• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.5
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• pp.604-611
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• 2013

This paper presents an second harmonic elimination method based on the impedance variation scheme. Through the power quality analysis from the nonlinear loads connected on the power system, the second harmonic problems have been analyzed with a case study analysis and the experiments. In the paper, the second Harmonic generation was simulated with a single phase SCR rectifier and the analytical model is proposed for the second harmonic generation. A novel impedance variation scheme is proposed and analyzed to eliminate the second harmonic. The experiment has been performed on the 60(MVA) industry manufacturing plant. The experimental result demonstrates the proposed impedance variation scheme successfully operate on the 60(MVA) industry manufacturing plant.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.3
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• pp.257-263
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• 2013

Acoustic nonlinearity of surface waves is an effective method to evaluate the micro damage on the surface of materials. In this method, the $A_1$ (magnitude of the fundamental wave) and $A_2$ (magnitude of the second-order harmonic wave) are measured for evaluation of acoustic nonlinearity. However, if there is another source of second-order harmonic wave other than the material itself, the linear relationship between $A_1{^2}$ and $A_2$ will not be guaranteed. Therefore, the second-order harmonic generation by another source should be fully suppressed. In this paper, we investigated the initial second-order harmonic generation in narrowband surface waves by multi-line laser beams. The spatial profile of laser beam was considered in the cases of Gaussian and square-like. The temporal profile was assumed to be Gaussian. In case of Gaussian spatial profile, the generation of the initial second-order harmonic wave was inevitable. However, when the spatial profile was square-like, the generation of the initial second-order harmonic wave was able to be fully suppressed at specific duty ratio. These results mean that the multi-line laser beams of square-like profile with a proper duty ratio are useful to evaluate the acoustic nonlinearity of the generated surface waves.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.250-254
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• 1989

Second-harmonic generation at a silver-electrolyte (0.1 M KCL + H2O) interface was enhanced by surface roughness. The intensity of the second-harmonic radiation was shown to be sensitive enough to detect molecular monolayers adsorbed on a silver surface.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.199.1-199.1
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• 2014

In nonlinear optics, the properties of nonlinear optical responses such as polarization and nonlinear analysis of the nonlinear surfaces were investigated using the jellium model by optical second harmonic generation. The nonlinear response of the Al metal surfaces were calculated using TDLDA. Band structure, lattice constant and bulk modulus of the Al metal were investigated. Effective potential and electron density were compared by changing different.

• Current Optics and Photonics
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• v.6 no.6
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• pp.576-582
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• 2022

Plasmonic high-order harmonic generation (HHG) is used in nanoscale optical applications because it can help in realizing a compact coherent ultrashort pulse generator on the nanoscale, using plasmonic field enhancement. The plasmonic amplification of nanostructures induces nonlinear optical phenomena such as second-order harmonic generation, third-order harmonic generation, frequency mixing, and HHG. This amplification also causes damage to the structure itself. In this study, the plasmonic amplification according to the design of a metal-coated sapphire conical structure is theoretically calculated, and we analyze the effects of this optical amplification on HHG and damage to the sample.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.430-432
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• 2010

We verified through a noncritical phase-matched second-harmonic generation experiment that the periodically-poled $LiNbO_3$ (PPLN) had a large effective nonlinear optical coefficient, demonstrating that the QPM grating was uniform throughout the entire length of PPLN. The quasi-phase matching temperature was $193.4^{\circ}C$. The maximum SHG output power at the fundamental power of 2.0 W was found to be 18.0 mW; generated second-harmonic beam was found to have no photorefractive effect.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2199-2200
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• 2009

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3866-3869
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• 2010

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.438-444
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• 2015

A new approach to the active phased arrays for the second harmonic generation is presented. Phase variation between the second harmonic oscillators by the mutual synchronization is analyzed theoretically. In this coupling, the active antenna consists of the FET oscillator which plays two roles in fundamental oscillation and frequency multiplying, and the patch antenna resonated at the second harmonic frequency. The radiated second harmonic wave was scanned by varying the free-running oscillation frequencies of the active antennas. In the experiment using the 2-elements array and the 4-elements array, the radiated beam of the second harmonic wave was scanned more widely compared with the case of the fundamental wave radiation.

• Journal of Photoscience
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• v.7 no.1
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• pp.9-13
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• 2000

An alternately assembled polycation-anionic dye film was prepared on a precursor assembly of poly(allylamine)hydrochloride (PAH) and poly(sodium styrenesulfonate) (PSS) or of poly (djallyldimethyl)ammonium chloride (PDDA) and PSS. The (PAH/PSS) precursor assembly gave better adsorptivity to the anionic dye than the (PDDA/PSS) one. Four kinds of anionic dyes (EB-T, AR-17 AR-18, AR-27) with different numbers of sulfonate substituents were compared. The extent of dye assembling was higher for the dye with a smaller number of sufonate substituents. Second harmonic generation (SHG) was clearly observed from the films. The SHG signal and the absorption intensity correlated well up to four polycation/dye bilayers, while further assembly did not increase the SHG signal appreciably. Second order nonlinear coefficients for ten bilayer assemblies were the order of pm/V.