• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.236-237
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• 2003

최근 공진기 형태가 없는 2차원 광결정(photonic crystal) 레이저가 그것의 2차원 되먹임과 거울 없는 발진 현상과 같은 특이한 특성으로 인해 많은 관심을 끌고 있다. 이러한 레이저는 photonic band edge에서 빛의 군속도의 감소에 근거하여 작동한다. 이 photonic crystal band edge 레이저는 2차원 형태의 Distributed-Feedback(DFB) 레이저 형태로 볼 수 있다. 지금까지 보고된 레이저는 0.1 정도의 매우 작은 굴절률 변화를 가지고 있고 크기가 (100$\mu$m)$^2$이상으로 상당히 크다. (중략)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.77-78
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• 2007

In this paper, we suppose that the 1-dimensional photonic crystal using holography lithography. We used Ag doped amorphous AsGeSeS which belongs in the chalcogenide materials have sensitive photoluminescence property. The purpose of this experiment is the process to complete 3-D photonic crystal after making 2-D photonic crystal. The lattice formation was made an observation by irradiating He-Ne laser with the AsGeSeS film leaned obliquely. Then, by measuring formed diffraction beam, the diffraction lattice was calculated.

• Journal of Information Display
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• v.2 no.4
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• pp.19-22
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• 2001

In this paper, we describe the electro-optic effects of photonic crystals made of a synthetic opal filled with a nematic liquid crystal(LC). By applying an external electric field, a shift in the Bragg reflection peak position(stop band) and a field-induced change in its peak reflectivity are observed. These significant surface alignment effects of the opal-LC composite are discussed in a similar manner for Freederick-type transitions of LC within a confined geometry in the presence of external fields.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1933-1935
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• 2002

In this paper, we present a study of the structure and electro-optic behavior of hybrid liquid-crystal-silica sphere composite photonic crystals, formed by filling the (26% by volume) void space of fee (face centered cubic) silica opals infiltrated with a nematic liquid crystal. Three dimensional photonic crystals of visible range were fabricated via a self assembly method of silica spheres of submicron diameter. The expected fee structure was confirmed by scanning electron microscopy (SEM) of the dehydrated crystal with glass removed. The photonic crystal exhibited significant electric-field-induced shift of the optical Bragg reflection peak when the liquid crystal has the long molecular axis oriented parallel to the sphere surfaces.

• Journal of the Optical Society of Korea
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• v.15 no.4
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• pp.398-402
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• 2011

In this paper, we have proposed a principle to design wideband, low dispersion and temperature stabilized slow light structure in slotted photonic crystal waveguide (SPCW). The infiltration of the silicon photonic crystal with polymer will enhance the slow light and increase the group index, whereas the different signs of thermo-optic coefficients of polymer and silicon make the proposed structure stable on temperature variation over $60^{\circ}C$ and improves the group index-bandwidth products of the designed structure. The SPCW structure is modified to maximize the slow light effect and minimize the dependence of the group index and hence the group velocity dispersion to temperature.

• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.733-738
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• 2016

We calculate optical properties of guided modes of a hybrid-guiding photonic crystal fiber. The design and modeling of such hybrid-guiding PCF is made by replacing air holes with inserts of high refractive index material layer by layer in order. The optical properties such as mode intensity profile, mode dispersion, optical birefringence, confinement loss, and chromatic dispersion during transition of the guiding mechanism are analyzed and discussed. The guided modes in the hybrid-guiding region are also compared with those of reference index-guiding and bandgap-guiding photonic crystal fibers.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.817-822
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• 2011

We propose a novel ring structure based on the stadium-shaped ring resonator (SSRR) with dual photonic crystal microcavity (DPCM) for biosensor and analyzed the sensing characteristics. The Q-factor of the photonic crystal microcavity (PCM) can be significantly enhanced when the PCM or DPCM has the same resonance condition as the SSRR. The simulation results show that the Q-factor of the SRR with DPCM was increased by three times in comparison with single PCM structure. We also defined a mutual interference between two PCMs. Assuming a detectable spectral resolution of 10 picometers, a refractive index resolution of $3.03\times10-5$ can be measured on the SSRR-DPCM.

• Journal of the Optical Society of Korea
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• v.7 no.1
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• pp.38-41
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• 2003

We present an analysis of highly-dispersive guided modes of two-dimensional photonic crystal waveguides. By the plane ave expansion method, band structures and mode profiles of two-dimensional photonic crystal waveguides are obtained. It is found that guided modes have very small group velocities and very large group velocity dispersions in the region near the f-point and in the region near the Brillouin zone edge. Especially, the group velocity dispersions are found to be millions of times larger than that of a conventional optical fiber. The contributions of the transverse resonance formed by two photonic band gap reflectors and the standing wave mode formed by periodic structures are discussed. We conclude that the highly-dispersive characteristics originate from the resonator-like aspect of the photonic crystal waveguide.

• Current Optics and Photonics
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• v.6 no.2
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• pp.129-136
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• 2022

We propose a photonic crystal fiber (PCF) with a slotted porous core and elliptical-hole cladding, for high birefringence in the terahertz regime. Asymmetry in the guided mode is obtained mainly by using arrays of elliptical air holes in the TOPAS^® polymer cladding. We investigate the tradeoff between several structural parameters and find optimized values that can have a high birefringence while satisfying the single-mode condition. The optical properties in the terahertz regime are thoroughly analyzed in numerical simulations, using a full-vector finite-element method with the perfectly-matched-layer condition. In an optimal design, the proposed photonic crystal fiber shows a high birefringence of 8.80 × 10^-2 and an effective material loss of 0.07 cm^-1 at a frequency of 1 THz, satisfying the single-mode-guidance condition at the same time. The proposed PCF would be useful for various polarization-management applications in the terahertz range.

• Korean Journal of Optics and Photonics
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• v.20 no.6
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• pp.339-345
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• 2009

The high power and single mode vertical cavity surface emitting laser(VCSEL)s with photonic crystal structures have been proposed and fabricated by reducing substantially the hole numbers used in the photonic crystal structures. It is found that only six holes enable VCSELs to operate a single mode and the reliability can be enhanced by filling the holes with polyimide. The single mode lasing characteristics were analyzed by varying the oxide aperture and the hole diameter in photonic crystal structures. As a result, the single mode lasing can be stably obtained in the photonic crystal vertical cavity surface emitting lasers.