• Title/Summary/Keyword: Plano-Convex Lens

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Design of Plano-Convex Lens Antenna Fed by Microstrip Patch Considering Integration with Microwave Planar Circuits

  • Yu, Seung-Gab;Yeon, Dong-Min;Kim, Yong-Hoon
    • Journal of electromagnetic engineering and science
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    • v.1 no.1
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    • pp.67-72
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    • 2001
  • In this paper, the plano-convex lens antenna fed by a single patch is studied for a microwave remote-traffic monitoring sensor with constraints of small size and low cost. Measurement of an AUT (Antenna Under Test) involves the considerations of a triangular groove for matched layer and metallic shielding effects. A formulation for extracting the parameters of a piano-convex lens antenna, based on geometrical optics, is introduced using Fermat`s principle of the equi-phased ray condition. Teflon ($\varepsilon_{{\gamma}}$/ =2.0) is chosen as a material of a plano-convex lens antenna for adjustment of aberrations on the lens surfaces automatically. A fabricated plano-convex lens shows 3-dB beamwidth of 7.5 degree and side-lobe level of -29 dB with an aperture distribution of the parabolic-squared taper on pedestal. This lens supports easier integration with the planar microwave circuits by using a microstrip single patch as a primary feeder of the lens antenna.feeder of the lens antenna.

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Improvement of the characteristics and fabrication of a planar waveguide lens (평면 광도파로 렌즈의 제작 및 특성 개선)

  • 정석문;김재창;윤태훈;김길중
    • Korean Journal of Optics and Photonics
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    • v.7 no.1
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    • pp.51-59
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    • 1996
  • In this paper, we propose a new type of a planar waveguide lens, a meniscus lens instead of a plano-convex lens used widely for the optical integrated circuits such as optical numerical processors. A plano-convex lens has a spherical aberration caused by the linear boundary. In the proposed meniscus lens, this linear boundary is replaced by a circular-boundary, and the spherical aberration is removed. To test the performance of the proposed lens, a meniscus lens is designed using Fermat principle and fabricated on the Y-cut $LiNbO_3$ substrate. First a $Ti:LiNbO_3$ planar waveguide is fabricated on the $LiNbO_3$ substrate by Ti indiffusion. Then a meniscus lens is fabricated on the planar waveguide by TIPE(Ti indiffued proton-exchange) method. A plano-convex lens is also fabricated on the same substrate to compare the spot size at the focal point. The measured spot size of the meniscus lens is reduced to 59% that of the plano-convex lens. This result shows that the proposed meniscus lens is more effective for optical integrated circuits than the plano-convex lens.

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A Study of Optical Properties of Intraocular Lenses and of Measurement of the Index of Reflection for an Unknown Liquid

  • Joo, Won Don;Jung, Mee Suk
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.236-242
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    • 2012
  • In general, such methods as interferometers or wavefront sensors are commonly used for testing of an optical system and optical components. In these cases, the surrounding environments are unlikely to affect the measurements. On the other hand, intraocular lenses of hydrophilic materials with special properties experience a certain difficulty in testing the optical properties. An intraocular lens is dried in the air, which causes deformation and changes the optical characteristics such as index of refraction and thickness. Thus, it is hard to measure the optical characteristics of an intraocular lens by using common methods. In this study, a special structure is used for measuring of the transmission wavefront aberration and effective focal length of an intraocular lens of hydrophilic materials by using a Shark-Hartmann sensor among the various measuring methods. As an application of this measuring method, this study shows a simple method to measure the index of refraction of unknown liquids with a plano-convex lens with a well known index of refraction. Also, this method is used to measure the optical properties of a plano-convex such as index of refraction and curvature by using a liquid with a well known index of refraction.

Analysis of Fourier-transform Holographic Kinoforms Using Exact Ray Tracing (엄밀한 광선추적법에 의한 푸리에변환 holographic kinoform의 분석)

  • 조두진
    • Korean Journal of Optics and Photonics
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    • v.4 no.4
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    • pp.390-396
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    • 1993
  • When a one-dimensional telecentric paraxial holographic kinoform is used as a Fourier transform lens, we analyzed three surface-relief structures, i.e., plano-convex, convex-plano and biconvex shapes, employing exact raytracing method based on Snell's law. For the kinoform of E/8 and focal length of 15 mm, the number of zones, the thickness, and the slope of parabolic surfaces are varied by changing the refractive indicies of kinoform material and surrounding medium. It is found that biconvex shape gives the best results in general, although off-axis performance degrades in all cases as the slope of parabolic surfaces increases.

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Micro lens system design for the optical fiber communication (광통신 변조기용 미세광학소자의 설계)

  • 홍경희
    • Korean Journal of Optics and Photonics
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    • v.3 no.4
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    • pp.217-221
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    • 1992
  • A micro lens system was designed for the modulator in optical fiber communication. One was the collimating lens which transferred the diffracted beam from optical fiber to the modulator. The other was the coupling lens which connected the modulated collimating beam to the optical fiber. The light source was He-Ne laser beam. The lens would be made of optical glass BK-7. We determined the tolerance of curvature radius, thickness and conic constant.

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Precision Measurement of Off-AXIS OTF (비축상 OTF의 정밀측정)

  • 조현모;이윤우;이회윤;이인원
    • Korean Journal of Optics and Photonics
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    • v.2 no.3
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    • pp.121-126
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    • 1991
  • The knife-edge scanning type OTF measuring equipment is improved to enhance the accuracy in off-axis OTF measurement and the accuracy of this equipment of evaluated by measuring the OTF of 50 mm plano-convex standard lens developed by SIRA group. Measured MTF values of the standard lens are in good agreement with SIRA results within $\pm$0.02 on axis and % $\pm$0.03 off-axis in 0-100 clmm frequency range except only a few spatial frequencies. Measured PTF values are good agreement with SIRA results within $\pm$$5^{\circ}$.

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Implementation of Milllimeter-Wave Antennas for Vehicular Radar Applications (차량 레이다용 밀리미터파 안테나 구현)

  • 박건우;배종진;김역식
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.1
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    • pp.73-82
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    • 1997
  • This paper discusses the design and implementation of parabola, lens, and $32{\times}8$ rectangular microstrip patch array antennas at 77GHz for vehicular radar applications. The parabola size was $7{\times}10$ cm and the f/D was 0.263. Open waveguide(WR-12) was utilized as the feed antenna. Two types of lens antennas with f/D=0.5 were investigated ; one was a plano-convex and the other was a double-convex. A patch array antenna was designed using a transmission line model and experimented. Comparing the theoretical values with the measured ones for four antennas, the results were agreed well in 3 dB BW and radiation patterns, while the gain of the patch array antenna was degraded as much as -25 dB due to the feed network and microstrip-to-coax-to-waveguide transition losses.

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Fabrication and Performance Evaluation of MR-16 Lamp Series with Narrow Angular Distribution of Luminous Intensity Using an Aspherical Planar-convex 2×2 Fly-eye Lens Type (평면-비구면 2×2 fly-eye 렌즈형태의 2차 렌즈를 사용한 고효율의 좁은 배광각을 갖는 MR-16 램프 시리즈 제작 및 성능평가)

  • Chu, Kyung-duk;Ryu, Jae Myung;Hong, Chun-Gang;Jeong, Youn Hong;Jo, Jae Heung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.8
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    • pp.25-33
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    • 2017
  • This paper reports the optical design of the MR-16 lamp series with a LED second lens and an aspherical plano-convex lens suitable for a simple and rapid injection molding fabrication method. The fabrication and performance evaluation of the MR-16 lamp series, which was designed with a narrow angular distribution of luminous intensity, were conducted to replace halogen lamps with LED lamps. Four types of LED lamps were fabricated, which have angular distributions of luminous intensity of $22.4^{\circ}$, $31.1^{\circ}$, $37.3^{\circ}$, and $59.9^{\circ}$ and luminous efficiencies of 76.5 lm/W, 75.2 lm/W, 72.0 lm/W, and 77.8 lm/W, respectively, while their spreading angles with an illuminance uniformity of 81% were $3^{\circ}$, $15^{\circ}$, $22^{\circ}$, and $49^{\circ}$, respectively. After eliminating a yellow tail of the LED lamps using a diffusion sheet, the angular distributions of the luminous intensity were measured to be $20.8^{\circ}$, $31.5^{\circ}$, $37.8^{\circ}$, and $68.7^{\circ}$.