CN112034634A - Light-operated terahertz wave modulation device and preparation method thereof - Google Patents
Light-operated terahertz wave modulation device and preparation method thereof Download PDFInfo
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- CN112034634A CN112034634A CN202010779066.0A CN202010779066A CN112034634A CN 112034634 A CN112034634 A CN 112034634A CN 202010779066 A CN202010779066 A CN 202010779066A CN 112034634 A CN112034634 A CN 112034634A
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/0009—Materials therefor
- G02F1/0018—Electro-optical materials
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
- G02F1/0305—Constructional arrangements
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
- G02F1/0305—Constructional arrangements
- G02F1/0316—Electrodes
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- Crystallography & Structural Chemistry (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
Abstract
The invention discloses a light-operated terahertz wave modulation device and a preparation method thereof, wherein the light-operated terahertz wave modulation device comprises: a substrate, a buffer layer, a heterogeneous layer, and a first electrode, the terahertz light-operated modulation device comprises a second electrode and a voltage current source, wherein the voltage current source comprises an anode output end and a cathode output end, the substrate comprises a first surface and a second surface which are opposite, the first electrode is arranged on the first surface, the second electrode is arranged on the second surface, a plurality of rows of transistors are formed on the heterogeneous layer and are mutually connected in series, the ohmic electrodes of the transistors in the plurality of rows are connected with the first electrode, the grids of the transistors in the two adjacent rows are mutually connected, the grids are connected with the second electrode, the ohmic electrodes, the grids, the first electrode and the second electrode form a composite metasurface structure, the grids regulate and control channel conductance between the two adjacent ohmic electrodes in each row, the composite metasurface structure is switched between the resonant metasurface and the grid, and the sensitivity of the terahertz light-operated modulation device is greatly improved.
Description
Technical Field
The invention relates to the technical field of communication, in particular to a light-operated terahertz wave modulation device and a preparation method thereof.
Background
Terahertz waves, also known as far-infrared waves, refer to electromagnetic waves with a frequency in the 0.1-10 terahertz band, which have been evaluated as one of the ten major technologies that change the world in the future, and are the last segment of the electromagnetic band that are not fully recognized and applied by humans. Because of high frequency, short pulse, strong penetrability, small energy and small damage to substances and human bodies, compared with X-rays, the terahertz imaging technology and the spectrum technology have more advantages and have wide prospects in the aspects of space detection, medical imaging, safety inspection, broadband communication and the like. In recent years, a plurality of terahertz modulation devices are proposed, including terahertz modulation devices based on quantum wells, photonic crystals, semiconductor silicon, metamaterials and the like, and the terahertz modulation devices can be classified into amplitude modulation, phase modulation, frequency modulation and the like according to modulation modes, and can be further classified into electric control, magnetic control, light control, piezoelectric and the like according to control modes. The key technical indexes of the terahertz modulation device are as follows: operating center frequency, operating bandwidth, modulation rate and response time, modulation depth, insertion loss, transmission loss, and the like. For example, the light-operated ultrafast terahertz intensity modulation device based on the one-dimensional photonic crystal gallium arsenide defect has the working frequency of 0.6 terahertz, the modulation bandwidth of 16GHz, the modulation depth of 50% and the response time of 130 ps.
The existing materials capable of realizing the modulation function are quite limited in terahertz wave bands, and the materials are usually accompanied with strong terahertz absorption loss. And low-loss terahertz materials such as high-resistance silicon, polymers and the like have long carrier recombination time and small nonlinear coefficient, and the terahertz modulation with high speed and large modulation depth is difficult to realize. Vanadium dioxide (VO2) is a phase-change ferroelectric material that undergoes a dielectric-to-metal transition (temperature: critical temperature 340K, light irradiation: picosecond or femtosecond pulse) under a warm, optical or electric field, and can have a change in conductivity of 3 to 5 orders of magnitude. In the medium phase, the terahertz wave can well transmit the VO2 film, and in the metal phase, the terahertz wave is reflected by the VO2 film. VO2 is a very promising terahertz functional material, especially in the aspect of high-speed modulation devices. How to utilize the existing terahertz functional material to develop a terahertz modulation device with large working bandwidth, high modulation rate and large modulation depth is a key technical problem which needs to be solved urgently in a terahertz communication system.
The existing terahertz modulation device has the following problems: the working frequency is mainly in low-frequency and millimeter wave band; the modulation bandwidth is narrow, generally only several GHz exists, the modulation rate is low, the highest modulation rate is generally in the MHz level, and the advantages of terahertz wave high carrier frequency and large transmission bandwidth cannot be exerted; the modulation depth is small, typically within 50%, and this index drops off rapidly with increasing modulation rate and operating frequency.
Disclosure of Invention
The invention overcomes the defects of the prior art and provides a light-operated terahertz wave modulation device and a preparation method thereof.
In order to achieve the purpose, the invention adopts the technical scheme that: a light-operated terahertz wave modulation device and a preparation method thereof comprise the following steps: the substrate, the buffer layer, the heterogeneous layer, the first electrode, the second electrode and the voltage current source are arranged in sequence.
The voltage current source comprises a positive electrode output end and a negative electrode output end, the substrate comprises a first surface and a second surface which are opposite, the first electrode is arranged on the first surface, the second electrode is arranged on the second surface, a plurality of rows of transistors are formed on the heterogeneous layer and are connected in series, ohmic electrodes of the plurality of rows of transistors are connected with the first electrode, grids of two adjacent rows of transistors are connected with each other, the grids are connected with the second electrode, the ohmic electrodes, the grids, the first electrode and the second electrode form a composite metasurface structure, the grids regulate and control channel conductance between every two adjacent rows of ohmic electrodes, and the composite metasurface structure is switched between the resonant metasurface and the wire grid.
In a preferred embodiment of the present invention, the voltage current source includes a positive output terminal and a negative output terminal, the positive output terminal is electrically connected to the first electrode, and the negative output terminal is electrically connected to the second electrode.
In a preferred embodiment of the present invention, when the substrate enters into avalanche breakdown state, it is converted into a current source, and the voltage current source adjusts the current output to the substrate to adjust the terahertz wave transmittance of the substrate.
In a preferred embodiment of the present invention, the substrate has a thickness of no more than 1500 μm.
In a preferred embodiment of the present invention, the first electrode and the second electrode are strip electrodes or ring electrodes.
In a preferred embodiment of the present invention, the substrate is a quartz crystal with a thickness of 1.5 mm.
A preparation method of a light-operated terahertz wave modulation device comprises the following steps:
s1, pretreating the substrate, and sequentially carrying out ultrasonic cleaning on the substrate, wherein the cleaning temperature of the ultrasonic cleaning is 50 ℃, and the time of each ultrasonic cleaning is 20 minutes;
s2, drying the substrate cleaned by the ultrasonic on a hot table at 100 ℃ for 8-12 minutes to obtain a pretreated substrate;
s3, photoetching is carried out on the pretreated substrate to form an asymmetric aluminum open resonant ring pattern;
s4, preparing a perovskite precursor solution, coating the solution on a substrate carved with a periodically distributed aluminum open resonator ring pattern by adopting a spin coating or blade coating method, and then placing the substrate on a hot bench with the temperature of 95-105 ℃ for annealing for 10-15 minutes to form a flat film with the thickness of 40-80nm on the substrate and the aluminum pattern.
In a preferred embodiment of the present invention, the spin coating method includes a first spin coating step and a second spin coating step.
The invention solves the defects in the background technology, and has the following beneficial effects:
(1) according to the invention, the perovskite film is used as the light-control functional layer of the terahertz modulation device, the perovskite material has excellent photoelectric properties, and has larger carrier mobility and carrier diffusion length, so that the energy density required by terahertz modulation can be reduced to be very low, the sensitivity of the terahertz modulation device is greatly improved, and compared with silicon or gallium arsenide, the perovskite film can be perfectly compatible on the basis of flexible metamaterial structures, multilayer metamaterial structures and other photonic devices in the future.
(2) The terahertz wave intensity modulation device can realize terahertz wave intensity modulation at normal temperature, has a wide modulation frequency range and a large modulation amplitude range, and can effectively modulate the terahertz wave intensity compared with the traditional terahertz wave modulation device. The present invention has the advantages that the hole array structure can be easily manufactured on the metal or semiconductor substrate by adopting various existing mature processes, and the selection requirement on intrinsic semiconductor and metal materials is lower, so the cost of the whole device is lower.
(3) Compared with the prior art, the terahertz modulation device with the structure has the advantages that the structure is simple and novel, the terahertz modulation device has higher energy gap frequency and superconducting transition temperature, has extremely low ohmic loss and tunability compared with common metal, the performance of the modulation device is improved, the modulation rate is higher, meanwhile, the voltage required by modulation is smaller, for terahertz waves with the polarization direction parallel to the grid bars of the wire grids, the resonance metasurface has high transmittance within the range lower than the electric dipole resonance frequency, the wire grids with high conductivity forbid the transmission of the terahertz waves with the polarization, and due to the broadband characteristic of the wire grids, the terahertz modulation with the broadband and the high efficiency can be realized.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Reference numerals:
fig. 1 is schematic diagrams before and after debugging of terahertz waves in the preferred embodiment of the present invention.
Detailed Description
In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.
A light-operated terahertz wave modulation device and a preparation method thereof comprise the following steps: the substrate, the buffer layer, the heterogeneous layer, the first electrode, the second electrode and the voltage current source are sequentially arranged, the voltage current source comprises an anode output end and a cathode output end, the substrate comprises a first surface and a second surface which are opposite, the first electrode is arranged on the first surface, the second electrode is arranged on the second surface, a plurality of rows of transistors are formed on the heterogeneous layer and are connected in series, ohmic electrodes of the plurality of rows of transistors are connected with the first electrode, grids of two adjacent rows of transistors are connected with each other, the grids are connected with the second electrode, the ohmic electrodes, the grids, the first electrode and the second electrode form a composite metasoma surface structure, the grids regulate and control channel conductance between two adjacent ohmic electrodes in each row, and the composite metasoma surface structure is switched between a resonant metasoma surface and a wire grid.
The voltage current source comprises an anode output end and a cathode output end, the anode output end is electrically connected with the first electrode, the cathode output end is electrically connected with the second electrode, the substrate is converted into the current source when entering an avalanche breakdown state, the voltage current source adjusts the current output to the substrate so as to adjust the terahertz wave transmittance of the substrate, the thickness of the substrate is not more than 1500 microns, the first electrode and the second electrode are strip electrodes or annular electrodes, and the substrate is made of quartz crystals with the thickness of 1.5 mm.
The perovskite film is used as a light-control functional layer of the terahertz modulation device, the perovskite material has excellent photoelectric properties, larger carrier mobility and carrier diffusion length, the energy density required by terahertz modulation can be reduced to be very low, the sensitivity of the light-control terahertz modulation device is greatly improved, and compared with silicon or gallium arsenide, the perovskite film can be perfectly compatible on the basis of a flexible metamaterial structure, a multilayer metamaterial structure and other photonic devices in the future.
The intensity modulation of the terahertz wave is realized at normal temperature, the modulation frequency range is wide, the modulation amplitude range is large, and compared with the traditional terahertz wave modulation device, the intensity modulation device can effectively modulate the intensity of the terahertz wave. The present invention has the advantages that the hole array structure can be easily manufactured on the metal or semiconductor substrate by adopting various existing mature processes, and the selection requirement on intrinsic semiconductor and metal materials is lower, so the cost of the whole device is lower.
Compared with the prior art, the terahertz modulation device with the structure has the advantages that the structure is simple and novel, the terahertz modulation device has higher energy gap frequency and superconducting transition temperature, has extremely low ohmic loss and tunability compared with common metal, the performance of the modulation device is improved, the modulation rate is higher, meanwhile, the voltage required by modulation is smaller, for terahertz waves with the polarization direction parallel to the grid bars of the wire grids, the resonance metasurface has high transmittance within the range lower than the electric dipole resonance frequency, the wire grids with high conductivity forbid the transmission of the terahertz waves with the polarization, and due to the broadband characteristic of the wire grids, the terahertz modulation with the broadband and the high efficiency can be realized.
A preparation method of a light-operated terahertz wave modulation device comprises the following steps:
s1, pretreating the substrate, and sequentially carrying out ultrasonic cleaning on the substrate, wherein the cleaning temperature of the ultrasonic cleaning is 50 ℃, and the time of each ultrasonic cleaning is 20 minutes;
s2, drying the substrate cleaned by the ultrasonic on a hot table at 100 ℃ for 8-12 minutes to obtain a pretreated substrate;
s3, photoetching is carried out on the pretreated substrate to form an asymmetric aluminum open resonant ring pattern;
s4, preparing a perovskite precursor solution, coating the solution on a substrate carved with a periodically distributed aluminum open resonator ring pattern by adopting a spin coating or blade coating method, and then placing the substrate on a hot bench with the temperature of 95-105 ℃ for annealing for 10-15 minutes to form a flat perovskite thin film with the thickness of 40-80nm on the substrate and the aluminum pattern.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.
Claims (8)
1. An optically controlled terahertz wave modulation device comprising: the substrate, the buffer layer, the heterogeneous layer, the first electrode, the second electrode and the voltage current source are arranged in sequence; it is characterized in that the preparation method is characterized in that,
the voltage current source comprises a positive electrode output end and a negative electrode output end, the substrate comprises a first surface and a second surface which are opposite, the first electrode is arranged on the first surface, the second electrode is arranged on the second surface, a plurality of rows of transistors are formed on the heterogeneous layer and are connected in series, ohmic electrodes of the plurality of rows of transistors are connected with the first electrode, grids of two adjacent rows of transistors are connected with each other, the grids are connected with the second electrode, the ohmic electrodes, the grids, the first electrode and the second electrode form a composite metasurface structure, the grids regulate and control channel conductance between every two adjacent rows of ohmic electrodes, and the composite metasurface structure is switched between the resonant metasurface and the wire grid.
2. The light-controlled terahertz wave modulation device according to claim 1, wherein: the voltage current source comprises a positive output end and a negative output end, the positive output end is electrically connected with the first electrode, and the negative output end is electrically connected with the second electrode.
3. The light-operated terahertz wave modulation device and the preparation method thereof according to claim 1, characterized in that: when the substrate enters an avalanche breakdown state, the substrate is converted into a current source, and the voltage current source adjusts current output to the substrate so as to adjust the terahertz wave transmittance of the substrate.
4. The light-controlled terahertz wave modulation device according to claim 1, wherein: the thickness of the substrate is not more than 1500 μm.
5. The light-controlled terahertz wave modulation device according to claim 1, wherein: the first electrode and the second electrode are strip electrodes or ring electrodes.
6. The light-controlled terahertz wave modulation device according to claim 1, wherein: the substrate is made of quartz crystal with the thickness of 1.5 mm.
7. A method for manufacturing the light-controlled terahertz wave modulating device according to claim 1, comprising the steps of:
s1, pretreating the substrate, and sequentially carrying out ultrasonic cleaning on the substrate, wherein the cleaning temperature of the ultrasonic cleaning is 50 ℃, and the time of each ultrasonic cleaning is 20 minutes;
s2, drying the substrate cleaned by the ultrasonic on a hot table at 100 ℃ for 8-12 minutes to obtain a pretreated substrate;
s3, photoetching is carried out on the pretreated substrate to form an asymmetric aluminum open resonant ring pattern;
s4, preparing a perovskite precursor solution, coating the solution on a substrate carved with a periodically distributed aluminum open resonator ring pattern by adopting a spin coating or blade coating method, and then placing the substrate on a hot bench with the temperature of 95-105 ℃ for annealing for 10-15 minutes to form a flat perovskite thin film with the thickness of 40-80nm on the substrate and the aluminum pattern.
8. The method for manufacturing an optically controlled terahertz wave modulating device according to claim 7, wherein: the spin coating method includes a first spin coating step and a second spin coating step.
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| CN202010779066.0A CN112034634A (en) | 2020-08-05 | 2020-08-05 | Light-operated terahertz wave modulation device and preparation method thereof |
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| CN202010779066.0A CN112034634A (en) | 2020-08-05 | 2020-08-05 | Light-operated terahertz wave modulation device and preparation method thereof |
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