A kind of terahertz wave band Meta Materials wave absorbing device
Technical field
The present invention relates to Terahertz Technology fields, and in particular to a kind of multiband Meta Materials wave absorbing device.
Background technique
In recent years, THz wave generating source and THz wave detection are acknowledged as restricting Terahertz Technology develops two greatly
Critical issue.And the absorption of THz wave and energy capture are basis and the THz wave calibration, tune for realizing Terahertz detection
The key problem of control, conversion and application.Relative to pyroelectricity material and quantum well structure, inhaled using the Terahertz of Meta Materials building
Wave device has the comprehensive advantages such as efficient absorption, highly integrated, flexible design, working and room temperature.Meta Materials are one kind by sub-wavelength people
Work order member arranges constituted artificial electromagnetic material according to certain rule.Since the size of artificial unit is much smaller than operation wavelength,
It therefore is a kind of uniform material of performance for operation wavelength.The advantages of Meta Materials is can be artificial single by adjusting
The structure and size and distribution form of member carry out the electromagnetic attributes of any control material, so that a variety of novel characteristics are obtained, such as negative folding
Penetrate rate, super lens, perfect absorption etc..The wherein perfect wave absorbing device based on Meta Materials, to incidence in a certain frequency point or frequency range
Electromagnetic wave is neither reflected nor is transmitted, and achievees the effect that fully absorb.
Currently, a variety of Meta Materials wave absorbing device structures have been proposed in researcher, but they also face several drawbacks:
One, structural unit bulky dimensions are unfavorable for the miniaturization and integrated development of device;Two, multilayered structure building wave absorbing device can be big
The difficulty and accuracy for increasing device fabrication greatly, are unfavorable for the commercialized development of device;Three, the design master of multiband absorber
It is related to one, two and three frequency band, is seldom related to the research of more multiband wave absorbing device.These problems will seriously restrict super
The development and practical application of material wave absorbing device part.
Summary of the invention
The purpose of the invention is to provide a kind of Meta Materials suction wave with multiple frequency bands for working in terahertz wave band
Device.
The object of the present invention is achieved like this: the Meta Materials wave absorbing device includes the multiple suction wave lists being continuously arranged along plane
Member, it is described it is each inhale wave unit include substrate (1), be located at substrate (1) right above metal layer (2), be located at metal layer (2) just on
Side dielectric layer (3) and be located at dielectric layer (3) right aboveShape structure (4),Shape structure (4) level is attached at Jie
Matter layer (3) surface;The substrate (1), metal layer (2), dielectric layer (3) cross section be rectangle,Shape structure (4)
Arm is parallel to the wherein a line of rectangle;Geometric center, the geometric center of metal layer (2), dielectric layer (3) of the substrate (1)
Geometric center andThe geometric center of shape structure (4) is point-blank.
Preferably, metal layer (2) andShape structure (4) is made of one of gold, silver, copper or aluminium metal material.
Preferably, the thickness d h2 of metal layer (2) is 0.2~1 micron.
Preferably, the material of dielectric layer (3) is polyimides, refractive index 1.8, extinction coefficient 0.06.
Preferably, the thickness t of dielectric layer (3) is 8~16 microns.
Preferably,The thickness d hl of shape structure (4) is 0.2~1 micron.
Preferably,The length L1 of shape structure (4) be 65~75 microns, L2 be 34~54 microns, width W be 6~
15 microns, spacing g is 14~27 microns.
Preferably, substrate (1) is one of High Resistivity Si, GaAs or quartz crystal, thickness d is 50~1000 micro-
Rice plays a part of to support Meta Materials wave absorbing device.
Preferably, a side length px of the cross section rectangle of substrate (1), metal layer (2), dielectric layer (3) is 80~90
Micron, another side length py are 75~85 microns.
Compared with prior art, the present invention its remarkable advantage are as follows:
1. the top layer of Meta Materials wave absorbing device usesShape metal strip, structure is simple, compact, it is easy to accomplish;
2. Meta Materials wave absorbing device proposed by the present invention can realize four absorptions in the frequency range of 0.5~3.8THz
Peak, and all with the absorptivity of almost Perfect;
3. Meta Materials wave absorbing device structure material therefor proposed by the present invention is all conventional material, it is easy to accomplish.
Detailed description of the invention
Fig. 1: three dimensional structure diagram of the invention.
Fig. 2: Fig. 1 main view.
Fig. 3: Fig. 1 bottom view.
Fig. 4: the reflectance map that Meta Materials wave absorbing device of the present invention is emulated using FDTD solutions.
Fig. 5: the normal incident absorption coefficient simulation result diagram of Meta Materials wave absorbing device of the present invention.
Fig. 6: the Meta Materials wave absorbing device of the present invention normal incident absorption coefficient in the lossy and lossless situation of dielectric layer respectively
Simulation result diagram.
Specific embodiment
Present invention is further described in detail with specific embodiment with reference to the accompanying drawing.
As shown in Figure 1, 2, 3, multiband Meta Materials wave absorbing device proposed by the present invention, each suction wave unit includes substrate
(1), it is located at the metal layer (2) right above substrate (1), the dielectric layer (3) being located at right above metal layer (2) and is located at dielectric layer
(3) right aboveShape structure (4),Shape structure (4) level is attached at dielectric layer (3) surface;The substrate (1), gold
Belong to layer (2), dielectric layer (3) cross section be rectangle,The arm of shape structure (4) is parallel to the wherein a line of rectangle;Institute
State the geometric center of substrate (1), the geometric center of metal layer (2), the geometric center of dielectric layer (3) andShape structure (4)
Geometric center is point-blank.
When multiple suction wave units are continuously arranged along plane, substrate (1), metal layer (2), dielectric layer (3) are linked together,
AndIt is then mutually isolated between shape structure (4), so that each suction wave unit is worked independently.
The dielectric layer (3) is lossy polyimides, refractive index 1.8, extinction coefficient 0.06.
The metal layer (2) andShape structure (4) is the same as using one of gold, silver, copper or aluminium, conductivity difference
Are as follows: σGold=4.1 × 107S/m、σSilver=6.1 × 107S/m、σCopper=5.8 × 107S/m and σAluminium=3.8 × 107S/m。
As embodiment, each each dimensional parameters of four-layer structure for inhaling wave unit are as follows: px=85 microns of lattice period, py
=80 microns;The length L1 of shape structure (4) is 71 microns, and L2 is 49 microns, and width W is 9 microns, and spacing g is 27 micro-
Rice;T=13 microns of the thickness of dielectric layer (3);Metal layer (2) andShape structure (4) is same to use copper product, and thickness is all
0.5 micron.
The absorptivity of five frequency band Meta Materials wave absorbing devices described in the present embodiment is defined as A=1-R-T, and R is reflectivity in formula,
T is transmissivity.In order to maximize absorptivity, it is desirable that small as far as possible in entire frequency range internal reflection rate and transmissivity.This
The metal layer (2) of the suction wave unit of invention design is all-metal film, and electromagnetic wave cannot transmit, and transmissivity levels off to zero, therefore inhales
Yield calculation formula can be reduced to A=1-R.
Fig. 4 is the reflectance curve figure emulated using simulation software FDTD Solutions to the present invention.
Fig. 5 is the normal incident absorption coefficient curve of the invention by reflectance curve calculating and plotting.It can from figure
It arrives, there are four apparent absorption peaks in 0.5~3.8THz.This four absorption peaks in 0.88THz, 2.07THz, 2.79THz and
Absorptivity at 3.49THz is respectively 98.59%, 99.94%, 97.71% and 99.78%, and average absorption ratio is up to
99.01%.This illustrates that wave absorbing device proposed by the present invention has reached the absorption of almost Perfect on four frequency points.
Fig. 6 is the Meta Materials wave absorbing device of the present invention normal incident absorption coefficient in the lossy and lossless situation of dielectric layer respectively
Simulation result diagram.As can be seen from the figure when dielectric layer is lossy, the absorptivity of each Frequency point, which is apparently higher than, to be made
With loss-free, to reflect energy that wave absorbing device is absorbed mainly based on dielectric loss, supplemented by the ohmic loss of metal.
The present invention has been explained by the above embodiments, but it is to be understood that, above-described embodiment is only for
Citing and explanation, and be not intended to limit the invention within the scope of described embodiment.Furthermore those skilled in the art can
With understanding, the present invention is not limited to the above embodiments, and introduction according to the present invention can also make more kinds of modifications
And modification, all fall within the scope of the claimed invention for these variants and modifications.Protection scope of the present invention is by attached
Claims and its equivalent scope defined.