KR20150010853A - Packing sheet, detection sensor for terahertz wave and detection apparatus using terahertz wave - Google Patents

Abstract

According to an embodiment of the present invention, a packaging paper for a terahertz wave comprises: a terahertz wave transmission layer consisting of a material which a terahertz wave passes through; and an electric field enhancing structure to enhance an electric field by reacting to a predetermined frequency band of terahertz waves passing through the terahertz wave transmission layer.

Description

TECHNICAL FIELD [0001] The present invention relates to a packaging sheet for a terahertz, a detection sensor, and a detection device using a terahertz wave. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002]

The present invention relates to a non-destructive method using a terahertz wave and a detection device using a terahertz wrapping paper, a detection sensor, and a terahertz wave capable of detecting a change in the inside of a packaging container by using a structure for improving sensitivity .

Various packaging technologies are being used in order to prevent corruption, deformation and damage during the distribution period when the product reaches the consumer from the producer, depending on the characteristics of the product. However, accidents involving decaying or degenerating the contents inside the product frequently occur due to negligence in distribution and storage. Therefore, there is a need for a detection method that can monitor the preservation state at all times during the distribution process. It is not well known how to check the state of the inside of the package by non-destructive method. It has been reported that the surface temperature of the product is measured indirectly by using an infrared camera or the internal state is indirectly inspected or millimeter wave is inspected. However, since the sensitivity is very low by the existing non-destructive method, There is a limit that can not measure trace amounts of foreign substances or trace amounts of physical / chemical / biological changes. For example, detection of foodborne pathogens in packaged and distributed foods can not detect trace microbial changes immediately on site, so they are detected through indirect indices through microbial growth modeling using infrared temperature measurements. As a result, there is a limit to the accuracy and accuracy of the species and amount of harmful bacteria, and this method of detecting indirect indices is detected in a state where microbial growth has already progressed due to low sensitivity. Therefore, preemptive response is difficult.

It is intended to provide a technique for measuring physical / chemical / biological changes in a packaging container using a structure capable of improving detection sensitivity by a non-destructive method using a terahertz wave.

Other objects and advantages of the present invention will become apparent from the following description, and it will be understood by those skilled in the art that the present invention is not limited thereto. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

The terahertz wave packaging sheet according to an embodiment of the present invention includes a terahertz wave transmitting layer made of a material that transmits a terahertz wave and a terahertz wave transmitted through the terahertz wave transmitting layer, Reinforced structure.

The terahertz wave wrapping paper may further include a filter layer combined with the electric field enhancing structure and allowing only a specific material to pass through the electric field enhancing structure.

The terahertz wave wrapping paper may further include an optional sensing layer which is bonded to the electric field enhancing structure and bonds only with a specific substance and a filter layer which passes only a specific substance to the selective sensing layer.

The terahertz wave packaging sheet may further include a terahertz wave blocking layer formed on both sides of the terahertz wave transmitting layer and the electric field strengthening structure and blocking the terahertz wave.

The electric field enhancing structure may be at least one of a diffraction grating, a metal mesh, a metamaterial, a metal layer including an opening having a width equal to or less than the wavelength of the light source, a structure for inducing surface plasmon resonance, and a photonic crystal structure.

In another embodiment of the present invention, a terahertz wave detection sensor inserted in a packaging container including a region through which a terahertz wave is transmitted includes a terahertz wave detection sensor comprising a substrate layer made of a material for transmitting a terahertz wave, Layer structure formed on the substrate and reinforcing the electric field in response to a predetermined frequency band of the terahertz wave transmitted through the substrate layer.

The terahertz wave detection sensor may further include a filter layer coupled to the electric field enhancing structure and allowing only the specific material to pass through the electric field enhancing structure.

The terahertz wave detection sensor may further include an optional sensing layer which is combined with the electric field enhancing structure and bonds only with a specific substance, and a filter layer which allows only a specific substance to pass through the selective sensing layer.

The electric field enhancing structure may be at least one of a diffraction grating, a metal mesh, a metamaterial, a metal layer including an opening having a width equal to or less than the wavelength of the light source, a structure for inducing surface plasmon resonance, and a photonic crystal structure.

According to another embodiment of the present invention, a terahertz wave detecting apparatus includes a terahertz wave transmitting layer made of a material that transmits a terahertz wave, a terahertz wave transmitting layer made of a terahertz wave transmitted through the terahertz wave transmitting layer, And a detector for detecting the characteristics of the terahertz wave generated from the terahertz light source and the wrapping paper for irradiating the terahertz wave with the wrapping paper.

The detection apparatus using the terahertz wave may include a determination unit for comparing the detected terahertz wave with the reference terahertz wave to determine whether there is a change in the surroundings of the field enhancement structure.

When the resonance frequency of the detected terahertz wave and the resonant frequency of the reference terahertz wave differ by more than the set range, it is possible to judge that there is a change around the electric field enhancing structure.

The wrapper may further include a filter layer coupled to the electric field enhancing structure and allowing only the specific material to pass through the electric field enhancing structure.

The wrapper may further include an optional sensing layer that is bonded to the electric field enhancing structure and bonds only with the specific material, and a filter layer that allows only the specific material to pass through the selective sensing layer.

The wrapping paper may further comprise a terahertz wave blocking layer formed on both sides of the terahertz wave transmitting layer and the electric field strengthening structure and blocking the terahertz wave.

According to another aspect of the present invention, there is provided a detection apparatus using a terahertz wave, comprising: a substrate layer made of a material that transmits a terahertz wave; and a substrate layer formed on the substrate layer, the terahertz wave having a predetermined frequency A terahertz wave detection sensor inserted in a packaging container including a region through which a terahertz wave is transmitted, the fieldhardening structure including an electric field enhancing structure for enhancing an electric field in response to a band; a terahertz light source for detecting a terahertz wave by a detection sensor; And a detector for detecting a characteristic of the terahertz wave generated from the sensor.

The detection apparatus using the terahertz wave may further include a determination unit for comparing the detected terahertz wave with a reference terahertz wave to determine whether there is a change in the surroundings of the electric field enhancing structure.

The terahertz wave detection sensor may further include a filter layer coupled to the electric field enhancing structure and allowing only the specific material to pass through the electric field enhancing structure.

The terahertz wave detection sensor may further include an optional sensing layer which is combined with the electric field enhancing structure and bonds only with a specific substance, and a filter layer which allows only a specific substance to pass through the selective sensing layer.

According to the disclosed invention, by using electromagnetic waves in the terahertz wave band, it is possible to detect changes in the inside of the packaging container in real time on the spot in a non-destructive manner.

Further, by using a structure capable of improving the detection sensitivity by a non-destructive method using a terahertz wave, it is possible to more accurately detect changes in the inside of the packaging container.

1 is a block diagram of a detection apparatus using a terahertz wave according to an embodiment of the present invention.
2 is a view for explaining a wrapping paper for a terahertz wave according to an embodiment of the present invention.
3 is a view for explaining a wrapping paper for a terahertz wave according to another embodiment of the present invention.
4 is a view for explaining a wrapping paper for a terahertz wave according to another embodiment of the present invention.
5 is a view for explaining a wrapping paper for a terahertz wave according to another embodiment of the present invention.
6 is a view for explaining a terahertz wave detection sensor according to an embodiment of the present invention.
FIG. 7 is a view for explaining a resonance frequency of a selective sensing layer according to an embodiment of the present invention. FIG.
8 is a view for explaining an electric field enhancing structure according to an embodiment of the present invention.
9 is a view for explaining a modified example of the wrapping paper including the electric field enhancing structure according to the embodiment of the present invention.
10 is a view for explaining an electric field enhancing structure according to an embodiment of the present invention.
11 is a view for explaining an electric field enhanced structure according to another embodiment of the present invention.
12 is a view for explaining an electric field enhanced structure according to another embodiment of the present invention.

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

1 is a block diagram of a detection apparatus using a terahertz wave according to an embodiment of the present invention.

Referring to FIG. 1, a detection apparatus 100 using a terahertz wave includes a light source 110, a terahertz wave wrapping paper 120, a detector 130, and a determination unit 140.

The light source 110 may irradiate the terahertz wave with the wrapping paper 120. For example, the light source 110 may be various types of devices capable of generating terahertz waves. Terahertz blue An electromagnetic wave located in the region between infrared rays and microwaves, and can generally have a frequency of 0.1 THz to 10 THz. However, it should be understood that the present invention can be considered as a terahertz wave even if it is somewhat deviated from such a range, as long as those skilled in the art can easily contemplate the present invention.

The terahertz wave wrapping paper 120 may include a terahertz wave transmitting layer made of a material that transmits a terahertz wave and a terahertz wave transmitting layer configured to enhance a field in response to a predetermined frequency band of the terahertz wave transmitted through the terahertz wave transmitting layer an optional sensing layer for binding only to a specific material, and a filter layer for passing only a specific material through the selective sensing layer. A detailed description thereof will be described later.

The detection unit 130 can detect the characteristics of the terahertz wave generated from the wrapping paper 120 for terahertz. For example, the detection unit 130 can detect the characteristics of the terahertz wave reflected, transmitted, diffracted, or scattered from the wrapping paper 120 for the terahertz. Specifically, for example, the detecting unit 130 can detect the intensity of the terahertz wave generated from the wrapping paper 120 for terahertz, the resonant frequency of the terahertz wave, and the like.

The determination unit 140 may compare the terahertz wave detected by the detecting unit 130 with the reference terahertz wave to determine whether there is a change in the surroundings of the electric field enhancing structure included in the wrapping paper 120. Changes in the surroundings may include physical / chemical / biological changes. Physical changes mean changes in temperature, volume, morphology, etc. Chemical changes mean quantitative changes in constituents such as substance, gas, and moisture. Biological changes include changes in microbial, virus, . ≪ / RTI > The degree of change can be judged based on the difference between the resonant frequency of the detected terahertz wave and the resonant frequency of the reference terahertz wave.

For example, when the resonance frequency of the terahertz wave detected by the detecting unit 130 and the resonance frequency of the reference terahertz wave are different from each other by a predetermined range or more, the judging unit 140 judges whether the resonance frequency of the terahertz wave is included in the terahertz wave wrapping paper 120 It can be determined that there is a change around the electric field strengthening structure.

In another example, the determination unit 140 may determine, based on the difference between the resonance frequency of the detected terahertz wave and the resonance frequency of the reference terahertz wave, It can be judged that there is a change of Specifically, for example, the determination unit 140 may determine the degree of the physical / chemical / biological change around the electric field enhancing structure based on the difference value.

The determination unit 140 compares the intensity of the terahertz wave detected by the detection unit 130 at a specific wavelength with the intensity of the reference terahertz wave to determine the intensity of the detected terahertz wave at the specific wavelength, When the intensity of the terahertz wave and the intensity of the reference THz wave are different from each other in the set range, it can be judged that there is a change in the surroundings of the electric field strengthening structure included in the THz wave packaging sheet 120.

By using the terahertz wave electromagnetic wave, the detection device using the terahertz wave can detect the change in the inside of the packaging container in real time in the field in a non-destructive manner.

In addition, the detection device using the terahertz wave can more accurately detect the physical / chemical / biological change inside the packaging container by using the structure capable of improving the detection sensitivity by the non-destructive method using the terahertz wave.

2 is a view for explaining a wrapping paper for a terahertz wave according to an embodiment of the present invention.

Referring to FIG. 2, a packaging container 200 including a region through which a terahertz wave is transmitted may include a space surrounded by the wrapping paper 201 for THz. Materials such as food can be inserted into the space.

The terahertz wave wrapping paper 201 may include a terahertz wave transmission layer 202, an electric field enhancing structure 203, an optional sensing layer 204, and a filter layer 205.

The terahertz wave permeable layer 202 is made of a material that transmits a terahertz wave.

The field enhancement structure 203 may enhance an electric field in response to a predetermined frequency band of the terahertz wave transmitted through the terahertz wave transmission layer 202. For example, the electric field enhancing structure 203 may be formed by a combination of a diffraction grating, a metal mesh, a metamaterial, a metal layer including an opening having a width equal to or less than the wavelength of the light source, a structure inducing surface plasmon resonance, Or the like. The opening may be in the form of a slit or a hole.

The selective sensing layer 204 may be a layer that bonds only with a specific material. For example, the selective sensing layer 204 may be a layer that fixes a sensing material to a support that bonds with a specific material. Here, the sensing substance may be a substance that binds only to a specific substance to be detected.

For example, when the specific substance is a specific ion, a specific gas, moisture, a harmful substance, etc., the selective sensing layer 204 may be bonded only with a specific ion, specific gas, moisture, . Here, a specific substance means a target substance to be detected.

The selective sensing layer 204 may also be a layer that senses changes in the physical environment, such as temperature and volume within the package. For example, when the temperature or the volume in the package changes, the change selectively occurs with respect to temperature or volume change. When the physical change such as the temperature or the volume in the package does not appear, the selective layer may not change have.

The filter layer 205 may pass only a specific material to the selective sensing layer 204. For example, the filter layer 205 may be formed on the innermost side of the packaging container 200, and may be formed of a specific material (for example, a specific ion, Only certain gases, moisture, and hazardous materials) may pass through the selective sensing layer 204.

If it is desired to detect a specific gas change inside the packaging container 200, the selective sensing layer 204 uses a layer capable of binding only the specific gas, and the filter layer 205 is a layer capable of passing only gas Can be used. For example, when the light source 210 irradiates a terahertz wave with the packaging paper 201, the detecting unit 220 can detect the resonant frequency of the terahertz wave generated from the paper sheet 201 for terahertz. The determination unit (not shown) compares the resonance frequency of the terahertz wave generated from the wrapping paper 201 for the terahertz wave with the resonance frequency of the reference terahertz wave (the resonance frequency in the absence of moisture) If the difference is larger than the set range, it can be judged that a specific gas is adsorbed around the electric field strengthening structure. That is, the determination unit (not shown) can determine that a specific gas is generated inside the packaging container 200. The set range can be set variously by a user or the like.

The determination unit (not shown) compares the resonance frequency of the terahertz wave detected by the detecting unit 220 with the resonance frequency of the reference terahertz wave ('resonance frequency when no specific gas is adsorbed'), If the difference is larger than the set range, it can be judged that a specific gas is adsorbed around the electric field strengthening structure. That is, the determination unit (not shown) can determine that a specific gas is generated in the packaging container 200. The set range can be set variously by a user or the like.

As another example, when it is desired to detect a change in the moisture inside the packaging container 200, the selective sensing layer 204 uses a layer capable of binding only with moisture, and the filter layer 205 can pass moisture only Layer can be used. For example, when the light source 210 irradiates a terahertz wave with the packaging paper 201, the detecting unit 220 can detect the resonant frequency of the terahertz wave generated from the paper sheet 201 for terahertz. The determination unit (not shown) compares the resonance frequency of the terahertz wave generated from the wrapping paper 201 for the terahertz wave with the resonance frequency of the reference terahertz wave (the resonance frequency in the absence of moisture) If the difference is larger than the set range, it can be judged that moisture is generated around the electric field strengthening structure. That is, the judging unit (not shown) can judge that moisture is generated inside the packaging container 200. The set range can be set variously by a user or the like.

The determination unit (not shown) compares the resonance frequency of the terahertz wave detected by the detecting unit 220 with the resonance frequency of the reference THz wave (the resonance frequency in the absence of moisture) If the difference is larger than the range, it can be judged that moisture is generated around the electric field strengthening structure. That is, the judging unit (not shown) can judge that moisture is generated inside the packaging container 200. The set range can be set variously by a user or the like.

As another example, when it is desired to detect a temperature change inside the packaging container 200, the selective sensing layer 204 uses a layer containing a thermochromic dye sensitive to heat, and the filter layer 205 passes through only air And a layer of a material having a low heat transfer rate can be used. For example, when the light source 210 irradiates a terahertz wave with the packaging paper 201, the detecting unit 220 can detect the resonant frequency of the terahertz wave generated from the paper sheet 201 for terahertz. The determination unit (not shown) compares the resonance frequency of the terahertz wave generated from the wrapping paper 201 for the terahertz wave with the resonance frequency of the reference terahertz wave (resonance frequency at the reference temperature) Is greater than the set range, it can be determined that there is a temperature change around the electric field strengthening structure, and the temperature inside the packaging container can be grasped by checking the temperature change according to the preset resonance frequency difference. That is, the determination unit (not shown) can determine whether or not a temperature change has occurred inside the packaging container 200. The set range can be set variously by a user or the like.

The determination unit (not shown) compares the resonance frequency of the terahertz wave detected by the detecting unit 220 with the resonance frequency of the reference THz wave (resonance frequency at the reference temperature) If there is a larger difference, it can be judged that there is a temperature change around the electric field strengthening structure. That is, the determination unit (not shown) can determine whether or not a temperature change has occurred inside the packaging container 200. The set range can be set variously by a user or the like.

3 is a view for explaining a wrapping paper for a terahertz wave according to another embodiment of the present invention.

Referring to FIG. 3, the packaging container 300 including the area through which the terahertz wave is transmitted may include a space surrounded by the terahertz wave packaging paper 301. Materials such as food can be inserted into the space.

The terahertz wave packaging sheet 301 may include a terahertz wave transmission layer 302, an electric field enhancing structure 303, an optional sensing layer 304, a filter layer 305, and a terahertz wave blocking layer 306. 3, the terahertz wave packaging sheet 301 includes a terahertz wave transmission layer 302 through which a terahertz wave can be transmitted and a terahertz wave blocking layer 306 through which a terahertz wave is blocked And the size and shape of the terahertz wave-permeable layer 302 and the terahertz wave-blocking layer 306 can be variously modified. In this manner, a region through which the terahertz wave is transmitted can be formed only in a part of the entire packaging container 300.

The terahertz wave permeable layer 302 is made of a material that transmits a terahertz wave.

The field enhancement structure 303 may enhance an electric field in response to a predetermined frequency band of the terahertz wave transmitted through the terahertz wave transmission layer 302. For example, the electric field enhancing structure 303 may be formed of a metal such as a diffraction grating, a metal mesh, a metamaterial, a metal layer including an opening having a width equal to or less than the wavelength of the light source, a structure for inducing surface plasmon resonance, Or the like.

The selective sensing layer 304 may be a layer that fixes the sensing material to the support, which bonds only with the specific material. For example, when the specific substance is a specific ion, a specific gas, moisture, a harmful substance, etc., the selective sensing layer 304 may be bonded only with a specific ion, specific gas, moisture or harmful substance, .

The filter layer 305 may pass only the specific material to the selective sensing layer 304. For example, the filter layer 305 may be formed on the innermost side of the packaging container 300, and may be formed of a specific material (for example, a specific ion, Only certain gases, moisture, and hazardous materials) may pass through the selective sensing layer 304.

The terahertz wave blocking layer 306 is formed on both sides of the terahertz wave transmitting layer 302, the electric field enhancing structure 303, the selective detecting layer 304, and the filter layer 305 and is capable of reflecting a terahertz wave .

In order to protect the product from ultraviolet rays, visible light, infrared rays, moisture, and harmful substances originally flowing from the outside of the package to the inside of the THz-wave blocking layer 306, a layer of a metal such as an aluminum film is used as a polymer packing material. PE, polypropylene (PP)), which contains a metallic component and reflects terahertz waves.

The detection structure composed of the terahertz wave transmission layer 302, the electric field enhancing structure 303, the selective sensing layer 304 and the filter layer 305 is formed only in a specific portion of the entire packaging paper so that the inside of the packaging sheet can be easily detected by the non- A sensing window can be formed.

4 is a view for explaining a wrapping paper for a terahertz wave according to another embodiment of the present invention.

Referring to FIG. 4, the packaging container 400 including the area through which the terahertz wave is transmitted may be a container for storing beverage. A portion or the lid portion of the side surface of the packaging container 400 may be formed of the terahertz wave packaging paper 401. In this way, a region through which the terahertz wave is transmitted can be formed only in a part of the packaging container 400, not the whole.

The terahertz wave wrapping paper 401 may include a terahertz wave transmission layer 402, an electric field enhancing structure 403, an optional sensing layer 404, and a filter layer 405.

The terahertz wave permeable layer 402 is made of a material that transmits a terahertz wave.

The field enhancement structure 403 may enhance the field in response to a predetermined frequency band of the terahertz wave transmitted through the terahertz wave transmission layer 402. For example, the electric field enhancing structure 403 may be formed of a metal such as a diffraction grating, a metal mesh, a metamaterial, a metal layer including an opening having a width equal to or less than the wavelength of the light source, a structure for inducing surface plasmon resonance, Or the like.

The selective sensing layer 404 may be a layer that fixes the sensing material to the support, which bonds only with the specific material. For example, when the specific substance is a specific ion, a specific gas, moisture, a harmful substance, etc., the selective sensing layer 404 may be bonded only with a specific ion, specific gas, moisture or harmful substance, .

The filter layer 405 may pass only certain materials to the optional sensing layer 304. For example, the filter layer 405 may be formed on the innermost side of the packaging container 400, and may be formed of a specific material (for example, a specific ion, Only certain gases, moisture, and hazardous materials) may pass through the selective sensing layer 304.

5 is a view for explaining a wrapping paper for a terahertz wave according to another embodiment of the present invention.

Referring to FIG. 5, the terahertz wave wrapper 500 includes a first region 510 capable of obtaining a reference THz wave characteristic and a second region 520 capable of obtaining a changed terahertz wave characteristic .

The first region 510 may include a terahertz parasitic layer 511, an electric field enhancing structure 512, an optional sensing layer 513 that does not include a sensing material, and a filter layer 514.

The second region 520 may include a terahertz wave transmission layer 521, an electric field enhancing structure 522, an optional sensing layer 523 including a sensing material, and a filter layer 524.

The functions of the layers included in each area have already been described above, and thus will be omitted.

When a light source (not shown) irradiates the terahertz wave to the first region 510, the detection unit (not shown) can detect the first resonant frequency f1 of the terahertz wave detected in the first region 510 have. Here, the first resonance frequency f1 is the resonance frequency of the reference THz wave. When a light source (not shown) irradiates the terahertz wave to the second region 520, the detection unit (not shown) can detect the second resonant frequency f2 of the terahertz wave detected in the second region 520 have. Here, the second resonant frequency f2 is a resonant frequency of the terahertz wave changed as the specific material included in the selective sensing layer 523 is coupled to the sensing material. In other words, when a specific material is coupled to the selective sensing layer 523, the second resonant frequency f2 changes.

(Not shown) detects a first resonance frequency f1 (a resonance frequency of a reference THz wave) of the terahertz wave detected in the first region 510 and a terahertz If the difference between the two resonance frequencies is greater than the set range, it can be judged that a physical / chemical / biological change has occurred inside the packaging container (not shown).

6 is a view for explaining a terahertz wave detection sensor according to an embodiment of the present invention.

Referring to FIG. 6, the packaging container 600 including the area through which the terahertz wave is transmitted may be a container for storing beverage. The packaging container 600 may include a region 610 through which a terahertz wave is transmitted to a part of the side surface.

The terahertz wave detection sensor 620 may include a substrate layer 621, an electric field enhancing structure 622, an optional sensing layer 623, and a filter layer 624.

The substrate layer 621 is made of a material that transmits a terahertz wave.

The electric field enhancing structure 622 may enhance an electric field in response to a predetermined frequency band of the terahertz wave transmitted through the substrate layer 621. For example, the electric field enhancing structure 622 may include a diffraction grating, a metal mesh, a metamaterial, a metal layer including an opening having a width equal to or less than the wavelength of the light source, a structure for inducing surface plasmon resonance and a photonic crystal structure, Or the like.

The selective sensing layer 623 may be a layer that fixes the sensing material to the support, which bonds only with the specific material. For example, when a specific substance is a specific ion, a specific gas, moisture, a harmful substance, etc., the selective sensing layer 623 may be bonded only with a specific ion, specific gas, moisture, .

The filter layer 624 may pass only a specific material to the selective sensing layer 623. For example, the filter layer 624 may be formed on the innermost side of the packaging container 600 and may be formed of a specific material (for example, a specific ion, Only certain gases, moisture, and harmful substances) may pass through the selective sensing layer 623.

If it is desired to detect a change in the moisture inside the packaging container 600, the selective sensing layer 623 uses a layer capable of binding only with moisture, and the filter layer 624 uses a layer capable of passing only moisture Can be used. For example, when the light source 630 irradiates the terahertz wave with the detection sensor 620, the detection unit 640 can detect the resonant frequency of the terahertz wave detected from the detection sensor 620. The determination unit (not shown) compares the resonance frequency of the terahertz wave detected from the detection sensor 620 with the resonance frequency of the reference terahertz wave ('resonance frequency in the absence of moisture'), If the difference is larger than the set range, it can be judged that moisture is generated around the electric field strengthening structure. That is, the judging unit (not shown) can judge that moisture is generated inside the packaging container 600.

FIG. 7 is a view for explaining a resonance frequency of a selective sensing layer according to an embodiment of the present invention. FIG.

7A and 7B, the terahertz wrapping paper 700 includes a terahertz wave transmission layer 701, an electric field enhancing structure 702, an optional sensing layer 703, and a filter layer 704 .

The terahertz wave permeable layer 701 is made of a material that transmits a terahertz wave.

The field enhancement structure 702 may enhance the field in response to a predetermined frequency band of the terahertz wave transmitted through the terahertz wave transmission layer 701. For example, the electric field enhancing structure 702 may be formed by a diffraction grating, a metal mesh, a metamaterial, a metal layer including an opening having a width equal to or less than the wavelength of the light source, a structure for inducing surface plasmon resonance, Or the like.

The selective sensing layer 703 may be a layer that fixes the sensing material to the support, which bonds only with the specific material 705. For example, when a specific substance is a specific ion, a specific gas, moisture, a harmful substance, etc., the selective sensing layer 703 may be bonded only with a specific ion, specific gas, moisture, .

The filter layer 704 may pass only the specific material 705 to the selective sensing layer 704. For example, the filter layer 704 can be formed on the innermost side of the packaging container, and only a specific material (e.g., a specific ion, a specific gas, moisture) among various kinds of materials existing in the inner space of the packaging container May pass through the selective sensing layer 703.

FIG. 7A shows a case where moisture is not coupled to the selective sensing layer 703, and FIG. 7B shows a case where moisture is coupled to the selective sensing layer 703. FIG. Hereinafter, it is assumed that a change in moisture inside the packaging container is desired to be detected. In this case, the selective sensing layer 703 can only couple with the water 705, and the filter layer 704 can pass only moisture and block other substances 706.

7A, when the light source 710 irradiates the terahertz wave with the wrapping paper 700, the detector 720 detects the first resonant frequency f1 of the terahertz wave sensed from the wrapping paper 700 for the terahertz, Can be detected. Here, the first resonance frequency f1 is the resonance frequency of the reference THz wave.

7 (b), when the light source 710 irradiates the terahertz wave with the wrapping paper 700, the detecting unit 720 detects the second resonant frequency f2 of the terahertz wave sensed from the wrapping paper 700 for the terahertz, Can be detected. The characteristic of the electric field enhancing structure 702 changes as the moisture 705 is coupled to the selective sensing layer 703 so that the second resonant frequency f2 is changed differently from the first resonant frequency of the reference TeraHeappe.

The determination unit (not shown) compares the first resonance frequency f1 (the resonance frequency of the reference THz wave) of the terahertz wave obtained in FIG. 7A with the THz frequency of the terahertz wave obtained in FIG. If the difference between the two resonance frequencies is larger than the set range, the second resonance frequency f2 can be judged to be generated inside the packaging container (not shown).

8 is a view for explaining an electric field enhancing structure according to an embodiment of the present invention.

Referring to FIG. 8A, the electric field enhancing structure may be a waveguide grating that causes Guided Mode Resonance (GMR) for a specific wavelength.

The waveguide diffraction grating layer 802 can diffract the incident light under a given condition (wavelength of incident light, incident angle, waveguide thickness, effective refractive index, and the like). The higher order diffraction waves except for the zeroth order can form a guided mode in the waveguide diffraction grating layer 802. At this time, the zero-order reflected wave-transmission wave occurs in guided mode and phase matching, and resonance occurs in which the energy of the waveguide mode is transmitted again to the zero-order reflected wave-transmission wave. As resonance occurs, 100% reflection occurs in the 0th-order reflection diffraction wave due to constructive interference, and 0th-order transmission diffraction wave is 0% transmission due to destructive interference, resulting in a very sharp resonance curve in a specific wavelength band.

8 (b) shows a diffraction grating (n _H = 1.80, n _L = 1.72, thickness = 80 μm, period = 200 μm) formed by a SU-8 photoresist on a transparent polymethylpentene substrate (n = 1.46) in a terahertz band, The result is GMR calculation using differential factor method (resonance occurs at 0.89 THz).

The dielectric constant of the cover layer 801 is? ₁ , the dielectric constant of the waveguide diffraction grating layer 802 is? ₂ , the dielectric constant of the lower substrate layer 803 is? ₃ , The dielectric constant epsilon ₂ of the waveguide diffraction grating layer can be expressed by the following equation (1).

[Equation 1]

Where ε _g is the mean value of the configuration of the diffraction grating, and repeating two types of dielectric constant (ε _H, ε _L) is, △ ε is the maximum amount of change in dielectric constant at, K is 2π / Λ, as the grid frequency Λ is the period of the grating And x is the distance from the origin to the X axis direction.

In this case, in order for the waveguide diffraction grating to resonate at a specific wavelength and incident angle of the incident light, that is, to generate the waveguide mode, the effective refractive index N of the waveguide satisfies the following condition.

)|N|<

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When a GMR occurs in a waveguide diffraction grating, the electric field is concentrated near the diffraction grating. Due to the near field enhancement phenomenon, the change in the refraction index near the waveguide diffraction grating appears as a change in the resonance frequency as a whole. Using this principle, the sensing film is formed near the waveguide grating, and the chemical-physical bonding of the fine sensing material within the sensing film is represented by a change in the resonance frequency, so that the sensing principle can be utilized as a high sensitivity sensing principle.

Here, this principle is applied in the teraflag area to form a GMR sensing element that reacts in the teraflag area in the wrapping paper, thereby making a teraphar sensing element with high sensitivity. In particular, it combines with the nondestructive characteristic of teraflas and enables non-destructive detection with high sensitivity.

8 (c) is a perspective view for explaining the structure and shape of the waveguide diffraction grating.

The diffraction grating may include grooves or ridges formed on the surface of the dielectric slab. As another example, the diffraction grating is a planar dielectric sheet having a periodically alternating refractive index (e.g., a phase grating) in the dielectric sheet. The exemplary phase grating may be formed by forming an array of periodic holes in and through the dielectric sheet.

As another example, the diffraction grating can include either a one-dimensional (1D) diffraction grating or a two-dimensional diffraction grating. The 1D diffraction grating may for example include a set of substantially straight grooves that are periodic and parallel only in a first direction (e.g. along the x-axis). An example of a 2D diffraction grating can include an array of holes in a dielectric slab or sheet, wherein the holes are periodically spaced (e.g. along both the x- and y-axes) according to two orthogonal directions . At this time, the 2D diffraction grating is also called a photonic crystal.

9 is a view for explaining a modified example of the wrapping paper including the electric field enhancing structure according to the embodiment of the present invention.

9A, the terahertz wave packaging sheet comprises a terahertz wave substrate layer 901, a first dielectric layer 902, a waveguide grating layer 903, a second dielectric layer 904, an optional sensing layer (not shown) 905, and a filter layer 906.

9 (a), the waveguide diffraction grating layer 903 is covered with dielectric layers 902 and 904 on the upper and lower sides. This case is a structure that mainly reduces the sideband around the peak of the resonance curve, and the anti-reflection condition is determined by the thickness of the dielectric. That is, the waveguide diffraction grating layer 903 may have a thickness corresponding to half of the resonance wavelength, and the dielectric layers 902 and 904 may be designed to have a thickness corresponding to one-fourth of the resonance wavelength. At this time, the refractive index of the dielectric layers 902 and 904 must be smaller than the effective refractive index of the waveguide diffraction grating layer 903.

Referring to FIG. 9B, the terahertz wave packaging sheet comprises a terahertz wave substrate layer 911, a waveguide layer 912, a waveguide grating layer 913, an optional sensing layer 914, and a filter layer (not shown) 915).

The structure of FIG. 9 (b) differs from that of the waveguide layer 912 formed between the substrate layer 911 and the waveguide diffraction grating layer 913 after the incident light is diffracted, Mode (guided mode). At this time, the refractive index of the waveguide layer 912 must be greater than the effective refractive index of the waveguide diffraction grating layer 913 and the refractive index of the substrate layer 911.

As another example, the waveguide layer 912 may be formed between the diffraction grating layer 913 and the selective sensing layer 914, not between the substrate layer 911 and the diffraction grating layer 913.

Referring to FIG. 9C, the terahertz wave packaging sheet has a terahertz wave transmission layer 921, a first diffraction grating layer 922, a second diffraction grating layer 923, an optional sensing layer 924, (925). The first diffraction grating layer 922 and the second diffraction grating layer 923 may be formed so as to be arranged so as to be crossed without overlapping.

9 (c), the first diffraction grating layer 922 and the second diffraction grating layer 923 can diffract incident light, and the first diffraction grating layer 922 has a guided mode ) Can be formed. At this time, the average refractive index of the first diffraction grating layer 922 should be greater than the average refractive index of the second diffraction grating layer 923 and the refractive index of the terahertz wave transmission layer 921.

In addition to the structure described in this embodiment, the structure may be modified into various shapes, and such structures may induce an electric field enhancement effect in the vicinity of the waveguide layer, thereby improving the sensitivity.

10 is a view for explaining an electric field enhancing structure according to an embodiment of the present invention.

Referring to FIG. 10, the electric field enhancing structure may be a metamaterial. Meta-material is basically an artificial material designed to have a negative permittivity or a negative permeability of a material, which is a core element of a lattice structure.

10 (a) to 10 (j), the meta-material may have various pattern shapes. The metal resonant structure is typically a thin metal line or a split ring resonator (SRR) as in the case of various metal patterns shown in FIG. 10. By arranging the metal resonant structure on the lattice constantly, the permittivity and permeability of the material can be arbitrarily adjusted have.

In particular, when such a meta material is formed on a certain dielectric substrate in a terahertz band and a terahertz wave is incident on the meta material, resonance occurs in a specific wavelength band and a region where the transmittance is rapidly reduced occurs. At this time, the resonance frequency changes in response to the minute change of the selective sensing layer disposed near the metamaterial, like the GMR example described above, and the change of the resonance frequency can be detected by the change of the resonance frequency. 7)

It is known that the meta-material also has a field enhancement effect near the meta-material and can be detected at a much higher sensitivity than a simple terahertz wave. In the present invention, by applying this principle, We want to use materials.

11 is a view for explaining an electric field enhanced structure according to another embodiment of the present invention.

11, the wrapper 1100 may include a substrate layer 1110, a metal mesh (mesh) structure 1120, an optional sensing layer 1130, and a filter layer 1140. Since the metal mesh structure 1120 strongly resonates in a specific wavelength band similar to the GMR structure, an electric field strengthening effect may occur near the metal mesh structure. The change in the inside of the wrapping paper can be detected with high sensitivity by bonding the metal mesh structure 1120 which can generate the electric field enhancement effect to the wrapping paper rather than merely inputting the terahertz wave.

12 is a view for explaining an electric field enhanced structure according to another embodiment of the present invention.

12, the wrapper 1200 may include a substrate layer 1210, a metal layer 1220, an optional sensing layer 1230, and a filter layer 1240. The metal layer 1220 includes a layer in which a hole or a slit-like structure having a width equal to or less than the wavelength of the light source is formed on the metal film. When the terahertz wave enters the metal layer 1220, the incident terahertz wave passes through the hole or slit in a specific wavelength band. As the THz waves pass, strong electric fields are formed around the holes or slits below the resonance wavelength. Accordingly, it is possible to detect a change in the inside of the wrapping paper with high sensitivity by bonding a metal layer capable of generating an electric field enhancement effect to the wrapping paper, rather than merely inputting a terahertz wave.

Although not shown, a structure (for example, a semiconductor-based structure or a metamaterial-based structure) or a photonic crystal structure that induces a surface plasmon resonance phenomenon in a terahertz region that can enhance an electric field in the vicinity of a structure . Likewise, it can be used as a structure to strengthen the electric field near the structure.

The embodiments described may be constructed by selectively combining all or a part of each embodiment so that various modifications can be made.

It should also be noted that the embodiments are for explanation purposes only, and not for the purpose of limitation. In addition, it will be understood by those of ordinary skill in the art that various embodiments are possible within the scope of the technical idea of the present invention.

100: Detection device using terahertz waves
110: Light source
120: wrapping paper for terahertz
130:
140:

Claims (19)

A terahertz wave transmission layer made of a material that transmits a terahertz wave; And
And a field enhancement structure for enhancing an electric field in response to a predetermined frequency band of the terahertz wave transmitted through the terahertz wave transmission layer.
The method according to claim 1,
Further comprising a filter layer coupled to the electric field enhancing structure and allowing only the specific material to pass through the electric field enhancing structure.
The method according to claim 1,
An optional sensing layer coupled with the electric field enhancing structure and bonded only to a specific material; And
And a filter layer passing only the specific material to the selective sensing layer.
The method according to claim 1,
Further comprising a terahertz wave blocking layer formed on both sides of the terahertz wave transmitting layer and the electric field strengthening structure and blocking the terahertz wave.
The method according to claim 1,
Wherein the electric field enhancing structure comprises:
Wherein at least one of a diffraction grating, a metal mesh, a metamaterial, a metal layer including an opening having a width equal to or less than the wavelength of the light source, a structure for inducing surface plasmon resonance, and a photonic crystal structure.
1. A terahertz wave detection sensor inserted in a packaging container including an area through which a terahertz wave is transmitted,
A substrate layer made of a material that transmits a terahertz wave; And
And an electric field reinforcing structure formed on the substrate layer and reinforcing an electric field in response to a predetermined frequency band of the terahertz wave transmitted through the substrate layer.
The method according to claim 6,
And a filter layer coupled to the electric field enhancing structure and passing only the specific material to the electric field enhancing structure.
The method according to claim 6,
An optional sensing layer coupled with the electric field enhancing structure and bonded only to a specific material; And
And a filter layer passing only the specific material to the selective sensing layer.
The method according to claim 6,
Wherein the electric field enhancing structure comprises:
At least one of a diffraction grating, a metal mesh, a metamaterial, a metal layer including an opening having a width equal to or less than the wavelength of the light source, a structure for inducing surface plasmon resonance, and a photonic crystal structure.
A terahertz wave transmission layer made of a material that transmits a terahertz wave and a terahertz wave transmitted through the terahertz wave transmission layer, and an electric field enhancing structure for enhancing an electric field in response to a predetermined frequency band of the terahertz wave transmission layer. ;
A terahertz light source for irradiating the terahertz wave with the packaging paper; And
And a detector for detecting a characteristic of the terahertz wave generated from the wrapping paper.
11. The method of claim 10,
And a determination unit comparing the detected terahertz wave with a reference terahertz wave to determine whether there is a change around the electric field enhancing structure.
12. The method of claim 11,
Wherein,
Wherein the resonance frequency of the detected terahertz wave and the resonant frequency of the reference terahertz wave are different from each other by more than a predetermined range.
11. The method of claim 10,
The wrapping paper
And a filter layer coupled to the electric field enhancing structure and passing only the specific material to the electric field enhancing structure.
11. The method of claim 10,
Wherein,
An optional sensing layer coupled with the electric field enhancing structure and bonded only to a specific material; And
And a filter layer passing only the specific material to the selective sensing layer.
11. The method of claim 10,
The wrapping paper
And a terahertz wave blocking layer formed on both sides of the terahertz wave transmitting layer and the electric field strengthening structure and blocking the terahertz wave.
A substrate layer made of a material that transmits a terahertz wave; and an electric field reinforcing structure formed on the substrate layer and reinforcing an electric field in response to a predetermined frequency band of a terahertz wave transmitted through the substrate layer, A terahertz wave detection sensor inserted in a packaging container including an area through which waves are transmitted;
A terahertz light source for irradiating a terahertz wave with the detection sensor;
And a detector for detecting a characteristic of the terahertz wave generated from the detection sensor.
17. The method of claim 16,
And a determination unit comparing the detected terahertz wave with a reference terahertz wave to determine whether there is a change around the electric field enhancing structure.
17. The method of claim 16,
The terahertz wave detection sensor
And a filter layer coupled to the electric field enhancing structure and passing only the specific material to the electric field enhancing structure.
17. The method of claim 16,
The terahertz wave detection sensor comprises:
An optional sensing layer coupled with the electric field enhancing structure and bonded only to a specific material; And
And a filter layer passing only the specific material to the selective sensing layer.

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