• Current Optics and Photonics
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• v.8 no.1
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• pp.65-71
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• 2024

We present a Yb-doped narrow-linewidth polarization-maintaining all-fiber amplifier that achieves a high mode-instability (MI) threshold, high output power, and 9.7-GHz spectral linewidth. Six wavelength-multiplexed laser diodes are used to pump this amplifier. First, we construct a high-power fiber amplifier based on a master oscillator-power amplifier configuration for experiments. Subsequently, we examine the MI threshold by individually pumping the amplifier with wavelengths of 976, 974, 981, 974, and 981 nm respectively. The experimental results demonstrate that the amplifier exhibits a high MI threshold (>3.5 kW) when pumped with a combination of wavelengths at 974 and 981 nm. Afterward, we inject an optimized phase-modulated seed with a nearly flat-top spectrum into this amplifier. Ultimately, laser output of 3.2 kW and 9.7 GHz are obtained.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.461-461
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• 2004

• Proceedings of the KSMRM Conference
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• 1999.11a
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• pp.91-91
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• 1999

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.2
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• pp.312-317
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• 2015

In this paper, the RF characteristics of multi-finger MOSFETs were improved by decreasing the parasitic capacitance in spite of increased gate resistance in a 90-nm CMOS technology. Two types of device structures were designed to compare the parasitic capacitance in the gate-to-source ($C_{gs}$) and gate-to-drain ($C_{gd}$) configurations. The radio frequency (RF) performance of multi-finger MOSFETs, such as cut-off frequency ($f_T$) and maximum-oscillation frequency ($f_{max}$) improved by approximately 10% by reducing the parasitic capacitance about 8.2% while maintaining the DC performance.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.258-261
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• 2000

In this paper, the design of Binary FSK Using Cellular Oscillator Network architecture is newly introduced and analyzed. With its easy frequency controllability and MHz range of quadrature signals, the Cellular Oscillator Network can be used in RF communication systems. Binary Frequency Shift Keying can also be implemented through digital loop-path switching. This FSK model is simulated and proved with typical 3V, 0.5$\mu\textrm{m}$ CMOS N-well process parameters.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.124.1-124.1
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• 2007

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 2000.08a
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• pp.33-37
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• 2000

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.858-861
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• 2006

In this paper we model the liquid crystal director field in the Patterned Vertical Alignment (PVA) LC using the fast Q-tensor method, which can model multidimensional director configurations with defects in the liquid crystal director field. We observed the dynamic behaviors of the defect experimentally by applying the voltage and modeled the LC director field with defect in the active area of the PVA cell. As a result, we could also calculate the optical transmittance.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.639-641
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• 2003

The parasitic capacitance between the high voltage electrodes and the backlight housing causes lowering lamp current, electric power leakage, and leading to lower brightness and efficiency in a multi-lamps backlight. In this study a new center balance swing operation method is introduced to be minimizing those housing effects.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.607-610
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• 2005

In this paper, Ni Germanosilicide using Ni-Ta/Co/TiN is proposed to improve thermal stability. The sheet resistance of Ni Germanosilicide utilizing pure Ni increased dramatically after the post-silicidation annealing at $600^{\circ}C$ for 30min. However, using the proposed Ni-Ta/Co/TiN structure, low temperature silicidation and wide range of RTP process window were achieved.