• Journal of the Microelectronics and Packaging Society
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• v.18 no.3
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• pp.39-43
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• 2011

Effects of cavity material on the Q-factor measurement of microwave dielectric materials were studied by HFSS simulation and the measurements using metal cavity. $TE_{01\delta}$ mode resonant frequency was determined from the electric and magnetic field patterns and the loaded Q-factor was calculated from 3dB bandwidth of $S_{21}$ spectrum. When the cavity metal materials were Cu, SUS and Au cavity, the level of Q-factor was similar. However, Q-factor was significantly decreased when the cavity metal material was CuO. The Q-factor measurements of dielectric resonator by network analyzer using various metal cavity exhibits consistent behavior.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.78-78
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• 2015

Metamaterials, artificially structured nanomaterials, have enabled unprecedented phenomena such as invisibility cloaking and negative refraction. Especially, hyperbolic metamaterials also known as indefinite metamaterials have unique dispersion relation where the principal components of its permittivity tensors are not all with the same signs and magnitudes. Such extraordinary dispersion relation results in hyperbolic dispersion relations which lead to a number of interesting phenomena, such as super-resolution effect which transfers evanescent waves to propagating waves at its interface with normal materials and, the propagation of electromagnetic waves with very large wavevectors comparing they are evanescent waves and thus decay quickly in natural materials. In this abstract, I will focus discussing our efforts in achieving the unique optical property overcoming diffraction limit to achieve several extraordinary metamaterials and metadevices demonstration. First, I will present super-resolution imaging device called "hyperlens", which is the first experimental demonstration of near- to far-field imaging at visible light with resolution beyond the diffraction limit in two lateral dimensions. Second, I will show another unique application of metamaterials for miniaturizing optical cavity, a key component to make lasers, into the nanoscale for the first time. It shows the cavity array which successfully captured light in 20nm dimension and show very high figure of merit experimentally. Last, I will discuss the future direction of the hyperbolic metamaterial and outlook for the practical applications. I believe our efforts in sub-wavelength metamaterials having such extraordinary optical properties will lead to further advanced nanophotonics and nanooptics research.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.3
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• pp.43-48
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• 2012

Errors of relative permittivity calculation caused by the variation of sample aspect ratio (diameter/height) and measuring geometry were analyzed by computer simulation and measurement. Firstly, the $S_{21}$ spectrum of the sample (permittivity 38) was simulated in the post resonator measuring apparatus by HFSS simulation. Then, the relative permittivity was calculated from the $TE_{011}$ mode resonant frequency. The relative permittivity varied by ca. 0.3% with sample aspect ratio variation (D/H=0.8~1.6). The relative permittivity varied by ca. 1~10% when the 1~10% of air-gap was introduced in between the dielectric disk and upper conductor. All the simulation results showed consistent tendency with real measurement.

• Korean Journal of Optics and Photonics
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• v.28 no.6
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• pp.361-365
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• 2017

In this paper, we demonstrate a facile fabrication technique for a periodically aligned metal nanoparticle array, for a narrow-band plasmonic absorber. The metal nanoparticles are fabricated by e-beam evaporation and heat treatment processes on top of a periodic aluminum groove template. The plasmonic absorber is constructed with the transferred metal nanoparticle array, sputtered 33-nm-thick $Al_2O_3$, and 200-nm-thick metal reflector layers on silicon substrate. 46-nm-diameter and 76-nm-lattice metal-nanoparticle-array-based plasmonic absorber has performed as a narrow-band absorber with a central wavelength of 572 nm and full width at half maximum (FWHM) of 109.9 nm.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.4-4
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• 2012

Proteins enable biology to be viable through molecular interactions (such as in antigen-antibody, ligand-receptor, and drug-target) with

• Journal of the Korean Vacuum Society
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• v.21 no.6
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• pp.342-347
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• 2012

The optical properties of InAs quantum dots (QDs) grown on a GaAs substrates by migration enhanced molecular beam epitaxy method have been investigated by using photoluminescence (PL) and time-resolved PL measurements. The luminescence properties of InAs/GaAs QDs have been studied as functions of temperature, excitation laser power, and emission wavelength. The PL peak of InAs QDs capped with $In_{0.15}Ga_{0.85}As$ layer (QD2) measured at 10 K is redshifted about 80 nm compared with that of InAs QDs with no InGaAs layer (QD1). This redshift of QD2 is attributed to the increase in dot size due to the diffusion of In from the InGaAs capping layer. The PL decay times of QD1 and QD2 at 10 K are 1.12 and 1.00 ns taken at the PL peak of 1,117 and 1,197 nm, respectively. The reduced decay time of QD2 can be explained by the improved carrier confinement and enhanced wave function overlap due to increased QD size. The PL decay times for both QD1 and QD2 are independent on the emission wavelength, indicating the uniformity of dot size.