• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.136-136
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• 2003

In fiber optic networks, system size and cost can be significantly reduced by development of optical components through planar optical waveguides. One important step to realize the compact optical devices is to develop planar optical amplifier to compensate the losses in splitter or other components. Planar amplifier provides optical gain in devices less than tens of centimeters long, as opposed to fiber amplifiers with lengths of typically tens of meters. To achieve the same amount of gain between the planar and fiber optical amplifier, much higher Er doping levels responsible for the gain than in the fiber amplifier are required due to the reduced path length. These doping must be done without the loss of homogeniety to minimize Er ion-ion interactions which reduce gain by co-operative upconversion. Sol-gel process has become a feasible method to allow the incorporation of Er ion concentrations higher than conventional glass melting methods. In this work, Er-doped $SiO_2$-A1$_2$ $O_3$ films were prepared by two different method via sol -Eel process. Tetraethylorthosilicate(TEOS)/aluminum secondary butoxide [Al (OC$_4$ $H_{9}$)$_3$], methacryloxypropylcnethoxysaane(MPTS)/aluminum secondary butofde [Al(OC$_4$ $H_{9}$)$_3$] systems were used as starting materials for hosting Er ions. Er-doped $SiO_2$-A1$_2$ $O_3$ films obtahed after heat-treating, coatings on Si substrate were characterized by X-ray din action, FT-IR, and N-IR fluorescence spectroscopy. The luminescence properties for two different processing procedure will be compared and discussed from peak intensity and life time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2600-2606
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• 2014

In this paper, a design method for a planar dipole pair antenna for an operation in the frequency band of 470-806 MHz for terrestrial indoor digital TV (DTV) is studied. The proposed antenna is composed of two planar dipoles connected through conducting strips, and the antenna is fed by a microstrip line. By employing different lengths of dipoles, a broadband characteristics is obtained, and the antenna is size-reduced by bending both ends of the longer dipole. The effects of design parameters on the antenna performance are examined by simulation, and the parameters are adjusted for terrestrial DTV band use. A prototype of the antenna for indoor DTV reception is fabricated on an FR4 substrate with a size of $240mm{\times}139.5mm$ and tested experimentally. The experiment results show that the frequency band for a VSWR < 2 ranges 458-864 MHz(61.4%), and it corresponds fairly well with the simulated band of 448-868 MHz(63.8%).

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.69-72
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• 1990

For the effective heat transfering in Lser Diodes, Beam-Lead structure were introduced which is applicable to hybrid Optoelectronic Integrated Circuits. A 5-layer planar structure Laser Diode is fabricated and Beam-Lead is made by Au plating. And carrier was made by etching Si substrate and LD was mounted on a carrier. The thermal resistance was measured and we could certain that Beam-Lead structure behaves well as a heat sink.

• Proceedings of the Korean Magnestics Society Conference
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• 2009.12a
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• pp.150-150
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• 2009

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.12
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• pp.159-165
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• 1995

A gate-recessed structure is introduced to SOI MOSFET's in order to increase the source-to-drain breakdown voltage. A significant increase in the breakdown voltage is observed compared with that of a planar single source/drain SOI MOSFET without inducing the appreciable reduction of the current drivability. We have analyzed the origin of the breakdown voltage improvement by the substrate current measurements and 2-D device simulations, and shown that the breakdown voltage improvement is caused by the reductions in the impact ionization rate and the parasitic bipolar current gain.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1821-1823
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• 1998

In this paper, arbitrarily-shaped microstrip patch antenna in multi-layered is analyzed using spatial domain MoM. The triangular patch function is adopted here as the expansion function for planar arbitrarily-shaped microstrip. For example, an edge-fed rectangular patch antenna on a single-layered substrate is analyzed. The results show the agreement between the calculation and measurement.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1367-1371
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• 2016

• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.166-173
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• 2003

This paper presents micromachining results on planar-lightwave-circuit (PLC) chips with Si substrate and the quartz substrate by using Ti:Sapphire femtosecond-pulsed laser. The ablation process with femtosecond laser pulses generates nothing of contamination, molten zone, microcracks, shock wave, delamination and recast layer. We also showed that the micromachine for PLC using femtosecond pulsed lasers is superior to that using nanosecond pulsed lasers. The insertion loss and the optical return loss of the 1 ${\times}$ 8 optical power splitters packaged with micromachined input- and output-port U-grooves were less than 11.0 ㏈ and more than 55 ㏈, respectively. The wavelength dependent loss (WDL) was distributed within $\pm$0.6 ㏈ and the polarization dependent loss (PDL) was less than 0.2 ㏈.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.56-59
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• 2000

In this study, Ferroelectric $Pb(Zr_x,Ti_{1-x})O_3$(x=0.53) thin films were fabricated by the spin-coating on the Pt/Ti/$SiO_2$/Si substrate using the PZT metal alkoxide solutions with various excess Pb contents. Etching of PZT film was performed using planar inductively coupled Ar(20)$/Cl_2/BCl_3$ plasma. The etch rate of PZT film was 2450 ${\AA}/min$ at Ar(20)$/BCl_3$(80) gas mixing ratio and substrate temperature of $80^{\circ}C$. The leakage current densities of before etching and after etching PZT thin film were $6.25\times10^{-8}A/cm^2$, $8.74\times10^{-7}A/cm^2$ with electric field of 0.07MV/em, respectively.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1513_1514
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• 2009

This paper reports on a fabrication of novel substrate integrated waveguide (SIW)-based shielded stripline applicable to the broadband transverse electromagnetic (TEM) single-mode propagation. We suggested a structure for half-SIW and half-shielded stripline, which combined through the benzocyclobutene (BCB) bonding layer. The electrical interconnection between the sidewall of anisotropic wet-etched silicon and patterned BCB layers is measured subsequent to the metalization on the side wall. The proposed SIW-based shielded stripline has great potential in terms of simple fabrication, integration with planar circuits and monolithic system fabricated on a SIW structure.