• Title/Summary/Keyword: near-field optical

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A Study on the Evaluation of the Optical Head of a Near-field Optical Recording System and Interference Pattern Analysis (근접장 광기록 헤드의 광학적 성능 평가와 정렬 오차에 대한 간섭 무늬 패턴 분석에 대한 연구)

  • Yoon Hyoung Kil;Gweon Dae Gab;Lee Jun Hee;Jung Jae Hwa;Oh Hyung Ryeol
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.5 s.170
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    • pp.80-86
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    • 2005
  • Optical performance evaluation results and an interference fringe pattern analysis of alignment errors for an optical head of a near-field receding (NFR) system are presented. The focusing unit is an optical head of a NFR system and is composed of a solid immersion lens (SIL) and an objective lens (OL). Generally, the size of the focusing unit is smaller than that of the conventional optical recording head. Hence there are difficulties to assemble the small focusing unit precisely. We composed an evaluation system with an interferometer and evaluated some focusing unit samples aligned and assembled by manual and present the obtained results. Using the conventional optical tool, Code V, a tolerance analysis of the alignment error between the SIL and the objective lens and an interference pattern analysis for the assembly error are executed. Then, through an analysis of the simulation results, the conceptual auto-alignment methodology using a neural network approach is considered.

Near-field interaction of atoms, molecules and dielectric particles in laser light

  • Minogin, V.G.
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.02a
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    • pp.198-198
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    • 2003
  • Two microscopic particles irradiated by light field influence each other by the forces coursed by the dipole-dipole interaction. The interaction changes also the resonance frequencies of the particles. We show that the dipole forces between atoms, molecules or dielectric particles irradiated by laser light play an important role at distances between the particles about or less the light wavelength. We discuss the properties of the near-field forces, including their dependence on direction and polarization of the laser light. We conclude that the near-field forces can be responsible for farmation of dimers in dense atomic gases. The near-field forces can be also used for control the motion of dielectric particles on micro and nanometer scale.

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Near field scanning optical interferometer using facet reflection of a tapered optical fiber (광섬유 탐침의 반사를 이용한 파면 분석 근접장 주사 광간섭계)

  • 유장훈;임상엽;이현호;박승한
    • Korean Journal of Optics and Photonics
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    • v.15 no.3
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    • pp.248-253
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    • 2004
  • We propose a near- field scanning optical interferometer (NSOI) based on the facet reflection of a nano-sized moveable tapered optical fiber. The interferometer can measure the position and the wave-front of a focused spot simultaneously. The interfering fringes are generated by the reflected beams from the sample surface and from the fiber facet. The wave-front analysis at the focusing position is obtained by using a phase shifting technique with a four-step algorithm. It is found that the resolution for controlling the focal position of our proposed NSOI is less than λ/3 and the measured wave-front aberration at the focal position is in good agreement with the ones obtained by a Twyman-Green interferometer.

Optical Cap Sensor for Magneto-Optic Near-Field Recording (MO 근접장 기록을 위한 광학 갭 센서)

  • Yoon, Yong-Joong;Park, Jae-Hyuk;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.3
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    • pp.245-250
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    • 2004
  • This paper proposes a new method of measuring an air interface distance between a solid immersion lens(SIL) applied magneto-optic technology and the disk surface. For applying near-field recording (NFR) technology to the magneto-optic storage devices for the next generation, it is positively necessary to maintain the small air gap under about 100㎚. We design an apparatus that consists of some optical components such as a prism, a polarizer and an analyzer. By using the Fresnel reflection coefficient equation, Jones matrices calculation and Malus's law, we establish a mathematical model for understanding the characteristics of the system. The simulations are based on the mathematical model and through the simulation results which is made with various cases we can estimate the performance of the new optical gap sensor system. Experimental results, which are also based on the mathematical model for specific cases, are in good agreement with simulated ones and demonstrate the possibility as the new optical gap sensor.