• Journal of the Optical Society of Korea
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• v.15 no.1
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• pp.9-14
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• 2011

In this study, the internal structure of an optical waveguide embedded in a flexible optical circuit board is observed with a confocal microscope. In order to increase the light reflection from an internal material interface with a very small index difference, and thus enhance the signal contrast, a theta microscopy scheme has been integrated into a conventional confocal microscope, and a high NA oil-immersion lens has been used. The interface reflectivity is increased from roughly 0.0015% to 0.025% by the proposed method, and the internal structure can thus be successfully measured.

• Journal of the Optical Society of Korea
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• v.15 no.3
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• pp.300-304
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• 2011

Optical microscopes are widely used for medical imaging these days, but biopsy is a lengthy process that causes many problems during the ex-vivo imaging procedure. The endo-microscope has been studied to increase accessibility to the human body and to get in-vivo images to use for medical diagnosis. This research proposes a multi-modal confocal endo-microscope for bio-medical imaging. We introduce the design process for a small endoscopic probe and a coupling mechanism for the probe to make the multi-modal confocal endo-microscope. The endoscopic probe was designed to decrease chromatic and spherical aberrations, which deteriorate the images obtained with the conventional GRIN lens. Fluorescence and reflectance images of various samples were obtained with the proposed endo-microscope. We evaluated the performance of the proposed endo-microscope by analyzing the acquired images, and demonstrate the possibilities of in-vivo medical imaging for early diagnosis.

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

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.99.3-99
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• 2001

In fluorescence mode confocal scanning microscope, level of detected signal is very low. In object scanning type confocal scanning microscope, the additional optical system with objective lens and plane mirror was proposed to increase signal intensity, but there was none for beam scanning type confocal scanning microscope. We propose reflecting optical systems which improve signal intensity in beam scanning type confocal scanning microscope. We choose one of the proposed optical systems and design the optical system, i.e., select optical components and assign distances between the selected components. To design the optical system, we use finite ray tracing method and make cost function to be minimized.

• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.424-430
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• 2010

In coherent anti-Stokes Raman scattering (CARS) microscopy reported until now, conventional microscope objectives are used, so that they are limited for introduction into a living body. Gradient-index (GRIN) rod lenses might be a solution for miniaturized microscope objectives for in-vivo CARS microscopy. However, due to the inherent large amount of chromatic aberration, GRIN rod lenses cannot be utilized for this purpose. CARS imaging catheter, composed of miniaturized microscope objective and fiber bundle, can be introduced into a living body for minimally invasive diagnosis. In order to design the catheter, we have to first investigate design requirements. And then, the optical design is processed with design strategies and intensive computing power to achieve the design requirements. We report the miniaturized objective lens system with diffraction-limited performance and completely corrected chromatic aberrations for an in-vivo CARS imaging catheter.

• Proceedings of the Optical Society of Korea Conference
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• 1996.09a
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• pp.84-84
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• 1996

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.303-304
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• 2008

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

• Current Optics and Photonics
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• v.6 no.6
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• pp.550-564
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• 2022

Optical microscopy is a useful tool for study in the biological sciences. With an optical microscope, we can observe the micro world of life such as tissues, cells, and proteins. A fluorescent dye or a fluorescent protein provides an opportunity to mark a specific target in the crowd of biological samples, so that an image of a specific target can be observed by an optical microscope. The optical microscope, however, is constrained in resolution due to diffraction limit. Super-resolution microscopy made a breakthrough with this diffraction limit. Using a super-resolution microscope, many biomolecules are observed beyond the diffraction limit in cells. In the case of volumetric imaging, the super-resolution techniques are only applied to a limited area due to long imaging time, multiple scattering of photons, and sample-induced aberration in deep tissue. In this article, we review recent advances in super-resolution microscopy for volumetric imaging. The super-resolution techniques have been integrated with various modalities, such as a line-scan confocal microscope, a spinning disk confocal microscope, a light sheet microscope, and point spread function engineering. Super-resolution microscopy combined with adaptive optics by compensating for wave distortions is a promising method for deep tissue imaging and biomedical applications.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.173-174
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• 2009