• 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.22 no.5
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• pp.239-244
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• 2011

We introduce Gaussian (or paraxial) optics that can be successfully applied to design, for use in a color analyzer, a non-imaging optical system on a measurement probe for LCD display. The color analyzer is used to decompose colored lights leaving from some measurement area on the LCD display to red, green, and blue. The color analyzer must include a condenser lens whose purpose is to gather colored lights to illuminate a small area on the sensor. In order to satisfy a reduction ratio between the measurement area and the sensing area with a non-imaging condition, a condenser lens is analytically treated by means of Gaussian optics so that good understanding of the non-imaging condenser lens is achieved as a good design is derived. As a result, the technique shows the necessity of analytical treatment in contrast to the design approach using only commercial software such as CODE-V, Light-Tools, and others. Of course, CODE V and Light-Tools are also utilized in this paper to confirm and complete the Gaussian optical design.

• Proceedings of the Optical Society of Korea Conference
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• 2001.08a
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• pp.214-215
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• 2001

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.100-107
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• 2005

The present work covers a new ray tracing scheme of an injection-molded plastic lens linked with finite element analysis fur injection molding processes. The traditional ray tracing schemes have been based on the assumption that optical property of the lens is homogeneous throughout the entire volume. However, this assumption is quite unrealistic for injection-molded plastic lenses since material properties vary at every point due to injection molding effects. In order to consider non-homogeneous property of a lens, a modified ray tracing method is proposed in connection with finite element analysis of injection molding. Through the analysis of the injection molding process, the distribution of refractive indices can be obtained. This information is then utilized in the proposed ray tracing scheme based on finite element meshes so as to take into account variation of the refractive indices. The effect of mold temperature is also investigated through finite element analysis, and the relevant optical quality is evaluated through the proposed ray tracing simulation.

• Korean Journal of Optics and Photonics
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• v.17 no.5
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• pp.447-454
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• 2006

We obtained analytic solutions of boundary conditions to the stable region of Z-fold $Cr^{4+}$ : YAG laser cavity when the conditions are with and without thermal tensing effect. Also we investigated the influence of the thermal tensing effect on the stability of cavity, beam waist, and astigmatic compensation using aberration transformation matrices. The thermal tensing effect almost has no influence on the stable region of the cavity when the crystal is located in the middle of two concave mirrors and when the distances from the concave mirror to the reflecting mirror and the output coupler are the same. The beam waist, however, is affected more in a tangential plane than in a sagittal plane, and so it is difficult to have astigmatic compensation when the thermal tensing effect exists. This result means that the thermal tensing effect should be considered even for the Kerr-lens mode-locking.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.401-404
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• 2004

The electron beam machining provides very high resolution up to nanometer scale, hence the E-beam writing technology is rapidly growing in MEMS and nano-engineering areas. In the optical column of the e-beam writer, there are several lenses condensing and focusing electron beams from electron gun with fringing magnetic fields. To achieve small spot size as 1-2 nm for higher power of electron beam, magnetic lenses should be designed considering their magnetic field distribution. In this paper, the magnetic field at two condenser lenses and object lens are calculated with finite element method and discussed its performances.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.13-19
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• 2003

산업의 발달과 더불어 초소형, 고정밀 제품에 대한 수요가 증가함에 따라 이를 가공할 수 있는 마이크로 가공기술 및 초정밀 공작기계를 구현할 수 있는 설계기술이 국가 경쟁력을 결정하는 핵심 기술로 인식되기에 이르렀다. 공작기계의 성능은 주축계 설계 및 제작기술, 이송계 설계 및 제작기술, 오차 보상기술, 베드 구조물 설계 및 방진기술, 시스템 종합기술 등에 의해 결정되며, 이중에서도 주축계의 설계 및 제작 기술은 가공정밀도 및 생산기술을 주도하는 핵심기술이라 할 수 있다.(중략)

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.202-203
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• 2000

광학 렌즈계의 성능 평가를 위한 OTF(Optical Transfer Function) 측정 방법은 Hopkins$^{(1)}$ 에 의해 기본 이론이 확립된 이래 세계 각국에서 활발하게 연구되어 왔으며, 가장 합리적이고 신뢰도가 높은 평가방법으로 인정되고 있다. OTF 측정 방법은 간섭계를 이용하는 측정 방법$^{(2)}$ 과 광학계에 의해 맺혀진 상을 주사 해석하는 방법$^{(3)}$ 으로 대별될 수 있으며, 세계적으로 20여가지 이상의 측정 장치가 개발되었다. 현재 세계 각국은 다양한 형태의 OTF 측정 장치를 보유하고 있으며, OTF의 정확도를 비교 검토하는 연구가 활발해져서 측정 표준을 확립하였고,$^{(4)}$ 국제적인 측정 비교 오차를 0.02 이하로 줄일 수 있게 되었다.$^{(5)}$ 특히 선진국에서는 측정 장치들 간의 상호 비교를 위해 표준 렌즈를 설계, 제작하였고, 이러한 표준 렌즈를 적절한 측정 조건하에서 측정 오차의 원인과 측정 정확도를 평가하는데 사용하였다. (중략)

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.3
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• pp.122-129
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• 2006

We propose the Fizeau-type phase shifting interferometer(FPSI) system for the performance test of high-order aspheric lenses. The proposed system is divided into two parts : optical part and signal processing part. Those two parts are operated by a program for hardware control. We also developed an analysis program adopting the phase shifting algorithm to analyze the obtained interferograms. We can confirm that the proposed system is efficient and adequate by direct comparison with the standard criterion in Mark IV interferometric system of Zygo. The peak-to-valley and RMS values of surface errors which are used to characterize high-order aspheric lenses are 0.845 wave and 0.1871 wave, respectively. The measurement errors between the proposed system and Mark IV are less than ${\lambda}/100$ and the repeatability is also calculated at less than ${\lambda}/100$.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.2
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• pp.47-53
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• 2012

Recently, by the increasing of data transmission rates, PCB is required high-speed data transmission rates and thin packaging. So optical PCB which is the combination of electrical layer and optical layer can be one of the solution to overcome the limitations of conventional electrical PCB. The most important factor in the implementation of optical PCB is optical interconnection. So the research on high-efficiency and passive alignment has been active. In this paper, we suggest built-in lens pluggable waveguide and we simulate its coupling efficiency and structural stability. Optical simulation results show that the proposed structure has higher efficiency than no lens structure about 1.86 times in transmitter and about 1.42 times in receiver. In structure simulation, inner lens has no damage in desorption process. Therefore, we shown that the proposed structure has a high coupling efficiency and structural stability.