KR101330925B1 - Miniaturized electron laser module - Google Patents

Abstract

The present invention provides an electron emission means for emitting and scanning electrons, a Wigler that emits electromagnetic waves in the terahertz (THz) region by periodically changing the path of electrons scanned in the electron column, and absorbs the electromagnetic waves emitted from the Wigler. An electromagnetic wave generating module for generating electromagnetic waves in a terahertz region, including an anode, the electron emitting means comprising: an emission source for emitting electrons by applying a voltage; And an eviction electrode for inducing electron emission with respect to the emission source, an acceleration electrode for forming electrons derived from the eviction electrode into parallel electron beams, and an aperture electrode for filtering electrons off the optical axis among the electron beams transmitted from the acceleration electrode. It has a; characterized in that it comprises a microlens.
Thereby, an ultra-small electromagnetic wave generating module capable of stably and efficiently generating electromagnetic waves in the terahertz (THz) region is provided.

Description

Miniature Electromagnetic Wave Generation Module {Miniaturized electron laser module}

The present invention relates to a miniature electromagnetic wave generating module, and more particularly, to a miniature radiation generating module capable of generating electromagnetic waves in the terahertz region.

Electromagnetic waves including light are classified into radio waves, microwaves, infrared rays, visible light, ultraviolet rays, and X-rays according to frequency domains, and there are various application fields suitable for respective frequency domains.

For example, radio waves and microwaves are used for wireless mobile communication, infrared rays are widely used for optical communication and various sensors, and visible light is used for various interferometers, sensors, measuring instruments, and medical devices. In addition, ultraviolet rays are widely used for sterilization, disinfection and curing of epoxy, and X-rays are used for radiography.

As such, electromagnetic waves are actively used in modern life and various industrial fields in almost all frequency domains, and wave sources or light sources and wave detectors for generating the corresponding waves are well developed in each region. There is a situation.

However, among these areas of electromagnetic waves, there is a very weak technology development for its use, which is the terahertz (THz) region.

The terahertz (THz) region is an intermediate region between microwaves and infrared rays, and refers to an electromagnetic wave band of 0.3 to 10 THz in frequency and 30 to 1000 μm in wavelength. This terahertz (THz) region is highly permeable to most materials except metals and moisture, and is therefore harmless to humans, making it suitable for a wide range of applications including molecular optics, biophysics, medicine, spectroscopy, image processing and security screening. Can be.

However, until now, the technological development that utilizes the terahertz (THz) region is weak, because physical and engineering limitations have not produced an efficient light source for generating electromagnetic waves in the terahertz (THz) region.

Accordingly, if a light source capable of efficiently generating electromagnetic waves in the terahertz (THz) region is developed, innovative developments in various fields that can utilize electromagnetic waves in the terahertz (THz) region may be achieved.

Accordingly, an object of the present invention is to provide an ultra-small electromagnetic wave generating module capable of efficiently generating electromagnetic waves in the terahertz (THz) region.

The object is that according to the invention, the electron emission means for emitting and scanning electrons, the Wigler to emit electromagnetic waves in the terahertz (THz) region by periodically changing the path of the electrons scanned in the electron column, and in the Wigler An ultra-small electromagnetic wave generating module for generating electromagnetic waves in a terahertz region, including an anode absorbing emitted electromagnetic waves, the electron emitting means comprising: an emission source for emitting electrons by applying a voltage; And an eviction electrode for inducing electron emission with respect to the emission source, an acceleration electrode for forming electrons derived from the eviction electrode into parallel electron beams, and an aperture electrode for filtering electrons off the optical axis among the electron beams transmitted from the acceleration electrode. It is achieved by a micro-electromagnetic wave generation module comprising a; micro lens having a.

Here, it is preferable that the thickness of the limiting electrode is larger than that of the eviction electrode and the acceleration electrode.

In addition, it is effective to apply a voltage to the acceleration electrode to collect the path of the electrons and form a parallel beam.

In addition, the wiggle is more preferably a cylindrical wiggle to emit electromagnetic waves in the terahertz (THz) region by periodically changing the path of electrons transmitted from the microlens.

In addition, it is more effective that the wiggle is provided in plural at regular intervals on the same axis from the microlens side toward the anode side.

According to the present invention, there is provided an ultra-small electromagnetic wave generating module capable of stably and efficiently generating electromagnetic waves in the terahertz (THz) region.

1 is a configuration diagram of an ultra-small electromagnetic wave generating module according to the present invention;
2a and 2b are views showing the trajectory of the electron beam according to the voltage applied to the acceleration electrode,
3 is a graph showing the voltage at the center of the acceleration electrode according to the voltage applied to the acceleration electrode,
4 is a graph showing a current passing through the aperture electrode according to the voltage applied to the acceleration electrode,
5 is a graph showing the strength of the current according to the radius of the aperture electrode when the voltage applied to the acceleration electrode is 0V and -200V;
6 is a graph showing the electron beam trajectory in the cylindrical Wigler.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an ultra-small electromagnetic wave generating module according to the present invention. As shown in this figure, the ultra-compact electromagnetic wave generating module 1 according to the present invention periodically changes the path of electrons transmitted from the electron-emitting means 3 and the electron-emitting means 3 by terahertz. Radiation generating means 5 for emitting electromagnetic waves in the region.

The electron emission means 3 includes an emission source 10 for emitting electrons according to voltage application, and a microlens 20 for converting electrons emitted from the emission source 10 into a parallel beam and transmitting the radiation to the radiation generating means 5. It is composed of

The emission source 10 preferably etches the tungsten wire so that the emission end toward the microlens 20 has a sharp structure. The sharp formation of the emissive end is intended to make the field easier to emit electrons even at low voltages by increasing the strength of the electric field to lower the potential barrier.

Here, the emission source 10 may be any one of porous tungsten, barium oxide (BaO), barium strontium oxide (BaSrO), calcium oxide (CaO), and aluminum oxide (Al ₂ O ₃ ) as a dispenser cathode material for emitting hot electrons. And may be any one of molybdenum (Molybdenum), carbon nanotubes (CNT), diamond-like carbon (DLC), zinc oxide (ZnO) that emits cold electrons.

The microlens 20 is preferably composed of three circular electrodes arranged in sequence on the same axis from the emission source 10 side toward the radiation generating means 5 side. Each circular electrode may be a multilayer of silicon chips or silicon films spread with an insulating layer of several hundred micrometers thick, and these circular electrodes may also have various bore diameters from several micrometers to several hundred micrometers. At this time, it is desirable that the roundness and edge acuity of the bore have a nanometer range and alignment accuracy between components belonging to less than 1 μm.

The circular electrodes constituting the microlens 20 may be made of silicon films having a thickness of 1 μm to 5 μm by electron-beam lithography and reactive-ion etching.

Hereinafter, the circular electrodes constituting the microlens 20 will be described in more detail.

The three circular electrodes constituting the microlens 20 are an extractor electrode 21 which extracts electrons from the emission source 10 and an electron beam parallel to the electron beam transmitted from the ejection electrode 21 (hereinafter, referred to as an electron beam). And an aperture electrode 25 (limiting aperture) for filtering electrons out of the optical axis among the parallel beams emitted from the acceleration electrode 23. .

In this case, the eviction electrode 21 is disposed adjacent to the emission source 10 and induces emission of electrons from the emission source 10 by applying a ground or positive voltage. In addition, the acceleration electrode 23 is disposed after the discharge electrode 21 and forms a parallel beam by applying a negative voltage. In addition, the aperture electrode 25 is disposed next to the acceleration electrode 23 and grounded to filter electrons that deviate from the optical axis.

Among them, an appropriate voltage level capable of forming a parallel beam in the acceleration electrode 23 and structural conditions of the aperture electrode 25 for filtering electrons off the optical axis from the aperture electrode 25 will be examined based on the experimental results. see.

The voltage applied to the acceleration electrode 23 is preferably applied within the range of -180V to -220V. This is because the electron beam transmitted from the eviction electrode 21 passes through the acceleration electrode 23 to form a parallel beam. Optimal voltage condition. In particular, when the voltage of -200V is applied to the acceleration electrode 23, it was confirmed that the experiment can form a more stable parallel beam.

2A and 2B are diagrams showing a trajectory of an electron beam according to a voltage applied to the acceleration electrode 23. When a voltage of 0 V was applied to the accelerating electrode 23, as shown in FIG. 2A, it was confirmed that the extraction electrode 21 continued to spread at a constant divergence angle of the electron beam.

On the other hand, when a voltage of −200 V is applied to the acceleration electrode 23, as shown in FIG. 2B, the electron beam passing through the eviction electrode 21 spreads out and passes through the acceleration electrode 23 to form a parallel beam. It was confirmed that the process proceeds to the aperture electrode 25 side.

3 is a graph showing the voltage at the center of the accelerating electrode 23 according to the voltage applied to the accelerating electrode 23, and FIG. 4 shows the aperture electrode 25 according to the voltage applied to the accelerating electrode 23. A graph showing the current passed.

Since a bore is formed at the center of the acceleration electrode 23, the voltage applied to the acceleration electrode 23 is not transmitted to all electrons passing through the optical axis. The electrons farther away from the optical axis and adjacent to the inner circumferential surface of the bore of the acceleration electrode 23 are subject to greater electrostatic force to the voltage applied to the acceleration electrode 23.

The voltage at the center of the acceleration electrode 23 is proportional to the voltage applied to the acceleration electrode 23, which is confirmed by the slope of 0.43 in the graph of FIG. 3. In this case, the central voltage may vary depending on the radius of the bore processed in the acceleration electrode 23.

When a voltage is applied to the acceleration electrode 23, the eviction electrode 21, the acceleration electrode 23, and the aperture electrode 25 form one microlens 20 to act as a convergent lens in the optical. do. Depending on the magnitude of the voltage applied to the accelerating electrode 23, the electron beams are collected or concentrated at one point while passing through the microlens 20.

At this time, when the electron beam is concentrated at one point, since the electrons cross each other and spread out again, a parallel beam cannot be formed. Therefore, the spreading electron beam has a large divergence angle when passing through the Wigler 30 of the radiation generating means 5, which will be described later, so that the wavelength distribution of the radiation is widened so that the wavelength of the terahertz (THz) region cannot be obtained. .

Therefore, by applying an appropriate voltage to the acceleration electrode 23 to increase the current of the electron beam passing through the aperture electrode 25 to pass through the Wigler 30 of the radiation generating means 5 to be described later in a parallel beam state. The wavelength of the terahertz region desired can be obtained by improving the radiation characteristics generated by the Wigler 30.

This is demonstrated by experiment, as shown in the graph of FIG. As shown in FIG. 4, when the voltage is applied to the acceleration electrode 23 too large, the current passing through the aperture electrode 25 becomes very high as in the -300V region. This means that the electron beam is collected at a point near the bore center of the aperture electrode 25 so that most of the electrons pass through the aperture electrode 25 and are transmitted to the wiggle 30 of the radiation generating means 5. do. Although the intensity of the current is increased, the electron beam passing through the aperture electrode 25 spreads again as it passes through the collected point, and has a large divergence angle when passing through the Wigler 30, thereby deteriorating characteristics of radiation.

On the other hand, as described above, in the region near -200V, it was confirmed that the electron beam was formed as a parallel beam, and when a voltage of -200V was applied to the acceleration electrode 23, a voltage of 0V was applied to the acceleration electrode 23. It was confirmed that the current increased by about 60% in the Wigler 30 of the radiation generating means 5 than when applied.

Therefore, in order for the electron beam delivered from the eviction electrode 21 to be formed as a parallel beam passing through the acceleration electrode 23, it is preferable that a voltage is applied to the acceleration electrode 23 within a range of -180 V to -220 V, in particular When a voltage of -200 V is applied to the acceleration electrode 23 can form a more stable parallel beam.

On the other hand, the structural conditions of the aperture electrode 25, the thickness thereof is larger than the eviction electrode 21 and the acceleration electrode 23, it is preferable that the radius is 10μm or less.

Although the voltage applied to the accelerating electrode 23 can be adjusted appropriately to form an electron beam passing through the aperture electrode 25 as a parallel beam, it is virtually impossible to make all electrons appear as parallel trajectories with respect to the optical axis. Therefore, by increasing the thickness of the aperture electrode 25 compared to the eviction electrode 21 and the acceleration electrode 23, the electrons having a large divergence angle off the optical axis is naturally absorbed through the long passage of the aperture electrode 25 The electron beam passing through the aperture electrode 25 can be maintained as a parallel beam. Thereby, the characteristic of the radiation emitted from the Wigler 30 of the radiation generating means 5 mentioned later can be made to have the characteristic corresponding to the wavelength of a terahertz (THz) area | region.

However, as the diaphragm electrode 25 becomes thicker, the strength of the current becomes weaker. As can be seen in the graph of FIG. 5, the intensity of the current increases when the radius of the diaphragm electrode 25 is appropriately increased. . That is, if the thickness of the aperture electrode 25 is a structural condition that filters electrons having a large divergence angle outside the optical axis, the radius of the aperture electrode 25 may be an important structural condition that determines the strength of the current.

As can be seen in the graph of FIG. 5, even when the radius of the aperture electrode 25 is made very large, the strength of the current increases very quickly, so that the strength of the current required by the Wigler 30 can be easily obtained. However, if the radius of the aperture electrode 25 is excessively large, the characteristics of the electron beam are deteriorated. Therefore, the radius of the aperture electrode 25 needs to be appropriately adjusted.

5 is a graph showing the strength of the current according to the radius of the aperture electrode 25 when the voltage applied to the acceleration electrode 23 is 0V and -200V. As can be seen from this graph, in the case where the voltage applied to the acceleration electrode 23 is 0V and -200V, as the radius of the diaphragm electrode 25 increases, the strength of the current increases rapidly. . However, when the voltage applied to the acceleration electrode 23 is 0V, the current intensity continues to increase. However, when the voltage applied to the acceleration electrode 23 is -200V, the current intensity increases and then the radius of the aperture electrode 25 is increased. It was confirmed that the increase rate of the current intensity was significantly lowered above 10 μm. This is because the larger the radius of the aperture electrode 25 becomes the open space inside the microlens 20, the weaker the peak voltage formed along the optical axis in the microlens 20.

Therefore, it was confirmed that the structural condition of the diaphragm electrode 25 is larger than the discharge electrode 21 and the acceleration electrode 23 while the radius is 10 μm or less.

Here, the material of the eviction electrode 21, the acceleration electrode 23, and the aperture electrode 25 constituting the microlens 20 is preferably made of silicon. And, the extraction electrode 21, the acceleration electrode 23, the aperture electrode 25 can be adjusted according to their respective roles, the extraction electrode 21 and the acceleration electrode 23 is preferably 100μm in diameter, The aperture electrode 25 may be several μm to several ten μm. In particular, in the case of the aperture electrode 25, the spot size of the electron beam increases rapidly and the characteristics of the electron beam deteriorate. However, if the diameter is too small, it is difficult to align with the rest of the electrode, and the electron beam passing therethrough is rapidly weakened.

In addition, since there is a limit to reducing the diameter of the aperture electrode 25, setting the diameter of the aperture electrode 25 to 10 μm or more helps to align and also the intensity of the electron beam passing through the aperture electrode 25. In order to prevent the deterioration of the characteristics of the electron beam, it is advantageous to increase the thickness of the aperture electrode 25 rather than to increase the diameter of the aperture electrode 25. When the thickness of the aperture electrode 25 is increased, electrons passing through the aperture electrode 25 and spreading at a slightly larger angle from the optical axis hit the surface inside the aperture electrode 25 and are absorbed.

In general, the thickness of the eviction electrode 21, the acceleration electrode 23, and the aperture electrode 25 is within 5 μm, and the thickness of the aperture electrode 25 is several tens of μm larger than the eviction electrode 21 and the acceleration electrode 23. Since the above-described advantages are advantageous, the thickness of the aperture electrode 25 is preferably larger than the eviction electrode 21 and the acceleration electrode 23.

On the other hand, the radiation generating means (5) and the Wigler (30) which emits electromagnetic waves in the terahertz (THz) region by periodically changing the path of electrons transmitted from the electron emitting means (3), It consists of an anode 40 for absorbing the emitted electromagnetic waves.

Among them, the wegler 30 is preferably composed of a plurality of cylindrical electrodes arranged at predetermined intervals on the same axis from the electron emitting means 3 side toward the anode 40 side. The parallel electron beam transmitted from the microlens 20 of the electron emission means 3 emits electromagnetic waves as the trajectory of the electrons changes as the periodic change of the voltage applied to the Wiggler 30 passes through the widdlers. , The wavelength λ of the emitted electromagnetic wave is determined by Equation 1 below according to the distance between the Waglers 30 and the speed v of the electron beam.

λ = D (β ^-1 -cosθ)-Equation 1

Where D = Wigler spacing, β = v / c (speed of vsms electron beam, c is the speed of light in vacuum), θ = measuring angle)

Since the voltage applied to the emission source 10 for emitting electrons is several hundred volts to several thousand volts, the speed of the electrons can be obtained by Equation 2 below.

- 식2

Equation 2

Where e is the charge of the electron, m is the mass of the electron, and V is the voltage applied to the electron emitting tip.

이다. 여기서

이다. 이때, 측정각에 대한 효과

는 1이하의 값이므로 무시할 수 있다. 이 경우 테라헤르츠 영역인 900μm의 파장의 방사선을 내기 위한 위글러(30)의 간격 D = 81.9μm가 될 수 있다. For example, if the voltage (V) is 2000V, the speed is

to be. here

to be. At this time, the effect on the measurement angle

Is less than 1 and can be ignored. In this case, the spacing D of the Wigler 30 for emitting radiation having a wavelength of 900 μm, which is a terahertz region, may be 81.9 μm.

Therefore, in order to emit electromagnetic waves having a wavelength of 300 to 900 μm, which is a terahertz region, the terahertz electromagnetic waves in a desired wavelength region are adjusted by adjusting the interval of the Wigler 30 and the applied voltage of the emission source 10 according to Equation 3 below. You can get it.

- 식3

Equation 3

6 is a graph showing the electron beam trajectory of the cylindrical wiggle 30. As can be seen from this graph, the trajectory of the electron beam changes periodically in the Wigler 30, but since the Wigler 30 is a cylindrical symmetrical to the optical axis, the electron beam does not deviate to one side and the beam does not occur. The waist is only getting bigger and smaller periodically. As a result, it can be seen that the characteristics of the radiation in the cylindrical wegler 30 can be kept constant. Therefore, it is possible to emit electromagnetic waves in the stable terahertz (THz) region.

The electromagnetic wave generation process of the terahertz (THz) region by the ultra-small electromagnetic wave generation module 1 according to the present invention having such a configuration will be described.

When a voltage is applied to the emission source 10, electrons are emitted and transferred to the microlens 20. At this time, the extraction electrode 21 of the microlens 20 is the electrons emitted from the emission source 10 by the ground (positive) or the application of a positive voltage is the microlens 20 by the extraction electrode 21 It is guided to and passed through the eviction electrode 21 to the acceleration electrode (23).

In the acceleration electrode 23, a negative voltage is applied to collect electron beams spreading from the extraction electrode 21 at a large divergence angle to form parallel beams, which are emitted to the aperture electrode 25.

In the electron beam delivered to the aperture electrode 25, some electrons still spread to a large divergence angle in addition to the parallel beam. These electrons are collected in a parallel beam while passing through the aperture electrode 25, and most of the electrons form a parallel beam at the aperture electrode 25 and are transmitted to the wiggler 30.

As described above, the parallel beam transmitted to the wiggle 30 is efficiently and stably emitted by the electromagnetic wave having a wavelength in the terahertz (THz) region while passing through the cylindrical wiggle 30.

As described above, according to the present invention, the electron beam emitted from the emission source 10 is formed as a stable parallel beam in the microlens 20, and is transmitted to the wegler 30 of the radiation generating means 5, and the cylindrical wiggler At 30, a small electromagnetic wave generating module capable of stably and efficiently generating electromagnetic waves in the terahertz (THz) region is provided by keeping the characteristics of radiation constant.

3: electron emitting means 5: radiation generating means
10: emission source 20: microlens
21: extraction electrode 23: acceleration electrode
25: aperture electrode 30: Wigler
40: anode

Claims (5)

Electron emission means for emitting and scanning electrons, a wiggle emitting electromagnetic waves in a terahertz (THz) region by periodically changing a path of electrons scanned in the electron column, and an anode absorbing electromagnetic waves emitted from the wiggle, In the ultra-small electromagnetic wave generation module for generating electromagnetic waves in the terahertz region, including:
The electron emitting means,
An emission source emitting electrons by voltage application; And
An emission electrode for inducing electron emission with respect to the emission source, an acceleration electrode for forming electrons derived from the emission electrode into parallel electron beams, and an aperture electrode for filtering electrons out of an optical axis among electron beams transmitted from the acceleration electrode ( a microlens including a limiting aperture;
The electrodes are each made of a silicon film having a bore diameter of several micrometers to several hundred micrometers and a thickness of 1 micrometer to 5 micrometer,
The aperture electrode has a greater thickness than the eviction electrode and the acceleration electrode, and
The wiggle is a cylindrical wiggle that emits electromagnetic waves in the terahertz (THz) region by periodically changing the path of electrons transmitted from the microlens,
Ultra-small electromagnetic wave generating module, characterized in that. delete delete The method of claim 1,
The Wigler is a very small electromagnetic wave generation module, characterized in that provided in a plurality at a predetermined interval on the same axis from the microlens side toward the anode side. In the method for generating electromagnetic waves in the terahertz region using the ultra-small electromagnetic wave generation module of claim 1,
A method for generating electromagnetic waves in the terahertz region by using a micro-electromagnetic wave generation module, characterized by applying a voltage of -180 to -220 V to the accelerating electrode to collect a traveling path of electrons to form a parallel beam.

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