• Korean Journal of Optics and Photonics
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• v.18 no.5
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• pp.345-350
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• 2007

The characteristics of the supercontinuum generated in photonic crystal fibers were investigated by using the generalized nonlinear $Schr\"{o}dinger$ equation and the split-step Fourier method. Based on the simulated results, we generated the supercontinuum spectrum with the flatness of ${\pm}4dB$ in the wavelength range of 650 to 900 nm by employing a 200-fs pulse of Ti:sapphire laser and a commercial photonic crystal fiber.

• Korean Journal of Optics and Photonics
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• v.21 no.6
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• pp.235-240
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• 2010

We fabricate highly birefringent photonic crystal fiber with new structure using a stack and draw method. Fabricated fiber has two big air holes, one at each side of the outside air cladding region, leading to core ellipticity during the drawing process. Birefringence of the fabricated Hi-Bi PCF is measured to be $2.29{\times}10^{-4}$ (at 1550 nm).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.188-194
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• 2011

We analyze transmission performance of radio frequency signal in WDM-ROF (wavelength division multiplexing - radio over fiber) system employing photonic crystal fiber. In a WDM-ROF system employing conventional single-mode fiber, transmission performance of radio frequency signal is analyzed depending on each WDM channel. In this case, each WDM channel experiences power fluctuation of received RF signal in remote node because of double sidebands of the modulated signal and wavelength dependent dispersion of single mode fiber. This RF power fluctuation acts as a design constraint in viewpoint of system design. By employing photonic crystal fiber (PCF) with dispersion compensation characteristics, the transmission performance of RF signal can be improved compared with the case with SMF only.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.6
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• pp.515-521
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• 2003

There are now many theoretical investigations and real manufactures for numerous applications of photonic crystals (PCs) associated with photonic band gap and photonic integrated circuits. However, there are some difficulties to design and fabricate the desired pattern quality. It is not easy to satisfy accurate critical dimension (CD) for patterns with arbitrary shapes and pitch sizes aligned in various directions. In this work, we report the optimum conditions to better fabricate and design, and greatly improve pattern quality in delineating two-dimensional (2D) PCs in the nanometer range using single- step e-beam lithography system with conventional exposure mode.

• Korean Journal of Optics and Photonics
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• v.13 no.1
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• pp.27-31
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• 2002

We design a 1$\times$4 optical splitter made of photonic crystal waveguides and analyze the properties of the optical splitter using the finite-difference time-domain method with perfectly-matched-layer absorbing boundaries. The photonic crystal is constructed from cylindrical rods in air on a square lattice. Our simulation results show that there are different transmission properties for four bend geometries and different incident-wave frequencies. The sum of the power transmission of the splitted light is over 93 percent at a certain geometry and frequency, and the incident power splits in the four arms with almost the same ratio.

• Journal of the Korean Vacuum Society
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• v.12 no.4
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• pp.288-292
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• 2003

The fabrication of silicon nano-master with pillar structures using E-beam lithography and ICP etching was investigated for application of 2-dimensional polymer photonic crystal waveguides with air hole structures. Pillar structures with square, hexagon, dodecagon and circle were successfully fabricated. The diameters and structures of fabricated pillars were measured by CD-SEM and SPM-AFM. It was found that the optimal dose for complete circle pillar structures was 432 $\mu$C/$\textrm{cm}^2$.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.164-165
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• 2003

A cholesteric liquid crystal (CLC) system exhibits one-dimensional (1-D) Photonic bandgap (PBG) characteristics in the transmission spectrum through a selective Bragg reflection. Related to the nonlinear optical (NLO) processes in a PBG structure of CLC, the inherent periodicity has been exploited to Phase-match the fundamental and the harmonic waves through the umklapp Processes. Near bandgap edges of a CLC, harmonic generations have been shown to be enhanced significantly through the field localization. (omitted)

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.3
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• pp.309-316
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• 2021

In this paper, the electrical power output of the micro-combustor thermophotovoltiac(TPV) system was analyzed. The system consists of a micro-combustor, photonic crystals(PhCs), and photovoltaic cells(PV cells). The system has a micro-combustor that can achieve over 1,000 K surface temperature by consuming 2.5 g/h hydrogen fuel. Also, this system incorporates current state-of-the-art PhCs surfaces(2D Ta PhCs and Tandem Filter) to increase electrical power output. In addition, InGaAsSb PV cell, which bandgap is 0.55 eV, was applied to convert a wide range of radiative energy. The performance analysis shows that a single micro-combustor TPV system can produce 0.4 W ~ 27.7 W electrical power with the temperature change of emitter(900 K ~ 1,500 K) and PV cell(250 K ~ 400 K).

• Proceedings of the Materials Research Society of Korea Conference
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• 2008.11a
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• pp.20.2-20.2
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• 2008

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.341-342
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• 2009