CN216927131U - One-dimensional focusing lens based on super surface - Google Patents
One-dimensional focusing lens based on super surface Download PDFInfo
- Publication number
- CN216927131U CN216927131U CN202220864456.2U CN202220864456U CN216927131U CN 216927131 U CN216927131 U CN 216927131U CN 202220864456 U CN202220864456 U CN 202220864456U CN 216927131 U CN216927131 U CN 216927131U
- Authority
- CN
- China
- Prior art keywords
- degrees
- terahertz
- split ring
- phase
- focusing lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000000758 substrate Substances 0.000 claims abstract description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000002184 metal Substances 0.000 claims abstract description 7
- 229910052751 metal Inorganic materials 0.000 claims abstract description 7
- 239000010453 quartz Substances 0.000 claims description 6
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 4
- 239000010931 gold Substances 0.000 claims description 4
- 229910052737 gold Inorganic materials 0.000 claims description 4
- 238000002834 transmittance Methods 0.000 claims description 2
- 230000008859 change Effects 0.000 abstract description 5
- 230000010354 integration Effects 0.000 abstract description 3
- 238000003384 imaging method Methods 0.000 abstract 1
- 235000012239 silicon dioxide Nutrition 0.000 abstract 1
- 239000000377 silicon dioxide Substances 0.000 abstract 1
- 238000000034 method Methods 0.000 description 6
- 230000010287 polarization Effects 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 230000006854 communication Effects 0.000 description 4
- 230000033228 biological regulation Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000005388 cross polarization Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
Images
Landscapes
- Aerials With Secondary Devices (AREA)
Abstract
The utility model discloses a one-dimensional focusing lens based on a super surface, belongs to the technical field of electromagnetic functional devices, and aims at terahertz waveband dynamic functional devices. The structure of the utility model comprises two layers, wherein the lower layer is a substrate made of silicon dioxide; the upper layer is a phase modulation unit structure of a metal C-shaped open ring, and discontinuous change of phases is realized according to the size of the structure, the opening direction and the size change of the open ring. And the long-distance y-polarized wave beam focusing is realized through the vertical incidence of the x-ray polarized terahertz waves. The terahertz wave band detector works in a terahertz wave band, has the advantages of simple structure, adjustable size and easiness in integration, and has potential application value in a terahertz imaging system.
Description
Technical Field
The utility model belongs to the field of electromagnetic functional devices, and particularly relates to a functional device for a terahertz waveband.
Background
The metamaterial provides an effective way for the control of the terahertz wave beam, but the three-dimensional metamaterial has the defects of large device size, high loss, complex manufacturing and the like. As research progresses, the proposal of the super surface provides a good solution to these difficulties. A meta-surface is a two-dimensional or quasi-two-dimensional form of meta-material that is formed by the arrangement of unit structures in a specific manner on a two-dimensional plane to purposefully select the electromagnetic response. The general metamaterial still depends on the propagation phase of the medium in the metamaterial to realize the control of electromagnetic waves, and the metamaterial mainly utilizes discontinuous abrupt phase of a structural surface to realize the wave front control of transmission or reflection waves. Compared with the metamaterial with a three-dimensional structure, the metamaterial has the advantages that the meta-surface has the capability of regulating and controlling the phase, amplitude and polarization state of electromagnetic waves, and has great flexibility in the aspect of manipulating the wave front of the electromagnetic waves. And the super surface has the advantages of small size, easy integration, low loss, simple preparation process and the like, and gradually becomes a substitute of a super material.
The terahertz modulation technology can be generally divided into 2 methods by differentiating according to modulation modes: one is indirect modulation, namely based on the existing microwave communication technology, a low-frequency microwave band modulation mode is adopted, and the communication process is realized from a frequency doubling technology to a terahertz frequency band; the other type is direct modulation, namely a modulation signal is directly loaded on a terahertz source, so that terahertz wireless communication is realized. From the current research situation, it is generally considered that the direct modulation can fully utilize the characteristics of terahertz waves to realize high-speed large-capacity communication.
The focusing lens is an important component of an optical system, and the traditional method for realizing focusing relies on continuous surface shape change of a device to realize control on the phase of electromagnetic waves, which inevitably brings defects of huge volume, high loss and the like of the device. A super-surface based sub-wavelength focusing lens can effectively solve these problems. Introducing discontinuous phase discontinuities on the super-surface and forming appropriate gradients can transform an incident plane wave into a focusable parabolic wave.
The utility model patent with the publication number of CN201911360016.2, which is applied in 2019, 12 and 25, and the publication number of CN201911360016.2, namely 'super surface lens for a regulation and control device' solves the problems that the lens of the prior art method has spherical aberration and can not be applied to a miniaturized regulation and control device. And the utility model patent of publication No. CN202110107317.5 applied on 26/1/2021 of "a super-surface lens and a spatial light modulator comprising the super-surface lens", can realize dynamic adjustment of spatial direction, optical focal length and numerical aperture of light beams passing through the super-surface lens by electrically adjusting the refractive index of a modulation material forming the super-surface lens. The two methods consume long time, have complex structure and high requirements on instruments and equipment, and have simple structure, convenient integration and smaller preparation difficulty.
SUMMERY OF THE UTILITY MODEL
In view of the above, in order to solve the above problems in the prior art, the present invention provides a one-dimensional focusing lens based on a super surface.
A one-dimensional focusing lens based on a super surface is characterized in that the structure comprises a quartz substrate and a phase modulation unit structure metal C-shaped split ring.
All the phase modulation unit structures are arranged in an array on the quartz substrate according to the phase focusing requirement.
The specific setting method of the C-shaped split ring is as follows: according to the phase focusing formula of the superlens
Where Φ is the phase-jump value, F is the focal length of the lens, R is the radial outward distance of the lens, λ is the wavelength, and k is an arbitrary integer. And selecting a certain point on the substrate as the center of the lens, determining the structure period, and calculating a modulation phase value according to the set focal point and the specific position of the structure on the lens.
The C-shaped split ring of the middle layer is mainly responsible for polarization conversion and phase regulation, namely the phase of the cross polarization transmitted wave can realize complete 2 pi range coverage by changing the size of the opening.
The basic structure of the lens is a C-shaped split ring structure, the C-shaped structure is obliquely arranged at 45 degrees, polarization conversion can be realized, transmitted waves after polarization conversion have wide-range phase change, and the polarization conversion phase can be adjusted by adjusting the size of the opening. The same aperture orientation, the larger the aperture, the larger the modulation phase. According to the principle of geometric phase modulation, the 45-degree inclined C-shaped structure is rotated by 90 degrees under the same opening size, and the phase change can be increased by 180 degrees.
And adjusting the opening size and the opening orientation of the open ring at each specific radial position according to the calculated phase value at each specific radial position to realize the phase modulation of the unit structure at the specific position, and performing simulation modulation and optimization on the structure size according to the phase value. Different unit structures are arranged in the x direction to realize the compensation phase, and the structure sizes in the y direction are the same. In practical applications, the dimensions may vary according to specific requirements.
Drawings
FIG. 1 is a schematic diagram of the overall arrangement of a one-dimensional super-surface lens according to the present invention;
FIG. 2 is a schematic view of a structure of a wiki lens unit of the present invention;
FIG. 3 is a graph of the single layer simulated transmittance and phase results of the present invention;
FIG. 4 is a field-simulated view of the focal point of the lens of the present invention;
Detailed Description
Fig. 1 is a schematic diagram of the overall arrangement design of the one-dimensional lens in this embodiment, and a focus of the superlens is preset according to the focusing characteristics of the superlens, so as to calculate phase modulation required by the terahertz waves from different positions converging at the focus. Accordingly, it is found that in the superlens having a cell period P of 200um, 16 cell structures are required to satisfy the phase modulation in the range of 2 pi when the focal point is set to 10 mm. The phase and opening angle of the 16 structures are shown in table 1.
Table 1: structural modulation phase and opening angle
As shown in FIG. 2, the unit structure of the present invention is schematically illustrated, the period of the quartz substrate in the x and y directions is Px＝P y200 μm, and the thickness h of the quartz substrate 100 μm; the width w of the gold split ring is 12.5 mu m, the outer diameter r of the gold split ring is 80 mu m, and the thickness h-h of the gold split ring1＝0.2μm；
The specific setting method of the C-shaped split ring is as follows according to the phase focusing formula of the superlens
Where phi is the phase jump value, F is the focal length of the lens, and R is the diameter of the lensOutward distance, λ is the wavelength, and k is an arbitrary integer.
And selecting a certain point on the substrate as the center of the lens, determining the structure period, and calculating a modulation phase value according to the set focus and the specific position of the structure on the lens.
The 16 superlens structures have a phase modulation effect, as shown in fig. 3, phases corresponding to 16 units cover a 2 pi phase, and the transmissivity is stabilized at more than 0.3.
The 16 phase modulation units are symmetrically arranged along the central line to form a one-dimensional phase modulation array, and the one-dimensional phase modulation array is copied and arranged to form a 6-row phase arrangement array. The phase modulation units in different rows have the same structure.
And (3) applying CST simulation software to carry out focusing simulation on the structure and simulate the focus state. FIG. 4 is a simulated field pattern of the focal point of the lens of the present invention. In the xoz cutting plane, the terahertz wave beam is converged 8.5mm behind the lens. The electric field pattern at the xoy focal plane at 8.5mm shows that the focused spot at 8.5mm is a cylindrical strip. The beam achieves cylindrical focusing.
Claims (2)
1. The one-dimensional focusing lens based on the super surface is characterized in that the one-dimensional focusing lens structure comprises two layers of a quartz substrate and a metal split ring structure, wherein the metal split ring structure layers are periodically arranged, the period in the x direction and the y direction is P (200 mu m), and the thickness h of the quartz substrate is 100 mu m; the width w of the split ring is 12.5 μm, the outer diameter r of the split ring is 80 μm, and the thickness h of the metal split ring10.2 μm; the metal split ring structure in each period comprises 16 unit structures with different split angles, wherein the split sizes of the unit structures 1-12 with the y-axis included angle of 45 degrees are respectively 10 degrees, 14 degrees, 16 degrees, 22 degrees, 28 degrees, 40 degrees, 49 degrees, 65 degrees, 95 degrees, 126 degrees, 150 degrees and 166 degrees, the unit structures 13-16 with the y-axis included angle of-45 degrees, the split sizes are respectively 46 degrees, 80 degrees, 126 degrees and 156 degrees, thereby meeting the phase gradient requirement of the generalized Snell's law and realizing focusing.
2. The super-surface based one-dimensional focusing lens according to claim 1, wherein the metal split ring is made of gold, the working frequency is 0.65THz, the focal length is 8.5mm, the transmittance is above 0.3, and the focusing light spot at 8.5mm is a cylindrical strip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220864456.2U CN216927131U (en) | 2022-04-14 | 2022-04-14 | One-dimensional focusing lens based on super surface |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220864456.2U CN216927131U (en) | 2022-04-14 | 2022-04-14 | One-dimensional focusing lens based on super surface |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216927131U true CN216927131U (en) | 2022-07-08 |
Family
ID=82236086
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220864456.2U Expired - Fee Related CN216927131U (en) | 2022-04-14 | 2022-04-14 | One-dimensional focusing lens based on super surface |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216927131U (en) |
-
2022
- 2022-04-14 CN CN202220864456.2U patent/CN216927131U/en not_active Expired - Fee Related
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| He et al. | Metasurfaces for terahertz wavefront modulation: a review | |
| US20190137793A1 (en) | Broadband electromagnetic wave phase modulating method and meta surface sub-wavelength structure | |
| CN105629364B (en) | Wavelength selective super-surface device | |
| CN109459805B (en) | Periodic medium grating and terahertz wave focusing lens | |
| CN110133759B (en) | Based on VO2Dynamic terahertz superlens | |
| CN110492250A (en) | A kind of tunable super lens of flexibility based on the super surface of dynamic | |
| CN110391579B (en) | Medium super-surface for generating double terahertz special beams | |
| CN109164574A (en) | The method for realizing wavefront modification based on the conformal super clever surface of medium | |
| CN114397717B (en) | Optical super-surface focused by multi-dimensional double-vector light beam | |
| CN114236817B (en) | Design method of multi-focus super surface based on vortex beam orbital angular momentum | |
| CN113805264B (en) | Broadband achromatic lens and beam deflector based on integrated metasurface | |
| CN214754180U (en) | Transmission type super-surface unit structure and electromagnetic wave amplitude and phase regulation and control device | |
| CN113687458A (en) | Far field multi-channel vortex light beam generator based on nano-sieve super-surface | |
| CN113655547B (en) | Super-lens array with adjustable resolution and implementation method | |
| CN216927131U (en) | One-dimensional focusing lens based on super surface | |
| CN114764156B (en) | Infrared all-dielectric orthogonal cylindrical superlens | |
| CN110568524B (en) | Zero-refractive-index metamaterial with low loss and design method | |
| Yang et al. | Terahertz Bessel Beam Scanning Enabled by Dispersion-Engineered Metasurface | |
| CN114865330A (en) | Terahertz superlens antenna | |
| CN114815277A (en) | Method and device for realizing tight focusing of optical field based on ultrathin planar structure | |
| CN113514905A (en) | Phase modulator of plasma super-surface etalon structure | |
| Zhang et al. | Anisotropic Plasmonic Metasurfaces with Linear Polarization‐Dependent Focusings | |
| CN103292910A (en) | Hartmann wave-front sensor based on metamaterials | |
| CN115347374B (en) | Super-surface unit structure and electromagnetic wave amplitude and phase regulating device | |
| CN214954178U (en) | Phase modulator of plasma super-surface etalon structure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20220708 |