• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.320-327
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• 2010

The IR signature data of a ship is mainly affected by location, meteorological conditions(atmosphere temperature, wind direction and velocity, humidity etc.), atmospheric transmittance, solar position and ship surface temperature etc. The IR signatures received by a remote sensor at a given temperature and wavelength region is consisted of the self-emitted component directly from the object surface, the reflected component of the solar irradiation at the object surface, and the scattered component by the atmosphere without ever reaching the object surface. Computer simulations for prediction of the IR signatures of ships are very useful to examine the effects of various sensor positions. In this paper, we have acquired the IR signature for different sensor positions by using computer program for prediction of the IR signatures. The numerical results show that the IR signature contrast as compared to the background sea considering the meteorological conditions, solar and sky irradiations.

• Journal of Sensor Science and Technology
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• v.24 no.4
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• pp.264-269
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• 2015

An infrared (IR) bolometer measures the change of resistance by absorbing incident IR radiation and generates a signal as a function of the radiation intensity. Since a bolometer requires temperature stabilization and light filtering except for the infrared rays, it is essential for the device to be packaged meeting conditions that above mentioned. Minimization of heat loss is needed in order to stabilize temperature of bolometer. Heat loss by conduction or convection requires a medium, so the heat loss will be minimized if the medium is a vacuum. Therefore, vacuum packaging for bolometer is necessary. Another important element in bolometer packaging is germanium (Ge) window, which transmits IR radiation to heat the bolometer. To ensure a complete transmittance of IR light, anti-reflection (AR) coatings are deposited on both sides of the window. Although the transmittance of Ge window is high for IR rays, it is difficult to use frequently in low-price IR bolometer because of its high price. In this paper, we fabricated IR window by utilizing silicon (Si) substrate instead of Ge in order to reduce the cost of bolometer packaging. To enhance the IR transmittance through Si substrate, it is textured using Reactive Ion Etching (RIE). The texturing process of Si substrate is performed along with the change of experimental conditions such as gas ratio, pressure, etching time and RF power.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1340-1342
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• 1998

The diamond-like carbon(DLC) film, as an antireflection layer, is coated on a commerically used Ge window. DLC films are deposited by using an rf(13.56 MHz) plasma CVD. The optimal value of thickness and refractive index of DLC layer has been determined from the computer simulation. IR-transmittances of DLC-coated Ge windows are estimated by measuring FTIR spectra in the wavelength range of$ 2.5{\sim}25{\mu}m$. By coating the DLC film on one side of the Ge window, the transmittance measured at a wavelength of $10{\mu}m$ is about 60 %, while that of the bare Ge is lower than 50 %. Also, a higher transmittance up to about 90 % is obtained by coating the DLC film on both sides of the window. It may be suggested that the further improvement of the IR-transmittance can be achieved by more precisely controlling the thickness and the refractive index of DLC layer and also by adopting various muliti-layer antireflection structures.

• Journal of the Korean Ceramic Society
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• v.32 no.12
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• pp.1424-1432
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• 1995

Chalcogenide glasses having IR (8~12${\mu}{\textrm}{m}$) transmittance were prepared and their densities, thermal and mechanical properties, IR-transmittances and chemical durabilities were determined. Glass transition temperatures (Tg) of Ge-As-Se, Ge-As-Se-Te and Ge-SE-Te system glasses were in the range of 280~3$65^{\circ}C$, 210~236$^{\circ}C$ and 210~26$0^{\circ}C$, respectively. Crystallization temperature (Tc) of Ge-Se-Te system glass was in the range of 305~40$0^{\circ}C$. Their thermal expansion coefficients($\alpha$) were in the range of 11.7~15.2$\times$10-6/K, 15.4~16.0$\times$10-6/K and 17.4~27.8$\times$10-6/K, respectively. Their MOR, hardness and fracture toughness were in the range of 15.2~18.6MPa, 36.1~58.2Kg/$\textrm{mm}^2$, 1.0~1.3 MPa.mm1/2, 18.9~24.9 MPa, 40.9~65.1Kg/$\textrm{mm}^2$, 1.3~1.5 MPa.mm1/2, and 24.1~30.8 MPa, 40.9~86.0Kg/$\textrm{mm}^2$, 1.4~1.8 MPa.mm1/2, respectively. IR transmittance of Ge-Se-Te system glass was about 60%. Ge-O extrinsic absorption peaks at 8, 12 ${\mu}{\textrm}{m}$ were significantly eliminated by the addition of Mg. Chemical durabilities in deionizied water of Ge-Se-Te system glass were good and IR-transmittances decreased with leaching time and temperature.

• Journal of the Korean institute of surface engineering
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• v.56 no.4
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• pp.233-242
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• 2023

In recent years, energy-management studies in buildings have proven useful for energy savings. Typically, during heating and cooling, the energy from a given building is lost through its windows. Generally, to block the entry of ultraviolet (UV) and infrared (IR) rays, thin films of deposited metals or metal oxides are used, and the blocking of UV and IR rays by these thin films depends on the materials deposited on them. Therefore, by controlling the thicknesses and densities of the thin films, improving the transmittance of visible light and the blocking of heat rays such as UV and IR may be possible. Such improvements can be realized not only by changing the two-dimensional thin films but also by altering the zero-dimensional (0-D) nanostructures deposited on the films. In this study, 0-D nanoparticles were synthesized using a sol -gel procedure. The synthesized nanoparticles were deposited as deep coatings on polymer and glass substrates. Through spectral analysis in the UV-visible (vis) region, thin-film layers of deposited zinc oxide nanoparticles blocked >95 % of UV rays. For high transmittance in the visible-light region and low transmittance in the IR and UV regions, hybrid multiple layers of silica nanoparticles, zinc oxide particles, and fluorine-doped tin oxide nanoparticles were formed on glass and polymer substrates. Spectrophotometry in the UV-vis-near-IR regions revealed that the substrates prevented heat loss well. The glass and polymer substrates achieved transmittance values of 80 % in the visible-light region, 50 % to 60 % in the IR region, and 90 % in the UV region.

• Journal of computational fluids engineering
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• v.22 no.1
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• pp.88-94
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• 2017

The IR signal entering into a sensor is composed of the following components: the self-emitted component directly from the object surface, the reflected components of the solar and sky irradiance at the object surface, and the scattered component by the atmosphere without reference to any object surfaces. The self-emitted and reflected components from the object can be lowered by the atmospheric layer between the object and the IR sensor. The principle factors influencing the atmospheric transmittance are the air temperature, the relative humidity and the observation distance. Previous studies on IR signal transmission through the atmosphere are focused on uniform atmospheric conditions and the non-uniform nature of the atmosphere was not properly treated in modeling. In this study, we use the local atmospheric transmittance to simulate the non-uniform atmosphere in analyzing the IR signal from the object surface. The results show that the nonuniform analysis of the atmosphere becomes more important as the wavelength of IR signal increases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1104-1108
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• 2004

A Study has been made of surface modification of various polymers by ion implantation to change the optical transmittance property at ultraviolet ray (UV, $200\sim400nm$). The substrates were PC (Polycarbonate), PET(Polyethyleneteraphtalate) and PP (Polypropylene). The effects of ion implantation on the change of optical transmittance were investigated in relation to ion species, implantation energies and ion fluences. The N, Ar, Kr, Xe ion implantation performed at ion energies from 20 to 50keV. The fluences ranged from $5\times10^{15}$ to $7\times10^{16}ions/cm^2$. UV/Vis transmittance spectroscopy, FT-IR and XPS were used to investigate optical transmittance, chemical structure and surface chemical state of irradiated polymer. Surface color was changed from the yellow to the dark brown and the transmittance of UV ray in the range UV-A($320\sim400nm$) decreased more than 80% after ion implantation.

• The Research Journal of the Costume Culture
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• v.31 no.1
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• pp.107-123
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• 2023

This research studied the electrical characteristics, IR transmission characteristics, stealth functions, and thermal characteristics of infrared thermal-imaging cameras of copper-sputtered samples. Nylon samples were prepared for each density as a base material for copper-sputtering treatment. Copper-sputtered NFi, NM1, NM2, NM3, NM4, and NM5, showed electrical resistance of 0.8, 445.7, 80.7, 29.7, 0.3, and 2.2 Ω, respectively, all of which are very low values; for the mesh sample, the lower the density, the lower the electrical resistance. Measuring the IR transmittance showed that the infrared transmittance of the copper-sputtered samples was significantly reduced compared to the untreated sample. Compared to the untreated samples, the transmittance went from 92.0-64.1%. When copper sputtered surface was directed to the IR irradiator, the IR transmittance went from 73.5 to 43.8%. As the density of the sample increased, the transmittance tended to decreased. After the infrared thermal imaging, the absolute values of △R, △G, and △B of the copper phase increased from 2 to 167, 98 to 192, and 7 to 118, respectively, and the closer the density of the sample (NM5→NFi), the larger the absolute value. This proves that the dense copper phase-up sample has a stealth effect on the infrared thermal imaging camera. It is believed that the copper-sputtered nylon samples produced in this study have applications in multifunctional uniforms, bio-signal detection sensors, stage costumes, etc.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.37-46
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• 2001

In this study, We compared the properties of tinted and colored lenses with the standards m the ordinary optical properties, coloration, UV, IR and luminous transmittance, color acceptance for traffic signal, and chromaticity. The UV, lR and luminous transmittance was analysed in the range of 175 nm to 3000 nm by using a UV-Vis-IR spectrophotometer and was used in the synthesis of spectrum of various color lens. A experimental function was made from the slope obtained from the transmittance change as a function of coloration time. We could expect the ordinary optical properties and color acceptance for traffic signal of various color lenses with the requirements of US standard(ANSI Z-80.3).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.21-23
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• 1994

By adding La₂O₃ to optical multicomponent glass composition, after making mother glass and core fiber that enable to enlarge the infrared transmittance region, then surveyed the optical properties. Through thermal analysis of the glass abstained by melt-quenching after selecting stable basic composition on devitrification and replace SiO₂ by 4-12wt% La₂O₃. As La₂O₃ increases up to l2wt% transition temperature, refractive index, density, deformation temperature increased, whereas thermal expansion coefficient decreased. As a result of inspectig transmittance in UV/VIS/IR region, visable region indicated the decrease of transmittance by increasing the La₂O₃ and transmittance region was enlarged by increasing the La₂O₃ in IR region. Also, fabricate core fiber at 820℃ and severy the optical loss we could fact that La₂O₃ composition added 12wt% showed the minimum optical loss.