• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.151-165
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• 1998

We investigated the optical properties of 3-component zoom camera lens whose character is being compact and having wide angle. Also, we calculated paraxial design condition and locus of each component by using Gaussian Bracket.

• Korean Journal of Optics and Photonics
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• v.25 no.1
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• pp.8-13
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• 2014

By using finite ray-tracing and curve fitting, a numerical method to determine the non-paraxial pupil function of a high-NA objective is presented. MTF degradations caused by the non-paraxial diffraction effect are analyzed for on-axial imaging of a far-infrared objective and aberration-free ellipsoidal mirror system. The ellipsoidal mirror system has the same paraxial specifications as the far-infrared objective.

• Korean Journal of Optics and Photonics
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• v.10 no.3
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• pp.237-242
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• 1999

Taking into consideration the thermal lensing effects of laser rods, depolarization losses of laser beams induced by the thermal birefringence were calculated. The numerical model proposed for the calculation, which is based on the paraxial ray optics formulation and provides explicit expressions of optical path lengths for various optical elements, was described in detail. Calculated results were compared with those of Jones matrix formulation and experiments. The calculated results are in good agreement with experimental results.

• Korean Journal of Optics and Photonics
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• v.20 no.3
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• pp.156-165
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• 2009

We theoretically derive the set of general paraxial zoom locus equations for all zoom lens systems with finite object distance, including the infinite object distance case, by using the Gaussian bracket method and matrix representation of paraxial ray tracing. We make the zoom locus program by means of a numerical calculation method according to these equations in Visual Basic Language. Consequently, the solutions of this method can be consistently and flexibly used in all types of zoom lens in the step of initial design about zoom loci. Finally, in order to verify the justification and usefulness of this method, we show that two examples, such as $M_{4a}$ and $M_{4h}$ types of 4 groups, and one example, $M_{5n}$ type of 5 groups, which are very complicated zoom lens systems, can be rapidly and diversely traced through various interpolations by using this program.

• Korean Journal of Optics and Photonics
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• v.24 no.1
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• pp.9-16
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• 2013

We try to find the generalized structural equation that gives a perspective understanding for telecentric lenses through paraxial optical algebraic equations and preconditions from a highly experienced design sense. The equation is named the $f{\theta}$ formula and this formula is applied to single lenses, double Gauss lenses, Cooke triplet lenses and the compound lens composed of a Cooke triplet lens and a double Gauss lens step by step. And this formula is also applied to single fly-eye lenses plus a telecentric lens and double fly-eye lenses plus a telecentric lens in sequence. As a result, we can confirm that this $f{\theta}$ formula leads to intuitive optical design with a structural understanding for telecentric lens systems.

• Korean Journal of Optics and Photonics
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• v.11 no.4
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• pp.239-245
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• 2000

In this paper, the fundamental properties of diffractive optical element were investigated. Also, this work deals with theoretical approaches for achromatization in DOE's optical system based on thin lens theory. It is found that achromatization could be satisfied by one hybrid lens only, which is composed of a diffractive and a refractive element. In order to have compact optical system, we used the tele-photo type lens composed of a positive and a negative power elements instead of retro-focus lens. From the Gaussian brackets and Seidel aberration theory, the initial design was numerically obtained. The aberration properties of an initial design was aplanat and flat field. In order to correct the chromatic aberrations, refractive and diffractive elements were used on front element. This hybrid lens is also useful for correction of higher order aberrations. Compared to conventional design composed of refractive lenses only, this approach dramatically improved the compactness of the optical system. Finally, residual aberration balancing results in a lens with focal length of 3.89 mm and overall length of 5.19 mm, which has enough performance over an f-number of 4.0. Also, it is expected to fulfill all the requirements of a digital still camera lens. This optical system is superior to the current refractive lens system in the number of elements, weight, and aberration properties. rties.

• Korean Journal of Optics and Photonics
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• v.29 no.1
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• pp.13-18
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• 2018

In this study, we present a symmetry graphical method to design an achromatic optical system composed of many lenses on an achromatic glass map. To take into account the lens spacing and the number of lenses, we use the relative ratio of paraxial ray height at each lens and the concept of an equivalent single lens. Converting an arbitrary optical system into various doublet systems, the most effective doublet is then selected to correct the color aberration, through material selection and the redistribution of the optical power. By designing a fisheye lens using this approach, an achromatic optical system is effectively obtained over the visible waveband.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.269-280
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• 2004

For the studying of the optical property of the human eye by using the Seidel aberrations with schematic eyes, we have used the several paraxial and fine schematic eyes. In another world, after fixing the iris ot aperture pinhole on the anterior of lens, we investigated how the surface contributions and the surface asphericity affected the optical properties of schematic eyes by using the Seidel aberration coefficients variation. Also, by analysis of dividing both a relaxed state and the accommodation state of the eye, we investigated the change of the optical properties during the change of accommodation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1422-1425
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• 2003

In the design of optical system, important variables of optical system (including indices, shapes, spaces, stops. etc.) must manipulate in order to balance out offensive aberration. In this paper, it carried out a basic study on the design of micro optical system usable for the acquaintance of visual information in the particular conditions such as capsule type endoscopes. In this study, specification for design of optical system selected voluntarily and the basic design of optical system carried out by using the ray tracing method on the assumption that ideal lenses without aberrations. In the designed optical system, the optimization including aberration correction and the performance evaluation of optical system carried out by using the CODE-V. The final designed optical system consists of seven sheets of lenses. Also the results of performance evaluation. the micro optical system combined with aspherical lenses was confirmed to have improved optical performance as compared with the micro optical system consisted of spherical lenses.

• Korean Journal of Optics and Photonics
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• v.9 no.4
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• pp.251-257
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• 1998

The equivalent lens conversion is extended to lens group conversion, and the more generalized conversion method is developed. The new conversion method can be used for hte direct thick-to-thick lens conversion. By using the equivalent lens conversion, a thin lens system can be converted into various thick lens system which have different axial thicknesses, but those converted lens systems have identical paraxial property and similar aberration characteristic. For an example, the equivalent lens conversion technique is applied to modification of a thelephoto lens design. The axial thicknesses of the front group elements of the system are reduced to 75% of their original values. The modified design by using the equivalent lens conversion has same focal length with original, and it has smaller aberration changes than the other design of which axial thicknesses are changed only.