• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.438-443
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• 2010

In this paper, behaviors of photonic crystal (PC) radiative structures and antenna arrays have been compared for two types of uniform and binomial excitations. Appropriate duality has been shown between them. These results can be generalized to other types of excitation and arrangement of photonic crystal radiative arrays such as linear, planar and circular arrays of three dimensional (3D) photonic crystal termination resonators. Using these results in designing photonic circuits has some advantages for shaping a particular radiative beam at the photonic crystal exit, for instance reducing the divergence angle of the main lobe in order to enhance the directivity, for better coupling, or for splitting the emitted beam, for dividing the output beam to the next devices in photonic integrated circuits (PIC). For analysis and simulation of the photonic crystal structures, the finite difference time domain (FDTD) method has been employed.

• Journal of the Optical Society of Korea
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• v.7 no.2
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• pp.79-83
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• 2003

In this paper, we describe the fabrication process of a photonic crystal fiber and present the measured optical properties of the photonic crystal fiber. The fabrication of the photonic crystal fiber involves stacking, jacketing, collapsing, and drawing using a conventional drawing tower The photonic crystal fiber drawing needs higher tension to maintain the uniform air hole structure. Thus, the temperature of the photonic crystal fiber drawing is lowered by a few hundred degrees Celsius than for the case of conventional optical fiber drawing. The optical properties of the fabricated photonic crystal fiber such as mode profile, optical loss, transmission spectrum, bending loss, and polarization dependent loss are measured.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.887-890
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• 2008

We present 2D slab silicon-based photonic crystal optical insulator to enhance light emission efficiency of light-emitting diode (LED). A 2D slab silicon photonic crystal is designed in such a way that light emitting diode die can be placed in the middle of the silicon photonic crystal. The device creates light propagation forbidden region in horizontal plane for Transverse Electric (TE) light with the wavelength range of 450 nm to 600 nm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.12
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• pp.1045-1057
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• 2009

The authors investigated the InGaN/GaN multi-quantum well blue light emitting devices with the implementation of the photonic crystals fabricated at the top surface of p-GaN layer and the bottom interface of n-GaN layer. The top photonic crystals result in the lattice-dependent photoluminescence spectra at the wavelength of 450 nm and however, the bottom photonic crystal shows a big shift of the photoluminescence peak from 444 nm to 394 nm. The sample with the bottom photonic crystal structure also shows the lasing effect at the wavelength of 468 nm. Furthermore, the quality enhancement for the crystal growth of GaN thin film on the bottom photonic crystal comes from the modulated compressive stress which was measured by the micro-Raman spectroscopy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.498-501
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• 2005

Photonic crystals, periodic structure with a high refractive index contrast modulation, have recently become very interesting platform for manipulation of light. The existence of a photonic bandgap, a frequency range in which propagation of light is prevented in all direction, makes photonic crystal very useful in application where spatial localization of light is required for waveguide, beam splitter, and cavity. But fabrication of 3 dimensional photonic crystal is still difficult process. a concept that has recently attracted a lot of attention is a planar photonic crystal based on a dielectric membrane, suspended in the air, and perforated with 2 dimensional lattice of hole. We show that the polymer slabs suspended in air with triangular lattice of air hole can exhibit the in-plane photonic bandgap for TE-like modes. The fabrication of Si master with pillar structure using hot embossing process was investigated for 2 dimensional low-index-contrast photonic crystal waveguide.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.62-63
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• 2008

Photonic crystas were fabricated using an anodic aluminum oxide(AAO) mask on GaN diode. The Photonic crystal structure has been investigated from Atomic Force Microscope(AFM). The hole diameter and lattice constant of photonic crystal are 60nm and 105nm, respectively. Photoluminescence of photonic crystal was enhanced and optical interference was increased by photonic crystal effect.

• Journal of the Optical Society of Korea
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• v.11 no.3
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• pp.97-100
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• 2007

We have investigated properties of a plastic photonic crystal fiber guiding terahertz radiations, THz photonic crystal fiber. The single-mode condition and dispersion of a plastic triangular THz photonic crystal fiber are investigated by using the plane wave expansion method and the beam propagation method. The THz photonic crystal fiber can perform as a single-mode fiber below 2.5 THz when the ratio of diameter (d) and period (${\Lambda}$) of air holes is less than 0.475. The THz photonic crystal fiber with ${\Lambda}=500{\mu}m$ and $d/{\Lambda}=0.4$ shows almost zero flattened dispersion behavior, $-0.03{\pm}0.02 ps/THz{\cdot}cm$, in the THz frequency range from 0.8 to 2.0 THz.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.16-21
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• 2005

Photonic crystals, periodic structure with a high refractive index contrast modulation, have recently become very interesting platform for the manipulation of light. The existence of a photonic bandgap, a frequency range in which the propagation of light is prevented in all directions, makes photonic crystal very useful in application where the spatial localization of light is required, for example waveguide, beam splitter, and cavity. However, the fabrication of 3 dimensional photonic crystals is still difficult process. A concept that has recently attracted a lot of attention is a planar photonic crystal based on a dielectric membrane, suspended in the air and perforated with two dimensional lattice of hole. The fabrication of Si master with pillar structure using hot embossing process is investigated for two dimensional, low-index-contrast photonic crystal waveguide. From our research we show that the multiple stamp copy process proved to be feasible and useful.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.589-593
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• 2014

Terahertz (THz) communication has important applications in high-speed and ultra broadband wireless access networks. The THz modulator is one of the key devices in a THz communications system. Wavelength division multiplexing (WDM) can expand the capacity of THz communications systems, so research on multi wavelength THz modulators has significant value. By combining photonic-crystal and THz technology, a novel type of multi wavelength THz modulator based on a triple-lattice photonic crystal is proposed in this paper. Compared to a compound-lattice photonic crystal, a triple-lattice photonic crystal has a larger gap width of 0.196. Simulation results show that six beams of THz waves can be modulated simultaneously with high performance. This modulator's extinction ratio is as large as 34.25 dB, its insertion loss is as low as 0.147 dB, and its modulation rate is 2.35 GHz.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.122-122
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• 2013

In this talk, some optical properties of quantum dot based mode-locked diode lasers and photonic crystal nano lasers will be discussed. Linewidth enhancement factor, chirp and interband injection locking technique of quantum dot mode-locked lasers will be presented. Also various types of photonic crystal buried heterostructure lasers toward coherent nano laser will be covered as well.