• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.424-430
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• 2010

In coherent anti-Stokes Raman scattering (CARS) microscopy reported until now, conventional microscope objectives are used, so that they are limited for introduction into a living body. Gradient-index (GRIN) rod lenses might be a solution for miniaturized microscope objectives for in-vivo CARS microscopy. However, due to the inherent large amount of chromatic aberration, GRIN rod lenses cannot be utilized for this purpose. CARS imaging catheter, composed of miniaturized microscope objective and fiber bundle, can be introduced into a living body for minimally invasive diagnosis. In order to design the catheter, we have to first investigate design requirements. And then, the optical design is processed with design strategies and intensive computing power to achieve the design requirements. We report the miniaturized objective lens system with diffraction-limited performance and completely corrected chromatic aberrations for an in-vivo CARS imaging catheter.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.30-36
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• 2015

The principle of an illumination and projection system including LED light sources for a spot type stage lighting system was presented, and its optical system was designed with optimizing parameters by the analytical methods. A dichroic mirror incorporated with an illumination system to optimizing LED source positions and to obtain the compact system. The projection system was optimized with specific constraints such as a chromatic aberration, distortion aberration and angle of incidence angles. Optimized design system has a beam angle from $10^{\circ}$ to $45^{\circ}$, and its illuminance was 4,500lux at distance of 6m on the work plane.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1603-1606
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• 2005

Eye Glass Display (EGD) with microdisplay to realize the virtual display can make the large screen, so virtual image has been developed by using microdisplay panel. This paper shows study of low cost lens design and simulation for microdisplay system with 0.6" Liquid Crystal on Silicon (LCoS) panel. Lens design optimized consider to spherical aberration, astigmatism, distortion, and chromatic aberration. Code V is used and it designed an aspheric lens about exit pupil 6mm, eye relief 20mm and 35 degree of field of view (FOV). With the application this aspheric lens to LCOS type's microdisplay, virtual image showed 50 inch at 2m. One side of the aspheric lens was constituted from diffractive optical element (DOE) for the improvement in a performance. It had less than ${\pm}2%$ of distortion value and modulation transfer function in axial had 20% of resolution with 30 lp/mm spatial frequency. The optical system is suitable for display of 0.6"-diagonal with SVGA.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.6
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• pp.96-101
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• 2020

In this paper, we present the results of our research to perform 3D laser scanning functions by adding a focusing lens to a conventional 2D laser scanner. For the optical design, the ray-tracing technique was used along with a total of four lenses as the variable incident focusing lens, the collimating lens, and the F-Theta lens. As design variables, the curvature of the incident focusing lens (Lens #1) was assumed to be us, l mm and sumed mm, and the incident angles were set at 0cidenus, l. In addition, the distance between the focusing lens and the collimating lens was set to vary from 5 mm to 15 mm. When the incident focal length was varied from 5 mm to 15 mm, the exit focal length was calculated to vary from 67.5 mm to 56.8 mm for the lens with R = 100 mm and from 108.5 mm to 99.0 mm for the lens with R = 150 mm. When the incident angle was 0°, the focal aberration was only slightly observable at 10㎛ in both the x- and y-direction. At 7.5° was the focal aberration of approximately 20~50㎛ was measured at 20㎛. To investigate the chromatic aberration of the designed optical device, the distortion of the focus was observed when the 550 nm beam was simulated on lens designed for a 980 nm wavelength.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.11-17
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• 2004

We tried to design and manufacture a night scope which is used in the leisure sports field. The whole system consists of an IR light source part, an objective lens part, an intensifier tube part and an eye_piece lens part. We designed an objective lens part to the infinite object imaging optical-system with 80mm focal-length, 40mm effective-aperture and 14mm image-field-size of which the chromatic aberration is reduced by using materials of BK7 and FD4. The resolution of this system is about 25lines/mm at the 40% MTF value criterion. The eye_piece lens is adopted goods to be used commercially to save cost of production. The design technique which gets in this development will be utilized greatly in good developments of the dot, the sight and the day/night riflescope system at the hereafter.

• Korean Journal of Optics and Photonics
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• v.33 no.6
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• pp.317-323
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• 2022

In this investigation, we describe a chromatic confocal sensor based on a geometric phase lens for measuring the thicknesses of transparent plates. In order to design a compact sensor, a geometric phase lens, which has diffractive and polarizing characteristics, is used as a device to generate chromatic aberration, and a fiber optic module is adopted. The systematic error of the sensor is reduced with wavelength peak detection by Gaussian curve fitting and the common error compensation obtained by the repeatedly consecutive experimental results. An approach to calculate the plate thickness is derived and verified with sapphire and BK7 plates. Because of the simple and compact design of the proposed sensor with rapid measurement capability, it is expected to be widely used in thickness measurements of transparent plates as an alternative to traditional approaches.

• 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.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.57.3-58
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• 2016

We analyze an optical system of a telescope based on Fresnel type objective lens as suggested by Hyde (1999). The Fresnel objective lens can be thin, light-weight and foldable, and therefore it is possible to develop a space telescope with an aperture larger than that of traditional telescopes. Moreover a lens, whatever it is either Fresnel type or conventional, allows much larger fabrication tolerances. We design a medium-sized telescope adopting Fresnel lens as an objective lens for use in space and possibly on the ground. The well-known chromatic aberration of the Fresnel primary lens is corrected by a field lens and another Fresnel lens using Schupmann method. An additional lens is used for forming images. We analyze the chromatic and off-axis aberrations of the proposed system analytically and suggest methods for the minimization of off-axis aberrations and for the operation in wider spectral range. We also conduct ray tracing and optimize the whole optical system with commercial software. Finally we present the design parameters of a telescope with an aperture of 0.5 to 1 meters, enabling diffraction limited operation for a moderate field of view about 10 arc-minutes.

• Korean Journal of Optics and Photonics
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• v.4 no.3
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• pp.243-251
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• 1993

We have derived Gaussian bracket expressions of aplanatic and achromatic conditions and obtained the numerical solutions for each of two modules of the telephoto type telescope objective free from the Seidel first order spherical aberration, coma, and longitudinal chromatic aberration. The system which is for use in sighting a target is optimized within the resolution of eyes. The objective lens satisfying the aplanatic and achromatic condition has f/8.5 with the half field angle 0.$3^{\circ}$, and the telephoto ratio is 0.839 with the focal length of 30 cm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05a
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• pp.123-126
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• 2005

Eye Glass Display (EGD) with microdisplay to realize the virtual display can make the large screen, so virtual image has been developed by using microdisplay panel. This paper shows study of low cost lens design and simulation for microdisplay system with 0.6"LCoS panel. Lens design optimized consider to spherical aberration, astigmatism, distortion, and chromatic aberration. Code V is used and it designed an aspheric lens about exit pupil 6mm, eye relief 20mm and 35 degree of field of view (FOV). With the application this aspheric lens to liquid crystal on silicon (LCOS) type's microdisplay, virtual image showed 50 inch at 2m. One side of the aspheric lens was constituted from diffractive optical element (DOE) for the improvement in a performance. It had less than 2.5% of distortion value and modulation transfer function in axial had 20% of resolution with 32 lp/mm spatial frequency. The optical system is suitable for display of 15.6 mm-diagonal with SVGA.