• Korean Journal of Optics and Photonics
• /
• v.28 no.5
• /
• pp.241-249
• /
• 2017

This paper presents the design and evaluation of the optical system for an uncooled thermal-imaging camera. The operating wavelength range of this system is from $7.7{\mu}m$ to $12.8{\mu}m$. Through optimization, we have obtained a LWIR (Long Wave Infrared) optical system with a focal length of 5.44 mm, which consists of four aspheric surfaces and two diffractive surfaces. The f-number of the optical system is F/1.2, and its field of view is $90^{\circ}{\times}67.5^{\circ}$. The hybrid lens was used to balance the higher-order aberrations, and its diffraction properties were evaluated by scalar diffraction theory. We calculated the polychromatic integrated diffraction efficiency, and the MTF drop generated by background noise. We have evaluated the thermal compensation of a LWIR fixed optical system, which is optically passively athermalized to maintain MTF performance in the focal depth. In conclusion, these design results are useful for an uncooled thermal-imaging camera.

• Korean Journal of Optics and Photonics
• /
• v.28 no.2
• /
• pp.75-82
• /
• 2017

We present a new type of receiver-transmitter optical system that can be adapted to the sensor head of a displacement-measuring interferometer. The interferometer is utilized to control positioning error and repetition accuracy of a wafer, down to the order of 1 nm, in a semiconductor manufacturing process. Currently, according to the tendency of scale-up of wafers, an interferometer is demanded to measure a wider range of displacement. To solve this technical problem, we suggest a new type of receiver-transmitter optical system consisting of a GRIN lens-Collimating lens-Afocal lens system, compared to conventional receiver-transmitter using a single collimating lens. By adapting this new technological optical structure, we can improve coupling efficiency up to about 100 times that of a single conventional collimating lens.

• Proceedings of the Optical Society of Korea Conference
• /
• 2004.02a
• /
• pp.70-71
• /
• 2004

40nm의 해상도를 갖는 연 X-선 결상현미경 시스템의 광학계를 결정하였다. 연 X-선 장치에서의 대물렌즈로써 대상시료내에 빔 초점(focusing)를 위한 광학계로 두개의 Ellipsoid형 광하계로 설계하였다. 또한 접안렌즈로는 Fresnel zone plate로 하여 설계 및 제작하였다. 또한 연 X-선이 지나가는 빔 경로 상에 놓여진 다양한 물질들에 대한 각각의 X-선 광자의 조사선량을 계산하였다. 살아있는 세포를 관찰하고자하는 본 장치의 목적에 부합되기 위한 세포가 피폭되는 임계 방사선 조사선량의 관점에서 연 X-선의 선원의 세기와 검출기의 증폭효율을 고찰하였다.

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

• Proceedings of the Optical Society of Korea Conference
• /
• 2005.07a
• /
• pp.34-35
• /
• 2005

Eye Glass Display(EGD)에 사용되는 광학계를 비구면과 Diffractive Optical Element(DOC)를 이용한 플라스틱 렌즈로 구성하여 소형, 경량으로 제작이 가능하게 설계하였다. 비구면과 DOE를 최적화한 1매의 렌즈로 광학계를 구성하여 display의 길이를 줄이고, 왜곡과 색수차를 보정하며 해상력을 향상 시켰다. 더불어, 광학계는 안경 착용자가 불편하지 않을 정도의 eye relief와 눈의 움직임에 여유를 가질 수 있는 크기의 eye motion box(exit pupil)를 가진다.

• Korean Journal of Optics and Photonics
• /
• v.33 no.6
• /
• pp.303-309
• /
• 2022

Since the pixel size of the image sensor used in optical systems is gradually decreasing, the resolution specification of the optical system should be inevitably higher. If aberration change according to the eccentricity of a specific lens group occurs, only the amount of eccentricity of a specific lens group may be calculated with the traditional resolution adjustment method so that the aberration of the optical system is minimized to a certain extent. As a result, it is possible to increase the resolution of the optical system and to respond to a sensor with a large number of pixels. However, in the traditional method, there should be no change in specific aberration due to the eccentricity of a specific lens group. In this paper, we propose a new method to eliminate such a limitation of the traditional method in a camera optical system with a floating system, which is to choose and control the arbitrary two lens groups to easily minimize the eccentricity of the optical system in order to obtain an optical system with high resolution.

• Korean Journal of Optics and Photonics
• /
• v.10 no.1
• /
• pp.15-20
• /
• 1999

Laser Scanning Unit (LSU), which is one of the core parts of laser printer, consists of LD Module, cylinder lens, polygon mirror and f$\theta$ lens. After making an initial design on each part, we optimized the one which satisfies the user specification. The optimized optical system has diffraction limited performance for the slit size of 2.7 mm$\times$1.6 mm, f$\theta$ characteristics less than 0.3% and field curvature less 1.2 mm. We also calcurate tolerance of each part based on RSS(Root Sum Square) method to manufacture LSU for mass production.

• Korean Journal of Optics and Photonics
• /
• v.25 no.1
• /
• pp.14-20
• /
• 2014

The equivalent of a thick lens is a lens which has the same power of refraction and paraxial imaging characteristics for a reference ray, but with a different axial thickness. In this study, thick lenses of an optical system were converted to their equivalent lenses referenced to pupil imaging. Aberration changes due to the lens conversion were compared to the general equivalent lens conversion referenced to object imaging.

• Proceedings of the Optical Society of Korea Conference
• /
• 2009.10a
• /
• pp.278-279
• /
• 2009

• The Optical Journal
• /
• s.91
• /
• pp.72-75
• /
• 2004

비구면의 사용으로 광학 설계자들은 최소의 렌즈로 보다 고성능의 광학계를 구현할 수 있게 되었다. 그러나 고정밀 비구면 렌즈는 제작이 까다롭고 비용이 많이 들기 때문에 특별한 용도로만 사용되고 있다. 최근 몇 년 사이에 전통적인 가공 방법과 비교하여 많은 장점을 가지고 있는 자기유동연마(magnetorheolpgical finishing)라는 새로운 비구면 가공기술이 개발되었다. 이 기술은 비구면의 장점을 더욱 다양하게 활용할 수 있도록 하는 첨단의 정밀