• Current Optics and Photonics
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• 제5권3호
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• pp.229-237
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• 2021

The capabilities of the near-field scanning optical microscope (NSOM) for obtaining high resolution lateral topographical images as well as for mapping the spectroscopic and optical properties of a sample below the diffraction limit of light have made it an attractive research field for most researchers dealing with optical characteristics of materials in nano scales. The apertured NSOM technique involves confining light into an aperture of sub-wavelength size and using it to illuminate a sample maintained at a distance equal to a fraction of the sub-wavelength aperture (near-field region). In this article, we present a setup for developing NSOM using a cantilever with a sub-wavelength aperture at the tip. A single laser is used for both cantilever deflection measurement and near-field sample excitation. The laser beam is focused at the apex of the cantilever where a portion of the beam is reflected and the other portion goes through the aperture and causes local near-field optical excitation of the sample, which is then raster scanned in the near-field region. The reflected beam is used for an optical beam deflection technique that yields topographical images by controlling the probe-sample in nano-distance. The fluorescence emissions signal is detected in far-field by the help of a silicon avalanche photodiode. The images obtained using this method show a good correlation between the topographical image and the mapping of the fluorescence emissions.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2004년도 추계 종합학술대회 논문집
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• pp.280-284
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• 2004

안테나의 특성 중 지향성(Directivity)과 관계있는 방사 패턴을 측정하기 위한 저가의 근역장 측정 시스템을 설계한다. 근역장 측정방법은 평면주사법에 기반을 둔 개선된 원통형 주사법 공식을 이용한다. 고가의 측정 장비인 네트워크 분석기를 대체하기 위한 방법을 제시하고 필요한 장치 규격을 제안한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.984-987
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• 2003

유기발광소자 안에 존재하는 비발광영역(dark spot)의 전압에 대한 영향을 근접장 마이크로파 현미경(near-field scanning microwave microscope)을 이용하여 관찰하였다. 유기발광소자는 glass/indiumtin oxide(ITO)/Cu-Pc/tris-(8-hydroquinoline)aluminum(Alq3)/aluminum(Al) 의 기본구조로 제작하였다. Dark spot은 ITO 기판을 부분적으로 에칭하여서 형성시켰다. Dark spot에 $0{\sim}l5 V$ 까지 전압을 인가시키면서 인가 전압에 따른 전기적 특성을 근접장 마이크로파 현미경 image의 변화와 반사계수인 $S_{11}$ 측정을 통하여 연구하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.147-150
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• 2003

유기발광소자 안에 존재하는 비발광영역(dark spot)의 전압에 대한 영향을 근접장 마이크로파 현미경(near-field scanning microwave microscope)을 이용하여 관찰하였다. 유기발광소자는 glass/indiumtin oxide(ITO)/Cu-Pc/tris-(8-hydroquinoline)aluminum(Alp3)/aluminum(Al)의 기본구조로 제작하였다. 비발광영역은 ITO 기판을 부분적으로 에칭하여서 형성시켰다. Dark spot에 0~15V 전압을 인가시키면서 인가 전압에 따른 dark spot 구조적 및 전기적 특성을 근접장 마이크로파 현미경 Image의 변화와 반사계수인 $S_11$측정을 통하여 연구하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.494-497
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• 2003

We report the dark spots in organic light emitting diodes by using a near-field scanning microwave microscope. Devices structure was glass / indium-tin-oxide(ITO) / copper-pthalocyiane(Cu-Pc) / tris-(8-hydroquinoline)aluminum(Alq3) / aluminum(Al). We made artificial dark spots by using a etching technique on a ITO substrate. Near-field scanning microwave microscope images and reflective coefficient of dark spots were measured and compared by the change of various applied voltage changes 0-15V.

• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.2120-2125
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• 2015

In this paper, a rectangular waveguide probe with a ridge-loaded straight slot (RLSS) is presented for a near-field scanning microwave microscope (NSMM). The RLSS is located laterally at the end wall of the cavity and is loaded on double ridges in a narrow straight slot to improve the spatial resolution compared with a straight slot. The probe consists of a rectangular cavity with an RLSS and a feed section of a WR-90 rectangular waveguide. When the proposed NSMM is located at distance of 0.1mm in front of a substrate without patches or strips, the simulated full width at half maximum (FWHM) of the probe improve by approximately 31.5 % compared with that of a straight slot without ridges. One dimensional scanning of the E-plane on a sample under test was conducted, and the reflection coefficient of the near-field scanning probe is presented.

• 비파괴검사학회지
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• 제25권6호
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• pp.459-466
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• 2005

The scanning laser source (SLS) technique has been proposed recently as an effective way to investigate small surface-breaking defects, By monitoring the amplitude and frequency changes of the ultrasound generated as the SLS scans over a defect, the SLS technique has provided enhanced signal-to-noise performance compared to the traditional pitch-catch or pulse-echo ultrasonic methods, An extension of the SLS approach to map defects in microdevices is proposed by bringing both the generator and the receiver to the near-field scattering region of the defects, To facilitate near-field ultrasound measurement, silicon microcantilever probes are fabricated using microfabrication technique and their acoustical characteristics are investigated, Then, both the laser-generated ultrasonic source and the microcantilever probe are used to monitor near-field scattering by a surface-breaking defect.

• Journal of Magnetics
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• 제18권3호
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• pp.317-320
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• 2013

We studied the polarization state in an apertureless scanning near-field microscopy (a-SNOM) operating in reflection mode by using three-dimensional Finite-difference Time-domain (FDTD) method. As a result, the electric field around tip apex in the near-field region enhanced four times stronger than the incident light for ppolarization when the tip-sample separation was 10 nm. We find that the p- and s-polarization state is maintained for the scattered light when the probe is perpendicular to the sample. When the probe is not perpendicular to the sample, the polarization state of scattered light will rotate an angle that equals to the inclination angle of probe with p-polarization illumination. On the other hand, the polarization state will not rotate with s-polarization illumination.

• 한국광학회지
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• 제15권1호
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• pp.51-55
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• 2004

표면 플라즈몬은 금속 표면에 존재하는 자유전자의 밀도파이며, 광자와 결합하여 존재한다. 본 논문에서는 근접장 주사 광학 현미경을 구성하고 이를 이용하여 표면에서 지수함수적으로 감소하는 표면 플라즈몬과 두 표면 플라즈몬에 의한 간섭무늬를 측정하였다. 표면 플라즈몬은 표면의 작은 광학적 분포에도 민감하게 변화하여, 광학 탐침이 금속 표면에 접근함에 따라서 표면 플라즈몬의 공명 조건에 영향을 준다. 이로 인해 광학 탐침이 금속 표면으로부터 약 250nm 떨어진 곳에서 광의 세기가 최대가 됨을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.522-525
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• 2004

ITO thin films $({\sim}150\;nm)$ are deposited on glass substrates by different deposition condition. The sheet resistance of ITO thin films measured by using a four probe station. The microstructure of these films is determined using a X-ray diffractometer (XRD) and a scanning electron microscope (SEM) and a atomic force microscope (AFM). The sheet resistance of ITO thin films compared $s_{11}$ values by using a near field scanning microwave microscope.