• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.538-545
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• 2014

Microlens array (MLA) films have been used as brightness-enhancement components in many illumination systems, such as a backlight, which should meet the industrial needs of low cost and high brightness performance. A hexagonally-arranged MLA (HA-MLA) was chosen due to its high filling factor, which was a prerequisite for achieving high brightness-enhancement capability. The moir$\acute{e}$ fringes produced in a film stack composed of two HA-MLA were investigated, under four different lens configurations, by optical simulation. It was found that randomizing the lens configuration, while keeping the filling factor high, was effective way to develop high-gain MLA films for backlight applications.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.197-198
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• 2008

본 논문에서는 Iterative Fourier Transform Algorithm $Method(IFTA)^{(1)}$를 사용하여 Diffractive Optical Element(DOE)를 통과한 빛의 Shape이 Input Beam의 각 조건에 따라 얼마나 원하는 형태에 가까워지는지를 Input 대비 Output의 Efficiency와 Signal to Noise Ratio(SNR) Simulation 을 통해 알아보았다. Input beam의 종류는 Gaussian, Supergaussian, Plane, Spherical, Quadratic wave 으로 하고 각각의 경우에 대해 Beam Diameter, Polarization, Wavelength를 변화시키며 DOE에서의 회절 현상을 simulation하였다. 이때 Polarization은 Linear, Circular, Elliptical 형태로 변화시켰고 Wavelength는 332.8nm에서 832.8nm까지의 범위에 대해 연구하였다. 또한 relative edge가 있을 때와 없을 때를 비교하여 가장 효율이 높은 Input Beam의 형태와 그 parameter에 대해 연구하였다.

• Journal of Information Display
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• v.13 no.4
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• pp.139-143
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• 2012

In this study, optical simulation was used to compare three optical structures that could be applied to the typical organic light-emitting diode to increase the outcoupling efficiency. These were spherical scattering particles (treated as Mie scatterers) embedded in the glass substrate, microlenses formed on the glass substrate, and a diffusing layer (DL) with a Gaussian scattering distribution function inserted between the indium tin oxide (ITO) and the glass substrate. It was found that the application of microlens array and that of scattering particles in the glass substrate exhibited similar enhancements in the outcoupling efficiency when the density and the refractive index of the scattering particles were optimized. The DL located at the interface between the glass and the ITO further enhanced the efficiency because it could further extract the trapped light in the waveguide mode. The appropriate combination of these three structures increased the outcoupling efficiency to about 42%, which is much greater than the typical values of 15-20% when there is no optical structure for light extraction.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.26.1-26.1
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• 2010

In this report, we present newly improved optical design for the Amon-Ra energy channel and its optical performance. The design is optimized parametrically with emphasis on improved light concentration. And then its performances are computed, first, from a laboratory test simulation using laser method (wave optics approach) and, second, from an in-orbit radiative transfer simulation using IRT method with 3D Earth model (geometrical optics approach). Two simulation test results show clear evidence of energy concentration improvement.

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.766-771
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• 2014

Single-ring all-pass filters with various coupling ratios are designed, fabricated, and characterized to assess the validity of the split-step time-domain modeling approach, which is considered for direct simulation of time-domain characteristics, such as optical delay, of various ring resonator devices. When the coupling ratio of the single-ring all-pass filter is 0.4 and 0.8, the delay time is measured to be about 145 and 42 ps respectively, which is comparable to the time-domain modeling results of 151 and 47 ps respectively. The measurements for two- and three-ring all-pass filters are also found to agree quite well with the simulation results. With these results it is confirmed that the split-step time-domain model could be efficiently incorporated into an optical-communication simulation module for ring resonator delay components in an all-optical packet switching system.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.564-568
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• 2006

Using the cross-gain modulation (XGM) characteristics of semiconductor optical amplifiers (SOAs), multi-functional all-optical logic gates, including XOR, AND, and OR gates are successfully simulated and demonstrated at 10Gbit/s. A VPI component maker^TM simulation tool is used for the simulation of multi-functional all-optical logic gates and the10 Cbit/s input signal is made by a mode-locked fiber ring laser. A multi-quantum well (MQW) SOA is used for the simulation and demonstration of the all-optical logic system. Our suggested system is composed of three MQW SOAs, SOA-1 and SOA-2 for XOR logic operation and SOA-2 and SOA-3 for AND logic operation. By the addition of two output signals XOR and AND, all-optical OR logic can be obtained.

• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.306-311
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• 2003

In this paper, we modeled the incident beam in order to analyze and evaluate the optical thin film device for wavelength division multiplexing in optical telecommunication network. As applied ray tracing method to the optical path, we were compared the accuracy of coupling efficiency simulated by two modeling methods. In the results of sinulation, ceil modeling method was preferred to annual modeling method in micro-optic device because of accuracy for coupling efficiency and Gaussian intensity distribution. In the results of optimal simulation for optical device using thin film filter, the distance (d1) between optical fiber and GRIN lens, the distance (d2) between GRIN lens and thin film filter and the coupling efficiency were 0.24 mm, 0.25 mm and -0.11 ㏈ respectively. As d2 was displaced at 0.25 mm and d1 was varied in order to evaluate the optimal value, d1 and maximum coupling efficiency were 0.24 mm and -0.35㏈, respectively. Then the results of experiment were corresponded to that of optimal simulation by cell modeling and it was possible to analyze the performance for optical device using thin film filter by the simulation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.284-287
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• 1996

In this paper, we investigated the optical coupling characteristics for $K^{+}$ ion-exchanged diffused channel waveguide by using coupled-mode equations. In this case, the optical-power-dividing was observed at the waveguide-type optical coupler with 3[$\mu\textrm{m}$] line-width and, 6[$\mu\textrm{m}$] separation between channel waveguides in which interaction lengths were 1 and 3[mm], respectively, On the basis of that we deformed simulation for $Ag^{+}$ ion-exchanged diffused channel waveguide. As a result of simulation, the optical-power-dividing was shown at the waveguide-type optical coupler wish 3[$\mu\textrm{m}$] line-width, 6[$\mu\textrm{m}$] separation between channel waveguides and 0.11[mm] interaction length.

• Journal of the Semiconductor & Display Technology
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• v.6 no.2 s.19
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• pp.41-44
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• 2007

Optical simulation of the rear and front panel geometries were needed to improve the luminance and efficiency in PDP cells. The 3-dimensional optical code can be used to analyze the variation of geometries and changing of optical properties. In order to improve the accuracy of simulated results, a new UV source, called a multi-cubes UV source, was designed. To design the source, at first UV distribution was calculated with the plasma fluid code and then the UV distribution was transformed to the multi-cube structures in the optical code. Compared to the results from existing UV source, called a planar UV source, could be improved the accuracy of visible light distribution. Simulated results were also compared to the visible distribution measured with the ICCD in a real PDP cell.

• Current Optics and Photonics
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• v.6 no.3
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• pp.260-269
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• 2022

Segmented planar imaging detector for electro-optical reconnaissance (SPIDER) is an emerging technology for optical imaging. However, this novel detection approach is faced with degraded imaging quality. In this study, a 6 × 6 planar waveguide is used after each lenslet to expand the field of view. The imaging principles of field-plane waveguide structures are described in detail. The local multiple-sampling simulation mode is adopted to process the simulation of the improved imaging system. A novel image-reconstruction algorithm based on deep learning is proposed, which can effectively address the defects in imaging quality that arise during image reconstruction. The proposed algorithm is compared to a conventional algorithm to verify its better reconstruction results. The comparison of different scenarios confirms the suitability of the algorithm to the system in this paper.