• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.172-173
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• 2002

An erbium-ytterbium co-doped phosphate glass waveguide amplifier, fabricated by two-step ion-exchange, is presented. The performance of the amplifiers are investigated in viewpoints of net gain, pump power, and noise figure. The waveguide has propagation loss of 0.7 dB/cm Including insertion loss at 1.304 $\mu\textrm{m}$. At a signal wavelength of 1.534 $\mu\textrm{m}$, a high net gain of 12.8 dB and low noise figure of less than 3.9 dB are archived in a 4 cm long waveguide when injected by 140 ㎽ of LD pump at 0.98$\mu\textrm{m}$ in single pass configuration.

• Transactions on Electrical and Electronic Materials
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• v.14 no.6
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• pp.321-323
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• 2013

100 nm thick Ga doped ZnO (GZO) thin films were deposited with DC and RF magnetron sputtering at room temperature on glass substrate and Al coated glass substrate, respectively. and the effect of the Al underlayer on the optical and electrical properties of the GZO films was investigated. As-deposited GZO single layer films had an optical transmittance of 80% in the visible wavelength region, and sheet resistance of 1,516 ${\Omega}/{\Box}$, while the optical and electrical properties of GZO/Al bi-layered films were influenced by the thickness of the Al buffer layer. GZO films with 2 nm thick Al film show a lower sheet resistance of 990 ${\Omega}/{\Box}$, and an optical transmittance of 78%. Based on the figure of merit (FOM), it can be concluded that the thin Al buffer layer effectively increases the performance of GZO films as a transparent and conducting electrode without intentional substrate heating or a post deposition annealing process.

• Journal of the Semiconductor & Display Technology
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• v.12 no.2
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• pp.13-17
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• 2013

In lighting system where several large-area organic light-emitting diode (OLED) lighting panels are involved, panel aging may appear differently from each other, resulting in a falling-off in lighting quality. To achieve uniform light output across large-area OLED lighting panels, we have employed an optical feedback circuit. Light output from each OLED panel is monitored by the optical feedback circuit that consists of a photodiode, I-V converter, 10-bit analogdigital converter (ADC), and comparator. A photodiode generates current by detecting OLED light from one side of the glass substrate (i.e., edge emission). Namely, the target luminance from the emission area (bottom emission) of OLED panels is monitored by current generated from the photodiode mounted on a glass edge. To this end, we need to establish a mapping table between the ADC value and the luminance of bottom emission. The reference ADC value corresponds to the target luminance of OLED panels. If the ADC value is lower or higher than the reference one (i.e., when the luminance of OLED panel is lower or higher than its target luminance), a micro controller unit (MCU) adjusts the pulse width modulation (PWM) used for the control of the power supplied to OLED panels in such a way that the ADC value obtained from optical feedback is the same as the reference one. As such, the target luminance of each individual OLED panel is unchanged. With the optical feedback circuit included in the lighting system, we have observed only 2% difference in relative intensity of neighboring OLED panels.

• Applied Microscopy
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• v.42 no.3
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• pp.174-178
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• 2012

In the present study, the oxidation behavior of $Cu_{50}Zr_{50}$ and $Cu_{46}Zr_{46}Al_8$ metallic glasses has been investigated using transmission electron microscopy with a particular attention on the oxidation behavior in the supercooled liquid state. Identification of the oxidation product after continuous heating treatment shows that in $Cu_{50}Zr_{50}$ metallic glass, $ZrO_2$ with the monoclinic structure forms on the supercooled liquid as well as on the crystallized matrix. On the contrary, in $Cu_{46}Zr_{46}Al_8$ metallic glass, $ZrO_2$ with the tetragonal structure forms on the supercooled liquid, but that with the monoclinic structure forms on the crystallized matrix. The result indicates that the $Cu_{50}Zr_{50}$ metallic glass exhibits far better oxidation resistance in the supercooled liquid state than the $Cu_{46}Zr_{46}Al_8$ metallic glass.

• Korean Journal of Materials Research
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• v.31 no.8
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• pp.471-479
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• 2021

The electrochemical reaction between lead borate glass frit doped with Sn metal filler and Ni-Cr wire of a J-type resistor during a term of Joule heating is investigated. The fusing behavior in which the Ni-Cr wire is melted is not observed for the control group but measured for the Sn-doped specimen under 30 V and 500 mA. The Sn-doped lead borate glass frit shows a fusing property compared with other metal-doped specimens. Meanwhile, the redox reaction significantly contributes to the fusing behavior due to the release of free electrons of the metal toward the glass. The electrons derived from the glass, which used Joule heat to reach the melting point of Ni-Cr wire, increase with increasing corrosion rate at interface of metal/glass. Finally, the confidence interval is 95 ± 1.95₉ %, and the adjusted regression coefficient, R in the optimal linear graph, is 0.93, reflecting 93% of the data and providing great potential for fusible resistor applications.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.90-95
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• 2008

An SHGC(Solar Heat Gain Coefficient) is a determinant of total flux of solar radiation coming indoor and a critical factor in evaluating heating and cooling load. U-value represents heat loss while SHGC denominates heat gain. Recently, windows with high solar gain, mid solar gain or low solar gain are being produced with the development of Low-E coating technology. This study evaluated changes in energy consumption for heating and cooling according to changes in SHGC when using double-layered Low-E glass and triple layered Low-E glass in relation to double layered clear glass as base glass. An Office was chosen for the evaluation. For deriving optical properties of each window, WINDOW 5 by LBNL, an U.S. based company. and the results were analyzed to evaluate performance of heat and cooling energy on anannual basis using ESP-r, an energy interpretation program. Compared to the energy consumption of the double layered clear glass, the double layered Low-E glass with high solar gain consumed $69.5kWh/m^2,yr$, 9% more than the double layered clear glass in cooling energy. The one with mid solar gain consumed $63.1kWh/m^2,yr$, 1% less than the base glass while the one with low solar gain consumed $57.6kWh/m^2,yr$, 10% less than the base glass. When it comes to tripled layered glass, the ones with high solar showed 2% of increase respectively while the one with mid solar gain and low solar gain resulted 5% and 11% in decrease in energy consumption due to low acquisition of solar radiation. With respect to cooling energy. it was found that the lower the SHGC. the less energy consumption becomes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.335-335
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• 2008

Phosphate glass samples with various $Cr_2O_3$ and $Er_2O_3$ contents based upon $55P_2O_5\cdot24BaO\cdot10K_2O\cdot4Al_2O_3\cdot6Yb_2O_3$ were prepared. The prepared glass compositions are dehydrated using gas bubble flow method in open system and investigated the effects of the eliminating of OH groups from the glass melts with bubbling time. It was found that the probability of $Er^{+3}$ fluorescence quenching by OH groups oscillations linear depends upon the OH groups absorption coefficients in the maximum of the stretch vibrations band at $3500cm^{-1}$ while $Er^{+3}$ concentration range is between $1.6\times10^{19}$ and $21.2\times10^{19}$ ion/$cm^3$.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.133-137
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• 2014

The recent development of electro-optic devices and anticorrosion media has made it necessary investigate infrared optical systems with solid-solid interfaces of materials with amorphous characteristics. One of the most promising classes of materials for these purposes seems to be chalcogenide glasses, which are based on the Ge_Sb_Se system, have drawn much attention because of their use in preparing optical lenses and fibers that are transparent in the range of 3-12 um. In this study, a standard melt-quenching technique was used to prepare amorphous Ge_Sb_Sechalcogenideto be used in the design and manufacture of infrared optical products. The results of structural, optical, and surface roughness analyses of high purity Ge_Sb_Sechalcogenide glasses after various annealing processes reported.

• Korean Journal of Materials Research
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• v.26 no.11
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• pp.598-603
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• 2016

The recent development of electro-optic devices and anticorrosion media has led to the necessity to investigate infrared optical systems with solid-solid interfaces of materials that often have the characteristic of amorphousness. One of the most promising classes of materials for those purposes seems to be the chalcogenide glasses. Chalcogenide glasses, based on the Ge-Sb-Se system, have drawn a great deal of attention because of their use in preparing optical lenses and transparent fibers in the range of 3~12 um. In this study, amorphous Ge-Sb-Se chalcogenide for application in an infrared optical product design and manufacture was prepared by a standard melt-quenching technique. The results of the structural, optical and surface roughness analysis of high purity Ge-Sb-Se chalcogenide glasses are reported after various annealing processes.

• Korean Journal of Optics and Photonics
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• v.3 no.4
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• pp.217-221
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• 1992

A micro lens system was designed for the modulator in optical fiber communication. One was the collimating lens which transferred the diffracted beam from optical fiber to the modulator. The other was the coupling lens which connected the modulated collimating beam to the optical fiber. The light source was He-Ne laser beam. The lens would be made of optical glass BK-7. We determined the tolerance of curvature radius, thickness and conic constant.