CN104505458B - A kind of portable continuously adjustabe Terahertz generator - Google Patents

Abstract

The invention discloses a portable continuously adjustable terahertz generator, which includes a terahertz waveguide, a container, a container cover, a fixing piece, a hemispherical lens, a heating resistor, a low temperature thermometer, a BSCCO high temperature superconducting terahertz source and an electrode plate; The container cover encapsulates the fixture in the container; the hemispherical lens is arranged at the center of the fixture, and a BSCCO high-temperature superconducting terahertz source is arranged at the center of the back of the hemisphere lens, and the hemispherical lens is pasted and heated on the fixture Resistance, low-temperature thermometer and electrode plate; four electrodes of the electrode plate, two electrodes of the heating resistor and two electrodes of the low-temperature thermometer are led to the outside through the container through the enameled wire; the electrodes of the BSCCO high-temperature superconducting terahertz source are passed through the gold wire It is connected with the electrode plate; the depth of the terahertz waveguide inserted into the container just touches the hemispherical surface of the hemispherical lens in the center of the fixing piece. The portable continuously adjustable terahertz generator is small in size, easy to use, low in cost, convenient to carry and move; it can be driven by batteries, has a simple system, is convenient to use, and has a fast cooling speed.

Description

A Portable Continuously Adjustable Terahertz Generator

technical field

The invention belongs to the technical field of high-temperature superconducting BSCCO terahertz generators, and in particular relates to a battery-driven portable continuously adjustable terahertz generator that can be directly immersed in liquid nitrogen and work.

Background technique

Terahertz (THz for short) waves generally refer to electromagnetic waves with a frequency between 0.1 THz and 10 THz, where 1 THz=1000 GHz. Terahertz waves have the characteristics of low photon energy, high spatiotemporal coherence, and characteristic spectrum, so they have broad application prospects in astronomy, biology, computer, communication and other scientific fields.

According to the AC Josephson effect, a DC voltage of 1 μV can generate oscillations with a frequency up to 484MHz, and the frequency of supercurrent oscillations in the junction can be continuously adjusted by changing the DC voltage across the junction, so the superconducting Josephson junction is an ideal voltage- Frequency converters can be used to create terahertz sources. In 2007, researchers from the United States, Turkey and Japan cooperated to form a platform-shaped Josephson junction array with 600 junctions in series on the high-temperature superconductor Bi ₂ Sr ₂ CaCu ₂ O _8+δ (BSCCO) through microfabrication technology, making the series The junction array is in a low-current bias state, and THz signals with epitaxial powers of several microwatts are detected by a thermal bolometer.

After recent years of development, the BSCCO-THz source has developed into a new type of continuous wave tunable solid-state THz source, which has the advantages of ease of use, continuous wave, tunability, good monochromaticity, and high power. However, as a superconducting device, the BSCCO-THz source needs to work in an extremely low temperature environment (mostly in the liquid helium temperature region). The traditional helium flow refrigerator not only has the disadvantages of complex system, cumbersome operation, long preparation period, and poor portability, but also the price of liquid helium is expensive, and the cost of experiments is high. At the same time, the noise of the mechanical refrigerator is large and it is not easy to carry. The application of the source has created a huge obstacle.

Contents of the invention

Purpose of the invention: In view of the deficiencies in the prior art, the purpose of the present invention is to provide a portable continuously adjustable terahertz generator, which overcomes the complexity and high cost of the BSCCO superconducting terahertz source system on traditional helium flow refrigerators and mechanical refrigerators , Not portable and other disadvantages, with the characteristics of economical, easy to use, portable, etc., to meet the needs of use.

Technical solution: In order to realize the above-mentioned purpose of the invention, the technical solution adopted in the present invention is:

A portable continuously adjustable terahertz generator, including a terahertz waveguide, a container, a container cover, a fixture, a hemispherical lens, a heating resistor, a cryogenic thermometer, a BSCCO high-temperature superconducting terahertz source, and an electrode plate; the container cover will The fixing part is packaged in the container; the hemispherical lens is set at the center of the fixing part, a BSCCO high temperature superconducting terahertz source is arranged at the center of the back of the hemispherical lens, and a heating resistor and a low temperature thermometer are pasted on the fixing part close to the hemispherical lens And the electrode plate; the four electrodes of the electrode plate, the two electrodes of the heating resistor and the two electrodes of the low-temperature thermometer are led to the outside through the container through the enameled wire; the electrodes of the BSCCO high-temperature superconducting terahertz source are connected to the electrode plate through gold wires ; The depth at which the terahertz waveguide is inserted into the container just touches the hemispherical surface of the hemispherical lens at the center of the fixture.

The terahertz waveguide used is a stainless steel tube.

The container, the container cover, and the fixing piece are all processed by using oxygen-free copper.

The connection mode between the container and the container cover is threaded connection, wherein the container is an internal thread, and the container cover is an external thread.

The diameter of the hemispherical lens is 6mm, and the material is sapphire.

The heating resistor is a patch resistor with a resistance value of 1kΩ.

The electrode plate, heating resistor and low temperature thermometer are connected to the external test system through enameled wire and pin headers

The terahertz generator provides the required current bias to the BSCCO high-temperature superconducting terahertz source through the pin header and measures the voltage across it, and also provides the working voltage to the heating resistor and the low-temperature thermometer through the pin header.

A thermometer for real-time detection of the temperature inside the terahertz generator container is provided on the fixing member.

The battery-driven device of the portable continuously adjustable terahertz generator includes a first rheostat, a second rheostat, a battery, a switch, a capacitor, a fixed value resistor, a first terminal, and a second terminal; the first rheostat, The second rheostat, the battery, the switch, the fixed value resistor, and the first terminal are connected in series, the second terminal is connected in parallel with the fixed value resistor, and the capacitor is connected in parallel with the series connected battery and switch.

The portable continuously adjustable terahertz generator of the present invention is made of a material with good thermal conductivity into a closed container that can be installed with a BSCCO superconducting terahertz source, and is directly immersed in liquid nitrogen to make it work, and the generated THz wave is exported by a waveguide , and through the heating resistance to change the working temperature to expand the frequency adjustment bandwidth, and at the same time can realize battery drive, so that the whole system is economical and practical, small and light, easy to operate, overcome the shortcomings of traditional helium flow refrigerators and mechanical refrigerators, and finally build a set of economical Easy-to-use portable continuously adjustable terahertz generator.

Beneficial effects: the portable continuously adjustable terahertz generator of the present invention is small in size, easy to use and low in cost. The BSCCO superconducting terahertz source can be driven by a battery to radiate continuously adjustable terahertz waves. It can be conveniently applied to various related fields. The main advantages are: small size, easy to carry and move. The diameter*height of the bottom surface of the container where the BSCCO superconducting terahertz source is located is about 4.0cm*2.3cm, and the length*width*height of the battery box is about 8.3cm*6.0cm*3.7cm; it can be driven by batteries, the system is simple, and it is easy to use; through A wide range of continuous frequency adjustment can be achieved by adjusting the bias voltage without external magnetic field assistance; compared with liquid helium, liquid nitrogen is cheap and greatly reduces costs; the container where the BSCCO superconducting terahertz source is located is directly immersed in liquid nitrogen , the cooling speed is fast.

Description of drawings

Figure 1 is a schematic diagram of the structure of a terahertz generator;

Figure 2 is a schematic diagram of the internal structure of the terahertz generator;

Fig. 3 is the structural representation of container;

Fig. 4 is the structural representation of container lid;

Fig. 5 is a circuit diagram of the battery drive device.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, Figure 2, Figure 3 and Figure 4, the portable continuously adjustable terahertz generator uses a stainless steel tube as a terahertz waveguide 1, and uses oxygen-free copper to process a container 2, a container cover 3 and a fixing piece 4, The container 2 and the container cover 3 are connected by threads (the container 2 is an internal thread, and the container cover 3 is an external thread); the depth of the terahertz waveguide 1 inserted into the container 2 should be such that it just touches the hemisphere of the hemispherical lens 5 in the center of the fixture 4 noodle. Oxygen-free copper is used as the processing material because of its better thermal conductivity, which is conducive to the conduction of low temperature from the outer container 2 and the container cover 3 to the BSCCO high-temperature superconducting terahertz source 7 . A hemispherical lens 5 is installed on the fixture 4, and the diameter of the hemispherical lens is about 6mm, and the material is sapphire. On the fixing part 4 , a heating resistor 6 , an electrode plate 8 and a low temperature thermometer 9 are pasted next to the hemispherical lens 5 . The heating resistor is a chip resistor with a resistance value of 1kΩ. The electrode plate is processed using PCB copper clad laminate as raw material, and is carved into four independent electrodes with a craft knife. Four electrodes of the electrode plate 8, two electrodes of the heating resistor 6 and two electrodes of the low-temperature thermometer are led to the outside through two small through holes opened on the container 2 with enameled wires respectively, and the through holes are sealed. Paste the self-developed BSCCO high-temperature superconducting terahertz source 7 (CN103956637A) on the center of the back of the hemispherical lens 5. The structure of the BSCCO high-temperature superconducting terahertz source 7 is shown in Figure 2. Board 8 is connected.

When working, as long as the main body of the terahertz generator is immersed in liquid nitrogen (the waveguide port is placed above the liquid nitrogen surface), the required low temperature environment can be provided. The low-temperature environment is transmitted to the BSCCO high-temperature superconducting terahertz source 7 through the container 2, the container cover 3, the fixture 4, and the hemispherical lens 5 to provide it with the temperature required for work. The electrodes of the BSCCO high-temperature superconducting terahertz source 7 are connected to the electrodes on the electrode plate 8 through gold wires, and the electrode plate 8, heating resistor 6 and low-temperature thermometer 9 are connected to the external testing system through enameled wires and pin headers. Therefore, the required current bias can be provided to the BSCCO high-temperature superconducting terahertz source 7 through the pin header and the voltage across it can be measured, and the working voltage can also be provided to the heating resistor 6 through the pin header. In addition, a low-temperature thermometer 9 capable of working at low temperatures (such as a platinum resistance thermometer PT1000) can be introduced next to the sample to detect the temperature inside the terahertz generator container in real time. When it is driven by a battery, it is only necessary to connect the corresponding pin header of the BSCCO high-temperature superconducting terahertz source 7 to the bias device driven by the battery. As shown in Figure 5 of the battery drive device, the first rheostat 11 realizes the voltage fine adjustment, the second rheostat 12 realizes the voltage coarse adjustment, and the first terminals 13 and 14 are connected to the current input and output of the BSCCO high temperature superconducting terahertz source 7, thereby changing Current bias; the function of the second terminals 21 and 22 is to read the voltage value of the fixed value resistor, and divide it by the resistance value to obtain the current value flowing through the BSCCO high-temperature superconducting terahertz source 7; the function of the capacitor is to protect the BSCCO high-temperature superconducting terahertz source 7 The Hertz source 7 is free from the influence of high-voltage pulses that may be caused by unstable battery voltage output. As long as the operating temperature and current bias of the BSCCO high-temperature superconducting terahertz source 7 are controlled, continuously adjustable terahertz waves can be obtained; the voltage of the heating resistor 6 can be controlled to change the operating temperature and expand the frequency adjustment bandwidth.

In the present invention, the container equipped with the BSCCO superconducting terahertz source is directly immersed in liquid nitrogen to achieve the purpose of cooling. The container is light and compact, has good sealing performance, and has good thermal conductivity (fast cooling speed). Low. It can be driven by batteries, and the whole system is simplified, easy to operate and easy to carry. With the self-developed BSCCO superconducting terahertz source as the core device, the source has the advantages of continuous wave generation, tunability, and good monochromaticity.

Claims (7)

1. A portable continuously adjustable terahertz generator, characterized in that it includes a terahertz waveguide (1), a container (2), a container cover (3), a fixing member (4), a hemispherical lens (5), a heating resistor (6), BSCCO high-temperature superconducting terahertz source (7), electrode plate (8) and cryogenic thermometer (9); the container cover (3) encapsulates the fixture (4) in the container (2); the The hemispherical lens (5) described above is located at the center of the fixture (4), and a BSCCO high temperature superconducting terahertz source (7) is set at the center of the back side of the hemispherical lens (5), and is close to the hemispherical lens on the fixture (4). (5) paste the heating resistor (6), the electrode plate (8) and the low temperature thermometer (9); the four electrodes of the electrode plate (8), the two electrodes of the heating resistor (6) and the two electrodes of the low temperature thermometer pass through The enameled wire is led to the outside through the container (2); the electrodes of the BSCCO high-temperature superconducting terahertz source (7) are connected to the electrode plate (8) through gold wires; the terahertz waveguide (1) is inserted into the container (2) Depth, just touching the hemispherical surface of the hemispherical lens (5) at the center of the fixture (4); the container (2), container cover (3), and fixture (4) are all processed using oxygen-free copper; The terahertz waveguide (1) is a stainless steel tube. 2. The portable continuously adjustable terahertz generator according to claim 1, characterized in that: the connection between the container (2) and the container cover (3) is screw connection, wherein the container (2) is an inner thread, the container lid (3) is an external thread. 3. The portable continuously adjustable terahertz generator according to claim 1, characterized in that: the diameter of the hemispherical lens (5) is 6 mm, and the material is sapphire. 4. The portable continuously adjustable terahertz generator according to claim 1, characterized in that: the heating resistor (6) is a chip resistor with a resistance value of 1kΩ. 5. The portable continuously adjustable terahertz generator according to claim 1, characterized in that: said electrode plate (8), heating resistor (6) and low temperature thermometer (9) are tested externally through enameled wires and pin headers The system is connected. 6. The portable continuously adjustable terahertz generator according to claim 5, characterized in that: the terahertz generator provides the required current bias to the BSCCO high-temperature superconducting terahertz source (7) through a row of pins And measure the voltage at its two ends, and provide working voltage to the heating resistor (6) and the low temperature thermometer (9) through the pin header at the same time. 7. The battery-driven device of the portable continuously adjustable terahertz generator according to claim 1, characterized in that it comprises a first rheostat (11), a second rheostat (12), a battery, a switch, a capacitor, a fixed-value resistor, First terminal (13,14), second terminal (21,22); described first rheostat (11), second rheostat (12), battery, switch, fixed value resistor, first terminal (13,14 ) in series, the second terminal (21, 22) is connected in parallel with the fixed value resistor, and the capacitor is connected in parallel with the battery and the switch connected in series.