• Korean Journal of Optics and Photonics
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• v.31 no.2
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• pp.81-87
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• 2020

This study examines the design technology of searchlight optics featuring narrow beam angles and high luminous intensities. Halogen and xenon lamps, which are conventional searchlight sources, are vulnerable to vibration and shock, and are large and heavy, making them difficult to transport. In addition, the parabolic mirror located at the rear of the searchlight has the disadvantages of poor performance and low light efficiency, due to the assembly error produced during manufacturing. To solve this problem, a 1-kW halogen lamp is replaced by a 150-W high-power COB LED, and a high-efficiency TIR lens is designed to meet the target performance. Afterward, the TIR lens array is proposed to solve the surface error generated during optical injection. After a prototype is manufactured based on the designed optical system, the optical performance is confirmed to be excellent, by comparing it to that of a commercial halogen-lamp searchlight.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.633-634
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• 2008

• Korean Journal of Optics and Photonics
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• v.24 no.1
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• pp.23-28
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• 2013

In this paper, an optical system was designed for 3D imaging laser radar with optical scanner. In order to make it easy to scan, the system was designed to inscribe the transmitting objective lens in the receiving lens. In transmitting optics, the beam expander was designed to have a zoom mechanism so that the transmitted beam size would be 4.8 m or 6.8 m at 1 km distance, when the laser source's numerical aperture value is between 0.13 and 0.22. The beam diameter at the target 1 km away was confirmed by design program. The receiving optics for the returning beam from the target was designed for the $16{\times}16$ array detector with $100{\mu}m$ pixel width. The spot diameter in every pixel was designed and verified to be less than $55{\mu}m$. The receiving optics' obscuration ratio by transmitting optics was 11%.

• Journal of Korean Ophthalmic Optics Society
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• v.1 no.2
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• pp.85-91
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• 1996

Among the 110 glasses wearers, the hyperopic glasses wearers were 18(16.36%) persons and myopic glasses wearers were 92(83.64%) persons. The distance for optical centers was coincided to the pupillary distance in 9(8.18%) persons and discrepant in 101(91.82%) persons. Ophthalmic dispensing Pupillary Distance resulted from testing by the trouble error range(Germany RAL-915), unadopt spectacles had been wearers 52(51.49%) persons. The 65(64.56%) persons and 36(35.64%) persons showed the induced esophoria and the induced exophria, respectively. The maximal induced esophoria was 3.69 prism diopters and maximal induced exophoria was 3.68 prism diopters.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.1-8
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• 2008

Purpose: We investigated opticians' and the public (including optometry students) opinions about university/college affiliated optical shops. Methods: Opinions about the university/college affiliated optical shops, their positive or negative effects, services range, how to obtain their operation cost, and so on were asked to 50 opticians and 51 public people (including optometry students) by a questionnaire survey, being statistically analysed. Results: Most respondents answered positive opinions about the university/college affiliated optical shops, anticipating better eye test ability of Koean optometry graduates through improved clinical education. Conclusions: The university/college affiliated optical shops are expected to contribute to clinical education and research in Korea. Legal revisions and efforts of each university/college are required.

• Korean Journal of Optics and Photonics
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• v.12 no.4
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• pp.305-311
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• 2001

The new and simple velocimetry model to be perpendicularly arranged with two optical systems with a projected and reduced rotatable line grating is so proposed as to withstand an external vibration. We measured successfully the various velocities (V_{chop}$) of a chopper by using the new velocimeter. As a result, when rotational angles of projected volume gratings in two optical systems are $\alpha=73^{\circ}$ and $\beta=73^{\circ}$, respectively, we measured successfully the chopper velocities within 1 % accuracy from $V_{chop}=43.52cm/s to 249.36cm/s$. In this new velocimetry, we can determine the confidence of .the system by comparing the z-component of velocity, to be measured in one optical system with $V_z$ to be measured in one optical system with $V_z^'$ to to be measured in another optical system, which should be same.e same.

• Korean Journal of Optics and Photonics
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• v.25 no.3
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• pp.125-130
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• 2014

Holographic optical elements (HOEs) provide systems of thin-film optics that could include a variety of functions and have many advantages as optical devices in various research fields. Research and developments based on the use of HOEs in the fields of communications and displays are in progress. This paper introduces the properties of HOEs and their applications in diffractive optical elements (DOEs), holographic projection screens, and head-mounted displays (HMDs). For widespread use of HOE technology in these various applications some challenges need to be solved, as discussed in this paper.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.121-128
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• 1998

In this paper, We researched the optical performance of eye by means of the Gullstrand EYE MODEL. And we also researched the glasses that are made by designing the eye glasses corrected with the Astigmatism and the optical performance of the glasses in the optical system which are compounded with eyes. This paper can be used as a reference material in designing the glasses for ametropic correction.

• Journal of Korean Ophthalmic Optics Society
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• v.2 no.1
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• pp.55-60
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• 1997

Numerically compares a calculation about a variable process of visual acuity for a artificial myopia with previously the tested result. The calculation is used to the value of Gullstrand's theoretical eyes and a method of geometrical optics. The theoretical eye simplified a entrance pupil and retina. Optical lens and eye changed a equivalent lens. Refractive power of a equivalent lens is converted to focal length within theoretical eyes, and this was calculated about relation of a blur circle on the retina and visual acuity.

• Korean Journal of Optics and Photonics
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• v.18 no.3
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• pp.196-201
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• 2007

A theoretical study of Brillouin optical time domain analysis (BOTDA) using two pulse lasers is performed. Even though a point detection is made for a pump pulse period, the dynamic range of BOTDA using two pulse lasers is approximately 5 dB more than that of a pulse and a CW laser when the fiber length is 140 km and the Stokes power is 1 mW.