• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.275-276
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• 2011

We have investigated the holographic grating formation on Ag-doped amorphous chalcogenide As2Se3 thin films with Ag layer. The basic optical parameter which is a refractive index and extinction coefficent was taken by n&k analyzer. The source of laser was selected based on these parameter. Holographic gratings have been formed using He-Ne laser (wavelength: 632.8 nm) Diode Pumped Solid State laser (DPSS, wavelength: 532.0 nm) under [P:P] polarized the intensity polarization holography. The diffraction efficiency was obtained by +1st order intensity.

• Applied Microscopy
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• v.32 no.3
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• pp.195-204
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• 2002

In this review, the fundamental concepts of delta function, convolution integral and Fourier transformation are discussed. The applications of Fourier transformation to slit function, two very narrow slits, two slits of appreciable width, periodic array of narrow slits, arbitary periodic function, diffraction gratings and gaussian functions are also introduced.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.2
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• pp.178-181
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• 1986

Dielectric waveguide gratings of the image-guide type can be made by periodically cutting notches on the sides or in the top is the image guide. In this paper modeling of grattings using a transmission-line equivalent circuit with equal line lenghth is biscussed, and systematic design procedure of dielectric-waveguide bandpass filter using coupled gratings is presented. It is shown that experimental results is in excellent agreement with the computed response.

• Journal of the Optical Society of Korea
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• v.2 no.1
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• pp.26-29
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• 1998

Novel, all-fiber drop-pass filters with the implementation of fiber gratings are reported. Good controllability of the drop and pass power is demonstrated. Some preliminary results on the performance of the drop-pass filters are presented.

• Journal of the Optical Society of Korea
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• v.8 no.1
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• pp.21-28
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• 2004

When femtosecond laser pulses are focused inside the bulk of transparent materials, the intensity in the focal volume becomes high enough to produce permanent structural modifications. This technique has been applied to fabricate three-dimensional photonic structures such as optical memory, waveguides, gratings, and couplers inside a wide variety of transparent materials. In this paper, we review the fabrication of optical elements in glasses with femtosecond laser pulses, including the fabrication of waveguides, couplers, Bragg gratings, zone plates, holographic memory, and micro holes.

• Journal of Information Display
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• v.4 no.1
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• pp.9-13
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• 2003

An overview of author activity in the area diffractive LCDs are given. The formation of colour spectrum DL CDs is made by switchable phase diffraction gratings created in a LC layer due to using of comb-like electrodes. The offered DLCDs functionate without polarizes, have high contrast and spectral of pure colours, broad viewing ngles. The existing production equipment can be adapted to manufacturing of DLCD without considerable alterations.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.119-122
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• 1987

By cascading the step discontinuities on planar dielectric waveguides with a ferrite layer through two uniform planar dielectric waveguides, nonreciprocal scaterring characteristics of planar dielectric waveguide gratings are analyzed. The calculated results at 35GHz shows that the isolation mechanism takes place near band stop frequency range.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1980-1986
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• 2016

In this study, we studied the gamma-radiation effect of fiber Bragg gratings (FBGs) on the high temperature annealing condition after grating inscription using a KrF UV laser (248 nm). The FBGs were fabricated in a different annealing temperature using the same commercial Ge-doped silica core fiber (SMF-28e) and exposed to gamma-radiation up to a dose of 31 kGy at the dose rate of 115 Gy/min. The high temperature annealing procedure for grating stabilization was applied to change the radiation sensitivity of the FBGs. According to the experimental data and analysis results, the gratings that were stabilized at different temperatures at 100, 150 and $200^{\circ}C$ have clearly shown that exposure to higher temperatures increases their radiation sensitivity. The radiation-induced Bragg wavelength shift (BWS) was shown a difference of up to about a factor of two depending on the annealing temperature conditions of the gratings.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2461-2465
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• 2013

This paper investigates the influence of hydrogen loading process on the radiation sensitivity of fiber Bragg gratings (FBG). We made the FBG inscribed in the same commercial Ge-doped fiber with different hydrogen loading periods. We measured the Bragg wavelength shift (BWS) of the FBG exposed to gamma-radiation up to a dose of 18 kGy, and evaluated the change of full width at half maximum (FWHM) and the FBG temperature sensitivity coefficient after irradiation. Varying hydrogen loading parameter led to BWS differences up to nearly a factor of two.

• Laser Solutions
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• v.17 no.2
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• pp.19-25
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• 2014

Optical embedded diffraction gratings with the bulk modification in BK-7 glass plates excited by tightly focused high-intensity femtosecond (130fs) Ti: sapphire laser (peak wavelength = 790nm) were demonstrated. The structural modifications with diameters ranging from 400nm to $4{\mu}m$ were photo-induced after plasma formation occurred upon irradiation with peak intensities of more than $1{\times}1013W/cm^2$. The graded refractive index profile was fabricated to be a symmetric around from the center of the point at which low-density plasma occurred. The maximum refractive index change was estimated to be $1.5{\times}10^{-2}$. The two optical embedded gratings in BK-7 glass plate were demonstrated with refractive index modification induced by the scanning of low-density plasma formation.