CN113740939B - Optical device with disordered functional unit configuration - Google Patents
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- CN113740939B CN113740939B CN202111128857.8A CN202111128857A CN113740939B CN 113740939 B CN113740939 B CN 113740939B CN 202111128857 A CN202111128857 A CN 202111128857A CN 113740939 B CN113740939 B CN 113740939B
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Abstract
The invention provides an optical device with disordered functional unit configuration, which comprises a substrate and a non-periodic micro-nano structure array of disordered functional units, wherein the substrate and the non-periodic micro-nano structure array of disordered functional units are sequentially arranged along the propagation direction of electromagnetic waves, the surface of the substrate is a plane or a curved surface, and the non-periodic micro-nano structure array of disordered functional units is a micro-nano structure array formed by non-periodically distributing a plurality of functional units with disordered internal structures on the plane or the curved surface; the internal structure of each functional unit distributed in the optical device is determined according to the phase distribution of the optical device. The optical device takes the disordered structure as the functional unit, on one hand, the strong coupling phenomenon among the functional units based on the regular configuration of homogeneous materials is eliminated, on the other hand, the randomness and the diversity of the disordered structure are utilized, the design freedom degree of the optical device is increased, the parameter space of the functional unit is expanded, and therefore the optical field regulation and control capability and the performance of the optical device are obviously improved.
Description
Technical Field
The application belongs to the field of super-surface optical devices, and particularly relates to an optical device with a disordered functional unit configuration.
Background
The super surface is a micro-nano structure array which is formed by taking an optical scattering structure with characteristic size as a sub-wavelength as a functional element and distributing the functional element on a plane or a curved surface, and the main function of the super surface is to regulate and control the phase, amplitude, polarization and frequency of incident light so as to correspondingly modulate the wave front of a light beam according to the distribution of the functional element. Therefore, compared with the traditional optical device, the super-surface optical device has flexible light modulation and control characteristics and shows remarkable advantages in the fields of optics and electromagnetism.
At present, the super-surface optical devices studied at home and abroad mostly adopt heterogeneous materials (i.e. the substrate adopts a low-refractive-index material, and the super-surface dielectric column adopts a high-refractive-index material, such as titanium dioxide grown on a quartz substrate by an atomic layer deposition method or amorphous silicon grown on a quartz substrate by a chemical vapor deposition method, etc.), so as to reduce the coupling effect between adjacent functional elements in the super-surface. The heterogeneous material increases the process cost, for example, the heterogeneous material grown by the additive process such as the atomic layer deposition method and the chemical vapor deposition method has slow processing, high cost, low yield, and is far less than the homogeneous material with mature process. In addition, due to the requirement of the structural reliability of the optical device, it is more preferable to use more stable and reliable homogeneous materials (such as quartz plate, silicon wafer, germanium wafer, etc.) for the fabrication of the super-surface optical device.
However, the design method of heterogeneous super-surface optics cannot be directly applied to homogeneous super-surface optics because: at present, the study of heterogeneous super-surface optical devices is commonly carried out by regular configurations such as cylinders, square columns, rectangular columns and the like, if functional elements of the super-surface based on homogeneous materials also adopt the structure, strong coupling exists between adjacent functional elements, so that the precise regulation and control of the super-surface on wavefront are damaged, and the performance of the super-surface optical device is influenced.
Disclosure of Invention
The invention aims to provide an optical device with disordered functional unit configuration, so as to eliminate the phenomenon of strong coupling between functional units based on the regular configuration of homogeneous materials.
In order to achieve the purpose, the invention provides an optical device with a disordered functional unit configuration, which comprises a substrate and a non-periodic micro-nano structure array of the disordered functional unit, wherein the substrate and the non-periodic micro-nano structure array of the disordered functional unit are sequentially arranged along the propagation direction of electromagnetic waves, the surface of the substrate is a plane or a curved surface, and the non-periodic micro-nano structure array of the disordered functional unit is a micro-nano structure array formed by non-periodically distributing a plurality of functional units with disordered internal structures on the plane or the curved surface; the internal structure of each functional unit distributed in the optical device is determined according to the phase distribution of the optical device.
The functional primitives include: the internal structure of the disordered two-dimensional code functional element is formed by disordered distribution of regular columnar structures with different numbers in a functional element on the super surface; and/or disorder perturbation type functional elements, wherein the internal structure of the disorder perturbation type functional elements consists of a regular structure and small-size disorder structures which are adjacent to the regular structure, have unequal number, unequal size and random shapes, and the ratio of the size of the small-size disorder structures to the size of the regular structure is in the range of 1/100 to 1/5.
For the disordered two-dimensional code functional unit, the ratio of the size of the columnar structure to the boundary size of the functional unit is in the range of 1/30 to 1/3, and the columnar structure is a cylinder, an elliptic cylinder, a square column or a rectangular column.
For the disordered perturbation type functional unit, the ratio of the size of the regular structure to the boundary size of the functional unit is in the range of 0.1 to 0.9, the regular structure is a columnar structure, a conical structure or a table-shaped structure, and the columnar structure is a cylinder, an elliptic column, a square column or a rectangular column.
The boundary shape of the functional primitive is a regular square, triangle, hexagon or a closed area formed by other curves; the functional elements have boundary dimensions of between λ/2 and 2 λ, where λ is the operating wavelength of the optical device.
The distances between the centers of adjacent functional elements are all the same, all different, or partially the same and partially different.
The substrate comprises a dielectric layer, and the functional elements and the dielectric layer of the substrate are made of the same material.
The materials of the inner part of the functional unit and the dielectric layer of the substrate comprise at least one of quartz, silicon, germanium, gallium nitride, silicon nitride, aluminum oxide, zinc selenide, zinc sulfide, calcium fluoride, magnesium fluoride, barium fluoride, lithium fluoride, gallium arsenide, high-resistivity silicon, polymethylpentene, polyethylene and polytetrafluoroethylene.
The substrate also comprises a metal reflecting layer, or the material of the functional unit has polarization selectivity.
The internal structure of each functional unit distributed in the optical device is determined according to the phase distribution of the optical device, and the method specifically comprises the following steps:
s1: establishing a plurality of different internal structures of the functional elements;
s2: obtaining the amplitudes and phases of various functional elements with different internal structures through electromagnetic simulation, screening out a plurality of functional elements with basically the same amplitudes, and taking the one-to-one correspondence relationship between the internal structures and the phases as a parameter space;
s3: matching the phase of each functional unit in the position according to the phase distribution formula of the optical device to a parameter space, thereby determining the internal structure of each functional unit in the position of each functional unit; wherein the phase distribution of the optical device is determined according to the functional requirements of the optical device.
The optical device with the disordered functional unit configuration takes the disordered structure as the functional unit, on one hand, the strong coupling phenomenon between the functional units based on the regular configuration of homogeneous materials is eliminated (the interaction between the functional units of the disordered structure is disordered and random, and the interaction between the functional units can be counteracted due to the randomness, so that the strong coupling is avoided), on the other hand, the randomness and the diversity of the disordered structure are utilized, the design freedom degree of the optical device is increased, the parameter space of the functional units is expanded, and the optical field regulation and control capability and the performance of the optical device are obviously improved.
Drawings
Fig. 1 is a schematic diagram of an optical path of an electromagnetic wave through an optical device in a disordered functional cell configuration according to one embodiment of the present invention.
FIG. 2 is a schematic three-dimensional structure of an optical device in disordered functional unit configuration according to one embodiment of the present invention.
FIG. 3 is a schematic top view of the overall configuration of an out-of-order functional cell in an embodiment of the present invention.
Fig. 4A to 4G are field distribution diagrams of an electromagnetic wave in the direction of propagation along the optical axis after being focused by an optical device in the configuration of the disordered functional unit in the embodiment of the present invention, wherein fig. 4A to 4G respectively show the cases of different wavelengths.
Fig. 5A to 5G are field distribution diagrams of an electromagnetic wave focused by an optical device in a disordered functional unit configuration in an embodiment of the present invention on a focal plane, wherein fig. 5A to 5G respectively show the situation at different wavelengths.
Detailed Description
An embodiment of the present invention is given below with reference to the accompanying drawings, and the scheme of the present invention is explained and explained in further detail.
The invention provides an optical device with a disordered functional unit configuration, which is used for optical field regulation and control and can be suitable for various wave bands from ultraviolet, visible light, near infrared to short wave infrared, medium wave infrared, long wave infrared, terahertz and the like. In particular, the optics of the disordered functional cell configuration include, and are not limited to, imaging lenses, mirrors, beam deflectors, polarizers, beam splitters, light absorbers, and the like, i.e., the functions of the optics of the disordered functional cell configuration include, and are not limited to, transmission imaging, reflection imaging, beam deflection, light splitting, and the like.
An optical device of disordered functional unit configuration according to one embodiment of the present invention will be described below by taking as an example that the optical device of disordered functional unit configuration is an imaging lens.
As shown in fig. 1, the optical device with disordered functional unit configuration comprises a substrate 1 and a non-periodic micro-nano structure array 2 of disordered functional units, which are sequentially arranged along the electromagnetic wave propagation direction.
As shown in fig. 1, since the optical device in the functional element configuration is an imaging lens and has a transmission imaging function in the present embodiment, an electromagnetic wave sequentially passing through the substrate 1 and the aperiodic micro-nano structure array 2 of the disordered functional element along the propagation direction of the electromagnetic wave is focused on a point on a focal plane 3, and the focal plane 3 is located downstream of the aperiodic micro-nano structure array 2 of the disordered functional element along the propagation direction of the electromagnetic wave.
Wherein the surface of the substrate 1 may be a plane or a curved surface. The aperiodic micro-nano structure array 2 of disordered functional primitives refers to a micro-nano structure array formed by non-periodically distributing a plurality of functional primitives with disordered internal structures on a plane or a curved surface. The internal structure is also the configuration of the functional unit.
In the present embodiment, the substrate 1 includes only a dielectric layer, so that electromagnetic waves can penetrate the substrate 1.
It should be noted that, in other embodiments, for various other types of optical devices (e.g., mirror, beam deflector, polarizer, beam splitter, optical absorber) with disordered functional unit configurations, such as mirror, beam deflector, polarizer, beam splitter, optical absorber, the substrate and the aperiodic micro-nano structure array of disordered functional units are included, except that other components may be further included, or the nature and structure of the device are further limited. For example, for a reflector, the optical device with the disordered functional unit configuration still comprises a substrate and a non-periodic micro-nano structure array of the disordered functional unit, wherein the substrate comprises a dielectric layer and a metal reflecting layer for reflection; for example, for a polarizer, the optical device with the functional unit configuration still comprises a substrate and a non-periodic micro-nano structure array of disordered functional units, wherein the material of the functional units needs to have polarization selectivity.
Internal structure of single functional unit
Each functional unit comprises an internal structure and a blank area (namely an area only containing air) positioned at the periphery of the internal structure, the internal structure and the blank area jointly form the whole of the functional unit, and the boundary of the functional unit is the boundary of the blank area. In the prior art, taking the prior patent with application number 202110374283.6 relating to super-surface lenses as an example, the internal structure of each functional unit is composed of a cylinder and the air surrounding the cylinder. Therefore, thousands to tens of thousands of functional elements are arranged on a plane to form a micro-nano structure array, namely the optical device of the super-surface lens is formed.
In the invention, the internal structure of each functional unit is disordered (that is, the internal structures are arranged in disorder, so that the internal structures of different functional units are different from each other), the internal structure is no longer a regular cylinder, but the internal structure of each functional unit can be formed by combining regular columnar structures which are not equal in number and are distributed in disorder, or can be formed by regular structures (such as cylinders) and small-size disordered structures which are not equal in number, different in size and random in shape and are adjacent to the regular structures.
Specifically, the functional primitives include, and are not limited to:
(1) An exemplary overall structure of a functional primitive of an unordered two-dimensional code is shown in fig. 3, the functional primitive includes an internal structure of the functional primitive and a blank area located at an edge of the internal structure, the internal structure of the functional primitive is formed by disordered distribution of regular columnar structures (including but not limited to a cylinder, an elliptic cylinder, a square column and a rectangular column) with different numbers in one functional primitive on a super surface, and the disordered two-dimensional code functional primitive is called as the disordered two-dimensional code functional primitive because the number and the distribution of the columnar structures in the functional primitive have disorder and are similar to a two-dimensional code in shape.
The size of the columnar structure is the boundary size of the functional unit divided by several times or several tens times, the boundary size of the functional unit is P, the size a of the columnar structure is in the range of P/30 to P/3, and the ratio of the size a of the columnar structure to the boundary size P of the functional unit is in the range of 1/30 to 1/3. The sizes, the number and the distribution of the square columns in the functional primitives are changed, and the disordered two-dimension code functional primitives with various different internal structures can be formed.
Taking the shape of the boundary of the functional cell as a square as an example, the size of the boundary of the functional cell is marked as P, the size of the columnar structure is marked as a, the size of the margin area is marked as b, then the overall size of the area where the internal structure of the functional cell is located is P-2b, and the area which can be filled with the columnar structure is split into (P-2 b) 2 /a 2 Small regions, i.e. corresponding randomly generated two-dimensional matrices of 0 and 1 have (P-2 b) 2 /a 2 Elements, then at most 2^ ((P-2 b) 2 /a 2 ) In different configurations, consider 2 10 ＝1024>1000, i.e. (P-2 b) 2 /a 2 >10, i.e. (P-2 b)/a>3.2 (round up to 4), here for example b = a, then P is required>6a. In fact, the ratio of P/a needs to be larger in consideration that not all the generated disordered two-dimensional code configurations meet the process processing requirements, and the edge margin area is not too small to meet the processing requirements.
(2) The disordered perturbation type functional element comprises an internal structure of the functional element and a blank area positioned at the edge of the internal structure, wherein the internal structure of the functional element is composed of a regular structure and small-size disordered structures which are adjacent to the regular structure, have unequal quantity, unequal size and random shapes, and the disordered structure in the functional element is far smaller than the regular structure in size and can be analogized to perturbation, so the disordered perturbation type functional element is called.
Regular structures include, but are not limited to, cylindrical, elliptical, square, rectangular, and the like, columnar structures. In addition, the regular structure can also be a cone-shaped structure or a table-shaped structure, and a columnar structure which is convenient to process is preferred in view of process processing. If the boundary size of the functional unit is P, the size of the regular structure is in the range of 0.1P to 0.9P. The small-size disordered structure can be a columnar structure, a conical structure, a table-shaped structure or a spherical structure, and the small-size disordered structure is preferably a columnar structure which is convenient to process and has the same height as the regular structure (but different cross section shape or size from the regular structure) due to process processing consideration. The size of the small-sized disordered structure is smaller than that of the regular structure, and preferably, the ratio of the size of the small-sized disordered structure to the size of the regular structure is in the range of 1/100 to 1/5.
It should be noted that, the number of the functional primitives is multiple, so that one part of the functional primitives may adopt an unordered two-dimensional code functional primitive, and the other part of the functional primitives may adopt an unordered perturbation type functional primitive.
(II) arrangement mode between different functional units
The arrangement between different functional primitives may be the same or different. The number of functional elements depends on the device size (i.e., the overall size of the micro-nano structure array) and the size of the functional elements, and may be hundreds to tens of millions.
Specifically, the boundary shapes of different functional primitives may be the same or different. The closed area can be regular square, triangle, hexagon and the like, and can also be formed by other curves. The shape of the internal structure of the functional cell is different regardless of whether the boundary shape is the same, because, as described above, the internal structure is composed of columnar structures distributed in disorder in unequal numbers, or is composed of regular structures and small-sized disordered structures with random shapes in unequal numbers, unequal sizes and adjacent thereto. How many functional cells can be adjacent to each functional cell depends on the shape of the boundary of the functional cell, for example, if the shape of the boundary of the functional cell is square or rectangular, there are four nearest neighbors, four next nearest neighbors. For example, if the boundary of the functional element is in the shape of an equilateral triangle, there are three nearest neighbors and six nearest neighbors. For the case that the boundary shape of the functional primitive is a regular shape such as square, rectangle, triangle, hexagon, etc., the boundary is divided by making a perpendicular bisector according to the connecting line of the centers of the adjacent functional primitives; for the case that the boundary shape of the functional primitive is other closed curves, finding the blank area (i.e. the area without the columnar structure) of the adjacent functional primitive edge, and drawing the curve which can separate the blank area in the blank area as the boundary. There is a margin area at the boundary of two adjacent functional units, i.e. the area outside the columnar structure without any columnar structure. The center of the functional primitive is the geometric gravity center of the boundary shape of the functional primitive, for example, the center of the functional primitive in a square or rectangle is the intersection point of two diagonal lines, the center of the functional primitive in a triangle is the intersection point of three central lines, and the centers of the functional primitives are determined by other various closed curves according to a corresponding method for solving the geometric gravity center mathematically.
The boundary sizes of different functional primitives may be the same or different. For the case where the boundary sizes are the same, the arrangement periods of the functional cells (i.e., the distances between the centers of adjacent functional cells) are the same, except that the specific parameters (e.g., the silicon pillar diameters) of the internal structures within each functional cell are different; in the case where the boundaries are different in size, that is, in the case where the distance between the centers of adjacent functional cells is not ordered as described later. In this embodiment, the boundary dimensions of the functional element are in the wavelength range, preferably λ/2 to 2 λ, where λ is the operating wavelength of the optical device.
For the aperiodic micro-nano structure array of the disordered functional units, not only the internal structure in each functional unit is disordered, but also the distance between the centers of the adjacent functional units is disordered. Specifically, the distances between the centers of adjacent functional primitives are set out of order, which means that the distances between the centers of adjacent functional primitives may be all the same, may be all different, or may be partially the same and partially different. The case where the distances between the centers of adjacent functional primitives are all the same is one of the special cases. The boundary size P of a functional cell is equal to the distance d between the centers of adjacent functional cells for the case where the distances d between the centers of adjacent functional cells are the same, and the boundary size P of a functional cell is unequal to the distance d between the centers of adjacent functional cells for the case where the distances d between the centers of adjacent functional cells are different.
Taking an embodiment of the present invention as an example, a schematic three-dimensional structure of an optical device in a functional cell configuration in which the shape of its boundary is the same and the size of its boundary is the same is shown in fig. 2. According to the functional requirements of the optical device, the internal structure, the size and the arrangement mode of the functional units are correspondingly changed, and the optical devices with various different configurations can be formed.
The number of the columnar structures in each functional cell depends on the shape and size of the boundary of the functional cell, the shape and size of the columnar structures, and the duty ratio, for example, the size of the boundary of the functional cell is P, the size of the columnar structures is D, and if the shape of the functional cell is square, the number of the columnar structures is at most (P/D) 2 The number of the functional elements is at least 1, and if the shape of the functional elements is rectangular, triangular, hexagonal or other shapes, the number maximum calculation formula is also different correspondingly. Preferably, the number of columnar structures in each functional cell may vary from a few to hundreds.
Material for optical device
The optical device with disordered functional unit configuration has the same material of the functional unit and the dielectric layer of the substrate 1. The material is a material selected for high transmission in the operating band of the optical device, including but not limited to quartz (SiO) 2 ) Silicon (Si), germanium (Ge), gallium nitride (GaN), silicon nitride (Si) 3 N 4 ) Alumina (Al) 2 O 3 ) Zinc selenide (ZnSe), zinc sulfide (ZnS), calcium fluoride (CaF) 2 ) Magnesium fluoride (MgF) 2 ) Barium fluoride (BaF) 2 ) Lithium fluoride (LiF), gallium arsenide (GaAs), high resistivity silicon (HRFZ-Si), polymethylpentene (TPX), polyethylene (PE), and Polytetrafluoroethylene (PTFE).
The functions of transmission imaging, reflection imaging, beam deflection, light splitting and the like all require that materials with high transmittance in a working waveband are selected. For example, quartz, alumina, calcium fluoride, magnesium fluoride or lithium fluoride can be selected for the ultraviolet band; the visible light wave band can be selected from quartz, gallium nitride, silicon nitride, aluminum oxide, zinc sulfide, calcium fluoride, magnesium fluoride, barium fluoride or lithium fluoride; the near infrared to short wave infrared band can be selected from quartz, silicon, aluminum oxide, zinc selenide, zinc sulfide, calcium fluoride, magnesium fluoride, barium fluoride or lithium fluoride; the medium wave infrared can be selected from silicon, germanium, aluminum oxide, zinc selenide, zinc sulfide, calcium fluoride, magnesium fluoride, barium fluoride, lithium fluoride or gallium arsenide; the long-wave infrared can be selected from silicon, germanium, zinc selenide, zinc sulfide, calcium fluoride, magnesium fluoride, barium fluoride or gallium arsenide; the terahertz wave band can be polymethyl pentene, polyethylene, polytetrafluoroethylene or high-resistance silicon.
Principle of (IV) optical device
The internal structure of each functional unit is a disordered structure, so that the internal structures of different functional units are different from each other, and the electromagnetic waves can obtain different complex amplitudes after passing through each functional unit.
In the present invention, the internal structure of each functional unit distributed in the optical device is determined according to the phase distribution of the optical device, and the phase distribution of the optical device is determined according to the functional requirements of the optical device (such as transmission imaging, reflection imaging, beam deflection, beam splitting, etc.).
The internal structure of each functional unit distributed in the optical device is originally determined according to the complex amplitude distribution of the optical device, and the relationship among the complex amplitude, the amplitude and the phase is as follows:
wherein A% is the complex amplitude of the optical device, A is the amplitude of the optical device,
is the phase of the optics.
Since the optical device requires the same amplitude of each functional element due to the requirement of superposition of electromagnetic wave interference, the internal structure of each functional element distributed in the optical device can be determined by determining the phase distribution of the optical device (instead of determining the complex amplitude distribution of the optical device originally).
For an optical device functioning as transmission imaging, the phase distribution formula is:
where λ is the operating wavelength, f is the focal length, and r is the distance between a location on the optical device and the center of the optical device.
For an optical device that functions as a reflective imaging, the phase distribution formula is:
where λ is the operating wavelength, f is the focal length, and r is the distance between a location on the surface of the optical device and the center of the optical device.
The phase distribution formulas of transmission imaging and reflection imaging are not different, the two optical devices are different in design in that the disordered functional elements of the transmission imaging optical device and the dielectric layer of the substrate are made of materials with high transmittance in the working waveband, and the phase of the transmission imaging is the phase of the electromagnetic waves after being transmitted by the disordered functional elements and the substrate; the optical device for reflection imaging comprises a disordered functional element made of a material with high transmittance in a working waveband, a dielectric layer of a substrate and a metal reflecting layer of the substrate, wherein the phase of reflection imaging is the phase of electromagnetic waves after passing through the disordered functional element and the dielectric layer, reaching the metal reflecting layer, being reflected and then passing through the dielectric layer and the disordered functional element.
For an optical device that functions as a beam deflection, the phase distribution equation is:
the phase distribution is given by
Wherein λ is the operating wavelength, θ is the deflection angle, and r is the distance between a position on the optical device and the center of the optical device.
The working principle of light splitting is to make the wavelength be lambda 1 Is deflected to an angle theta 1 At a wavelength of λ 2 Is deflected to an angle theta 2 Therefore, the spatial separation of the electromagnetic waves with different wavelengths is realized, and therefore, the phase distribution formula of the light splitting is (namely, the phases simultaneously satisfy the following two formulas):
wherein λ 1 And λ 2 At the operating wavelength, θ 1 And theta 2 And r is the distance between a position on the optical device and the center of the optical device.
Wherein the internal structure of the single functional unit is distributed according to the phase of the optical device at the position thereof, so that the internal structure of each functional unit distributed in the optical device is determined according to the phase distribution of the optical device.
The internal structure of each functional unit distributed in the optical device is determined according to the phase distribution of the optical device, and the method specifically comprises the following steps:
step S1: establishing a plurality of different internal structures of the functional elements;
among them, the built functional cells of various internal structures need to satisfy the requirements of the boundary size of the functional cell and the size of the internal structure described above.
The different internal structures of the functional primitive are represented by different parameter sets, for example, for the unordered two-dimensional code functional primitive, it can be represented as a plurality of parameters whose number is the total number of possible positions of the columnar structure, and each parameter is respectively represented by 0 and 1 to indicate whether the columnar structure exists at the position.
Step S2: obtaining the amplitudes and phases of various functional elements with different internal structures through electromagnetic simulation, screening out a plurality of functional elements with basically the same amplitudes, and taking the one-to-one correspondence relationship between the internal structures and the phases as a parameter space;
and step S3: according to the phase distribution formula of the optical device, the phase of the position of each functional unit is matched to the parameter space, so that the internal structure of the functional unit of the position of each functional unit is determined.
As above, since amplitude coincidence is defined, the complex amplitude is not considered here, but the phase. In step S3, the position coordinates of the center of each functional unit in the optical device are determined according to the distance between the centers of adjacent functional units, that is, the distance r from a certain position on the optical device where the center of each functional unit is located to the center of the optical device can be determined, r is substituted into the phase distribution formula, the phase of the required phase distribution formula at the position of each functional unit can be determined, and the configuration parameters of the functional unit at the position can be determined by matching the phase distribution formula in the parameter space of the functional unit.
Therefore, the optical device with the disordered functional unit structure can be suitable for various wave bands from ultraviolet, visible light, near infrared to short wave infrared, medium wave infrared, long wave infrared, terahertz and the like. The size of the functional elements needs to be adjusted accordingly in different wavelength bands, and as mentioned above, the boundary size P of the functional elements is in the range of λ/2 to 2 λ, where λ is the operating wavelength, and the boundary size P of the functional elements changes accordingly as the applicable wavelength λ changes. Correspondingly, as the boundary size P of the functional primitive changes, the size of the columnar structure forming the disordered two-dimensional code functional primitive also changes correspondingly, and as mentioned above, the size of the columnar structure ranges from P/30 to P/3; the sizes of the regular structure and the small-size disordered structure which form the disordered perturbation type functional unit are correspondingly changed, as mentioned above, the size of the regular structure is in the range of 0.1P to 0.9P, and the ratio of the size of the small-size disordered structure to the size of the regular structure is in the range of 1/100 to 1/5.
The experimental results are as follows:
the internal structure and effect of the functional unit of the optical device with disordered functional unit configuration in the middle infrared band are explained as an example.
The optical device with the disordered functional unit configuration in the embodiment of the invention is an optical imaging lens based on the disordered two-dimensional code functional unit, the function of the optical imaging lens is transmission imaging, the diameter of the optical imaging lens is 100 micrometers, the focal length of the optical imaging lens is 200 micrometers, the working waveband of the optical imaging lens is 4.0-4.6 micrometers of a medium-wave infrared waveband, the boundary size P of the functional unit is 2.6 micrometers, the height H of the disordered two-dimensional code structure of the optical imaging lens is 3 micrometers, and the optical imaging lens is made of silicon with high transmittance in medium-wave infrared. The overall structure schematic diagram of the optical device with the disordered functional unit configuration is shown in fig. 1 and 2, and the configuration schematic diagram of the disordered two-dimensional code functional unit is shown in fig. 3.
The design steps of the optical device with the disordered functional unit configuration are as follows: firstly, randomly generating a two-dimensional matrix consisting of 0 and 1 corresponding to structural parameters in disordered two-dimensional code functional primitives, wherein 1 represents a columnar structure, and 0 represents air. And then, calculating the functional elements with different structural parameters by adopting an electromagnetic simulation means based on a finite difference time domain algorithm to obtain the phase and amplitude corresponding to each structural parameter. Therefore, a parameter space containing 1000 groups of disordered two-dimensional code functional primitives with different configurations is established based on an electromagnetic simulation means of a finite difference time domain algorithm, namely, the one-to-one corresponding relation between the phase and amplitude of electromagnetic waves with different wavelengths in a 4.0-4.6 mu m wave band after passing through the 1000 groups of disordered two-dimensional code functional primitives and the structural parameters is established. The phase profile of the optics is then determined from the transmission imaging requirements. And finally, matching the phase distribution with the parameter space of the disordered two-dimensional code functional elements, and further determining the structural parameters of each disordered two-dimensional code functional element distributed on the optical device.
And performing simulation verification on the broadband imaging capability of the optical device with the disordered functional unit configuration. After the electromagnetic wave with the wavelength of 4.0-4.6 μm is focused by the optical device with disordered functional unit configuration, the field distribution pattern along the optical axis propagation direction is shown in fig. 4A-4G, and the field distribution pattern on the designed focal plane with the focal length of 200 μm is shown in fig. 5A-5G. Wherein, FIGS. 4A-4G show the cases of different wavelengths, respectively, and FIGS. 5A-5G show the cases of different wavelengths, respectively
The above embodiments are merely preferred embodiments of the present invention, which are not intended to limit the scope of the present invention, and various changes may be made in the above embodiments of the present invention. All simple and equivalent changes and modifications made according to the claims and the content of the specification of the present application fall within the scope of the claims of the present patent application. The invention has not been described in detail in order to practice the invention.
Claims (9)
1. An optical device with disordered functional unit configuration is characterized by comprising a substrate and a non-periodic micro-nano structure array of disordered functional units, wherein the substrate and the non-periodic micro-nano structure array of disordered functional units are sequentially arranged along the propagation direction of electromagnetic waves, the surface of the substrate is a plane or a curved surface, and the non-periodic micro-nano structure array of disordered functional units is a micro-nano structure array formed by non-periodically distributing a plurality of functional units with disordered internal structures on the plane or the curved surface; the internal structure of each functional unit distributed in the optical device is determined according to the phase distribution of the optical device;
the functional primitives include:
the internal structure of the disordered two-dimensional code functional element is formed by disordered distribution of regular columnar structures with different numbers in a functional element on the super surface; and/or
The disordered perturbation type functional primitive comprises a regular structure and small-size disordered structures which are adjacent to the regular structure in unequal number, unequal size and random shapes, wherein the ratio of the size of the small-size disordered structures to the size of the regular structure is in the range of 1/100 to 1/5;
the boundary size of the functional unit is lambda/2-2 lambda, wherein lambda is the working wavelength of the optical device; the amplitudes of the multiple functional elements are basically the same and have different internal structures, and the functional element of each internal structure corresponds to one phase in the working waveband; the interaction among various functional primitives is disordered and random, and the interaction among the functional primitives can be offset due to the randomness, so that strong coupling is avoided.
2. An optical device having a disordered functional cell configuration as claimed in claim 1, wherein for a disordered two-dimensional code functional cell, the ratio of the dimensions of the columnar structures to the dimensions of the boundaries of the functional cell is in the range 1/30 to 1/3, and the columnar structures are cylindrical, elliptical, square or rectangular columns.
3. An optical device having a disordered functional cell configuration as claimed in claim 1, wherein for a disordered perturbing functional cell the ratio of the size of the regular structure to the size of the boundary of the functional cell is in the range 0.1 to 0.9, the regular structure is a columnar structure, a pyramidal structure or a mesa structure, and the columnar structure is a cylinder, an elliptic cylinder, a square cylinder or a rectangular cylinder.
4. An optical device of disordered functional cell configuration as claimed in claim 1 wherein the boundary shapes of the functional cells are closed regions of regular squares, triangles, hexagons or other curved lines.
5. An optical device having a chaotic functional unit configuration according to claim 1, wherein distances between centers of adjacent functional units are all the same, all different, or a portion of the same portion different.
6. An optical device of disordered functional unit configuration as claimed in claim 1 wherein the substrate includes a dielectric layer, the material of the dielectric layers of the functional units and the substrate being the same.
7. An optical device in a disordered functional cell configuration as claimed in claim 6 wherein the materials of the functional cells and dielectric layers of the substrate include at least one of quartz, silicon, germanium, gallium nitride, silicon nitride, aluminum oxide, zinc selenide, zinc sulfide, calcium fluoride, magnesium fluoride, barium fluoride, lithium fluoride, gallium arsenide, high resistivity silicon, polymethylpentene, polyethylene and polytetrafluoroethylene.
8. An optical device of disordered functional element configuration as claimed in claim 6 wherein said substrate further comprises a metallic reflective layer or the material of the functional elements is polarization selective.
9. An optical device having a disordered functional unit configuration according to claim 1, wherein the internal structure of each functional unit distributed in the optical device is determined according to the phase distribution of the optical device, and in particular comprises:
step S1: establishing a plurality of different internal structures of the functional elements;
step S2: obtaining the amplitudes and phases of various functional elements with different internal structures through electromagnetic simulation, screening out a plurality of functional elements with basically the same amplitudes, and taking the one-to-one correspondence relationship between the internal structures and the phases as a parameter space;
and step S3: matching the phase of the position of each functional unit according to the phase distribution formula of the optical device to a parameter space so as to determine the internal structure of the functional unit at the position of each functional unit; wherein the phase distribution of the optical device is determined according to the functional requirements of the optical device.
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| CN107340559A (en) * | 2017-07-04 | 2017-11-10 | 北京理工大学 | High efficiency and broad band circular polarization switching device and method based on super clever surface |
| CN111897036A (en) * | 2020-08-05 | 2020-11-06 | 南开大学 | Achromatic microlens array metasurfaces |
| CN112558293A (en) * | 2020-11-26 | 2021-03-26 | 中国科学院上海微系统与信息技术研究所 | Compact common-path confocal infrared dual-waveband optical system and manufacturing method thereof |
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| CN112558293A (en) * | 2020-11-26 | 2021-03-26 | 中国科学院上海微系统与信息技术研究所 | Compact common-path confocal infrared dual-waveband optical system and manufacturing method thereof |
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