• 제목/요약/키워드: subwavelength

검색결과 62건 처리시간 0.023초

광 지연선로를 이용한 스퀸팅이 없는 위상배열 안테나의 근접장 서브파장 포커싱 (Squint-less Phased Array Antenna Near-field Subwavelength Focusing with True-time Optical Delay Line)

  • 정영진
    • 한국광학회지
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    • 제30권3호
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    • pp.94-100
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    • 2019
  • 본 연구에서는 광 지연선로를 이용한 스퀸팅(squinting)이 없는 위상배열 안테나의 근접장 미세파장 포커싱(subwavelength focusing)을 디자인하고 전산모사를 통해 검증하였다. 마이크로파 파장에서 위상배열 안테나의 수치적 계산을 위해 호이겐스-프레넬(Huygens-Fresnel) 원리를 적용하였다. 제안하는 시스템은 첩 광섬유 격자(chirped fiber grating)에 기반한 광 지연선로를 이용하여 빔 스퀸팅이 생기지 않는다는 것을 전산모사를 통해 확인하였다. 그리고 개별 안테나의 배열은 광학렌즈시스템에서 회절 소자로 간주할 수 있음에 착안해 높은 개구율(numerical aperture)을 구현하고 미세파장 포커싱을 얻었다. 또한, 위상배열 안테나의 안테나 사이 거리를 반파장 이하로 줄여 사이드 로브를 억제할 수 있음을 보였다.

Angle-sensitive Pixels Based on Subwavelength Compound Gratings

  • Meng, Yunlong;Hu, Xuemei;Yang, Cheng;Shen, Xinyu;Cao, Xueyun;Lin, Lankun;Yan, Feng;Yue, Tao
    • Current Optics and Photonics
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    • 제6권4호
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    • pp.359-366
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    • 2022
  • In this paper, we present a new design for angle-sensitive pixels (ASPs). The proposed ASPs take advantage of subwavelength compound gratings to capture the light angle, which enables pixel size to reach the wavelength scale of 0.7 ㎛ × 0.7 ㎛. The subwavelength compound gratings are implemented by the wires of the readout circuit inherent to the standard complementary metal-oxide-semiconductor manufacturing process, thus avoiding additional off-chip optics or post-processing. This technique allows the use of two pixels for horizontal or vertical angle detection, and can determine the light's angle in the range from -45° to +45°. The proposed sensor enables surface-profile reconstruction of microscale samples using a lensless imaging system.

Fabrication of Plasmon Subwavelength Nanostructures for Nanoimprinting

  • Cho, Eun-Byurl;Yeo, Jong-Souk
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.247-247
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    • 2012
  • Plasmon subwavelength nanostructures enable the structurally modulated color due to the resonance conditions for the specific wavelength range of light with the nanoscale hole arrays on a metal layer. While the unique properties offered from a single layer of metal may open up the potential applications of integrated devices to displays and sensors, fabrication requirements in nanoscale, typically on the order of or smaller than the wavelength of light in a corresponding medium can limit the cost-effective implementation of the plasmonic nanostructures. Simpler nanoscale replication technologies based on the soft lithography or roll-to-roll nanoimprinting can introduce economically feasible manufacturing process for these devices. Such replication requires an optimal design of a master template to produce a stamp that can be applied for a roll-to-roll nanoimprinting. In this paper, a master mold with subwavelength nanostructures is fabricated and optimized using focused ion beam for the applications to nanoimprinting process. Au thin film layer is deposited by sputtering on a glass that serves as a dielectric substrate. Focused ion beam milling (FIB, JEOL JIB-4601F) is used to fabricate surface plasmon subwavelength nanostructures made of periodic hole arrays. The light spectrum of the fabricated nanostructures is characterized by using UV-Vis-NIR spectrophotometer (Agilent, Cary 5000) and the surface morphology is measured by using atomic force microscope (AFM, Park System XE-100) and scanning electron microscope (SEM, JEOL JSM-7100F). Relationship between the parameters of the hole arrays and the corresponding spectral characteristics and their potential applications are also discussed.

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Subwavelength 결함접지구조(defected grounded structure : DGS)를 이용한 Homogeneous Dual Composite Right/Left-Handed 메타물질 구현 (Homogeneous Dual Composite Right/Left-Handed Metamaterial Using Subwavelength Defected Ground Structure(DGS))

  • 박우영;임성준
    • 전기학회논문지
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    • 제58권11호
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    • pp.2242-2246
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    • 2009
  • In this paper, a homogeneous dual composite right/left-handed (D-CRLH) transmission line (TL) is proposed by using a defected ground structure (DGS) on the ground plane. In order to satisfy a homogeneity condition of metamaterial, a subwavelength unit cell is designed by way of a spiral DGS and a meander stub. From a dispersion diagram, it is expected that the frequency bands for the left-handed (LH) property is 3.5 - 4.4 GHz. At 3.8 GHz in the LH band, backward propagating phenomenon is observed from full-wave analysis. The experimental results show that the proposed TL has a stop-band in 1.75 - 3.6 GHz.