• Current Optics and Photonics
• /
• v.5 no.3
• /
• pp.229-237
• /
• 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.

• Korean Journal of Optics and Photonics
• /
• v.15 no.1
• /
• pp.51-55
• /
• 2004

Surface plasmons (SPs) are charge density oscillations that propagate along an interface between a dielectric and metal. In this paper, the electric field of SPs and the intereference of two SPs are observed by using Near-field Scanning Optical Microscope (NSOM). The excitation condition of SPs is changed as the optical tip approaches the metal surface, because the excitation condition of SPs is very sensitive to surface structures. To measure the microscope field of SPs, the distance between metal surface and optical tip must contain a specific interval.

• ETRI Journal
• /
• v.26 no.3
• /
• pp.189-194
• /
• 2004

We demonstrate a high-speed recording based on field-induced manipulation in combination with an optical reading of recorded bits on Au cluster films using the atomic force microscope (AFM) and the near-field scanning optical microscope (NSOM). We reproduced 50 nm-sized mounds by applying short electrical pulses to conducting tips in a non-contact mode as a writing process. The recorded marks were then optically read using bent fiber probes in a transmission mode. A strong enhancement of light transmission is attributed to the local surface plasmon excitation on the protruded dots.

• Korean Journal of Optics and Photonics
• /
• v.10 no.4
• /
• pp.267-272
• /
• 1999

We attached a fiber tip on the branch of a quartz crystal oscillator in order to make a feedback control system for near field optical microscope. The electrical impedance of the quartz crystal oscillator depends on the distance between the surface of the sample and the tip caused by the surface damping. Using this method, we can directly monitor the distance between the sample and the tip without inserting extra beam which might give extra optical noise. We characterize the XY scanning resolution and the amplitude of the vibrating tip and the Z-dependent decay of the evanescent wave.

• Proceedings of the Optical Society of Korea Conference
• /
• 2001.02a
• /
• pp.122-123
• /
• 2001

본 연구에서는 주사 근접장 광학 현미경(Near-field Scanning Optical Microscope, 이하 NSOM이라 한다)을 이용하여 빛이 전파되고 있는 광 도파로 주변에 형성되는 evanescent field를 측정함으로써 광도파로 내부에서의 빛의 전파특성을 알아보았다. 광소자의 설계에 있어서 광도파로 내부에서의 빛이 어떻게 전파되어지는 가는 매우 중요한 인자가 된다. (중략)

• Korean Journal of Optics and Photonics
• /
• v.13 no.4
• /
• pp.301-307
• /
• 2002

The propagation characteristic of an optical waveguide was investigated by measuring with a near-field scanning optical microscope (NSOM) the evanescent field formed at the neighbor of its core-cladding interface. For this purpose, the NSOM system was developed specially as a form of Photon scanning tunneling microscope. The evanescent field distributions of several channel waveguides were measured at the wavelength of 1550 ㎚, and the usefulness of the system was verified by comparing experimental results with simulation results. In particular, the interference phenomena of the guided modes during their propagation along a multimode channel waveguide could be observed directly from the measured evanescent field distribution.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.3
• /
• pp.5-14
• /
• 2003

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.07a
• /
• pp.122-123
• /
• 2002

능동적으로 안정화시킨 반도체 레이저의 빛살되먹임을 이용한 근접장 광학현미경(Near-field Scanning Optical Microscope)을 이용하여 칼코게나이드계 유리인 a-As$_2$S$_3$에서 광조사에 따른 자체집광 현상과 구조변화를 관찰하였다. 여러 비선형 광학현상 중 광 커르 효과(Optical Kerr effect)에 기인하는 자체집광(Self-focusing)은 광범위하게 연구되어 왔다. (중략)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.05b
• /
• pp.327-330
• /
• 2000

The scanning Maxwell-stress microscopy (SMM) is a dynamic noncontact electric force microscopy that allows simultaneous access to the electrical properties of molecular system such as surface potential, surface charge, dielectric constant and conductivity along with the topography. The Scanning near-field optical / atomic force microscopy (SNOAM) is a new tool for surface imaging which was introduced as one application of the atomic force microscope (AFM). Operated with non-contact forces between the optical fiber and sample as well as equipped with the piezoscanners, the instrument reports on surface topology without damaging or modifying the surface for measuring of optical characteristic in the films. We report our recent results of its application to nanoscopic study of domain structures and electrical functionality in organic thin films by SMM. Furthermore, we have illustrated the SNOAM image in obtaining the merocyanine dye films as well as the optical image.

• Proceedings of the Optical Society of Korea Conference
• /
• 2009.02a
• /
• pp.153-154
• /
• 2009