한국소음진동공학회:학술대회논문집 (Proceedings of the Korean Society for Noise and Vibration Engineering Conference)
- 한국소음진동공학회 2000년도 춘계학술대회논문집
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- Pages.1528-1532
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- 2000
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- 1598-2548(pISSN)
근접장 광학계의 광학적 및 기계적 특성 분석과 근접장 간격제어
Optical and Mechanical Characteristics of NF System and NF Gap Control
- 발행 : 2000.06.22
초록
The conventional optics and near field optics are compared numerically in the view points of the spot size and propagation characteristics. The decaying characteristics of near field light require the optics to access the object within several tens of nanometers. Therefore the gap control is one of the main issues in the near field optics area. In this paper the gap control is done by using the shear force of the NF(Near Field) probe and the characteristics are examined. The probe is modeled as a 2'nd order mass-spring-damper system driven by a harmonic force. The primary cause of the decrease in vibration amplitude is due to the damping force - shear force - between the surface and the probe. Using the model, damping constant and resonance frequency of the probe is calculated as a function of probe-sample distance. Detecting the amplitude and phase shift of the NF probe attached to the high Q-factor piezoelectric tuning fork, we can control the position of the NF probe about 0 to 50nm above the sample. The feedback signal to regulate the probe-sample distance can be used independently for surface topography imaging. 3-D view of the shear force image of a testing sample with the period of