A zoom method, device and electronic device of a zoom system with a super lens

Abstract

The present application provides a zoom method, device and electronic device of a zoom system with a metalens, wherein the method includes: obtaining a zoom instruction, the zoom instruction carries a zoom parameter; determining the phase coefficient of the metalens when zooming according to the zoom parameter; and zooming the metalens based on the phase coefficient. Through the zoom method, device and electronic device of a zoom system with a metalens provided by the embodiments of the present application, the zoom of the metalens in the zoom system can be quickly realized according to the zoom parameter carried in the zoom instruction. The zoom is completed by the zoom system itself during the entire zoom process, and there is no need to perform mechanical operation on the zoom system, thereby greatly shortening the response time of the zoom system, improving the zoom accuracy, and the zoom range is not limited by the mechanical structure of the zoom system, so that the zoom range of the metalens is larger.

Description

Technical Field

[0001] The present application relates to the field of zoom technology, and in particular to a zoom method, device and electronic equipment of a zoom system with a super lens. Background Art

[0002] At present, as an emerging optical element, metalens is being increasingly used in optical devices due to its light and thin characteristics. Using the metalens as a zoom system to replace the zoom system composed of traditional lenses is becoming the mainstream choice of optical manufacturers. In order to zoom the zoom system, in general, mechanical operations such as changing the angle between the metalens in the zoom system or rotating the metalens are used to change the focal length of the metalens in the zoom system to achieve the zoom operation of the zoom system; however, the zoom time of the mechanical operation method is long and the zoom accuracy is low. Summary of the invention

[0003] To solve the above problems, the purpose of the embodiments of the present application is to provide a zoom method, device and electronic device of a zoom system with a super lens.

[0004] In a first aspect, an embodiment of the present application provides a zoom method of a zoom system having a super lens, the method comprising:

[0005] Obtaining a zoom instruction, wherein the zoom instruction carries a zoom parameter;

[0006] Determining a phase coefficient of the superlens when zooming according to the zoom parameter;

[0007] Based on the phase coefficient, the metalens is zoomed.

[0008] In a second aspect, an embodiment of the present application further provides a zoom device having a zoom system with a super lens, the device comprising:

[0009] An acquisition module, used for acquiring a zoom instruction, wherein the zoom instruction carries a zoom parameter;

[0010] A processing module, used to determine the phase coefficient of the metalens when zooming according to the zoom parameter;

[0011] A zoom module is used to zoom the metalens based on the phase coefficient.

[0012] In a third aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processing unit, the steps of the method described in the first aspect are executed.

[0013] In a fourth aspect, an embodiment of the present application further provides an electronic device, comprising a memory, a processing unit, and one or more programs, wherein the one or more programs are stored in the memory and configured so that the processing unit executes the steps of the method described in the first aspect above.

[0014] In the solutions provided in the first to fourth aspects of the embodiments of the present application, the phase coefficient used when the metalens is zoomed is determined by the zoom parameters carried in the zoom instruction, and the metalens is zoomed based on the phase coefficient. Compared with the method of changing the focal length of the metalens in the zoom system by mechanical operations such as changing the angle between the metalens in the zoom system or rotating the metalens in the related art, the zoom of the metalens in the zoom system can be quickly achieved according to the zoom parameters carried in the zoom instruction. The zoom is completed by the zoom system itself during the entire zooming process, and there is no need to perform mechanical operation on the zoom system, thereby greatly shortening the response time of the zoom system and improving the zoom accuracy. In addition, the zoom range is not limited by the mechanical structure of the zoom system, so that the zoom range of the metalens is larger.

[0015] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A flowchart of a zoom method of a zoom system with a metalens provided in Embodiment 1 of the present application is shown;

[0018] Figure 2 The phase distribution curve of the second metalens in Example 1 provided in Embodiment 1 of the present application is shown;

[0019] Figure 3 A schematic diagram showing the zooming of the focus of the third metalens moving on the focal plane in Example 2 provided in Example 1 of the present application is shown;

[0020] Figure 4 The phase distribution curve of the third metalens in Example 2 provided in Example 1 of the present application is shown;

[0021] Figure 5A schematic diagram of a zoom device of a zoom system with a metalens provided in Example 2 of the present application is shown;

[0022] Figure 6 A schematic diagram of the structure of an electronic device provided in Example 3 of the present application is shown.

[0023] Icons: 200, acquisition module; 202, processing module; 204, zoom module; 51, bus; 52, processing unit; 53, transceiver; 54, bus interface; 55, memory; 56, user interface; 551, operating system; 552, application. DETAILED DESCRIPTION

[0024] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0026] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0027] At present, as an emerging optical element, metalens are being increasingly used in various optical devices due to their light and thin characteristics. Using metalens as a zoom system to replace the zoom system composed of traditional lenses is becoming the mainstream choice of optical manufacturers. In order to zoom the zoom system, in general, mechanical operations such as changing the angle between metalens in the zoom system or rotating the metalens are used to change the focal length of the metalens in the zoom system to achieve the zoom operation of the zoom system; however, the zoom time of the mechanical operation method is long and the zoom accuracy is low.

[0028] Based on this, the following embodiments of the present application propose a zoom method, device and electronic device of a zoom system with a metalens. The phase coefficient used when zooming the metalens is determined by the zoom parameters carried in the zoom instruction, and the metalens is zoomed based on the phase coefficient. Therefore, the zoom operation of the metalens in the zoom system can be quickly implemented according to the zoom parameters carried in the zoom instruction. During the entire zooming process, there is no need to mechanically operate the zoom system, and the zooming is completed by the zoom system itself, thereby greatly shortening the response time of the zoom system and improving the zoom accuracy. In addition, the zoom range is not limited by the mechanical structure of the zoom system, so that the zoom range of the metalens is larger.

[0029] Before introducing the zoom method, device and electronic device of the zoom system with a metalens proposed in the following embodiments of the present application, it is necessary to design a zoom database so that the zoom system can achieve zooming of the metalens according to the data stored in the zoom database. The specific process of how to design and obtain the data stored in the zoom database is described below:

[0030] First, the zoom system is described: the zoom system includes: a processing unit and a super lens.

[0031] The super lens is zoomed under the control of the processing unit.

[0032] The zoom database is pre-set in the processing unit.

[0033] The super lens comprises: a substrate, a phase change material layer and a plurality of nanostructures; the plurality of nanostructures are arranged on the substrate; and the phase change material layer is filled between the plurality of nanostructures.

[0034] The selectable materials, sizes and periods of the nanostructures are all stored in a preset nanostructure database.

[0035] The nanostructure database is pre-set in the processing unit.

[0036] The dimensions of the nanostructure include: nanostructure length, nanostructure width and nanostructure height.

[0037] The phase change material layer includes, but is not limited to: an electro-induced phase change material layer, a tensile phase change material layer, a photosensitive phase change material layer and a thermosensitive phase change material layer.

[0038] The cases of zooming the metalens include the following two cases: changing the focal length of the metalens (i.e., moving the focal plane on the optical axis of the metalens) and changing the position of the focus of the metalens on the focal plane (i.e., the focus of the metalens moves up and down on the initial focal plane of the metalens).

[0039] Then, for the case of changing the focal length of the metalens, the process of designing the data stored in the zoom database includes the following steps (1) to (8):

[0040] (1) Determine the operating wavelength of the metalens, the maximum aperture of the metalens, and the minimum focal length f within the zoom range of the metalens min and maximum focal length f max ;

[0041] (2) According to the first preset increment, f min Incremental operation, if the focal length after the incremental operation is less than f max , it is considered that the focal length after the incremental operation is within the zoom range of the metalens, and the incremental operation is continued, ... until the focal length after the incremental operation is equal to f max , get min and f max Multiple focal lengths f between zl1 ……f zln , and obtained by f min 、f zl1 ……f zln 、f max The focal length set [f min 、f zl1 ……f zln 、f max ];

[0042] (3) Substituting each focal length in the focal length set into the following formula 1, respectively, to obtain the theoretical phase distribution when the metalens is zoomed to each focal length in the focal length set: wherein the theoretical phase distribution of each focal length is a curve;

[0043]

[0044] f sj1 ∈[f min 、f zl1 ……f zln 、f max ]

[0045] Among them, φsj1 (r,λ) represents the theoretical phase distribution when the superlens is zoomed to each focal length in the focal length set; r represents the distance from the nanostructure in the superlens to the center of the superlens; the value range of r is (0, R); R represents the maximum aperture of the superlens; f sj1 are the focal lengths in the focal length set;

[0046] (4) The phase coefficient of the metalens when zooming to each focal length in the focal length set is calculated by the following formula 2:

[0047]

[0048] Among them, a k represents the phase coefficient when the metalens is zoomed to each focal length in the focal length set; k represents a k the number of

[0049] (5) According to the calculated phase coefficient when the metalens is zoomed to each focal length in the focal length set, the actual phase distribution when the metalens is zoomed to each focal length in the focal length set is calculated by the following formula 3:

[0050]

[0051] Among them, φ sj2 (r,λ) represents the actual phase distribution when the metalens is zoomed to each focal length in the focal length set;

[0052] (6) Obtaining the nanostructure height of the nanostructure in the metalens from the nanostructure database, and calculating the equivalent refractive index of the metalens when it is zoomed to each focal length in the focal length set according to the nanostructure height and the calculated actual phase distribution when the metalens is zoomed to each focal length in the focal length set by the following formula 4:

[0053] φ sj2 (r,λ)=k*neff sj1 *D (4)

[0054] Among them, neff sj1 represents the equivalent refractive index when the metalens is zoomed to each focal length in the focal length set;

[0055] (7) changing the phase change state of the phase change material layer in accordance with a phase change mode that matches the properties of the phase change material layer, so that the equivalent refractive index of the metalens changes to the equivalent refractive index neff when the metalens is zoomed to each focal length in the focal length set; sj1 , and recording a first phase change parameter of a phase change method used when the phase change state of the phase change material layer is changed when the super lens is zoomed to each focal length in the focal length set;

[0056] (8) According to the equivalent refractive index neff when the metalens is zoomed to each focal length in the focal length set sj1 and the first phase transition parameter, forming an equivalent refractive index neff when the metalens is zoomed to each focal length in the focal length set sj1 A first corresponding relationship with the first phase change parameter, and storing the obtained first corresponding relationship in a zoom database.

[0057] In the above step (2), in one embodiment, min The first preset increment for the incremental operation is 0.01 (millimeter) mm.

[0058] That is: f min With f zl1 The difference between them is 0.01mm; f zln With f max The difference between them is 0.01mm.

[0059] In the above step (4), we use The theoretical phase distribution φ of each focal length is obtained sj1 The (r, λ) curves are fitted respectively to obtain the phase coefficient when the superlens is zoomed to each focal length in the focal length set.

[0060] Here, the phase coefficient of the obtained metalens when zooming to each focal length in the focal length set is obtained using The theoretical phase distribution φ of each focal length is obtained sj1 The results of fitting the theoretical phase distribution curve of (r, λ) respectively; the phase coefficient includes: multiple phase sub-coefficients.

[0061] In one embodiment, the phase coefficient may include 5 phase sub-coefficients.

[0062] In the above step (7), as mentioned above, the phase change material layer includes but is not limited to: an electro-induced phase change material layer, a tensile phase change material layer, a photosensitive phase change material layer and a thermosensitive phase change material layer.

[0063] Then according to the properties of different phase change material layers, the phase change modes that match the properties of the phase change material layers include the following phase change modes:

[0064] First, when the phase change material layer is an electro-induced phase change material layer, the phase change mode that matches the properties of the phase change material layer is the electro-induced phase change mode. Since the electro-induced phase change mode changes the phase change state of the electro-induced phase change material layer by changing the voltage of the electro-induced phase change material layer, so as to make the super lens zoom; then the first phase change parameter that matches the electro-induced phase change mode is voltage.

[0065] In one embodiment, in order to change the phase change state of the electro-phase change material layer according to the above-mentioned electro-phase change method, the processing unit can be connected to the super-lens through a power supply to control the power supply to apply different voltages to the super-lens to change the phase change state of the electro-phase change material layer.

[0066] Second, when the phase change material layer is a retractable phase change material layer, the phase change mode that matches the properties of the phase change material layer is a mechanical stretching phase change mode. Since the mechanical stretching phase change mode changes the phase change state of the retractable phase change material layer by changing the period of the nanostructure (i.e., the position of the nanostructure on the substrate) to make the super lens zoom, the first phase change parameter that matches the mechanical stretching phase change mode is the displacement distance of the nanostructure.

[0067] In one embodiment, in order to change the phase change state of the stretchable phase change material layer according to the above-mentioned mechanical stretching phase change method, the processing unit can be connected to the superlens through a micromechanical motor to control the micromechanical motor to displace the nanostructure by different distances to change the position of the nanostructure in the superlens on the substrate, thereby changing the phase change state of the stretchable phase change material layer.

[0068] The third type is that when the phase change material layer is a photosensitive phase change material layer, the phase change mode that matches the properties of the phase change material layer is the photosensitive phase change mode. Since the photosensitive phase change mode is to change the phase change state of the photosensitive phase change material layer by changing the intensity of the light beam irradiating the photosensitive phase change material layer, so that the temperature of the light beam irradiated by the light beam with changed light intensity changes, the super lens can be zoomed; then the first phase change parameter that matches the photosensitive phase change mode is the intensity of the light beam irradiating the photosensitive phase change material layer.

[0069] In one embodiment, in order to change the phase change state of the photosensitive phase change material layer according to the above-mentioned photosensitive phase change method, the processing unit can control a laser connected to the processing unit to irradiate the photosensitive phase change material layer with light beams with different light intensities, so that the photosensitive phase change material layer changes its phase change state under the action of different temperatures generated by the irradiation of light beams with different light intensities.

[0070] Fourthly, when the phase change material layer is a thermosensitive phase change material layer, the phase change mode that matches the properties of the phase change material layer is a thermosensitive phase change mode. Since the thermosensitive phase change mode changes the phase change state of the thermosensitive phase change material layer by changing the temperature of the thermosensitive phase change material layer, so as to make the super lens zoom; then the first phase change parameter that matches the thermosensitive phase change mode is the temperature of the thermosensitive phase change material layer.

[0071] In one embodiment, in order to change the phase change state of the thermosensitive phase change material layer according to the above-mentioned thermosensitive phase change method, the processing unit can be connected to a heating device in contact with the thermosensitive phase change material layer to control the heating device to heat the thermosensitive phase change material layer to different temperatures to change the phase change state of the thermosensitive phase change material layer.

[0072] In the above step (8), when the phase change mode is an electro-induced phase change mode, the first corresponding relationship is: the corresponding relationship between the equivalent refractive index and the voltage when the superlens is zoomed to each focal length in the focal length set.

[0073] When the phase change mode is a mechanical stretching phase change mode, the first corresponding relationship is: the corresponding relationship between the equivalent refractive index when the superlens is zoomed to each focal length in the focal length set and the period of the nanostructure.

[0074] When the phase change mode is a photosensitive phase change mode, the first corresponding relationship is: the corresponding relationship between the equivalent refractive index when the superlens is zoomed to each focal length in the focal length set and the light intensity of the light beam irradiating the photosensitive phase change material layer.

[0075] When the phase change mode is a thermosensitive phase change mode, the first corresponding relationship is: the corresponding relationship between the equivalent refractive index when the superlens is zoomed to each focal length in the focal length set and the temperature of the thermosensitive phase change material layer.

[0076] The first corresponding relationship between the equivalent refractive index when the superlens is zoomed to each focal length in the focal length set and the first phase change parameter is the corresponding relationship between the equivalent refractive index when the superlens is zoomed to each focal length within the zoom range of the superlens and the first phase change parameter.

[0077] After describing the formation process of the first correspondence used in the case of changing the focal length of the metalens through the above steps (1) to (8), the process of designing and obtaining the data stored in the zoom database in the case of changing the position of the focus of the metalens on the focal plane is introduced. The process of designing and obtaining the data stored in the zoom database in the case of changing the position of the focus of the metalens on the focal plane includes the following steps (11) to (19):

[0078] (11) Determine the working wavelength of the metalens, the maximum aperture of the metalens, and the focus distance range of the metalens, and determine the maximum focus distance d according to the focus distance range. max and the minimum focus distance d min ;

[0079] (12) When the second preset increment is obtained, the minStart to perform an incremental operation on the focus distance. If the focus distance after the incremental operation is less than the maximum focus distance, it is considered that the focus distance value after the incremental operation is within the focus distance range, and continue to perform an incremental operation on the focus distance after the incremental operation until the focus distance after the incremental operation is equal to d max , and obtain multiple focus distances d within the focus distance range. zl1 ……d zln , and obtained by d min ,d zl1 ……d zln ,d max The focus distance set composed of [d min ,d zl1 ……d zln ,d max ];

[0080] (13) according to each focus distance in the focus distance set and the distance between the metalens and the initial focal plane of the metalens, respectively calculating the focal length of the metalens zoomed according to each focus distance in the focus distance set;

[0081] (14) The theoretical phase distribution of the metalens when zooming according to each focus distance in the focus distance set is calculated by the following formula 5:

[0082]

[0083] d sj ∈[d min ,d zl1 ……d zln ,d max ]

[0084] Among them, φ sj3 (x, y, λ) represents the theoretical phase distribution of the metalens according to each focus distance in the focus distance set; f sj2 represents the focal length of the superlens according to each focus shift distance in the focus shift distance set; (x, y) represents the position coordinates of the nanostructure relative to the center of the superlens; f0 represents the distance between the superlens and the initial focal plane of the superlens; d sj represents each focus distance in the focus distance set;

[0085] (15) The phase coefficient of the superlens zoomed according to each focus distance in the focus distance set is calculated by the following formula 6:

[0086]

[0087] Among them, a prepresents the phase coefficient of the super lens zooming according to each focus distance in the focus distance set; p represents a p the number of

[0088] (16) Based on the calculated phase coefficient of the metalens zooming at each focus distance in the focus distance set, the actual phase distribution of the metalens zooming at each focus distance in the focus distance set is calculated by the following formula 7:

[0089]

[0090] Among them, φ sj4 (r, λ) represents the actual phase distribution of the metalens when zooming according to each focus distance in the focus distance set;

[0091] (17) The nanostructure height of the nanostructure in the metalens is obtained from the nanostructure database. Based on the nanostructure height and the calculated actual phase distribution of the metalens zoomed at each focus distance in the focus distance set, the equivalent refractive index of the metalens zoomed at each focus distance in the focus distance set is calculated respectively by the following formula 8:

[0092] φ sj4 (r,λ)=k*neff sj2 *D (8)

[0093] Among them, neff sj2 represents the equivalent refractive index of the metalens when zooming according to each focus distance in the focus distance set;

[0094] (18) According to the phase change mode matching the properties of the phase change material layer, the phase change state of the phase change material layer is changed, so that the equivalent refractive index of the metalens changes to the equivalent refractive index neff of the metalens according to each focus distance in the focus distance set. sj2 , and recording a second phase change parameter in a phase change mode used when the phase change state of the phase change material layer is changed when the metalens is zoomed according to each focus distance in the focus distance set;

[0095] (19) Based on the equivalent refractive index of the metalens when zoomed according to each focal distance in the focal distance set and the second phase change parameter, a second correspondence between the equivalent refractive index of the metalens when zoomed according to each focal distance in the focal distance set and the second phase change parameter is formed, and the obtained second correspondence is stored in the zoom database.

[0096] In the above step (18), the specific process of changing the phase change state of the phase change material layer according to the phase change mode matching the properties of the phase change material layer is similar to the content described in the above step (7) and will not be repeated here.

[0097] In the above step (19), the second correspondence between the equivalent refractive index of the metalens when zooming according to each focal distance in the focal distance set and the second phase change parameter is the correspondence between the equivalent refractive index of the metalens when zooming according to each focal distance within the focal distance range and the second phase change parameter.

[0098] When the phase change mode is an electro-induced phase change mode, the second corresponding relationship is: the corresponding relationship between the equivalent refractive index of the metalens according to each focus shift distance in the focus shift distance set and the voltage.

[0099] When the phase change mode is a mechanical stretching phase change mode, the second corresponding relationship is: the corresponding relationship between the equivalent refractive index of the superlens according to each focus distance in the focus distance set and the period of the nanostructure.

[0100] When the phase change mode is a photosensitive phase change mode, the second corresponding relationship is: the corresponding relationship between the equivalent refractive index of the superlens according to each focus distance in the focus distance set and the light intensity of the light beam irradiating the photosensitive phase change material layer.

[0101] When the phase change mode is a thermosensitive phase change mode, the second corresponding relationship is: the corresponding relationship between the equivalent refractive index when the superlens is zoomed to each focal length in the focal length set and the temperature of the thermosensitive phase change material layer.

[0102] Here, the equivalent refractive index neff of the metalens formed by the above steps (11) to (19) according to each focus distance in the focus distance set is sj2 The specific process of the second corresponding relationship with the second phase change parameter is the same as the equivalent refractive index neff when the super lens is zoomed to each focal length in the focal length set described in the above steps (1) to (8). sj1 The process is similar to the first corresponding relationship of the first phase change parameter and will not be repeated here.

[0103] After obtaining the first correspondence relationship and the second correspondence relationship as data in a zoom database through the above, the zoom database is set in the zoom system and used by the zoom system when performing zooming of the super lens.

[0104] The present application describes in detail a zoom method of a zoom system with a super lens through the following embodiments.

[0105] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0106] Example 1

[0107] The execution body of the zoom method of the zoom system with a super lens proposed in this embodiment is the above-mentioned processing unit.

[0108] See also Figure 1 A flowchart of a zoom method of a zoom system with a metal lens is shown, and the zoom method of the zoom system with a metal lens comprises the following specific steps:

[0109] Step 100: Obtain a zoom instruction, where the zoom instruction carries a zoom parameter.

[0110] In the above step 100, the zoom parameters include: the target focal length of the metalens and the focus shift distance of the metalens.

[0111] Step 102: Determine the phase coefficient of the superlens when zooming according to the zoom parameter.

[0112] In the above step 102, when the zoom parameter is the target focal length, the processing unit in the zoom system uses the first corresponding relationship stored in the zoom database to zoom the metalens.

[0113] Then, when the zoom parameter is the target focal length, in order to determine the phase coefficient when the metalens is zoomed, the first theoretical phase distribution when the metalens is zoomed to the target focal length can be calculated based on the target focal length, the working wavelength of the metalens and the maximum aperture of the metalens; then, the phase coefficient when the metalens is zoomed to the target focal length can be calculated using the first theoretical phase distribution obtained.

[0114] Specifically, in order to determine the phase coefficient of the metalens when zooming according to the zoom parameter, the above step 102 can perform the following steps (1) to (3):

[0115] (1) when the target focal length is within the zoom range of the metalens, obtaining the operating wavelength of the metalens and the maximum aperture of the metalens;

[0116] (2) The first theoretical phase distribution when the metalens is zoomed to the target focal length is calculated by the following formula 9:

[0117]

[0118] Wherein, φ1(r,λ) represents the first theoretical phase distribution; λ represents the working wavelength of the superlens; f represents the target focal length; r represents the distance from the nanostructure in the superlens to the center of the superlens, and the value range of r is (0, R); R represents the maximum aperture of the superlens;

[0119] (3) using the following formula 10 to obtain the phase coefficient when the metalens is zoomed to the target focal length;

[0120]

[0121] Among them, a m represents the mth phase coefficient among the i phase coefficients when the superlens is zoomed to the target focal length.

[0122] In the above step (1), the operating wavelength of the superlens and the maximum aperture of the superlens are pre-cached in the processing unit.

[0123] In the above step (2), the first theoretical phase distribution is a curve.

[0124] In the above step (3), the processing unit uses The curve φ1(r,λ) of the first theoretical phase distribution is fitted to obtain a phase coefficient when the superlens is zoomed to the target focal length.

[0125] Optionally, when the zoom parameter is the focus distance of the metalens, the processing unit in the zoom system uses the second corresponding relationship stored in the zoom database to zoom the metalens.

[0126] Then, when the zoom parameter is the focal distance of the metalens, in order to determine the phase coefficient when the metalens is zoomed, the focal length of the metalens after zooming can be calculated based on the distance between the metalens and the initial focal plane of the metalens and the focal distance of the metalens, and the second theoretical phase distribution of the metalens when zoomed according to the focal distance can be calculated based on the distance between the metalens and the initial focal plane of the metalens, the focal distance of the metalens and the focal length after zooming the metalens; then, the phase coefficient of the metalens when zooming according to the focal distance can be obtained based on the second theoretical phase distribution of the metalens when zoomed according to the focal distance.

[0127] Specifically, in order to determine the phase coefficient of the metalens when zooming according to the zoom parameter, the above step 102 may also perform the following steps (11) to (14):

[0128] (11) when the focus shift distance is within the focus shift distance range, obtaining the distance between the metalens and the initial focal plane of the metalens;

[0129] (12) calculating the focal length of the metalens after zooming according to the focus shift distance and the distance between the metalens and the initial focal plane of the metalens;

[0130] (13) The second theoretical phase distribution of the metalens zoomed according to the focus shift distance is calculated by the following formula 11:

[0131]

[0132] Wherein, φ1(x, y, λ) represents the second theoretical phase distribution; f1 represents the focal length of the superlens after zooming; (x, y) represents the position coordinates of the nanostructure relative to the center of the superlens; f0 represents the distance between the superlens and the initial focal plane of the superlens; d represents the focus shift distance of the superlens;

[0133] (14) The phase coefficient of the superlens zooming according to the focus shifting distance is obtained using the following formula 12;

[0134]

[0135] Among them, a n represents the nth phase coefficient among the j phase coefficients of the superlens zoomed according to the focus shift distance.

[0136] In the above step (11), the focus shift distance range and the distance between the superlens and the initial focal plane of the superlens are cached in the processing unit.

[0137] In the above step (12), based on the focus shift distance and the distance between the metalens and the initial focal plane of the metalens, the processing unit can calculate the focal length of the metalens zoomed according to the focus shift distance using the Pythagorean theorem. The specific process will not be repeated here.

[0138] In the above step (14), the processing unit uses The curve φ1(x, y, λ) of the second theoretical phase distribution is fitted to obtain the phase coefficient of the superlens zooming according to the focus shifting distance.

[0139] Step 104: zoom the metalens based on the phase coefficient.

[0140] In the above step 104, in the case where the phase coefficient when the metalens is zoomed to the target focal length is obtained through steps (1) to (3) executed in the above step 102, the first actual phase distribution when the metalens is zoomed to the target focal length can be calculated based on the obtained phase coefficient when the metalens is zoomed to the target focal length, and the first equivalent refractive index when the metalens is zoomed to the target focal length can be calculated based on the obtained first actual phase distribution when the metalens is zoomed to the target focal length; finally, the metalens is zoomed based on the obtained first equivalent refractive index.

[0141] Specifically, when the phase coefficient when the metalens is zoomed to the target focal length is obtained, in order to zoom the metalens based on the phase coefficient, the step 104 may perform the following steps (21) to (23):

[0142] (21) The first actual phase distribution when the metalens is zoomed to the target focal length is calculated by the following formula 13:

[0143]

[0144] Wherein, φ2(r,λ) represents the first actual phase distribution;

[0145] (22) Obtaining the height of the nanostructure in the metalens, and calculating the first equivalent refractive index when the metalens is zoomed to the target focal length according to the following formula 14:

[0146] φ2(r,λ)=k*neff1*D (14)

[0147] in, D represents the height of the nanostructure, neff1 is the first equivalent refractive index;

[0148] (23) Zooming the metalens according to the obtained first equivalent refractive index.

[0149] In the step (23), after obtaining the first equivalent refractive index, the zoom system may perform the following steps (231) to (233):

[0150] (231) obtaining a first corresponding relationship, wherein the first corresponding relationship is a corresponding relationship between an equivalent refractive index and a first phase change parameter when the metalens is zoomed to each focal length within a zoom range of the metalens;

[0151] (232) generating a first metalens phase change instruction using a first phase change parameter corresponding to an equivalent refractive index closest to the first equivalent refractive index in the first corresponding relationship;

[0152] (233) According to a phase change mode that matches the obtained first phase change parameter, the superlens is controlled to execute the first superlens phase change instruction, the phase change state of the phase change material layer in the superlens is changed, the superlens is zoomed, and the focal length of the superlens is adjusted to the target focal length.

[0153] In the above step (231), the zoom system obtains the first corresponding relationship from the stored zoom database.

[0154] In the above step (233), the phase change mode matched with the first phase change parameter means that when the first phase change parameter is voltage, the phase change mode matched with the first phase change parameter is an electro-induced phase change mode.

[0155] Then, the processing unit controls the superlens to execute the first superlens phase change instruction according to the phase change mode matching the obtained first phase change parameter, so as to change the phase change state of the phase change material layer in the superlens, including: the processing unit sends the first superlens phase change instruction to the power supply to control the power supply to power the superlens according to the voltage carried in the first superlens phase change instruction, so as to change the phase change state of the electro-induced phase change material layer in the superlens.

[0156] When the first phase change parameter is the period of the nanostructure, the phase change mode matching the first phase change parameter is the mechanical stretching phase change mode.

[0157] Then, the processing unit controls the superlens to execute the first superlens phase change instruction according to the phase change mode matching the obtained first phase change parameter, and changes the phase change state of the phase change material layer in the superlens, including: the processing unit sends the first superlens phase change instruction to the micromechanical motor to control the micromechanical motor to displace the nanostructure according to the displacement distance corresponding to the period of the nanostructure carried in the first superlens phase change instruction, and changes the position of the nanostructure in the superlens on the substrate, so as to change the phase change state of the stretchable phase change material layer in the superlens.

[0158] When the first phase change parameter is the light intensity of the light beam irradiating the photosensitive phase change material layer, the phase change mode matching the first phase change parameter is the photosensitive phase change mode.

[0159] Then, the processing unit controls the superlens to execute the first superlens phase change instruction according to the phase change mode matching the obtained first phase change parameter, and changes the phase change state of the phase change material layer in the superlens, including: the processing unit sends the first superlens phase change instruction to the laser, controls the laser to emit a light beam with the light intensity carried in the first superlens phase change instruction to the photosensitive phase change material layer, and irradiates the photosensitive phase change material layer with the light beam with the light intensity carried in the first superlens phase change instruction, so that the temperature of the photosensitive phase change material layer changes, and the photosensitive phase change material layer with the changed temperature changes its phase change state.

[0160] When the first phase change parameter is the temperature of the thermosensitive phase change material layer, the phase change mode matching the first phase change parameter is a thermosensitive phase change mode.

[0161] Then, the processing unit controls the superlens to execute the first superlens phase change instruction according to the phase change mode matching the obtained first phase change parameter, so as to change the phase change state of the phase change material layer in the superlens, including: the processing unit sends the first superlens phase change instruction to the heating device, controls the heating device to heat the thermosensitive phase change material layer according to the temperature carried in the first superlens phase change instruction, so as to change the phase change state of the thermosensitive phase change material layer in the superlens.

[0162] Optionally, when the phase coefficient of the metalens zooming according to the focal distance is obtained by steps (11) to (14) executed in the above step 102, a second actual phase distribution of the metalens zooming according to the focal distance can be calculated based on the phase coefficient of the metalens zooming according to the focal distance, and a second equivalent refractive index when the metalens is zoomed according to the focal distance can be calculated based on the calculated second actual phase distribution; finally, the metalens is zoomed based on the obtained second equivalent refractive index.

[0163] Specifically, when the phase coefficient of the metalens zooming according to the focus shifting distance is obtained, in order to zoom the metalens based on the phase coefficient, the step 104 may perform the following steps (31) to (33):

[0164] (31) The second actual phase distribution of the metalens zoomed according to the focus shift distance is calculated by the following formula 15:

[0165]

[0166] Wherein, φ2(x, y, λ) represents the second actual phase distribution;

[0167] (32) The second equivalent refractive index when the metalens is zoomed according to the focus shift distance is calculated according to the following formula 16:

[0168] φ2(x,y,λ)=k*neff2*D (16)

[0169] Wherein, neff2 is the second equivalent refractive index;

[0170] (33) Zooming the metalens according to the obtained second equivalent refractive index.

[0171] In the step (33), after obtaining the second equivalent refractive index, the zoom system may perform the following steps (331) to (333):

[0172] (331) obtaining a second corresponding relationship, wherein the second corresponding relationship is a corresponding relationship between an equivalent refractive index and a second phase change parameter when the metalens is zoomed at each focal distance within the focal distance range;

[0173] (332) generating a second metalens phase change instruction using a second phase change parameter corresponding to the equivalent refractive index closest to the second equivalent refractive index in the second corresponding relationship;

[0174] (333) According to the phase change mode matching the obtained second phase change parameter, the superlens is controlled to execute the second superlens phase change instruction, the phase change state of the phase change material layer in the superlens is changed, and the superlens is zoomed according to the focus shifting distance of the superlens.

[0175] The phase change mode of the second phase change parameter matching refers to:

[0176] When the second phase change parameter is voltage, the phase change mode that matches the second phase change parameter is an electro-induced phase change mode.

[0177] When the second phase change parameter is the period of the nanostructure, the phase change mode matching the second phase change parameter is the mechanical stretching phase change mode.

[0178] When the second phase change parameter is the light intensity of the light beam irradiating the photosensitive phase change material layer, the phase change mode matching the second phase change parameter is the photosensitive phase change mode.

[0179] When the second phase change parameter is the temperature of the thermosensitive phase change material layer, the phase change mode matching the second phase change parameter is a thermosensitive phase change mode.

[0180] The specific process of controlling the superlens to execute the second superlens phase change instruction and changing the phase change state of the phase change material layer in the superlens according to the phase change mode matching the obtained second phase change parameter is similar to the process of controlling the superlens to execute the first superlens phase change instruction and changing the phase change state of the phase change material layer in the superlens according to the phase change mode matching the obtained first phase change parameter in the above step (233), and will not be repeated here.

[0181] The zoom method of the zoom system with a super lens proposed in this embodiment is further described through the following two examples:

[0182] Example 1: When the focal length of a metalens needs to be changed, the zoom system is composed of two metalens, where the second metalens is located on the light-emitting side of the first metalens, the operating wavelength of the first metalens and the second metalens is 940 nanometers (nm), and the zoom range of the second metalens is 1.3 mm to 1.8 mm. The focal length of the first metalens is f 11 , the focal length of the second metalens is f12 , the focal length f of the zoom system bjxt satisfy:

[0183]

[0184] n is the distance between the first superlens and the second superlens, n = 1.24mm, the maximum aperture of the first superlens is 0.5mm, and the maximum aperture of the second superlens is 0.96mm. 11 =1mm, the zoom range of the second super lens is (-0.8mm, -0.3mm), and the phase distribution curve of the second super lens is as follows: Figure 2 shown.

[0185] The remainder of 2π is taken for the phase curve of the second superlens to obtain the phase distribution along the radial direction r, and the formula 10 is fitted with the obtained phase distribution along the radial direction r to obtain a phase coefficient that meets the requirements. The phase coefficient that meets the requirements is input into the zoom system to realize the zoom control of the zoom system.

[0186] Example 2: When it is necessary to change the position of the focus of the metalens on the focal plane, refer to Figure 3 The schematic diagram of the focus of the third super lens moving and zooming on the focal plane shown in FIG. 1 is that the working wavelength of the third super lens is 940 nm, the focus shift distance ranges from -0.18 mm to +0.18 mm, the substrate of the third super lens is silicon, and the refractive index for the wavelength of 940 nm is 3.6, and the maximum aperture of the third super lens is 0.5 mm. Substituting the above parameters into the above formula 11, the following is obtained: Figure 4 Phase distribution curve diagram of the third superlens shown.

[0187] Combine Formula 12 with the above Figure 4 The phase distribution curve shown is fitted to obtain a phase coefficient that meets the requirements, and the obtained phase coefficient is input into the zoom system to achieve off-axis focus control of the zoom system.

[0188] In summary, the present embodiment proposes a zoom method for a zoom system with a metalens, by using the zoom parameters carried in the zoom instruction to determine the phase coefficient used when the metalens is zoomed, and the metalens is zoomed based on the phase coefficient. Compared with the method of changing the angle between the metalens in the zoom system or rotating the metalens in the related art to change the focal length of the metalens in the zoom system, the zoom operation of the metalens in the zoom system can be quickly implemented according to the zoom parameters carried in the zoom instruction. During the entire zooming process, there is no need to perform mechanical operation on the zoom system, and the zooming is completed by the zoom system itself, thereby greatly shortening the response time of the zoom system and improving the zoom accuracy. In addition, the zoom range is not limited by the mechanical structure of the zoom system, so that the zoom range of the metalens is larger.

[0189] Example 2

[0190] This embodiment provides a zoom device of a zoom system with a super lens, which is used to execute the zoom method of the zoom system with a super lens proposed in the above-mentioned embodiment 1.

[0191] See also Figure 5 The structure diagram of a zoom device of a zoom system with a metal lens is shown in FIG. 1 . This embodiment provides a zoom device of a zoom system with a metal lens, and the device includes:

[0192] An acquisition module 200 is used to acquire a zoom instruction, where the zoom instruction carries a zoom parameter;

[0193] A processing module 202 is used to determine a phase coefficient of the metalens when zooming according to the zoom parameter;

[0194] The zoom module 204 is used to zoom the metalens based on the phase coefficient.

[0195] The super lens comprises: a substrate, a plurality of nanostructures and a phase change material layer; the plurality of nanostructures are arranged on the substrate, and the phase change material layer is filled between the plurality of nanostructures.

[0196] The zoom parameters include: the target focal length of the metalens.

[0197] When the zoom parameter is the target focal length, the processing module 202 is specifically configured to:

[0198] When the target focal length is within the zoom range of the metalens, obtaining the operating wavelength of the metalens and the maximum aperture of the metalens;

[0199] The first theoretical phase distribution when the metalens is zoomed to the target focal length is calculated by the following formula:

[0200]

[0201] Wherein, φ1(r,λ) represents the first theoretical phase distribution; λ represents the working wavelength of the superlens; f represents the target focal length; r represents the distance from the nanostructure in the superlens to the center of the superlens, and the value range of r is (0, R); R represents the maximum aperture of the superlens;

[0202] The phase coefficient when the metalens is zoomed to the target focal length is obtained using the following formula;

[0203]

[0204] Among them, a mrepresents the mth phase coefficient among the i phase coefficients when the superlens is zoomed to the target focal length.

[0205] Specifically, when the zoom parameter is the target focal length of the metalens, the zoom module 204 is specifically used to:

[0206] The first actual phase distribution when the metalens is zoomed to the target focal length is calculated by the following formula:

[0207]

[0208] Wherein, φ2(r,λ) represents the first actual phase distribution;

[0209] The height of the nanostructure in the metalens is obtained, and the first equivalent refractive index when the metalens is zoomed to the target focal length is calculated according to the following formula:

[0210] φ2(r,λ)=k*neff1*D

[0211] in, D represents the height of the nanostructure, neff1 is the first equivalent refractive index;

[0212] The superlens is zoomed according to the obtained first equivalent refractive index.

[0213] Specifically, the zoom module is used to zoom the metalens according to the obtained first equivalent refractive index, including:

[0214] Acquire a first corresponding relationship, where the first corresponding relationship is: a corresponding relationship between an equivalent refractive index and a first phase change parameter when the superlens is zoomed to each focal length within the zoom range of the superlens;

[0215] Generate a first metalens phase change instruction using a first phase change parameter corresponding to an equivalent refractive index closest to the first equivalent refractive index in the first corresponding relationship;

[0216] According to the phase change mode matching the obtained first phase change parameter, the superlens is controlled to execute the first superlens phase change instruction, the phase change state of the phase change material layer in the superlens is changed, the superlens is zoomed, and the focal length of the superlens is adjusted to the target focal length.

[0217] In one embodiment, the zoom parameter includes: the focus distance of the metalens. When the zoom parameter is the focus distance of the metalens, the processing module 202 is specifically configured to:

[0218] When the focus shift distance is within the focus shift distance range, obtaining the distance between the metalens and an initial focal plane of the metalens;

[0219] Calculating the focal length of the superlens after zooming according to the focus shift distance and the distance between the superlens and the initial focal plane of the superlens;

[0220] The second theoretical phase distribution of the metalens zoomed according to the focus shift distance is calculated by the following formula:

[0221]

[0222] Wherein, φ1(x, y, λ) represents the second theoretical phase distribution; f1 represents the focal length of the superlens after zooming; (x, y) represents the position coordinates of the nanostructure relative to the center of the superlens; f0 represents the distance between the superlens and the initial focal plane of the superlens; d represents the focus shift distance of the superlens;

[0223] The phase coefficient of the superlens zooming according to the focus shifting distance is obtained using the following formula:

[0224]

[0225] Among them, a n represents the nth phase coefficient among the j phase coefficients of the superlens zoomed according to the focus shift distance.

[0226] Specifically, when the zoom parameter is the focus distance of the metalens, the zoom module 204 is specifically used to:

[0227] The second actual phase distribution of the metalens zoomed according to the focus shift distance is calculated by the following formula:

[0228]

[0229] Wherein, φ2(x, y, λ) represents the second actual phase distribution;

[0230] The second equivalent refractive index when the metalens is zoomed according to the focus shift distance is calculated according to the following formula:

[0231] φ2(x,y,λ)=k*neff2*D

[0232] Wherein, neff2 is the second equivalent refractive index;

[0233] The superlens is zoomed according to the obtained second equivalent refractive index.

[0234] Specifically, the zoom module 204 is used to zoom the metalens according to the obtained second equivalent refractive index, including:

[0235] Acquire a second corresponding relationship, where the second corresponding relationship is a corresponding relationship between an equivalent refractive index and a second phase change parameter when the metalens is zoomed at each focus distance within the focus distance range;

[0236] Generate a second metalens phase change instruction using a second phase change parameter corresponding to an equivalent refractive index closest to the second equivalent refractive index in the second corresponding relationship;

[0237] According to the phase change mode matching the obtained second phase change parameter, the superlens is controlled to execute the second superlens phase change instruction, the phase change state of the phase change material layer in the superlens is changed, and the superlens is zoomed according to the focus shift distance of the superlens.

[0238] In summary, the present embodiment proposes a zoom device with a zoom system having a metalens, which determines the phase coefficient used when the metalens is zoomed through the zoom parameters carried in the zoom instruction, and zooms the metalens based on the phase coefficient. Compared with the method of changing the focal length of the metalens in the zoom system by mechanical operations such as changing the angle between the metalens in the zoom system or rotating the metalens in the related art, the zoom operation of the metalens in the zoom system can be quickly implemented according to the zoom parameters carried in the zoom instruction. During the entire zooming process, there is no need to perform mechanical operation on the zoom system, and the zooming is completed by the zoom system itself, thereby greatly shortening the response time of the zoom system and improving the zoom accuracy. In addition, the zoom range is not limited by the mechanical structure of the zoom system, so that the zoom range of the metalens is larger.

[0239] Example 3

[0240] This embodiment provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the zoom method of the zoom system with a metalens described in the above embodiment 1 are executed. The specific implementation can be found in method embodiment 1, which will not be described in detail here.

[0241] In addition, see Figure 6 The structural diagram of an electronic device shown in FIG. 1 is a schematic diagram of a structure of an electronic device. This embodiment further provides an electronic device, which includes a bus 51 , a processing unit 52 , a transceiver 53 , a bus interface 54 , a memory 55 and a user interface 56 . The electronic device includes a memory 55 .

[0242] In this embodiment, the electronic device further includes: one or more programs stored in the memory 55 and executable on the processing unit 52, and configured so that the processing unit executes the one or more programs to perform the following steps (1) to (3):

[0243] (1) obtaining a zoom instruction, wherein the zoom instruction carries a zoom parameter;

[0244] (2) determining a phase coefficient of the metalens when zooming according to the zoom parameter;

[0245] (3) Based on the phase coefficient, the metalens is zoomed.

[0246] The transceiver 53 is used to receive and send data under the control of the processing unit 52.

[0247] Among them, the bus architecture (represented by bus 51), bus 51 can include any number of interconnected buses and bridges, and bus 51 links various circuits including one or more processors represented by processing unit 52 and memory represented by memory 55. Bus 51 can also link various other circuits such as peripherals, voltage regulators, and power management circuits together, which are all well known in the art, so this embodiment will not be further described. Bus interface 54 provides an interface between bus 51 and transceiver 53. Transceiver 53 can be one element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on a transmission medium. For example: transceiver 53 receives external data from other devices. Transceiver 53 is used to send data processed by processing unit 52 to other devices. Depending on the nature of the computing system, a user interface 56, such as a keypad, display, speaker, microphone, joystick, can also be provided.

[0248] The processing unit 52 is responsible for managing the bus 51 and general processing, such as running the general operating system 551 as mentioned above. The memory 55 can be used to store data used by the processing unit 52 when performing operations.

[0249] Optionally, the processing unit 52 may be, but is not limited to: a central processing unit, a single-chip microcomputer, a microprocessor or a programmable logic device.

[0250] It can be understood that the memory 55 in the embodiment of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM) and direct RAM bus random access memory (DRRAM). The memory 55 of the system and method described in the present embodiment is intended to include, but is not limited to, these and any other suitable types of memory.

[0251] In some implementations, the memory 55 stores the following elements, executable modules or data structures, or a subset thereof, or an extended set thereof: an operating system 551 and application programs 552 .

[0252] The operating system 551 includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., which are used to implement various basic services and process hardware-based tasks. The application 552 includes various application programs. The program for implementing the method of the embodiment of the present application can be included in the application 552.

[0253] In summary, the present embodiment proposes a computer-readable storage medium and an electronic device, which determines the phase coefficient used when the metalens is zoomed through the zoom parameters carried in the zoom instruction, and zooms the metalens based on the phase coefficient. Compared with the method of changing the focal length of the metalens in the zoom system by changing the angle between the metalens in the zoom system or rotating the metalens in the related art, the zoom operation of the metalens in the zoom system can be quickly implemented according to the zoom parameters carried in the zoom instruction. During the entire zooming process, there is no need to perform mechanical operation on the zoom system, and the zooming is completed by the zoom system itself, thereby greatly shortening the response time of the zoom system and improving the zoom accuracy. In addition, the zoom range is not limited by the mechanical structure of the zoom system, so that the zoom range of the metalens is larger.

[0254] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A zoom method of a zoom system with a super lens, characterized in that: The method comprises: Obtaining a zoom instruction, wherein the zoom instruction carries a zoom parameter; Determining a phase coefficient of the superlens when zooming according to the zoom parameter; Based on the phase coefficient, zooming the metalens; Wherein, the zoom parameters include: target focal length or focus shift distance of the metalens; Determining the phase coefficient of the superlens when zooming according to the zoom parameter includes: Determining the theoretical phase distribution of the metalens when zooming according to the zoom parameter; Fitting the theoretical phase distribution to obtain a phase coefficient corresponding to the polynomial; The step of zooming the metalens based on the phase coefficient comprises: According to the phase coefficient, an actual phase distribution of the metalens when zooming is obtained; Calculating the equivalent refractive index of the metalens when zooming according to the actual phase distribution; Obtaining a correspondence between an equivalent refractive index and a phase change parameter stored in a zoom database, and zooming the metalens using a phase change parameter corresponding to an equivalent refractive index that is closest to the calculated equivalent refractive index in the correspondence; Wherein, calculating the equivalent refractive index of the superlens when zooming according to the actual phase distribution includes: The equivalent refractive index is calculated according to the following formula: φ(t,λ)=k*neff*D Wherein, φ(t,λ) represents the actual phase distribution; t represents the position parameter of the nanostructure in the superlens relative to the center of the superlens; λ represents the operating wavelength of the superlens; neff is the equivalent refractive index; D represents the height of the nanostructure.

2. The method according to claim 1, characterized in that The super lens comprises: a substrate, a plurality of nanostructures and a phase change material layer; the plurality of nanostructures are arranged on the substrate, and the phase change material layer is filled between the plurality of nanostructures; When the zoom parameter is the target focal length, the theoretical phase distribution includes a first theoretical phase distribution, and the theoretical phase distribution when the metalens is zoomed is determined according to the zoom parameter, and the theoretical phase distribution is fitted to obtain a phase coefficient corresponding to a polynomial, including: When the target focal length is within the zoom range of the metalens, obtaining the operating wavelength of the metalens and the maximum aperture of the metalens; The first theoretical phase distribution when the metalens is zoomed to the target focal length is calculated by the following formula: Wherein, φ1(r,λ) represents the first theoretical phase distribution; λ represents the working wavelength of the superlens; f represents the target focal length; r represents the distance from the nanostructure in the superlens to the center of the superlens, and the value range of r is (0, R); R represents the maximum aperture of the superlens; The phase coefficient when the metalens is zoomed to the target focal length is obtained using the following formula; Among them, a m represents the mth phase coefficient among the i phase coefficients when the superlens is zoomed to the target focal length.

3. The method according to claim 2, characterized in that When the zoom parameter is the target focal length of the metalens, the actual phase distribution includes a first actual phase distribution, and the equivalent refractive index includes a first equivalent refractive index; obtaining the actual phase distribution when the metalens is zoomed according to the phase coefficient; and calculating the equivalent refractive index when the metalens is zoomed according to the actual phase distribution, comprising: The first actual phase distribution when the metalens is zoomed to the target focal length is calculated by the following formula: Wherein, φ2(r,λ) represents the first actual phase distribution; The height of the nanostructure in the metalens is obtained, and the first equivalent refractive index when the metalens is zoomed to the target focal length is calculated according to the following formula: φ2(r,λ)=k*neff1*D in, D represents the height of the nanostructure, and neff1 is the first equivalent refractive index.

4. The method according to claim 3, characterized in that The corresponding relationship includes a first corresponding relationship, and the corresponding relationship between the equivalent refractive index and the phase change parameter stored in the zoom database is obtained, and the phase change parameter corresponding to the equivalent refractive index closest to the calculated equivalent refractive index in the corresponding relationship is used to zoom the metalens, including: Acquire a first corresponding relationship, where the first corresponding relationship is: a corresponding relationship between an equivalent refractive index and a first phase change parameter when the superlens is zoomed to each focal length within the zoom range of the superlens; Generate a first metalens phase change instruction using a first phase change parameter corresponding to an equivalent refractive index closest to the first equivalent refractive index in the first corresponding relationship; According to the phase change mode matching the obtained first phase change parameter, the superlens is controlled to execute the first superlens phase change instruction, the phase change state of the phase change material layer in the superlens is changed, the superlens is zoomed, and the focal length of the superlens is adjusted to the target focal length.

5. The method according to claim 1, characterized in that When the zoom parameter is the focus shift distance of the metalens, the theoretical phase distribution includes a second theoretical phase distribution, and the theoretical phase distribution when the metalens is zoomed is determined according to the zoom parameter, and the theoretical phase distribution is fitted to obtain a phase coefficient corresponding to a polynomial, including: When the focus shift distance is within the focus shift distance range, obtaining the distance between the metalens and an initial focal plane of the metalens; Calculating the focal length of the superlens after zooming according to the focus shift distance and the distance between the superlens and the initial focal plane of the superlens; The second theoretical phase distribution of the metalens zoomed according to the focus shift distance is calculated by the following formula: Wherein, φ1(x, y, λ) represents the second theoretical phase distribution; f1 represents the focal length of the superlens after zooming; (x, y) represents the position coordinates of the nanostructure relative to the center of the superlens; f0 represents the distance between the superlens and the initial focal plane of the superlens; d represents the focus shift distance of the superlens; The phase coefficient of the superlens zooming according to the focus shifting distance is obtained using the following formula: Among them, a n represents the nth phase coefficient among the j phase coefficients of the superlens zoomed according to the focus shift distance.

6. The method according to claim 5, characterized in that When the zoom parameter is the focus shift distance of the metalens, the actual phase distribution includes a second actual phase distribution, and the equivalent refractive index includes a second equivalent refractive index; and the actual phase distribution of the metalens when zooming is obtained according to the phase coefficient; Calculating the equivalent refractive index of the metalens when zooming according to the actual phase distribution includes: The second actual phase distribution of the metalens zoomed according to the focus shift distance is calculated by the following formula: Wherein, φ2(x, y, λ) represents the second actual phase distribution; The second equivalent refractive index when the metalens is zoomed according to the focus shift distance is calculated according to the following formula: φ2(x,y,λ)=k*neff2*D Wherein, neff2 is the second equivalent refractive index.

7. The method according to claim 6, characterized in that The corresponding relationship includes a second corresponding relationship, and the corresponding relationship between the equivalent refractive index and the phase change parameter stored in the zoom database is obtained, and the phase change parameter corresponding to the equivalent refractive index closest to the calculated equivalent refractive index in the corresponding relationship is used to zoom the metalens, comprising: Acquire a second corresponding relationship, where the second corresponding relationship is: a corresponding relationship between an equivalent refractive index and a second phase change parameter when the metalens is zoomed at each focus distance within the focus distance range; Generate a second metalens phase change instruction using a second phase change parameter corresponding to an equivalent refractive index closest to the second equivalent refractive index in the second corresponding relationship; According to the phase change mode matching the obtained second phase change parameter, the superlens is controlled to execute the second superlens phase change instruction, the phase change state of the phase change material layer in the superlens is changed, and the superlens is zoomed according to the focus shift distance of the superlens.

8. A zoom device having a zoom system with a super lens, characterized in that: The device comprises: An acquisition module, used for acquiring a zoom instruction, wherein the zoom instruction carries a zoom parameter; A processing module, used to determine the phase coefficient of the metalens when zooming according to the zoom parameter; A zoom module, used for zooming the metalens based on the phase coefficient; Wherein, the zoom parameters include: target focal length or focus shift distance of the metalens; The processing module is used to determine the theoretical phase distribution of the metalens when zooming according to the zoom parameter; Fitting the theoretical phase distribution to obtain a phase coefficient corresponding to the polynomial; The zoom module is used to obtain the actual phase distribution according to the phase coefficient; Calculating the equivalent refractive index of the metalens when zooming according to the actual phase distribution; Obtaining a correspondence between an equivalent refractive index and a phase change parameter stored in a zoom database, and zooming the metalens using a phase change parameter corresponding to an equivalent refractive index that is closest to the calculated equivalent refractive index in the correspondence; Wherein, calculating the equivalent refractive index of the superlens when zooming according to the actual phase distribution includes: The equivalent refractive index is calculated according to the following formula: φ(t,λ)=k*neff*D Wherein, φ(t,λ) represents the actual phase distribution; t represents the position parameter of the nanostructure in the superlens relative to the center of the superlens; λ represents the operating wavelength of the superlens; neff is the equivalent refractive index; D represents the height of the nanostructure.

9. The device according to claim 8, characterized in that The super lens comprises: a substrate, a plurality of nanostructures and a phase change material layer; the plurality of nanostructures are arranged on the substrate, and the phase change material layer is filled between the plurality of nanostructures; When the zoom parameter is the target focal length, the theoretical phase distribution includes a first theoretical phase distribution, and the processing module is specifically configured to: When the target focal length is within the zoom range of the metalens, obtaining the operating wavelength of the metalens and the maximum aperture of the metalens; The first theoretical phase distribution when the metalens is zoomed to the target focal length is calculated by the following formula: Wherein, φ1(r,λ) represents the first theoretical phase distribution; λ represents the working wavelength of the superlens; f represents the target focal length; r represents the distance from the nanostructure in the superlens to the center of the superlens, and the value range of r is (0, R); R represents the maximum aperture of the superlens; The phase coefficient when the metalens is zoomed to the target focal length is obtained using the following formula; Among them, a m represents the mth phase coefficient among the i phase coefficients when the superlens is zoomed to the target focal length.

10. The device according to claim 9, characterized in that When the zoom parameter is the target focal length of the metalens, the actual phase distribution includes a first actual phase distribution, and the equivalent refractive index includes a first equivalent refractive index; and the zoom module is specifically configured to: The first actual phase distribution when the metalens is zoomed to the target focal length is calculated by the following formula: Wherein, φ2(r,λ) represents the first actual phase distribution; The height of the nanostructure in the metalens is obtained, and the first equivalent refractive index when the metalens is zoomed to the target focal length is calculated according to the following formula: φ2(r,λ)=k*neff1*D in, D represents the height of the nanostructure, and neff1 is the first equivalent refractive index.

11. The device according to claim 10, characterized in that The corresponding relationship includes a first corresponding relationship, and the zoom module is used to obtain the corresponding relationship between the equivalent refractive index and the phase change parameter stored in the zoom database, and use the phase change parameter corresponding to the equivalent refractive index closest to the calculated equivalent refractive index in the corresponding relationship to zoom the metalens, including: Acquire a first corresponding relationship, where the first corresponding relationship is: a corresponding relationship between an equivalent refractive index and a first phase change parameter when the superlens is zoomed to each focal length within the zoom range of the superlens; Generate a first metalens phase change instruction using a first phase change parameter corresponding to an equivalent refractive index closest to the first equivalent refractive index in the first corresponding relationship; According to the phase change mode matching the obtained first phase change parameter, the superlens is controlled to execute the first superlens phase change instruction, the phase change state of the phase change material layer in the superlens is changed, the superlens is zoomed, and the focal length of the superlens is adjusted to the target focal length.

12. The device according to claim 8, characterized in that When the zoom parameter is the focus shift distance of the metalens, the theoretical phase distribution includes a second theoretical phase distribution, and the processing module is specifically configured to: When the focus shift distance is within the focus shift distance range, obtaining the distance between the metalens and an initial focal plane of the metalens; Calculating the focal length of the superlens after zooming according to the focus shift distance and the distance between the superlens and the initial focal plane of the superlens; The second theoretical phase distribution of the metalens zoomed according to the focus shift distance is calculated by the following formula: Wherein, φ1(x, y, λ) represents the second theoretical phase distribution; f1 represents the focal length of the superlens after zooming; (x, y) represents the position coordinates of the nanostructure relative to the center of the superlens; f0 represents the distance between the superlens and the initial focal plane of the superlens; d represents the focus shift distance of the superlens; The phase coefficient of the superlens zooming according to the focus shifting distance is obtained using the following formula: Among them, a n represents the nth phase coefficient among the j phase coefficients of the superlens zoomed according to the focus shift distance.

13. The device according to claim 12, characterized in that When the zoom parameter is the focus shift distance of the metalens, the actual phase distribution includes a second actual phase distribution, and the equivalent refractive index includes a second equivalent refractive index; the zoom module is specifically used for: The second actual phase distribution of the metalens zoomed according to the focus shift distance is calculated by the following formula: Wherein, φ2(x, y, λ) represents the second actual phase distribution; The second equivalent refractive index when the metalens is zoomed according to the focus shift distance is calculated according to the following formula: φ2(x,y,λ)=k*neff2*D Wherein, neff2 is the second equivalent refractive index.

14. The device according to claim 13, characterized in that The corresponding relationship includes a second corresponding relationship, and the zoom module is used to obtain the corresponding relationship in the zoom database, and use the phase change parameter corresponding to the equivalent refractive index closest to the equivalent refractive index in the corresponding relationship to zoom the metalens, including: Acquire a second corresponding relationship, where the second corresponding relationship is: a corresponding relationship between an equivalent refractive index and a second phase change parameter when the metalens is zoomed at each focus distance within the focus distance range; Generate a second metalens phase change instruction using a second phase change parameter corresponding to an equivalent refractive index closest to the second equivalent refractive index in the second corresponding relationship; According to the phase change mode matching the obtained second phase change parameter, the superlens is controlled to execute the second superlens phase change instruction, the phase change state of the phase change material layer in the superlens is changed, and the superlens is zoomed according to the focus shift distance of the superlens.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processing unit, the steps of the method described in any one of claims 1 to 7 are executed.

16. An electronic device, characterized in that: The electronic device comprises a memory, a processing unit and one or more programs, wherein the one or more programs are stored in the memory and are configured so that the processing unit executes the steps of the method according to any one of claims 1 to 7.

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