• Title/Summary/Keyword: Gaussian optics

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The Influence of Cental Obstruction and Gaussian Factor on the Central Spot Distribution and the Encircled Energy (굉학계의 중앙 차폐와 가우시안 인자가 중심 Spot 분포와 Encircled Energy에 미치는 영향)

  • Park, Seong-Jong;Sim, Sang-Hyun;Chung, Chang-Sub
    • Journal of Korean Ophthalmic Optics Society
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    • v.10 no.4
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    • pp.347-355
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    • 2005
  • We investigate the distribution of central spot and the encircled energy in order to assess the performance of central obstructed optical system having central obstruction, when the central obstruction and the degree of truncated Gaussian amplitude of incident beam change. When the radius of central obstruction increases the radius of central spot on the image plane decreases, and when the degree of truncated Gaussian amplitude of incident beam increases the radius of central spot on the image plane increases. As the central obstruction and the degree of truncated Gaussian amplitude of incident beam increase, the depth of focus increases and the encircled energy of central spot decreases. We know from theses results that the effect of Gaussian factor is small as the central obstruction increases. These results was applied to develope the large optical reflection system.

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The Image-forming Property of Optical System having Gaussian Amplitude for Polychromatic Source (다색 광원에 대한 가우시안 진폭을 갖는 광학계의 결상 특성)

  • Park, Seong Jong;Park, Hae Jong
    • Journal of Korean Ophthalmic Optics Society
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    • v.4 no.2
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    • pp.33-38
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    • 1999
  • To investigate the image-forming property of optical system having Gaussian amplitude for polychromatic source, we calculated the chromaticity variation and the illuminance distribution. Considered polychromatic sources in this paper are A light which is on incandescent-tungsten lamp, C light which is a daylight, and $D_{65}$ light which is a extend daylight to the near ultraviolet. The polychromatic sources represent the different chromaticity values at a geometrical image point. The chromaticity variation of optical system having a Gaussian amplitude is smaller than that having an uniform amplitude. The illuminance distributions for polychromatic sources present nearly the same values, and the depth of focus for optical system having a Gaussian amplitude is wider than that having an uniform amplitude. From these results, we know that the depth of focus increases and the chromaticity variation decreases, when the incident light amplitude is modulated from an uniform amplitude to a Gaussian amplitude.

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Numerical Calculation Method for Paraxial Zoom Loci of Complicated Zoom Lenses with Infinite Object Distance by Using Gaussian Bracket Method (가우스 괄호법을 이용한 무한 물점을 갖는 복잡한 줌 렌즈의 수치해석적인 근축광선 줌 궤적 추적법)

  • Yoo, Nam-Jun;Kim, Won-Seob;Jo, Jae-Heung;Ryu, Jae-Myung;Lee, Hae-Jin;Kang, Geon-Mo
    • Korean Journal of Optics and Photonics
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    • v.18 no.6
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    • pp.410-420
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    • 2007
  • We theoretically derive the set of utilizable paraxial zoom locus equations for all complicated zoom lens systems with infinite object distance, such as a camera zoom lens, by using the Gaussian bracket method and the matrix representation of paraxial ray tracing. And we make the zoom locus program according to these equations in Visual Basic. Since we have applied the paraxial ray tracing equations into Gaussian bracket representation, the resultant program systematically simplifies various constraints of the zoom loci of various N group types. Consequently, the solutions of this method can be consistently used in all types of zoom lens in the step of initial design about zoom loci. Finally, in order to verify the usefulness of this method, we show that one example among 4 groups and that among 5 groups, which are very complex zoom lens systems, can be rapidly and with versatility traced through various interpolations by using this program.

Optical Signals Using Superposition of Optical Receiver Modes

  • Lee, Jae Seung
    • Current Optics and Photonics
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    • v.1 no.4
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    • pp.308-314
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    • 2017
  • A particular optical receiver has its own optical receiver modes (ORMs) determined by its optical and electrical filters. Superposing the ORM waveforms at the transmitter, we can generate a new type of optical signals, called ORM signals. After optical detection, they produce pre-specified voltage waveforms accurately, which is advantageous for digital signal processing. Assuming a Gaussian optical receiver, where the optical and electrical filters are Gaussian, we illustrate various phase-shift keying ORM signals using two ORMs by changing their relative phase. We also illustrate multi-level ORM signal patterns using two or more ORMs.

Non-imaging Optical Design of a Measurement Probe for LCD Display Used in a Color Analyzer (LCD 디스플레이용 색채계 렌즈에 관한 비결상 광학설계)

  • Rim, Cheon-Seog
    • 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.

Gaussian apodization and superresolution optical imaging system for soft X-ray region (Gaussian Apodization이 되어 있는 X-선 결상계의 초분해능)

  • 송영란;이민희;이상수
    • Korean Journal of Optics and Photonics
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    • v.7 no.2
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    • pp.89-95
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    • 1996
  • Superresolution optics, employing Gaussian apodization, is rigorously treated at the soft X-ray wave-length(λ=0.013 ${\mu}{\textrm}{m}$) region. In the diffraction integral, the line integral along the imaginary axis is found small, and it is ignored, so that the diffraction integral consists of the integration along the real axis. The resolution of the diffracted image is not effected by the pupil angular frequency bandwidth $2{\omega}_0$, which is one of the most important the characteristic features of Gaussian apodization ($e^{-o^2x^2}$ optics. The superresolution optics has resolution ($\frac{1}{2}{\times}FWHM)$=$\Delta$x=0.008 $\mu$m which is smaller than the Rayleigh criterion of 2λ=0.026 ${\mu}{\textrm}{m}$ for NA=0.25. The optical system has ${\omega}_0{\ge}\frac{1}{2}{\sigma}$, which gives the peak intensity of the diffracted image larger than $e^{-2}$ times intensity obtainable by the infinite sperture.

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Adaptive Detection of a Moving Target Undergoing Illumination Changes against a Dynamic Background

  • Lu, Mu;Gao, Yang;Zhu, Ming
    • Journal of the Optical Society of Korea
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    • v.20 no.6
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    • pp.745-751
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    • 2016
  • A detection algorithm, based on the combined local-global (CLG) optical-flow model and Gaussian pyramid for a moving target appearing against a dynamic background, can compensate for the inadaptability of the classic Horn-Schunck algorithm to illumination changes and reduce the number of needed calculations. Incorporating the hypothesis of gradient conservation into the traditional CLG optical-flow model and combining structure and texture decomposition enable this algorithm to minimize the impact of illumination changes on optical-flow estimates. Further, calculating optical-flow with the Gaussian pyramid by layers and computing optical-flow at other points using an optical-flow iterative with higher gray-level points together reduce the number of calculations required to improve detection efficiency. Finally, this proposed method achieves the detection of a moving target against a dynamic background, according to the background motion vector determined by the displacement and magnitude of the optical-flow. Simulation results indicate that this algorithm, in comparison to the traditional Horn-Schunck optical-flow algorithm, accurately detects a moving target undergoing illumination changes against a dynamic background and simultaneously demonstrates a significant reduction in the number of computations needed to improve detection efficiency.

Gaussian Decomposition Method in Designing a Freeform Lens for an LED Fishing/Working Lamp

  • Nguyen, Anh Q.D.;Nguyen, Vinh H.;Lee, Hsiao-Yi
    • Current Optics and Photonics
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    • v.1 no.3
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    • pp.233-238
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    • 2017
  • In this paper we propose a freeform secondary lens for an LED fishing/working lamp (LFWL). This innovative LED lamp is used to replace the traditional HID fishing lamp, to satisfy the lighting demands of fishing and the on-board activities on fishing boats. To realize the freeform lens's geometry, Gaussian decomposition is involved in our optics-design process for approaching the targeted light intensity distribution curve (LIDC) of the LFWL lens. The simulated results show that the illumination on the deck, on the sea's surface, and underwater shows only small differences between LED fishing/working lamps and HID fishing lamps. Meanwhile, a lighting efficiency of 91% with just one third of the power consumption can be achieved, when the proposed LED fishing/working lamps are used instead of HID fishing lamps.

CORRELATION SEARCH METHOD WITH THIRD-ORDER STATISTICS FOR COMPUTING VELOCITIES FROM MEDICAL IMAGES

  • Kim, D.;Lee, J.H.;Oh, M.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1991 no.05
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    • pp.9-12
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    • 1991
  • The correlation search method yields velocity information by tracking scatter patterns between medical image frames. The displacement vector between a target region and the best correlated search region indicates the magnitude and direction of the inter-frame motion of that particular region. However, if the noise sources in the target region and the search region are correlated Gaussian, then the cross-correlation technique fails to work well because it estimates the cross-correlation of both signals and noises. In this paper we develop a new correlation search method which seeks the best correlated third-order statistics between a target and the search region to suppress the effect of correlated Gaussian noise sources. Our new method yields better estimations of velocity than the conventional cross-correlation method.

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