• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.5
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• pp.123-128
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• 2022

Applying rigorous modal transmission-line theory (MTLT), the properties of resonant diffraction gratings under conical light incidence is investigated. The mode vectors pertinent to resonant diffraction under conical mounting vary less with incident angle than those associated with diffraction gratings in classical mounting. Furthermore, as the evanescent diffracted waves drive the leaky modes responsible for the resonance effects, the conical mounting imbues diffraction gratings with larger angular tolerance than their classical counterparts. Based on these concepts, the angular-spectral and wavelength-spectral performance of resonant diffraction gratings in conical and classical mounts by numerical calculations with spectra found for conical incidence are quantified. These results will be useful in various applications demanding resonant diffraction gratings that are efficient and physically sparse.

• Transactions on Electrical and Electronic Materials
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• v.4 no.6
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• pp.1-4
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• 2003

Anti-reflection properties of post diffusion doped spin-on source (in-situ AR coating) have been investigated in some detail. A simple experiment for reflectivity study using oblique incidence of light and necessary modification of the theory of minimum reflectivity at oblique incidence has been established. The comparative study of the in-situ AR coating with available spin-on AR film on silicon Solar Cell Surface have been investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.198-201
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• 1997

We investigated the generation of pretilt angle for nematic liquid crystal (NLC) in a cell with slanted non-polarized ultraviolet (UV) light irradiation on mixtured polyimide (PI) surfaces. It was found that the monodomain alignment of NLC is obtained in a cell with an angle of incidence of 75∼85 degrees on PI surface. We consider that the monodomain alignment of NLC is attributed to anisotropic dispersion force effect due to photo-depolymerization of polymer on Pl surfaces. We successfully observed that the pretilt angle of NLC is generated above 5 degree with an angle of incidence of 75∼85 degree. It is considered that the pretilt angle generation in NLC is attributed to interaction between the LC molecules and the Polymer surfaces.

• Korean Journal of Optics and Photonics
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• v.14 no.4
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• pp.399-405
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• 2003

We manufactured a clamp-type optical current transformer (COCT) head using FD10 glass. It was manufactured of two parts of FD10 glass with symmetrical structure and was designed so that light propagates along the critical angle in order to avoid a phase difference with the light within the sensor head at reflection. Also, we measured and analyzed the current of conductor from 0 to 1,000 AT, change of optical power with incidence angle of light, temperature and polarization of light, long-term current measurement using COCT head, and demonstrated the feasibility of manufactured COCT through those experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1597-1600
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• 2005

Recently, the trends of TFT-LCD are large scale and thin thickness, so, the demands of Light Guide Panel(LGP) which is able to substitute for prism sheets are appeared. Functions of LGP obtaining polarization of light of the prism sheet as well as the incidence and reflection of light are demanded. This prismless type LGP to complete functions of the existing LGP and polarization at once must be supported by micro machining technology of LGP surface. In this research, we have used the STAMPER method for the mass product and In-Line process, and the optimized conditions are established by analyzing the cutting force and conditions according to the material and processing properties when the prismless type LGP mold is fabricated. Parameters of the cutting condition were the workpiece and cutting depth.

• Journal of Radiation Protection and Research
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• v.23 no.1
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• pp.59-63
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• 1998

The light sensitivity and angular dependence of the $Mg_2SiO_4$:Tb(MSO-5) TLD which affect the accuracy of the radiation dose measurement are investigated. Light-induced thermoluminescence of MSO-S TLD under the 200 lux fluorescent and the incandescent lamp for 8 hours are corresponding to 11 and 3 mR exposure, respectively. TL intensity ratio of the incident angle of ${\pm}80^{\circ}$ to normal incidence for MSO-S and badge type MSO-L are about 0.8 and 0.15, respectively.

• Current Optics and Photonics
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• v.7 no.2
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• pp.136-146
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• 2023

Based on calculations using the macroscopic Maxwell's equations with mesoscopic boundary conditions, light absorption by a layered metal-insulator-metal (MIM) metamaterial system embedded in three different environments is investigated. Increasing the top metal thickness shifts the broad absorption band to lower dielectric-constant regions and longer wavelengths, for either TM or TE waves. Boosting the dielectric-layer thickness redshifts the broadband absorption to regions of larger dielectric constant. In air, for the dielectric-constant range of 0.86-3.40, the absorption of the system exceeds 98% across 680-1,033 nm. In seawater with optimized dielectric constant, ≥94% light absorption over 400-1,200 nm can be achieved; particularly in the wavelength range of 480-960 nm and dielectric-constant range of 0.82-3.50, the absorption is greater than 98%. In an environment with even higher refractive index (1.74), ≥98% light absorption over 400-1,200 nm can be achieved, giving better performance. The influence of angle of incidence on light absorption of the MIM system is also analyzed, and the angle tolerance for ≥90% broadband absorption of a TM wave is up to 40° in an environment with large refractive index. While the incident-angle dependence of the absorption of a TE wave is nearly the same for different circumstances, the situation is different for a TM wave.

• Journal of Korean Ophthalmic Optics Society
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• v.1 no.1
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• pp.93-102
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• 1996

The optical system of lens must be designed to tramsmit light over wide wavelength range and to have lower reflectivity in order to obtain higher spectral transmittance. However, the reflection color light appears due to the remain-reflection light in any optical system of lens. The wavelength of the reflection color light can be controlled by the structure of the number of layers, thickness of layer, reflective index, wavelength of incidence, and substrate etc. In the optical systems of the single layer and the double layers, the reflection color light appears in the condition of the anti-reflection of ${\lambda}s/{\lambda}$ = 1.0 by the color mixture of the remain-reflection lights in the ranges of the longer wavelength side and the shorter one of the ${\lambda}s/{\lambda}$ = 1.0, and of the double layers and triple layers, the reflection color light positioned at P1 < ${\lambda}s/{\lambda}$ < P2 appears in the condition of the antireflection of ${\lambda}s/{\lambda}$ = $PI{\ll}1$ and $P2{\gg}1$. In the optical system of the multi-layers, many antireflection points are existed at the various s/ values, and the reflection color light by the color mixture of the remain-reflection lights in the ranges except for the antireflection points.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.760-765
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• 2008

Low power laser therapy is internationally certified and is known to be effective in stimulating DNA in living organisms, increasing protein synthesis and activating cell division, smoothing blood circulation, promoting cell activation, cell regeneration and function. It also has anti-inflammatory, anti-edemic, anti-fibrous dysplastic and neuralogic hyperfunctional effects. This study was intended to verify the effect of LED irradiation therapy on wound healing in cell and animal tests by applying LED irradiator using a laser and laser diode, which was independently designed and developed to emit beams of similar wavelength to that of a laser. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity and reservation. In case of cell proliferation experiment, each experiment was performed to irradiation group and non-irradiation group for tissue cells. MTT assay method was chosen to verify the cell increase of two groups and the effect of irradiation on cell proliferation was examined by measuring 590 nm transmittance of micro-plate reader. In the wound healing experiment, 1$cm^2$ wounds on the skin wound of SD-Rat(Sprague-Dawley Rat) were made. Light irradiation group and none light irradiation group divided, each group was irradiated one hour a day for 9 days. As a result, the cell increase of tissue cells was verified in irradiation group as compared to non-irradiation group. And, compared with none light irradiation group, the lower incidence of inflammation and faster recovery was shown in light irradiation group.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.11-17
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• 2005

Egg masses of C. plumosus were collected from Jungnang Stream in Seoul and reared in an incubator chamber. The larvae of C. plumosus were treated with potential endocrine disruption chemicals (EDCs) such as Diethylhexyl phthalate (DEHP), Bisphenol A (BPA) and Tebufenozide, and the effects of morphological abnormalities were observed. The deformities of the mentum following exposure to EDCs showed the smooth/round tooth, the loss of ${\ge}$1 tooth, reduced median lateral teeth (MLT) and light brown color. The incidence rates of the mentum deformity were associated with chemicals: BPA (73.7 ${\sim}$ 90.9%)>tebufenozide (57.6 ${\sim}$ 78.9%)>DEHP (46.2 ${\sim}$ 85.7%). The deformity type of the mentum showed MIX (MLT+LT, 32 ${\sim}$ 46%)>MLT (25 ${\sim}$ 34%)>LT (lateral teeth, 3 ${\sim}$ 7%). Also, the incidence of MIX type was in the order of BPA (46%)>DEHP (33%) >tebufenozide (32%), and that of MLT type showed DEHP (34%)>tebufenozide (31%)>BPA (25%). As the concentration of Tebufenozide increased, the incidence of light brown mentum was dose dependent. While the incidences of light brown mentum following exposure to BPA and DEHP were not associated with their concentrations.