• Current Optics and Photonics
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• v.4 no.1
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• pp.50-56
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• 2020

The design of a concentration system for a solar side-pumped slab laser was investigated. The side size of the slab laser medium is 2 mm × 20 mm. Based on the principle of the edge ray, a secondary concentrating system consisting of a rectangular parabolic mirror (RPM) and a rectangular dielectric-filled compound parabolic concentrator (RDCPC) was demonstrated. The focal length of RPM is 1200 mm and the size is 734 mm × 2000 mm. The outlet size of the RDCPC is 2 mm × 20 mm. The concentration effect was analyzed by using Tracepro optical software. The results showed that the concentration efficiency reached 81.3% and the uniformity of the spot was 91.4% after optimization. This design of concentration system is of great reference value for a solar side-pumped slab laser.

• Korean Journal of Optics and Photonics
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• v.5 no.3
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• pp.356-363
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• 1994

By Gaussian optics, a zoom eyepiece is analyzed, which has the diameter of exit pupil 0.5 em, eyerelief 1 em, and angular magnification $M_a=7~15$. The initial design is based on this analysis. Telescope objective which was previously designed has focal length($(f_u')$ 21.0 em, and its clear aperture is 6.2 em. Zoom telescope has half field angle $\beta=1.5^{\circ}$ at the entrance pupil and at exit pupil it is $\beta'=1.5^{\circ}\times(7~15)=10.5^{\circ}~22.5^{\circ}$. Zoom eyepiece consists of three groups, of which each one satisfies the Seidel 3,d order aplanatization. Final design is obtained by optimization for the finite ray aberration, and the zoom eyepiece is assessed on the basis of the resolution of eyes.f eyes.

• Current Optics and Photonics
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• v.4 no.5
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• pp.441-445
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• 2020

A novel design for a Fresnel lens for a solar end-pumped laser is demonstrated in this paper. The new hybrid Fresnel lens includes two parts, inner and outer. The inner part is a twice-total-internal-reflection and vertical-transmission lens. The outer part is a once-total-reflection and vertical-transmission lens. The radius of the Fresnel lens is 600 mm, and its focal length is 750 mm. The concentrating performance of the Fresnel lens is examined using TracePro. The results show that the concentration efficiency has been greatly improved. The total concentration efficiency of the hybrid Fresnel lens reaches 73.2% when the radius of the laser rod is 3 mm. This design can simplify the concentration system of a solar end-pumped solid-state laser.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.13-17
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• 2008

Purpose: Study the method to attach to traditional pattern for the demands of eyeglasses' function which is becoming extended to cultural psychological and social aspects. Methods: To understand the symbolic characteristic of traditional pattern, especially through using palmette, embroidery, and practicing it on glasses' temple and cleaner. Results: Globalization stimulates crossing-consumption cultural trend rapidly. Thus, new glasses pattern involving Korean ethnic feature is a new source that could well adapt to this tendency. This report presents new aspect which corresponds to the demand of modern consumers. By modernizing Traditional pattern and method, we could discover the cultural value of glasses design. Conclusions: Glasses imply social position of users and became a measure that reveal a part of style that presents modern psychological language. Thus, the glasses design using traditional pattern makes a chance to change the beauty sense from western style to oriental one. And it achieves the desire of cultural consumption through glasses design.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.57.3-58
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• 2017

We report the detailed design of an unprecedented wideband(band7+8) corrugated feed horn in ASTE focal plane array aiming for future ALMA receiver. We have found that such design constraints as return loss, cross-polarization level, beam width and phase curvature can be controlled by optimizing critical corrugation parameters at the throat and flare region of the horn. The success of optimization manifest itself through simulated aperture effciency over 80 % at the entire frequency range. Physical implications of the resulting corrugation parameters are discussed.

• Korean Journal of Optics and Photonics
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• v.29 no.3
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• pp.110-118
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• 2018

We have designed a mid-infrared optical system for an airborne electro-optical targeting system. The mid-IR optical system is a dual-field-of-view (FOV) optics for an airborne electro-optical targeting system. The optics consists of a beam-reducer, a zoom lens group, a relay lens group, a cold stop conjugation optics, and an IR detector. The IR detector is an f/5.3 cooled detector with a resolution of $1280{\times}1024$ square pixels, with a pixel size of $15{\times}15{\mu}m$. The optics provides two stepwise FOVs ($1.50^{\circ}{\times}1.20^{\circ}$ and $5.40^{\circ}{\times}4.23^{\circ}$) by the insertion of two lenses into the zoom lens group. The IR optical system was designed in such a way that the working f-number (f/5.3) of the cold stop internally provided by the IR detector is maintained over the entire FOV when changing the zoom. We performed two analyses to investigate thermal effects on the image quality: athermalization analysis and Narcissus analysis. Athermalization analysis investigated the image focus shift and residual high-order wavefront aberrations as the working temperature changes from $-55^{\circ}C$ to $50^{\circ}C$. We first identified the best compensator for the thermal focus drift, using the Zernike polynomial decomposition method. With the selected compensator, the optics was shown to maintain the on-axis MTF at the Nyquist frequency of the detector over 10%, throughout the temperature range. Narcissus analysis investigated the existence of the thermal ghost images of the cold detector formed by the optics itself, which is quantified by the Narcissus Induced Temperature Difference (NITD). The reported design was shown to have an NITD of less than $1.5^{\circ}C$.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.355-360
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• 2010

Purpose: Analysis performance for spectacle lens which sales in domestic market and optimization design a spectacle lens which is corrected aberration. Methods: Measured center thickness, radius and aspherical surface coefficient for spherical and aspherical lenses which were ${\pm}$5.00D. Refractive index for every lens was 1.6 and they came from 4 different companies. I used 3 types of equipment to measure lenses. ID-F150 (Mitutoyo) : Center Thickness, FOCOVISION (SR-2, Automation Robotics) : Radius, PGI 1240S (Taylor Hobson) : Aspherical surface coefficient. Designed a lens which had 27 mm of distance from lens rear surface to center of eye, 4 mm of pupil diameter and small aberration on center vision $30^{\circ}C$. To shorten axial distance compared with the measured lens rise merits for cosmetic. Lens Design tool was CODE V (Optical Research Associates). Results: -5.00D aspherical lens had somewhat high astigmatism and distortion compared with the spherical lens. But it had a merit for cosmetic because of short axial height and decrease edge thickness. Improved a performance of distortion and ascertain merits for cosmetic due to short axial height and decrease edge thickness same as (-) lens in case of +5.00 aspherical lens. Though an optimization process front surface aspherical lens had a good performance for astigmatism and distortion and the merit for beauty compared with measured spherical lens. Conclusions: Design trend for domestic aspherical lens is decrease axial height and thickness to increase a merit for cosmetic not but increase performance of aberration. From design theory for optimization design front surface aspherical spectacle lens which has improved performance of aberration and merit for cosmetic at the same time compared with the measured lens. Expect an improved performance from design back aspherical lens compared with front aspherical lens.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.83-86
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• 2007

In this study, a program has been developed to enable a simulation of spherical aberration - originated from a spherical surface and an aspheric surface - via ray tracing and calculation of the degree of spherical aberration. This process has been verified for the variation of spherical aberration generated from ray tracing for aspheric surfaces such as an oval, a parabola, and a hyperbola. By comparing it with the spherical surface, the principle and necessity of the aspheric surface lens design have been understood. In addition, it allows confirming the accuracy of the simulation by developing a ray tracing program in relation to the mirror plane of a parabola.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.02a
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• pp.76-83
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• 2002

The injection molding of the plastic optics is basically same as the conventional molding except it requires very intricate control of all the molding processing parameters. In the plastic optics, the problem of injection molding is the shrinkage. The shrinkage must be removed and predicted. This shrinkage is becoming more important than any other problems in precision molding because it can affect the focal length of a lens or the total performance of the optical system. This study focused on avoiding the shrinkage that the mold design allows for the optics. In making mold, the surface accuracy(P-V) of the lower and lower mold are $0.201{\mu}m\;and\;0.434{\mu}m$ respectively. A surface roughness(Ra) is below $0.02{\mu}m$ due to selecting the appropriate tools and using the injection molding machine in high degree. In injection molding of the plastic lens, mold temperature, resine temperature and injecting pressure are important process parameters. Injection molding process is carried out according to varying mold temperature and injecting pressure. As a result P-V(peak to valley) of spheric lens is $3.478{\mu}m$ and that of aspheric lens is $1.786{\mu}m$.

• Korean Journal of Optics and Photonics
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• v.29 no.3
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• pp.104-109
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• 2018

We explain the basic principle of transformation optics, and introduce several design techniques for transformation cavities that can maintain the characteristics of whispering gallery modes (WGMs) even if the cavity is strongly deformed from a circular shape. As a method of obtaining various transformation cavities under a specific conformal mapping, we suggest a method of parallel movement of the initial cavity domain, and a method of rotating the ellipse as a cavity domain. The internal wave pattern and the far-field output characteristics of several designed resonant modes are numerically calculated. From these results, it is confirmed that a variety of GRIN resonators are possible for a given conformal coordinate transformation.