 8%, the average positional deviation of the optical traps can be approximately 60 nm, and the positional inaccuracy relative to a 4 μm trap spacing is approximately 1.5%.

[0082] In one embodiment, the phase-type metasurface can generate aperiodic or arbitrary geometric optical tweezer arrays. For example, it can generate a free-pattern array containing approximately 183 optical traps with an average spacing of approximately 3 μm; it can generate an Ammann-Beenker quasi-crystal array containing approximately 225 optical traps with an average spacing of approximately 4 μm; it can generate a 32×32 square array with 1024 optical traps and an average spacing of approximately 2.5 μm; and it can also generate a ring array containing approximately 16 optical traps with a spacing of approximately 1.45 μm.

[0083] In one embodiment, a titanium dioxide phase-type metasurface with a diameter of approximately 3.5 mm can be used. This phase-type metasurface contains approximately 114 million subwavelength pixels and is configured to generate a 600×600 optical tweezer array on the focal plane, with a total of 360,000 optical traps. The spacing between adjacent optical traps is approximately 2.5 μm, and the array coverage area is approximately 1.5 mm × 1.5 mm. Through high-resolution microscopic imaging and mosaic analysis, the uniformity of light intensity across the entire array can be measured to be approximately 92%.

[0084] In one embodiment, the chip area, number of subwavelength pixels, and available captured light power of the phase-type metasurface can be further increased based on the aforementioned 600×600 array. Alternatively, multiple large-area phase-type metasurface regions can be integrated on the same chip substrate to generate hundreds of thousands to millions of optical traps. Thus, each high-quality optical trap can be formed by the collaborative encoding of multiple subwavelength pixels, thereby expanding the number of optical traps while maintaining micrometer-level trap spacing and high uniformity.

[0085] In some embodiments, the substrate carrying the metasurface 630 can be mounted on a two-dimensional translation stage. By translating the two-dimensional translation stage, another metasurface encoded with different phase patterns can be aligned with the incident laser, thereby rapidly switching optical tweezer arrays with different geometries without having to realign the optical path.

[0086] In some embodiments, multiple metasurfaces 630 can be integrated on a single substrate, each metasurface 630 being encoded with a different phase pattern, corresponding to optical tweezer arrays of different geometries. In this way, the speed and convenience of array switching can be further improved.

[0087] In some embodiments, the metasurface 630 can be placed directly inside or near the high-vacuum glass cavity 690 to directly trap atoms at its focal plane. In this way, optical components such as the first high-NA lens 640, mirrors 651 to 653, 1:1 relay telescope 660, and second high-NA lens 680 can be eliminated, further simplifying the system structure and reducing optical losses.

[0088] Figure 7 A schematic structural diagram of a multi-metasurface integrated device 700 according to some embodiments of the present disclosure is shown. Figure 7 An example is shown of an implementation where multiple metasurfaces are integrated on a single substrate. Figure 7 From left to right: macroscopic optical image of a multi-metasurface integrated device, scanning electron microscope (SEM) image of a local area of ​​the metasurface, and a three-dimensional structural diagram of a single meta-atom.

[0089] The multi-metasurface integrated device 700 may include a substrate 710 and a plurality of phase-type metasurfaces 720a, 720b, 720c, 720d, 720e, and 720f formed on the substrate 710. In some embodiments, the size of the substrate 710 may be selected according to the actual application requirements. By way of example and not limitation, the substrate 710 may be made of an optical-grade transmissive material to provide good optical transmittance and mechanical stability.

[0090] Multiple phase-type metasurfaces 720a-720f can be arranged in an array on the surface of substrate 710. In some embodiments, each phase-type metasurface 720a-720f can be encoded with a different phase pattern, corresponding to optical tweezers arrays of different geometries. It is understood that by translating the translation device carrying the multi-metasurface integrated device 700, any one of the phase-type metasurfaces can be aligned with the incident modulated beam, thereby quickly switching between optical tweezers arrays of different geometries without replacing the device or realigning the entire optical system.

[0091] In practical operation, this type of metasurface device can utilize the phase-type metasurface arranged on it to perform a second modulation on the incident beam that has been modulated by the pre-structure, thereby generating and focusing an optical tweezers array.

[0092] In some embodiments, substrate 710 can be used as a substrate for optical tweezers chips. By integrating one or more large-area phase-type metasurfaces on the same substrate, and combining them with high-power-tolerant materials and subwavelength pixel arrays, optical tweezers chips for generating hundreds of thousands to millions of optical traps can be formed.

[0093] Figure 7 The central portion shows a scanning electron microscope image 730 of a local region of a phase-type metasurface. This image reveals that the phase-type metasurface is composed of a large number of periodically arranged subwavelength meta-atoms. As used herein, when referring to a “meta-atom,” it can refer to the basic subwavelength structural unit that constitutes the metasurface, whose characteristic size is smaller than the wavelength of the incident light beam. In this document, the term meta-atoms is used interchangeably with subwavelength pixels.

[0094] Figure 7 The right side shows a schematic diagram 740 of the three-dimensional structure of a single elementary atom. In this example, the elementary atom 741 can be a columnar structure formed on the surface of the substrate 710. In some embodiments, the height and cross-sectional dimensions of the elementary atom 741 can be designed according to the wavelength of the incident beam and the desired phase modulation range. By way of example and not limitation, the elementary atom 741 can be made of silicon-rich silicon nitride (SRN) or titanium dioxide (TiO2) materials. By adjusting the cross-sectional dimensions of the elementary atom, continuous phase modulation of the incident beam in the range of 0-2π can be achieved. Reference will be made below. Figure 11 The meta-atom / subwavelength pixel structure according to some embodiments of the present disclosure is described in further detail.

[0095] The multi-metasurface integrated device 700 provided in this disclosure achieves rapid switching of optical tweezers array geometry by integrating multiple metasurfaces encoded with different phase patterns on a single substrate. Compared with traditional solutions that require replacing optical components or redesigning metasurfaces, device 700 significantly improves the flexibility and experimental efficiency of the optical tweezers system, while reducing the complexity and cost of experimental operations. At the same time, device 700 retains the advantages of metasurface optical tweezers systems, including high scalability, high optical efficiency, high stability, and ease of chip-level integration and large-scale manufacturing.

[0096] In some embodiments, the substrate 710 carrying the multi-metasurface integrated device 700 can be mounted on a two-dimensional translation stage. By controlling the movement of the two-dimensional translation stage in the plane, any one of the phase-type metasurfaces 720a-720f can be precisely aligned with the incident modulated beam, thereby completing the switching of optical tweezer arrays with different geometries in a short time.

[0097] In some embodiments, the plurality of phase-type metasurfaces 720a-720f can be encoded with different types of optical tweezer array phase patterns, such as periodic arrays, non-periodic arrays, quasi-crystalline patterns, and custom patterns. By way of example and not limitation, one metasurface can encode a square lattice optical tweezer array, another metasurface can encode a quasi-crystalline pattern optical tweezer array, and a third metasurface can encode an optical tweezer array of a custom shape.

[0098] In some embodiments, the multiple phase-type metasurfaces 720a-720f can be made of the same material or different materials. For example, some metasurfaces can be made of silicon-rich silicon nitride to enable large-scale manufacturing compatible with CMOS processes, while others can be made of titanium dioxide to achieve higher power handling capabilities.

[0099] Figure 8 A schematic block diagram of a single-atom trapping device 800 according to some embodiments of the present disclosure is shown. As shown, the single-atom trapping device 800 may include a first device 810, a second device 820, and a third device 830.

[0100] The first device 810 can be configured to apply a first modulation to the light beam output from the light source to obtain a modulated light beam. In some embodiments, the first device 810 can perform intensity modulation and on / off state modulation functions on the light beam. By way of example and not limitation, the first device 810 may include an acousto-optic modulator and associated driving circuitry.

[0101] The second device 820 can be configured to incident the modulated beam onto a phase-type metasurface, causing the phase-type metasurface to apply a second modulation to the modulated beam, thereby generating and focusing an optical tweezers array at the focal plane of the phase-type metasurface. In some embodiments, the second device 820 may include a phase-type metasurface and a support structure for fixed installation. It is understood that the core function of the second device 820 is to rely on the phase-type metasurface to perform phase control of the incident beam, simultaneously realizing the generation and focusing of the optical tweezers array.

[0102] The third device 830 can be configured to load an atomic cloud into the optical tweezers array such that individual atoms in the atomic cloud are captured by individual optical tweezers in the optical tweezers array. In some embodiments, the third device 830 may be equipped with an atomic cooling structure and an atomic transport structure to prepare an ultracold atomic cloud and transport the atomic cloud to the region where the optical tweezers array is located.

[0103] In actual operation, the first device 810 preferentially modulates the output beam of the light source to obtain a modulated beam; the second device 820 guides the modulated beam into the phase-type metasurface, and generates and converges the optical tweezers array by means of the phase modulation effect of the metasurface; the third device 830 sends the pre-cooled atomic cloud into the effective range of the optical tweezers array to complete the single-atom trapping operation.

[0104] The single-atom trapping device 800 provided in this disclosure simplifies the optical path structure of traditional single-atom trapping methods and reduces system complexity and alignment difficulty by simultaneously generating and focusing an optical tweezers array using a phase-type metasurface. Compared with conventional technologies, this device 800 has stronger scalability, enabling the expansion of the single-atom array scale by increasing the area of ​​the metasurface, the number of pixels, and the available incident light power, and can further form optical tweezers chips ranging from hundreds of thousands to millions. Simultaneously, the generated optical tweezers array exhibits higher uniformity and stability, higher optical efficiency, and is easily integrated at the chip level and manufactured on a wafer-level scale, providing a technological foundation for constructing large-scale neutral atom quantum computing and quantum simulation platforms.

[0105] In some embodiments, the single-atom trapping device 800 may further include a fourth device configured to translate the substrate carrying the phase-type metasurface, aligning another phase-type metasurface encoded with a different phase pattern with the incident modulated beam to switch the optical tweezers array. By way of example and not limitation, the fourth device may include a two-dimensional translation stage and associated control components.

[0106] In some embodiments, the single-atom trapping device 800 may further include a fifth device configured to project an optical tweezer array output from the focal plane of the phase-type metasurface onto the particle trapping region via an optical projection device.

[0107] In some embodiments, the single-atom trapping device 800 may further include a sixth device configured to receive and detect signals emitted by the trapped atoms. By way of example and not limitation, the sixth device may include a single-photon sensitive imaging device and associated signal processing components.

[0108] While specific functions have been discussed above with reference to specific modules, it should be noted that the functions of the modules discussed herein can be divided into multiple modules, and / or at least some functions of multiple modules can be combined into a single module. The specific actions performed by the modules discussed herein include the specific module itself performing the action, or alternatively, the specific module calling or otherwise accessing another component or module that performs the action (or performs the action in conjunction with the specific module). Therefore, a specific module performing an action can include the specific module performing the action itself and / or another module that performs the action, called or otherwise accessed by the specific module.

[0109] It should also be understood that this article can describe various technologies within the general context of software and hardware components or program modules. (Combined) Figure 8 The first through sixth devices described may be implemented in hardware or in hardware in combination with software and / or firmware. For example, these devices may be implemented as computer program code / instructions configured to execute in one or more processors and stored in a computer-readable storage medium. Alternatively, these devices may be implemented as hardware logic / circuit. For example, in some embodiments, one or more of the first devices 810 through the third devices 830 (and optionally a fourth, fifth, or sixth device) may be implemented together in a System on Chip (SoC). The SoC may include an integrated circuit chip (which includes a processor (e.g., a Central Processing Unit (CPU), microcontroller, microprocessor, digital signal processor (DSP), etc.), memory, one or more communication interfaces, and / or one or more components of other circuitry) and may optionally execute received program code and / or include embedded firmware to perform functions.

[0110] According to another aspect of this disclosure, an electronic device is also provided, comprising: at least one processor; and at least one memory communicatively connected to said at least one processor, said at least one memory storing instructions that, when executed individually or jointly by said at least one processor, cause said at least one processor to perform a method according to this disclosure.

[0111] According to another aspect of this disclosure, a non-transitory computer-readable storage medium storing computer instructions is also provided, wherein the computer instructions, when executed individually or jointly by one or more processors of a computer, cause the computer to perform the method according to this disclosure.

[0112] According to another aspect of this disclosure, a computer program product is also provided, comprising a computer program whose computer instructions, when executed individually or jointly by one or more processors of a computer, cause the computer to perform the method according to this disclosure.

[0113] See Figure 9 The following description serves as a structural block diagram of the electronic device 900 disclosed herein, which is an example of a hardware device applicable to various aspects of this disclosure. The electronic device can be different types of computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the disclosure described and / or claimed herein.

[0114] Figure 9 A block diagram of an electronic device according to an embodiment of the present disclosure is shown. (As follows) Figure 9 As shown, the electronic device 900 may include at least one processor 901, working memory 902, I / O device 904, display device 905, storage device 906 and communication interface 907 that are capable of communicating with each other via system bus 903.

[0115] Processor 901 may be a single processing unit or multiple processing units, and all processing units may include single or multiple computing units or multiple cores. Processor 901 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuits, and / or any device that manipulates signals based on operating instructions. Processor 901 may be configured to acquire and execute computer-readable instructions stored in working memory 902, storage device 906, or other computer-readable media, such as program code of operating system 902a, program code of application program 902b, etc.

[0116] Working memory 902 and storage device 906 are examples of computer-readable storage media for storing instructions that are executed by processor 901 to perform the various functions described above. Working memory 902 may include both volatile and non-volatile memory (e.g., RAM, ROM, etc.). Furthermore, storage device 906 may include hard disk drives, solid-state drives, removable media including external and removable drives, memory cards, flash memory, floppy disks, optical disks (e.g., CDs, DVDs), storage arrays, network-attached storage, storage area networks, etc. Working memory 902 and storage device 906 may be collectively referred to herein as memory or computer-readable storage media, and may be non-transitory media capable of storing computer-readable, processor-executable program instructions as computer program code that can be executed by processor 901 as a specific machine configured to perform the operations and functions described in the examples herein.

[0117] I / O device 904 may include input devices and / or output devices. Input devices may be any type of device capable of inputting information to electronic device 900, and may include, but are not limited to, a mouse, keyboard, touch screen, trackpad, trackball, joystick, microphone, and / or remote control. Output devices may be any type of device capable of presenting information, and may include, but are not limited to, video / audio output terminals, vibrators, and / or printers.

[0118] Communication interface 907 allows electronic device 900 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunication networks, and may include, but is not limited to, modems, network interface cards, infrared communication devices, wireless communication transceivers and / or chipsets, such as Bluetooth. TM Equipment, 802.11 equipment, Wi-Fi equipment, WiMAX equipment, cellular communication equipment and / or the like.

[0119] The application program 902b in the working register 902 can be loaded to execute the various methods and processes described above. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 900 via the storage device 906 and / or the communication interface 907. When the computer program is loaded and executed by the processor 901, one or more steps of the data processing methods described above can be performed.

[0120] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0121] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable task scheduler, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0122] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0123] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0124] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0125] A computing system may include clients and servers. Clients and servers are generally located far apart and typically interact through a communication network. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other.

[0126] Figure 10 A schematic flowchart of a phase pattern design process 1000 according to some embodiments of the present disclosure is shown. Figure 10 As shown, in the exemplary phase pattern design process 1000, the target light intensity distribution of the target optical tweezers array can be determined first, and then a weighted Gerchberg-Saxton iteration can be performed between the metasurface plane and the focal plane. In each iteration, the incident amplitude of the metasurface plane is set to a uniform amplitude to satisfy the pure phase constraint, and the focal plane is updated with weights based on the deviation between the calculated light intensity distribution and the target light intensity distribution, until a phase pattern for encoding to the phase-type metasurface is obtained.

[0127] exist Figure 10In the process shown, after obtaining the phase pattern, the continuous phase distribution can be further mapped to the cross-sectional size or other geometric parameters of each element atom based on the phase response library of subwavelength pixels, so that the phase pattern can be realized by the actual metasurface structure; this mapping can be combined with local neighborhood correction to reduce the influence of the coupling of adjacent element atoms on the generation of large numerical aperture light fields.

[0128] The following is a detailed description Figure 10 The phase pattern involves process 1000. As shown in the figure. Figure 10 A schematic flowchart of a phase pattern design process 1000 according to some embodiments of the present disclosure is shown. This process can be used to solve for the phase pattern to be encoded on a phase-type metasurface in order to generate and focus a target configuration optical tweezer array.

[0129] In some implementations, the exemplary phase pattern design process 1000 begins with the step 1001 of determining the target optical tweezers array. Based on the geometry and performance requirements of the target optical tweezers array, a corresponding target light intensity distribution 1002 can be extracted, which includes the position and intensity information of each optical trap. It is understood that the target optical tweezers array can be periodic, aperiodic, quasi-crystalline, or a custom pattern, corresponding to different target light intensity distributions.

[0130] Based on the target light intensity distribution, step 1003, which involves iteratively calculating the phase pattern, can be performed. This iterative process is achieved through a weighted Gerchberg-Saxton forward / backward propagation step 1004, which involves reciprocating iterative calculations between the metasurface plane and the focal plane.

[0131] In each iteration, a pure phase constraint 1005 can be applied to the incident light field on the metasurface plane. For example, the incident amplitude of the metasurface plane can be set to a uniform amplitude, and the light field can be controlled only through phase modulation. A target light intensity constraint 1006 can be applied to the light field on the focal plane, and the weights are updated according to the deviation between the currently calculated light intensity distribution and the target light intensity distribution. The updated weights are fed back to the weighted Gerchberg-Saxton iteration step to gradually reduce the deviation between the calculated result and the target. After multiple rounds of iteration and convergence, a phase pattern that meets the design requirements can be obtained.

[0132] Specifically, Figure 10 Step 1001 is used to specify the optical tweezers array to be generated, including the spatial position of each optical tweezer in the focal plane and the relative light intensity requirements. Step 1002 forms a target focal plane light intensity distribution based on the optical tweezers array, so that the target light field in the focal plane has a corresponding intensity peak at each optical tweezer position, and uses this target light intensity distribution as a constraint condition for subsequent phase retrieval.

[0133] In a forward propagation process in step 1004, the complex optical field on the metasurface plane is used as input and propagated from the metasurface plane to the focal plane through Rayleigh-Sommerfeld diffraction integration to obtain the calculated complex amplitude of the focal plane. The magnitude of this calculated complex amplitude corresponds to the light intensity distribution generated in the current iteration, and the phase of this calculated complex amplitude is used to preserve the propagation phase information of the current optical field.

[0134] In the focal plane constraint step 1006, the calculated amplitude obtained from forward propagation is not directly retained. Instead, the focal plane amplitude is constrained based on the target light intensity distribution. For the weighted Gerchberg-Saxton iteration, the target amplitude distribution for the next iteration can be updated based on the focal plane amplitude calculated in the current iteration and the target amplitude of the previous iteration, thereby providing feedback correction for the intensity deviation at each optical tweezer position.

[0135] After completing the focal plane amplitude update, the process retains the phase information of the complex amplitude calculated by the focal plane, and combines the updated amplitude with the phase to form the updated focal plane optical field. The updated optical field is then transmitted from the focal plane back to the metasurface plane through reverse light propagation. In the metasurface plane constraint step 1005, the amplitude of the returned optical field is reset to a uniform amplitude, and the phase of the returned optical field is retained, thereby obtaining the pure phase optical field for the metasurface plane in the next iteration.

[0136] By repeatedly performing forward propagation, focal plane amplitude constraint and weight update, back propagation, and pure phase constraint on the metasurface plane, the iterative process gradually converges to a metasurface phase distribution that can generate the light intensity distribution of the target focal plane. Since the process maintains pure phase constraint on the metasurface plane throughout, the resulting phase distribution is suitable for encoding into a phase-type metasurface without the need for independent amplitude modulation on the metasurface.

[0137] Compared to the standard Gerchberg-Saxton iteration, Figure 10 The weighted iterative process shown further considers the requirements of the dot-shaped optical traps in the optical tweezers array for uniformity and speckle background, and is adapted to the subwavelength pixel size and direct focusing capability of the metasurface hologram. Therefore, it is more suitable for generating large-scale, dot-shaped optical tweezers arrays with relatively uniform light intensity.

[0138] In some implementations, a phase response library 1007 may be pre-built. By way of example and not limitation, the phase response library may be constructed based on a rigorous coupled-wave analysis (RCWA), finite-difference time-domain (FDTD) simulation model, or a neural network surrogate model 1008 to characterize the correspondence between the geometric parameters of subwavelength pixels and their phase responses.

[0139] After obtaining the converged phase pattern, step 1009 of mapping subwavelength pixels can be performed. Based on the phase response library, the continuous phase distribution is mapped to the geometric parameters corresponding to each subwavelength pixel, so that the continuous phase pattern can be realized through the actual metasurface physical structure.

[0140] Alternatively, a local neighborhood correction step 1010 may be performed during the mapping process to compensate for coupling errors between adjacent subwavelength pixels, reduce the impact of primitive coupling effects on light field generation, and improve the accuracy and uniformity of the actual metasurface-generated optical tweezer array.

[0141] After completing the structural mapping of the phase pattern, a phase-type metasurface 1011 can be fabricated based on the subwavelength pixel parameters obtained from the mapping. The fabricated phase-type metasurface can apply phase modulation to the incident beam, ultimately generating and focusing an optical tweezers array 1012.

[0142] The phase pattern design process provided in this disclosure solves the target phase pattern by combining a weighted iterative phase recovery algorithm with pure phase constraints, and is further enhanced by subwavelength pixel mapping and neighborhood correction. This results in a metasurface phase encoding scheme that highly matches the target light intensity distribution, ensuring that the final generated optical tweezers array has good uniformity and focusing quality.

[0143] Figure 11 A schematic diagram of a meta-atom / subwavelength pixel structure 1100 according to some embodiments of the present disclosure is shown. Figure 11 As shown, structure 1100 may include a substrate 1110 and a plurality of elementary atoms 1120 located on the substrate 1110. The plurality of elementary atoms 1120 are arranged according to a subwavelength period P, each elementary atom 1120 having the same height H and a lateral dimension W determined according to the target phase response. By changing the lateral dimension W, different elementary atoms 1120 can apply different phase delays to the incident beam, thereby macroscopically forming the phase pattern required for a phase-type metasurface.

[0144] In some embodiments, the period P can be approximately 290 nm, and the lateral dimension W can be approximately 100 nm to 190 nm; when the elementary atom 1120 is made of silicon-rich silicon nitride, the height H can be approximately 750 nm, and when the elementary atom 1120 is made of titanium dioxide, the height H can be approximately 600 nm. These parameters can be matched to 520 nm trapped light, enabling the phase-type metasurface to provide phase modulation in the range of 0 to 2π.

[0145] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0146] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the methods, systems, and devices described above are merely exemplary embodiments or examples, and the scope of the invention is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. An optical tweezers system, characterized in that, include: A modulation device is disposed between a light source and a phase-type metasurface, and is used to apply a first modulation to the light beam output by the light source so that the first-modulated light beam is incident on the phase-type metasurface; Substrate; and The phase-type metasurface, formed on the substrate, is composed of a subwavelength pixel array configured to apply a second modulation to the incident first modulated light beam to generate and focus an optical tweezer array.

2. The optical tweezers system according to claim 1 further includes a translation device connected to the substrate for translating the substrate to switch the optical tweezers array.

3. The optical tweezers system according to claim 2, wherein, The substrate is equipped with multiple phase-type metasurfaces, each of which is encoded with a different phase pattern and corresponds to optical tweezer arrays with different geometric configurations.

4. The optical tweezers system according to claim 1, wherein, The phase-type metasurface encoding has a phase pattern calculated by an iterative phase recovery algorithm.

5. The optical tweezers system according to claim 1 further includes a detection device configured to receive and detect signals emitted by particles captured by the optical tweezers array.

6. The optical tweezers system according to claim 1 further includes an optical projection device configured to receive the optical tweezers array output from the focal plane of the phase-type metasurface and project the received optical tweezers array onto the particle trapping region.

7. The optical tweezers system according to claim 1, wherein, The phase-type metasurface is made of silicon-rich silicon nitride or titanium dioxide.

8. The optical tweezers system according to claim 1, wherein, The phase-type metasurface is configured to generate an array of optical tweezers with periodic, aperiodic, quasicrystalline, or custom patterns.

9. The optical tweezers system according to claim 1, wherein, The optical tweezers array has the number of optical traps ranging from hundreds of thousands to millions.

10. A method for capturing a single atom, characterized in that, include: A first modulation is applied to the beam output from the light source to obtain a modulated beam; The modulated beam is incident on a phase-type metasurface, and the phase-type metasurface applies a second modulation to the modulated beam to generate and focus an optical tweezer array at the focal plane of the phase-type metasurface. as well as An atomic cloud is loaded into the optical tweezers array so that individual atoms in the atomic cloud are captured by individual optical tweezers in the optical tweezers array.

11. The method of claim 10, further comprising: The substrate supporting the phase-type metasurface is translated so that another phase-type metasurface encoded with different phase patterns is aligned with the incident modulated beam, thereby switching the optical tweezers array.

12. The method according to claim 10, wherein, The phase-type metasurface encoding has a phase pattern calculated by an iterative phase recovery algorithm.

13. The method according to claim 10, wherein, After incident the modulated beam onto the phase-type metasurface, the method further includes: An optical tweezers array output from the focal plane of the phase-type metasurface is projected onto the particle trapping region using an optical projection device.

14. The method of claim 10, wherein, After a single atom in the atomic cloud is captured by a single optical tweezer in the optical tweezer array, the method further includes: The system receives signals emitted by the trapped atoms and detects those signals.

15. The method according to claim 10, wherein, The loading of the atomic cloud into the optical tweezers array includes loading a metal atomic cloud cooled to a micro Kelvin temperature into the optical tweezers array.

16. The method according to claim 15, wherein, The neutral atomic cloud includes strontium atomic clouds, rubidium atomic clouds, cesium atomic clouds, ytterbium atomic clouds, or isotopic atomic clouds of strontium.

17. The method according to claim 10, wherein, The phase-type metasurface is placed inside or near the particle trapping region, and atoms are trapped at the focal plane of the phase-type metasurface.

18. A metasurface device, characterized in that, include: substrate; as well as A phase-type metasurface layer is formed on the substrate, the phase-type metasurface layer being composed of a subwavelength pixel array; The phase-type metasurface layer is encoded with a phase pattern, and the subwavelength pixel array is configured to apply a second modulation to the incident first modulated beam to generate and focus an optical tweezer array.

19. The metasurface device according to claim 18, wherein, Multiple phase-type metasurface layers are formed on the substrate, and each phase-type metasurface layer is encoded with a different phase pattern, corresponding to optical tweezer arrays with different geometric configurations.

20. The metasurface device according to claim 18, wherein, The phase-type metasurface layer is made of silicon-rich silicon nitride or titanium dioxide.

21. A single-atom trapping device, characterized in that, include: A first device for applying a first modulation to the light beam output by a light source to obtain a modulated light beam; A second device for incidenting the modulated beam onto a phase-type metasurface, causing the phase-type metasurface to apply a second modulation to the modulated beam, thereby generating and focusing an optical tweezer array at the focal plane of the phase-type metasurface; as well as A third device for loading an atomic cloud into the optical tweezers array such that individual atoms in the atomic cloud are captured by individual optical tweezers in the optical tweezers array.

22. An electronic device, comprising: At least one processor; as well as At least one memory communicatively connected to the at least one processor, the at least one memory storing instructions that, when executed individually or jointly by the at least one processor, cause the at least one processor to perform the method of any one of claims 10-17.

23. A non-transitory computer-readable storage medium storing computer instructions, wherein, When executed individually or jointly by one or more processors of the computer, the computer instructions cause the computer to perform the method according to any one of claims 10-17.

24. A computer program product comprising a computer program, wherein the computer instructions, when executed individually or jointly by one or more processors of a computer, cause the computer to perform the method according to any one of claims 10-17.

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