Device for imaging terahertz radiation sources
SUBSTANCE: invention relates to imaging terahertz (THz) radiation (ν=0.1-10 THz or λ=30-3000 mcm) and can be used to design devices for detecting and analysing terahertz radiation. The device for imaging terahertz radiation sources has a converter for converting terahertz radiation to infrared radiation, which consists of a layer of artificial metamaterial with resonant absorption of terahertz radiation, deposited on a solid-state substrate made of sapphire, placed between an input terahertz lens and an infrared camera lens situated on the side of the substrate. The converter is based on a gelatin matrix which contains metal nanoparticles and is provided with a cut-off filter placed in front of the matrix to allow filtration of thermal radiation of the terahertz radiation source with wavelength of not more than 30 mcm.
EFFECT: high noise-immunity of the design, low noise level and high sensitivity while simplifying the design of the imaging device.
16 cl, 6 dwg
The technical field to which the invention relates.
The invention relates to the field of optical and optoelectronic technology, in particular to the Visualizers terahertz (THz) radiation (ν=0,1÷10 THz or λ=30÷3000 μm), and can be used to create devices for the recording and analysis of THz-radiation.
From the point of view of practical applications one of the most promising aspects of the application of THz-radiation is used in medicine for imaging, golograficheskaya and tissue imaging, therapy and surgery. In addition, the Terahertz radiation also finds its application in biochemical and biophysical research when determining the THz spectra of the absorption and reflection of organic and biological molecules, proteins, DNA, etc. to determine the concentration of substances in the special technique of counter-terrorism and counter-narcotics, when creating devices for remote detection of toxic and explosive substances.
In the study of the sources of THz radiation, monitoring and control fields, the measurement of weak flows THz radiation in tasks that require registration of low-energy signals in the Terahertz range, there is the need for visualization of the sources of THz radiation.
Rendering images at low power, it is to rule, is any object scanning focused beam of THz radiation, or long exposures. However, in the first case, this requires powerful sources of THz radiation, and the second image is low contrast, which does not allow to obtain reliable information about the object.
Known Converter THz-radiation in the infrared (IR) radiation, made in the form of ultra-thin (not less than 50 times smaller than the wavelength of THz-radiation) of the multilayer structure on the basis of the dielectric layer. By the fall of the THz-radiation on the surface of the dielectric layer is made metallized topological drawing, forming a frequency-selective surface. On the reverse side of the dielectric layer deposited continuous layer with metallic conductivity, over which is applied a thin layer of material having high emissivity in the infrared range (coefficient of dullness, close to unity) [EN 2447574, H03D 7/00, publ. 10.04.2012]. The disadvantages of this solution should include the complexity of design and limited use due to high noise levels that require the use of additional filtering tools.
It is also known solution visualization device, comprising: a Converter THz radiation in the infrared radiation, consisting of a layer IP is ostendo created metamaterial resonance absorption of THz radiation, deposited on a solid substrate of sapphire, located between the input THz lens and the lens receiving chamber (visible light), located on the side of the substrate; a source of visible light is configured to illuminate the back side of the Converter; and a camera with a lens and a detector adapted to detect radiation of visible light from the rear side of the Converter. This Converter consists of a liquid crystal layer deposited on a rigid substrate made of sapphire glass, and contains an absorbent layer comprising particles of metal powder (iron, aluminum, tin or copper), and the detector receives the image radiation is visible light, formed on the rear face of the Converter [US 2008179519, G02F 1/13, publ. 31.07.2008]. This solution is the closest to the claimed invention, the essential features and made for the prototype. Among the disadvantages of this solution include low sensitivity with high level of noise, non-uniform pixel response, excessive design complexity.
In connection with the foregoing, at present, the urgent task is to develop new ways of visualizing THz-radiation.
The present invention is the development of simple devices provide the emission THz radiation by converting the latter to the infrared radiation and reception with the help of infrared cameras with a wide range of applications.
Technical result achieved the claimed invention is to increase the noise immunity design, reduced noise and increased sensitivity while at the same time simple design visualization device.
The above technical result is reached that use the visualization device sources of THz radiation, containing the Converter THz radiation in the infrared radiation, consisting of a layer of artificial metamaterial resonance absorption of THz-radiation deposited on a solid substrate, located between the input THz lens and lens IR camera. In contrast to the prototype Converter is made on the basis of the gelatinous matrix containing nanoparticles of metal, and provided with a low pass filter placed in front of a matrix with filter heat radiation source of THz radiation with wavelengths less than 30 ám.
In a preferred embodiment of the invention gelatinous matrix Converter may contain metal nanoparticles with a size of about 2 nm, with a peak density of electronic States at the Fermi level, with the possibility of conversion of THz radiation into heat. When the nanoparticles are isolated from each other and made dispergirovannykh in a gelatin emulsion matrix Converter and preferably made from plumage is of one metal with a peak density of States of electrons at the Fermi level, for example, Nickel, or made of compounds with heavy fermions. In addition, in the preferred embodiment of the invention, the substrate can be made of sapphire, and the lens of the infrared camera is located on the side of the substrate.
Among preferred are also options for implementation, in which metal nanoparticles are distributed on the surface of the Converter with surface density determined from the relationship:
where Q is the power required to maintain the nanoparticles in the gelatinous matrix at temperature T+ΔT, W;
T is the temperature of the Converter, To;
ΔT is the magnitude of the temperature increase of the nanoparticle relative to T as a result of its exposure to terahertz radiation, To;
Δελ- sensitivity infrared camera on the surface density of the radiation power, which is determined from the relationship:
where σ=5,67·10-8W·m-2·K-4- Stefan-Boltzmann constant;
Δ tABBtemperature sensitivity infrared camera, refer to the absolutely black body, K.
Low pass filter may be configured to filter infrared radiation from the source of THz radiation in the wavelength range of 3-30 μm and transmission of THz-radiation from the source with a wavelength of not less than 30 μm. This is predpochtitelno perform low pass filter, the gelatinous matrix containing nanoparticles, and the sapphire substrate closely adjacent to each other to ensure the protection of the nanoparticles in the gelatinous matrix of the lateral flow of infrared radiation.
The diameter of the input THz lens, mostly made significantly large relative to the diameter of the lens of the infrared camera with the ability to protect the nanoparticles Converter from noise emissions, and the IR camera may further comprise a low pass filter with a hole for the lens with the ability to protect the Converter from the background THz-radiation of the camera and its housing, where the low pass filters the IR camera and the Converter is preferably made of a homogeneous material with wavelength intervals of not more than 120 μm.
In yet another embodiment, the invention may be running gelatinous matrix Converter containing metal nanoparticles deposited on facing the lens of an infrared camera to the surface of the low pass filter of the Converter, in addition made in the form of the substrate. It makes possible the use of an infrared camera with an operating range of 7-15 μm.
In another embodiment, the invention may be additionally included in the device smoothly tunable laser light source.
List of drawings
The invention is sdaetsa schema visualization source of THz radiation, presented in figure 1. It should be noted that the accompanying diagram illustrates only one of the most preferred embodiment of the invention, and therefore could not be considered as limitations of the content of the invention, which includes other variants of execution.
Figure 2 presents a description of the emissivity of a black body (ABB) at a temperature of 300 K;
Figure 3 - dependence of the power Q as a function of growth temperature δ tmfor the Ni nanoparticles of radius R0=1.2 nm in spherical gelatinous sheath;
Figure 4 - the increase in temperature ΔT as a function of time of heating/cooling t for Ni nanoparticles of radius R0=1.2 nm in spherical gelatin shell for five values of Qi.
In addition, to understand the essence of the claimed invention figure 5 presents the transmission spectrum of the layer of air of thickness 1.2 m under normal conditions, and figure 6 presents the transmission spectra of different varieties of tissues in the THz-range of wavelengths (from the bottom up: wool, denim, silk, cotton and synthetics).
Information confirming the possibility of carrying out the invention
Using ultra-sensitive IR camera with high resolution (~14-38 MK) , and optical elements of THz-band produced by the industry, you can offer prosteishem rendering objects-sources of THz-radiation (Figure 1).
In accordance with the scheme presented in figure 1, the THz lens 2 forms in THz-ray image of the object, which is the source of 1 THz-radiation on two-dimensional Converter 4, which converts the THz radiation in the infrared. Generated by the Converter 4, the image in the infrared rays, in turn, is subject to the lens of the infrared camera 6. The filter 3 is used to filter thermal radiation of the object in the wavelength range of 3-30 μm, which is the peak body radiation with a temperature of ≈300 K, and the substrate 5 sapphire provides this example of the invention, the filtering of thermal radiation of an infrared camera to protect the Converter from the IR camera.
The Converter 4 is a gelatinous matrix containing metal nanoparticles with a size of ≈2 nm, with a peak density of electronic States at the Fermi level. In these particles is the transformation of energy THz-rays into heat due to the excitation and the subsequent scattering of electrons. When reducing the size of metal nanoparticles distance between the energy levels of electrons increases to values equal to the energy of THz-quantum, and due to this, the nanoparticles are heated in the Terahertz rays.
If in the gelatinous matrix to make quite a lot of metal nanoparticles, THz-radiation will heat the nanoparticles to tempera is URS the sensitivity of the IR camera or higher. The latter is heated, creates an image in the infrared rays. IR camera with high temperature resolution and a large number of pixels (~320×256 pixels) allows, therefore, to visualize the THz-radiation source object THz-radiation.
To save the property of the nanoparticles to convert THz radiation into heat, it is necessary that their size was relatively small and was, as stated above, about 2 nm, it is necessary to maintain the isolation of the nanoparticles, preventing the formation of nanoparticles clusters ("lumps"). Isolation of nanoparticles from each other is achieved, in particular, when performing their dispergirovannykh in the matrix, transparent to THz radiation, for example in gelatin emulsion, using technology developed in the production of photographic materials.
As the material for the nanoparticles converters is preferable to choose a transition metal with a peak density of States of electrons at the Fermi energy EFthat allows you to provide heating of the nanoparticles to a higher temperature than in the case of a normal metal. In particular, the claimed invention proposes using nanoparticles of Nickel. As is known, the width of the 3d band of Nickel is equal to ≈5.5 eV, and part of it is above EFthat determines the intense scattering of the electrons in the Nickel. In addition, the alignment with other metals Nickel greatest density of States at the Fermi level .
To implement the claimed invention, following the above example implementation, the average particle size of Ni is chosen equal to ≈2,4 nm, i.e. less than the average free path length of an electron (≈4 nm). Such particle size and the presence of a peak of the density of States at the Fermi level of Ni increases the probability of scattering of electrons on the surface of the nanoparticles, i.e. increase the probability of energy transfer obtained by the electron from the photon - ion nanoparticles and thereby increase the conversion efficiency of the Terahertz energy into heat.
The average size of Ni nanoparticles were also selected from the condition of equality of the energy gap between the electronic levels in the 3d-zone average energy of phonons in Ni, estimated 20.5 MeV.
The top edge of the 3d band of Ni is higher than the Fermi level of about 0.5 eV , which provides the ability of the Ni nanoparticles to convert into heat energy photons just THz-band. However, this broadband absorption ability is accompanied by an undesirable property: nanoparticles Converter can be heated by infrared photons with energies up to 0,513 eV (wavelengths ≥2,42 μm). Thus the photons, the most dangerous from the point of view of contribution to background noise, the corresponding area under the peak with λ≈10 µm, fall within the absorption band (see Figure 2). Therefore, to protect the nanoparticles convertert undesirable heating of the filter, able to filter out background infrared radiation from a source object with wavelengths λ<30 μm, but skipping useful THz radiation with wavelengths λ>30 μm (see Figure 2).
To achieve the stated technical result was evaluated the most important technical parameters of THz-IR Converter from the point of view of determining their impact on the degree of temperature increase of the Ni nanoparticles with a diameter of 2.4 nm in gelatin allocation in particle heat. In the present embodiment of the invention selected temperature sensitivity high-sensitivity cameras, such as Mirage P production companies Infrared Cameras, Inc., USA .
Obviously, temperature sensitivity δ tABBspecified in the technical specifications known IR cameras, refer to the radiation of a blackbody. Then the threshold ∆ Ελthe camera on the surface density of the radiation power can be determined from the condition (1):
where σ is the Stefan-Boltzmann constant, and the ABB=300 K. When ΔTABB=14 MK for the IR camera (see ) the value of ∆ ελequal 8,58·10-8W/mm2.
Surface power density of the radiation Eλfor the body blackness level α is defined as
where Tα- body temperature with the degree of blackness α. When the growth temperature of this body on δ tαthe surface density of the radiation power will increase by the value of:
In order Luggage Mirage P was able to notice the heat of the blackbody (i.e., heating at 14 MK), the surface density of the radiation power according to (1), should increase the value of ∆ ελ=8,58·10-8W/mm2. This means that in order for the body with a degree of blackness α was also observed camera the Mirage P, the surface power density of the radiation should increase the value of ΔΕλalso equal 8,58·10-8W/mm2. Equating ΔΕλ=Δελwhen the equality of the initial temperatures of the two bodies (TABB=Tα=300 K) defined that is required for this condition:
Thus, in order for the surface with the degree of blackness of α was observed IR camera, the growth surface power density of the radiation must be at least ∆ Ελ=8,58·10-8W/mm2and the growth temperature should be not less than ΔT=δ tABB/α.
Calculating power values of Qifor five values of the degree of blackness αiwas carried out by solving the heat equation with regard to the source of heat. In particular, the power values of Qicalculated by solving the problem about the temperature change of the Ni particles inside the gelatinous shell, resulting in the selection of its warmth. The temperature change of the Ni particles is described by the heat conduction equation in spherical coordinates given f is NCLI source q(r):
where T(t, r) is the temperature, ρ is bulk density, C - specific heat, λ is thermal conductivity, q(r) is the density of a source of heat, r is the spherical radius. The calculations were carried out assuming that thermophysical parameters do not depend on temperature and can be described as follows:
R0<r≤R:λ=λ2, ρ=ρ2C=C2, q=0,
where R0is the radius of the nanoparticles, R is the radius of the gelatin shell (R>>R0; in this problem, R=5·10-7m, this condition is due to what dominirovaniem gelatin in the volume of the Converter).
The heat conduction equation was solved under the following initial and boundary conditions:
The solution of (5-7) was carried out by the numerical method of lines [6, 7] concerning ΔT=T-TRwhere TR=300 K, for materials, whose characteristics are shown in Table 1.
|The characteristics of the materials used in the assessments|
|Bulk density||Specific heat capacity|
|Nickel||ρ1=8,9 g/cm3||C1=440 j/kg·K||λ1=90,9 W/m·K|
|Gelatin||ρ2=1.3 g/cm3||With2=J/kg·K||λ2=0.3 W/m·K|
For five values of the degree of blackness αithe estimated power values of Qirequired for heating the Ni nanoparticles with a size of 2.4 nm in the temperature ΔTm(see figure 3) and maintaining it at a temperature (300 K+ ∆ Tm), and the corresponding values of the surface density of the number of nanoparticles of Nickel on the surface of the Converter is equal to Ni=Δελ/(Qi/2), are presented in Table 2.
During the carried out calculations have also been defined temporal characteristics of the Converter. They showed that as the time of heating the Ni nanoparticles in the gelatin, and the time it cooled to the initial temperature 300 K) is approximately equal to 13 NS (Figure 4). Such small values indicate that the proposed THz-IR Converter can operate in real time - both in active and in passive mode.
|The parameters of THz-IR Converter at different degrees of blackness αinanoparticles Ni|
|Δ tm, MK||14||20||28||46,7||140|
Another important characteristic of THz-IR Converter, which determines the area of its application, is it working distance H, that is, the distance between the THz lens and object source of THz radiation.>
Working distance H is determined from the condition of equality of the effective area of the Converter S* (i.e. square, capable to heat capacity of THz-radiation) and geometric square Converter Senvhe sees the IR camera.
At the same time the effective area of the Converter S*, is able to be heated to a temperature δ t=δ tABB/α undertaken by its connection with THz-power P delivered from person to efficient Converter:
where the power P is determined from the relationship:
Sh- the effective area of the human body, radiating the Terahertz radiation in the THz lens, Sh≈1,1·1012μm2(it corresponds to the square of half the diameter of 40 cm and a height of 175 cm);
Ω is the solid angle in which the person sees the diameter of the THz lens, glad;
Ttotalthe total transmission THz-lens and a heat filter  (we estimated its value as Ttotal≈0,08 - in the region of wavelengths of ~30 µm, which make the largest contribution to the total THz-radiation from the human body);
Tinthe transmittance of the layer of air between man and THz lens;
0,5 - coefficient input to roughly take into account that the human body is not blackbodies;
Thus, THz-power delivered from person to gelatinous matrix embedded in her nanoparticles of Ni, is equal to R≈0,23 Ω·Tin, W. And the effective area that can become hot THz-power of the human body, is equal to S*=α·P/ ∆ Ελ=5,75·10-2·α·Ω·Tin/σ·T3·Delta tABB.
Evaluation of the geometric area of the Converter can be made on the basis of the parameters of the standard lens IR camera Mirage P and evaluating the geometric area of the Converter, which sees the camera. According to the website , the minimum distance d between the subject (in our case, the THz-IR Converter) and a lens of the infrared camera is 4 inches, that is, d=101,6 mm When the angle of field of view γ=26° height Converter h can be determined from formula (10):
When standard is m aspect ratio 4:3 frame width w of the Converter can be calculated as follows:
w=(4/3)·47 mm=62,65 mm
Thus, the geometric area of the Converter is equal to Senv=h×w=47 mm×62,65 mm=2,94·103mm2.
Taking into account these parameters and taking into account the equality of the square Converter Senvand the effective area S*, which can heat the THz-radiation power of the human body temperature δ t=δ tABB/α, working distance n between the THz lens and object source of THz radiation can be determined from equation (11):
In this equation, as the solid angle Ω, and the transmission of air Tinare functions of the distance H. Defining for the considered example embodiment of the invention the diameter of the lens THz lens is equal to 0.3 m, estimating the transmittance of the layer of air Tinfrom the experimental data (see figure 3), in calculating the value of Ω and appreciating the value of Tinfor one the e distance H, substituting Ω and Tinin equation (11), it is possible to determine the values of N that satisfy (11).
Assuming, in accordance with Figure 5 that in the wavelength range between 30 and 250 microns, the average transmittance of the layer of air of thickness 1.2 m is ≈0,55, the transmission of air for any distance H can be defined by the formula Tin≈(0,55)kwhere k=N/(1.2 m). Values of N for different values of αisatisfying the equation (11), are given in Table 2.
The above criteria for evaluating the effectiveness of the visualization device sources of THz radiation allow to define the scope of the optimum use of the device depending on the applied part of the Converter nanoparticles of metal, the characteristics of the lens of an infrared camera and properties of the environment. For example, when used in the composition of the device according to the invention, the Converter containing nanoparticles of Nickel, with an average value of the degree of blackness αi=working distance of 0.5 N to the radiation source will be 2,82 m (see Table 2). Thus, this variant of implementation due to the absorption of THz radiation in the air will not permit, for example, to ensure the implementation of the passive mode of display for security tasks - due to the lack of distance in 2,82 m for their decisions, because they require the ability to work at distances of ≈4-20 m moreover, is the information and communications technology security in addition to working distance H, it is necessary to take into account the absorption of clothing high-frequency part of the THz-radiation of the human body (see Fig.6), i.e. the part of the frequency that is most efficiently converted Ni nanoparticles in the warmth. However, the above calculations show the effectiveness of this variant embodiment of the invention in passive mode imaging in the Terahertz rays, for example, in medicine, where the distance between the patient, which is the radiation source, and THz lens a little.
Based on the above assessment of the efficiency of use of the device according to the invention is considered, its implementation can also be used as active using the advanced part of the device smoothly tunable laser source used is known from the prior art in systems of active visualization and passive remote detection of hidden objects, such as weapons and contraband in real-time. However, if you use THz-IR Converter in the low-frequency part of the THz-band (in the submillimeter and millimeter wavelengths, where the transmission service highly enough, it is preferable to use in the Converter nanoparticles and the Ni, but, for example, from heavy-fermion compounds, such as CePd3, CeAl3, CeCu6and others). In the heavy-fermion compounds due to the narrow and partially filled f-zone electrons at the Fermi level  the density of States of electrons at the Fermi level for two to three orders of magnitude higher than conventional metals. This leads to extremely high intensity of electron scattering, i.e., the high conversion efficiency of the low-frequency part of the THz radiation into heat (the range of wavelengths from 0.3 mm to ~1 cm, in which the transmittance of tissues is large enough (see Fig.6)).
Typically, sources of interest THz-radiation intensity is low. Therefore, to ensure an acceptable ratio "signal/noise" should choose the right material for THz lenses-lens, to protect the nanoparticles Converter from noise emissions, and to use THz lens with a large enough diameter (much larger than the diameter of the lens of an infrared camera), it is preferable to select the type of camera, which has a range of registration (3-5 μm) shifted relative to the wavelength with the maximum emissivity of a body heated to 300 K (≈5-20 μm).
The ratio of the flows of THz-radiation from the object is collected THz lens and focused on the Converter, and from the lens of an infrared camera that falls in the same envelope is, in proportion to the area ratio of the object and an entrance aperture of a lens of an infrared camera. To make the UX from the object much more flow from the inlet lens IR camera, the diameter of the THz lenses-lens must be much larger than the hole diameter of the lens of the infrared camera (~10 mm).
For THz lenses-lens is used HDPE high density polyethylene, which does not transmit infrared radiation from an object. These lenses filter out infrared radiation in the wavelength range of 7 to 14 microns, which is the peak of the distribution of infrared radiation, for example, from an object-person. In addition, they delay ultraviolet radiation and to substantially attenuate visible light.
Protection nanoparticles Converter from noise emissions in the claimed solution of the invention can be achieved by the following measures: (a) using a low pass filter, which has a wavelength segments λwith≈30 μm and is able to filter out infrared radiation, but skip useful THz-radiation from the test object; this filter must be installed before (along the beam) gelatin matrix with nanoparticles; (b) installing the filter from sapphire for gelatinous matrix with nanoparticles. Sapphire passes the useful radiation in the range of 3-5 microns, that is, the radiation from the heated nanoparticles gelatinous matrix, but filters out thermal radiation is s in the wavelength range of 8 to 40 μm, which is the main share of the heat flow from the IR camera. In addition, sapphire is lower than other optical THz materials, the transmittance in the wavelength range λ>50 μm, which also helps to reduce noise THz-background sent from the camera to the Converter. Thus, it is possible to cut off the flow of background radiation from the IR camera to the Converter, while having the opportunity to observe the infrared image generated by the Converter.
In the proposed scheme imaging THz-radiation low pass filter, the gelatinous matrix containing nanoparticles, and the sapphire substrate should fit snugly to each other. This protects the nanoparticles in the gelatinous matrix of the lateral flow of infrared radiation.
As an additional protection nanoparticles Converter from background THz-radiation of the camera and its housing on the camera should be worn low pass filter with a hole for the lens, made from materials which are used for low pass filters. This filter must have a wavelength segments λwith≈120 μm. This measure would effectively filter out the most dangerous part of the spectrum of radiation from the camera body, and the long-wavelength part of the THz-radiation (λ>120 µm), skip this filter would contribute a relatively small contribution to the total background exposure to nanoparticles Converter.
Declared the second solution of the invention allows the use of the visualization device as in conditions when the temperature of the infrared camera during operation becomes higher than the temperature of THz-IR Converter, and when their temperature is the same. However, in the latter case, since there is no need to protect the Converter from the background radiation of the infrared camera, you can refuse sapphire substrate using, for example, as the substrate is actually the back side of the low pass filter of the Converter, on which is applied a gelatin matrix with nanoparticles. In addition, instead of the infrared camera with a working range of 3-5 μm, you can use the infrared camera, with a working range of 7-15 μm, which is the traditional working range IR cameras, which greatly simplifies and cheapens the construction of the device as a whole without losing quality. In addition, in the absence of background radiation of the IR camera is not required and installation of the low pass filter between the THz-IR Converter and the infrared camera. The simplification of the structure described above does not affect the immunity of the device and the sensitivity of the claimed device, as it is due to the lack of need for additional noise reduction measures due to the absence of the noise source. In the absence of IR heating chamber above the temperature of the Converter all of the above requirements to the choice of the material of the nanoparticles, their size and distribution, as well as applications is their protection from the background radiation of the radiation source and the environment remain in full compliance with the above variants of carrying out the invention.
Thus, it is clear that the claimed technical solution allows for the execution of the Converter on the basis of the gelatinous matrix containing metal nanoparticles and application in the design of the low pass filter placed in front of a matrix with filter heat radiation source of THz radiation with wavelengths not more than 30 μm, to improve noise immunity design, reduced noise and increased sensitivity while at the same time simple design visualization device in a wide range of application.
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1. The visualization device sources of terahertz radiation, containing the Converter terahertz radiation, infrared radiation, consisting of a layer of artificial metamaterial with resonant absorption of terahertz radiation deposited on a solid substrate, located between the input terahertz lens and the lens of the infrared camera, wherein the Converter is made on the basis of the gelatinous matrix containing nanoparticles of metal, and provided with a low pass filter placed in front of a matrix with filter heat radiation source of terahertz radiation with wavelengths less than 30 ám.
2. The visualization device according to claim 1, wherein the gelatinous matrix Converter contains metal nanoparticles with a size of about 2 nm, with a peak density of electronic States at the Fermi level, with the possibility of conversion terahertz radiation into heat.
3. The visualization device according to claim 2, characterized in that the metal nanoparticles in the gelatinous matrix isolated from each other and made dispergirovannykh in a gelatin emulsion matrix Converter.
4. The visualization device according to claim 3, characterized in that the metal nanoparticles in the matrix Converter is made of parentnodestyle with the peak of the density of States of electrons at the Fermi level.
5. The visualization device according to claim 4, characterized in that the nanoparticles are made of Nickel.
6. The visualization device according to claim 4, characterized in that the nanoparticles are made of compounds with heavy fermions.
7. The visualization device according to any one of claims 1, 2, 3 or 4, characterized in that the low pass filter is configured to filter infrared radiation from a source of terahertz radiation in the wavelength range of 3-30 μm and transmission of terahertz radiation from a source with a wavelength of not less than 30 μm.
8. The visualization device according to any one of claim 2, 3 or 4, characterized in that the metal nanoparticles distributed on the surface of the Converter with surface density determined from the relation:
where Q is the power required to maintain the nanoparticles in the gelatinous matrix at temperature T+ΔT, W;
T is the temperature of the Converter, To;
ΔT is the magnitude of the temperature increase of the nanoparticle relative to T as a result of its exposure to terahertz radiation, To;
Δελ- sensitivity infrared camera on the surface density of the radiation power, which is determined from the relation:
where σ=5,67·10-8W·m-2·K-4- Stefan-Boltzmann constant;
Δ tABBtemperature sensitivity infrared camera, Pref is given to the absolutely black body, K.
9. The visualization device according to claim 1, characterized in that the substrate is made of sapphire, and the lens of the infrared camera is located on the side of the substrate.
10. The visualization device according to claim 9, characterized in that the diameter of the input terahertz lens is made large relative to the diameter of the lens of the infrared camera with the ability to protect the nanoparticles Converter from noise radiation.
11. The visualization device according to claim 1, wherein the gelatinous matrix Converter containing metal nanoparticles deposited on facing the lens of the infrared camera surface low pass filter of the Converter, in addition made in the form of the substrate.
12. The visualization device according to claim 11, characterized in that use an infrared camera with an operating range of 7-15 μm.
13. The visualization device of claim 10, wherein the infrared camera further comprises a low pass filter with a hole for the lens with the ability to protect the Converter from the background of terahertz radiation to the camera and her hull.
14. The visualization device according to item 13, wherein the low pass filters infrared camera and the Converter is made of homogeneous materials with wavelength intervals of not more than 120 μm.
15. The visualization device according to claim 1, characterized in that the complement is Ino contains smoothly tunable laser source.
16. The visualization device according to claim 9, characterized in that the low pass filter, the gelatinous matrix containing nanoparticles, and the sapphire substrate are flush with each other to ensure the protection of the nanoparticles in the gelatinous matrix of the lateral flow of infrared radiation.
SUBSTANCE: backlighting device (20) comprises a substrate (22), where multiple point sources of light are placed in the form of light diodes (21), and slots (23), which are also arranged on the substrate. Multiple point sources of light include the first point source of light (21), which is placed near the slot (23), and the second point source of light (21), which is placed in a position distant from the slot (23) compared to the first point source of light (21). The light beam in the surroundings of the slots is higher than the light beam in the area different from the surroundings of the slots.
EFFECT: reduced heterogeneity of brightness of a display panel without increase in number of process operations.
15 cl, 12 dwg
FIELD: physics, optics.
SUBSTANCE: backlight for a colour liquid crystal display includes white light LEDs formed using a blue LED with a layer of red and green phosphors over it. In order to achieve a uniform blue colour component across the surface of a liquid crystal display screen and achieve uniform light output from one liquid crystal display to another, the leakage of blue light of the phosphor layer is tailored to the dominant or peak wavelength of the blue LED chip. The backlight employs blue LED chips having different dominant or peak radiation wavelength.
EFFECT: different leakage amounts of light through the tailored phosphor layers offset the attenuation on wavelength of the liquid crystal layers.
15 cl, 13 dwg
SUBSTANCE: liquid crystal display device (100) of the present invention includes a liquid crystal display panel (10) and a lateral illumination unit (20) which emits light from a position which is lateral with respect to the panel (10). The panel (10) includes a front substrate (1), a back substrate (2) and a light-diffusing liquid crystal layer (3). The unit (20) includes a light source (7), which is situated in a position which is lateral with respect to the panel (10), and a light-guide (6), having a light-output surface (6b) through which light emitted by the light source (7) as well as light incident on the light-guide (6) is emitted towards the end surface (1a) of the substrate (1). The surface (6b) is slanted relative a direction which is vertical with respect to the front surface (1b) of the substrate (1), such that it faces the back surface of the panel (10).
EFFECT: preventing generation of a bright line in the panel.
3 cl, 6 dwg
SUBSTANCE: in carrier pin (11) used for support of optical elements (43-45) though which part of light passes from light-emitting diode (24) a part of peak (14) contacting with light-diffusing plate (43) is formed of light-reflective material while a part of rack (12) supporting peak (14) is formed of light-transmitting material.
EFFECT: eliminating mom-uniformity of lighting.
12 cl, 13 dwg
SUBSTANCE: backlight unit (49) of a display device (69), having a liquid crystal display panel (59), equipped with a base (41), a diffusing plate (43) mounted on the base, and a light source which illuminates the diffusing plate with light. The light source has a plurality of light-emitting modules (MJ) which include a light-emitting diode (22) which serves as a light-emitting element, and a divergent lens (24) covering the light-emitting diode. The light-emitting modules are placed on a grid on the base supporting the diffusing plate. Carrier pins (26) for mounting the diffusing plate are located on points on the base. The carrier pins are placed on sections of lines linking neighbouring pairs of light-emitting modules.
EFFECT: eliminating non-uniformity of luminance.
10 cl, 14 dwg
SUBSTANCE: backlight unit (49) of a display device (69), having a liquid crystal display panel (59), has a base (41), a diffusing plate (43) which is supported by the base, and a point light source for irradiating the diffusing plate with light. The point light source has a light-emitting diode (22) mounted on a mounting substrate (21). A plurality of light-emitting diodes covered by divergent lenses (24) are provided. Optical axes (OA) of the divergent lenses are inclined relative the diffusing plate, and the divergent lenses, having different inclinations of optical axes, are placed randomly on the base. The divergent lenses, having optical axes that are inclined in opposite directions, are paired and the pairs are arranged in a matrix.
EFFECT: reduced non-uniformity of luminance and hue.
25 cl, 12 dwg
SUBSTANCE: lighting device 12 comprises multiple point sources 17 of light and a base 14, where point sources of light 17 are placed, which are classified into two or more colour ranges A, B and C, in accordance with light colours. Each colour range is defined by means of a square, each side of which has length equal to 0.01 in the colour schedule of light space of the International Lighting Commission 1931.
EFFECT: reproduction of light of practically even light.
26 cl, 15 dwg
SUBSTANCE: lighting device includes multiple LED 16, circuit board 17S LED, chassis 14, connection component 60 and reflecting plate 21. LED 16 are installed on circuit board 17S LED. Both plates 17S and 17C LED are attached to chassis 14. Connection component 60 is electrically connects circuit boards 17S and 17C LED between each other. Reflecting plate 21 is put on surface 17A of light sources installation. In the lighting device, connection component 60 is located on surface 17B of attachment of connection component of circuit board 17S LED. Surface 17B of attachment of connection device is opposite to the surface, on which reflecting plate 21 is put.
EFFECT: increasing brightness of reflected light.
23 cl, 22 dwg
SUBSTANCE: device has a holder (11) which attaches a mounting plate (21) to a backlight base (41) while covering at least the edge (21S) of the mounting plate (21) on the backlight base (41), said edge being situated in the direction of the short side of the mounting plate. The surface of the mounting plate covered by the holder has a non-uniform reflection area which can be in form of a connector or a terminal.
EFFECT: improved uniformity of the amount of light from the backlight unit.
21 cl, 39 dwg
SUBSTANCE: back light unit (49) for display device (69) equipped with LCD panel (59) contains a frame (41), dissipating plate (43) supported by the frame and point light sources supported by mounting substrates (21) provided at the frame. Point light sources contain LEDs (22) installed at mounting substrates. Mounting substrates (21) are interconnected by connectors (25) thus forming rows (26) of mounting substrates (21). Varieties of rows (26) of mounting substrates (21) are located in parallel; a row (26) of mounting substrates (21) is formed by long and short mounting substrates (21) and location of such long and short mounting substrates (21) is changed to the opposite row-by-row. Positions of connectors (25) are not levelled in a straight line in direction of rows (26) of mounting substrates (21).
EFFECT: providing uniform brightness of the dissipating plate.
23 cl, 10 dwg
FIELD: measurement equipment.
SUBSTANCE: device comprises a measurement bench, a radiation receiver, a processing and control unit with a device of information output. At the same time the measurement bench comprises a base, where two rotary devices are fixed, being arranged so that their axes of rotation are mutually perpendicular. On the first rotary device there is a fixation device for the investigated source of radiation. On the second rotary device there is a holder, on which there is an inlet window of a radiation transfer channel, such as an optic-fibre channel, and its outlet window is fixed on the receiver of optical radiation, such as a spectrometer.
EFFECT: higher accuracy of measurements during simplification of an assembly process and simultaneous automation of a process of measurements.
FIELD: measurement equipment.
SUBSTANCE: base for this cryostat is a casing 1, made in the form of a sleeve from a heat insulation material (for instance, foam plastic). On the bottom of the inner part of the casing there is a sample holder 2, made of a material with high heat conductivity for reduction of temperature gradient (for instance, of copper). In the bottom of the casing 1, near the generating inner wall, there is one or several holes 3. The bottom outer part of the body is made so that it is tightly (without gaps) installed into a neck part of a vessel 4 with a liquid cryoagent 5. In process of evaporation the cold gaseous cryoagent arrives via holes 3 inside the casing and displaces warm (moist) air from it, and therefore eliminates the possibility of freezing of a holder and a sample investigated on it. Vapours of the coolant wash the holder, which results in its cooling.
EFFECT: invention makes it possible to exclude variation of incident radiation spectrum due to availability of windows, to make it possible to do investigation in wide range of temperatures, is simple to implement and inexpensive.
SUBSTANCE: proposed device comprises analysed object, radiation receiver and imitator. Analysed object and radiation receiver are arranged on two- and one-axis traverse gear. Two-axis traverse gear allows model rotation about mutually perpendicular horizontal and vertical axes. One-axis traverse gear allows radiation receiver rotation about vertical axis in horizontal plane of model rotation.
EFFECT: measurement of reflected radiation intensity at whatever directions of incident rays.
SUBSTANCE: singly connected or multiply connected diaphragm 3 in the cold screen of a multielement photodetector does not fall outside the limits of the section of an area which is common for overlapping figures which are sections of oblique pyramids. Bases of the pyramids coincide with the exit pupil of the objective lens 4, which forms an image on a matrix of photosensitive elements 1. Vertices of the pyramids are in corners of the photosensitive field of matrix 1. The sectional plane of the pyramid coincides with the plane of the diaphragm 3. The design of the photodetector according to the invention prevents stray radiation falling on the matrix of photosensitive elements.
EFFECT: improved parametres of the photodetector.
8 cl, 9 dwg
FIELD: engineering of devices for determining angular distribution of radiation reflected from object surface.
SUBSTANCE: claimed device contains radiation emitter, radiation receiver, transformer of radiation to photocurrent and information processing block, base in form of a ring and two semi-rings. On each semi-ring, emitter and receiver of radiation are mounted. Semi-rings are mounted perpendicularly to measurement plane. One of semi-rings is moveable relatively to the base. Also, aforementioned semi-rings may be made shortened.
EFFECT: it is possible to determine angular distribution of radiation which is reflected from object surface being examined, at any angles of falling radiation by changing positions of radiation receiver within limits of spatial angles of distribution of reflected radiation for different positions of radiation source.
2 cl, 3 dwg
FIELD: measuring technique.
SUBSTANCE: assembly and measuring unit can be used for measurement and registration of light transmission of window units and other light-transparent structures and their members. Assembly for measuring total coefficient of window frames light transmission has A type diffusion light source, which has semi-sphere, illumination devices disposed inside semi-sphere, shields protecting against incident light, external photoelectric member, light-measuring chamber which has semi-sphere and non-transparent partition provided with opening for placing window unit, measuring unit, which has internal photoelectric members, analog signal switch and measuring unit. Semi-spheres of diffusion light source and of light-measuring chamber have the same structure and are mounted in a such way that axis of symmetry of assembly is directed along horizontal line; units are connected one to another for placement of window frame in opening of partition of light-measuring chamber, which partition is mounted in vertical. Diameters of semi-spheres do not exceed 1,2 maximal size of diagonal of tested window unit. Non-transparent partition provided with opening for placement of window unit is unmovable connected with semi-sphere of diffusion light source and it is provided with small-sized lockers which determine position of window unit. Illumination devices are connected with power circuit through voltage stabilizer. Opening is protected by screens against direct light coming from illumination devices. Measuring unit of assembly for measuring total coefficient of light transmission has internal photoelectric members and analog signal switch. Any internal photoelectric member is connected with analog signal switch through "current-voltage" electron converter, which has input voltage lower than 1 Ohm. Output of analog signal switch is connected with first measuring channel, which has digital milli-voltmeter with double integration and with second measuring channel which has analog-to-digital converter with preamplifier. Outputs of first and second measuring channels are connected by data buses through digital signal switch with matching unit, which is in turn connected by data buses and control buses with computer and with control bus provided with control unit, which both are connected with analog signal switch, analog-to-digital converter and digital double integration milli-voltmeter with through control buses.
EFFECT: reduced sizes of assembly; reduced number of illumination devices; reduced power consumption; higher comfort at use; reduced error of measurement; higher speed of measurement process; simplified processing of results of measurement.
FIELD: process engineering.
SUBSTANCE: invention relates to sandwiched moulded articles to be used as boards, films for hothouses or as window elements. Moulded article 1 consists of outer layer 2 and inner layer 3 located below outer layer 1 and made of thermoplastic polymer. Said outer layer 2 is made of at least one thermoplastic polymer and at least one nano-sized absorber of IR-radiation 8 selected from tin oxide alloyed with antimony or indium or rare earth metals borides in the form of nanoparticles. Additional additives to mould article 1 can be UV-absorbers, organic IR-radiation absorbers not in the form of particles, stabilisers, antioxidants, dyes, inorganic salts, pearl pigments, radiation reflectors in IR-spectrum near band, anti-sweat means or fillers. Besides, this invention discloses the process of making said article 1 by coextrusion of outer layer 2 and inner layer 3.
EFFECT: efficient protection of surfaces of, for example, buildings, automobiles or hothouses, efficient control over internal heat.
12 cl, 1 dwg
SUBSTANCE: in a photosensitive structure, which is a multilayer semiconductor heterostructure which is sensitive to terahertz radiation at effective photocurrent temperature, said heterostructure having a quantum well in form of a layer of a narrow-bandgap solid solution containing Hg and Te and enclosed between barrier layers of a wide-bandgap three-component solid solution of CdyHg1-yTe, where y is a value preferably in the range from 65% to 72%, the narrow-bandgap quantum well is formed from a three-component solid solution of Hg1-xCdxTe with content of Cd defined by a value x in the range from 4% to 12%, wherein the width of the quantum well is selected for the given terahertz frequency subrange of the received radiation at temperature of 4.2 K or 77 K depending on content of Cd in accordance with table 1 given in the claim. When the disclosed photosensitive structure is made as a desired terahertz photodetector - selective photodetector, in the latter, having a terahertz radiation sensitive photodetector line, which is in form of saeries-arranged areas of a multilayer semiconductor heterostructure having effective photosensitivity in different terahertz subranges at temperature of 4.2 K or 77 K, said areas having a working detector layer on a quantum well formed from a narrow-bandgap three-component solid solution of Hg1.xCdxTe and enclosed between barrier layers of a wide-bandgap three-component solid solution of CdyHg1-yTe, where y is a value preferably in the range from 65% to 72%, and a means of maintaining said temperature, for areas of the multilayer semiconductor heterostructure with selected terahertz frequency subranges of the received radiation, given by the following intervals of energy values of the received radiation ħω: 8-16, 16-24, 24-32, 32-40, 40-48, 48-56, 56-64 meV, the width of the quantum well is equal to 11 nm with content of Cd in the working detector layer on the quantum well - Hg1-xCdxTe on series-distributed areas of the photodetector line in accordance with said terahertz frequency subranges of the received radiation at temperature of 4.2 K, defined by the following intervals of values x, respectively: 7.1-7.9, 7.9-8.7,8.7-9.4,9.4-10.1, 10.1-10.9, 10.9-11.5, 11.5-12.2%, or at temperature of 77 K, defined by the following intervals of values x, respectively: 5-5.9, 5.9-6.7, 6.7-7.5, 7.5-8.3, 8.3-9.0, 9.0-9.8, 9.8-10.5%.
EFFECT: invention improves manufacturability of desired terahertz photodetectors by creating structural conditions for operation of the photodetector element on the level of stable high sensitivity in different subranges in a wide frequency range of the terahertz received radiation depending on the width of the quantum well.
3 cl, 2 tbl, 2 dwg
SUBSTANCE: invention can be used in production of dense wear-resistant ceramic and solid electrolytes. The method of producing powder of a zirconium, yttrium and titanium composite oxide involves preparing a starting solution of nitrates, adding an organic acid and a titanium-containing compound into said solution, followed by heat treatment. The organic acid used is glycine in amount of 1.6-2.5 mol per 1 g-atom of the sum of metal cations (Zr+4+Ti+4+Y+3). The titanium-containing compound used is a hydrolysable titanium compound with the ratio Zr+4:Ti+4=(0.99-0.85):(0.15-0.01). The starting solution is further mixed with 30% hydrogen peroxide with the ratio H2O2:Ti+4=(4.7-12):1. The hydrolysable titanium compound used can be titanium tetrabutylate or titanium sulphate or titanium tetrachloride.
EFFECT: invention prevents waste discharge, reduces power consumption and simplifies production of nanopowder of a zirconium, titanium and yttrium composite oxide.
3 cl, 3 ex