• Journal of Radiation Protection and Research
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• v.41 no.3
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• pp.282-285
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• 2016

Background: To optimize the photon transmission efficiency of light guides used in scintillation detectors, LightTools code, which can construct and track light, was used to analyze photon transmission effectiveness with respect to light guides thickness. Materials and Methods: This analysis was carried out using the commercial light guide, N-BK 7 Optical Glass by SCHOTT, as a model for this study. The luminous exitance characteristic of the LYSO scintillator was used to analyze the photon transmission effectiveness according to the thickness of the light guide. Results and Discussion: The results of the simulations showed the effectiveness of the photon transmission according to the thickness of the light guide, which was found to be distributed from 13.38% to 33.57%. In addition, the photon transmission efficiency was found to be the highest for light guides of 4 mm of thickness and a receiving angle of $49^{\circ}$. Conclusion: Through such simulations, it is confirmed that photon transmission efficiency depends on light guide thickness and subsequent changes in the internal angle of reflection. The aim is to produce an actual light guide based on these results and to evaluate its performance.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.93-102
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• 2021

In this research, we present a natural lighting system with transmission distance of 30m and lighting efficiency of 35% (30m standard) for operating hours of 7h/day (based on clear sky). The system is composed of parabolic reflective mirror and modified light pipe that can secure more than 88% of light concentration efficiency. The light loss rate of newly designed light pipe transmission system is demonstrated to 0.8 %/m in the straight-line part and 2%/m in the curved part. Modified light pipe daylighting system shows better performance over fiber optic daylighting system in terms of transmission distance (1.5 times longer) and illuminance (3.05 times higher).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.6
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• pp.480-486
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• 2006

The radiation characteristics of a high-luminance light-emitting diode (LED) light source were studied to evaluate its potential as an energy-saving light source for fishing lamps. The angle of the LED light source with 50% illuminance was $8-15^{\circ}$, and it had strong directional characteristics. The wavelengths at which the radiance and irradiance were maxima were 709, 613, 473, 501, 525, and 465 nm for red, orange, blue, peacock blue, green, and white light, respectively. The underwater transmission characteristics of the LED light source were superior in the order blue, white, peacock blue, and green in optical water type I: blue, peacock blue, white, and green in optical water type II; and blue, peacock blue, green, and white in optical water type III. Setting the underwater transmission characteristics of the LED light source in optical water type I at 100%, the transmission of water types II and III decreased to 67 and 17%, respectively. Based on the underwater transmission characteristics calculated in optical water types I-III, the blue and peacock blue LED light sources can be used as an energy-saving light source for fishing lamps.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.551-554
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• 2008

In the recent year, Unmanned helicopters of airline industries are using in various industries such as monitoring system, agriculture and forest fire. A unmanned helicopter is needed a powerful engine for transport weighty payload and have to need a light weight. Therefore it is necessary a light weight transmission of the unmanned helicopter. Initially a rectangular transmission housing has been considered, but an empty space in the housing is not useful for light weight design. In this study, new model has been introduced into the transmission housing by using rapid prototyping. As a result, the weight of new transmission housing can be reduced very much as 67%.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.113-115
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• 2003

We investigate transmission of light in nanoscale structures. We present spatial and temporal domain measurements of the dephasing of surface plasmon excitations in metal films with periodic nano-hole arrays. By probing coherent spatial SP propagation lengths of a few f1. $\mu$m and an ultrafast decay of the SP polarization on a 10 fs timescale, we demonstrate that the SP transmission peaks are homogeneously broadened by the SP radiative lifetime. The pronounced wavelength and hole size dependence of the dephasing rate shows that the microscopic origin of the conversion of SP into light is a Rayleigh-like scattering by the periodic hole array. We have experimentally studied the dephasing of surface plasmon excitations in metallic nano-hole arrays. By relating nanoscopic SP propagation, ultrafast light transmission and optical spectra, we demonstrate that the transmission spectra of these plasmonic bandgap structures are homogeneously broadened. The spectral line shape and dephasing time are dominated by Rayleigh scattering of SP into light and can varied over a wide range by controlling the resonance energy and/or hole radius. This opens the way towards designing SP nano-optic devices and spatially and spectrally tailoring light -matter interactions on nanometer length scales.

• Journal of information and communication convergence engineering
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• v.6 no.2
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• pp.192-197
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• 2008

High-speed harmonic optical modulation-demodulation schemes are presented and a possibility of the schemes for applying to high-speed light wave transmission system is tested at microwave frequency range. An example of this concept is as follows : Light wave is modulated succeedingly through cascaded optical modulators by a sub-carrier to produce a modulated light wave at harmonic frequency which is higher than the feasible frequency of the individual modulators. For demodulation of the base-band signal, the high frequency optical sub-carrier is down-converted by the same kind of optical modulator with the same concept of harmonic modulation.

• Journal of Sensor Science and Technology
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• v.26 no.6
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• pp.408-413
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• 2017

In this paper, we newly developed a byte-inverted transmission method for flicker-free visible light communication (VLC). The VLC transmitter sends original data in the former half period of the clock, and inverted data and in the latter half period of the clock. The VLC receiver receives the original data in the in the former half period of the clock. In this system, we used 480Hz clock that was generated from the 60Hz power line. The average optical power of the LED array in the transmitter is constant, thus flicker-free, in the observation time longer than the period of the clock that is about 2ms. This period is shorter than the maximum flickering time period (MFTP) of 5ms that is generally considered to be safe. This configuration is very useful in constructing indoor wireless sensor networks using LED light because it is flicker-free and does not require additional transmission channel for clock transmission.

• Journal of the Semiconductor & Display Technology
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• v.10 no.1
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• pp.91-94
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• 2011

This paper presents light transmission efficiency by optical adhesive thickness between MLA and aperture layer and by aperture hole size. The gap between MLA and Aperture layer is adjusted by the shim. The more optical adhesive thickness increases, the better light transmission efficiency increases up to a point. After that, the light transmission efficiency decreases because stray lights cannot transmit through the aperture layer owing to cut-off by aperture layer. And as a result of light transmission efficiency with changing aperture hole size, the light transmission efficiency is proportional to area of aperture hole. The more specified process is made, the better data and sample will be got.

• Journal of Convergence for Information Technology
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• v.10 no.2
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• pp.32-38
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• 2020

In this paper, we analyze the modulation scheme for high speed transmission in visible light communication system, and study non-orthogonal multiplexing, dimming level and transmission power ratio. Conventional visible light communication has a disadvantage in that it is difficult to multi-transmit to increase the transmission speed. Multi-transmission technique is necessary for high-speed transmission at the transmitter. Since general visible light communication has a limitation in multiple transmission, various researches for high-speed transmission have been conducted. In order to solve this problem, this paper proposes a multiple modulation scheme for high-speed visible light communication using non-orthogonal multiplex transmission scheme and a future research direction.

• Tribology and Lubricants
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• v.17 no.6
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• pp.482-489
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• 2001

Changes in light transmission characteristics caused by various types of oil contaminations were experimentally measured with a built-in type wear monitoring device. Three kinds of iron powders of different size distribution, carbon duct, two kinds of solutions and grease were used for the test contaminants in this work. Light intensity of the transmitted light was measured with the contamination level. Results showed that the transmitted light intensity decreased linearly with the contamination concentration in the oil and the slope was affected by the size distribution. Light attenuation was also caused greatly by carbon dust, water contamination and poly-meric fibers in terms of the light absorption. As a result, it was proved that the optical measurement device could be applicable effectively for detecting any significant change in lubricating oils.