• Korean Management Science Review
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• v.11 no.3
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• pp.103-128
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• 1994

Due to the trend of evolution toward a broadband communication network with fiber-optics, the design and operation of fiber-optic network have been received a great deal of research attention recently. Furthermore, even a single fiber link failure in the network may result in severe service loss. Thus, the network survivability becomes an importantissue in planning and designing the network. This survey is on modelling of various fiber-optic subscriber loop network(FSLN) design problems, which are essential ones for providing broadband communication services and B-ISDN services. Models are classified and investigated as either conventional decomposition-iteration approach or integrated design method. To build survivable networks, SHR models are also suggested by ring control schemes. The result of this study will be effectively applied to build a design model for FSLN in the practical applications.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.407.3-408
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• 2002

A portable near infrared (NIR) system which was newly integrated by our lab has been used to develop a non-invasive blood glucose monitoring. The portable NIR system includes a tungsten halogen lamp, a photo diode array type-InGaAs detector, and specialized reflectance fiber optic probes. The shape of probes is composed of two parts. one for illumination into sample and the other for receiving the radiation from sample. Three kinds of probes with different distance between illumination and receiving part. such as 0.03. 0.1. and 0.5mm, were investigated for optimization. (omitted)

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.739-745
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• 2014

We have demonstrated a $Ti:LiNbO_3$ electro-optic electric-field sensor utilizing a $1{\times}2$ Y-fed balanced-bridge Mach-Zehnder interferometric (YBB-MZI) modulator, which uses a 3-dB directional coupler at the output and has two complementary output waveguides. A dc switching voltage of ~25 V and an extinction ratio of ~12.5 dB are observed at a wavelength of $1.3{\mu}m$. For a 20 dBm rf input power, the minimum detectable electric fields are ~8.21, 7.24, and ~13.3 V/m, corresponding to dynamic ranges of ~10, ~12, and ~7 dB at frequencies of 10, 30, and 50 MHz respectively. The sensors exhibit almost linear response for an applied electric-field intensity from 0.29 V/m to 29.8 V/m.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.730-734
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• 2005

Flow injection analysis (FIA) system was developed to monitor glucose concentrations in biotechnological processes. A fiber optic oxygen sensor was used to determine consumption of oxygen concentration by reaction of immobilized glucose oxidase (GOD). The GOD was immobilized on VA-Epoxy carrier and integrated into FIA system. A calibration curve for glucose was obtained in the range of 0.5 $g/L{\sim}3.0$ g/L.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.48-48
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• 2006

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.2
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• pp.34-39
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• 2005

The precision stage is an essential device for optic fiber assembly systems, micro machines and semiconductor equipments. A new piezoelectric inchworm type actuator is proposed to implement an actuator-integrated long-stroke linear stage. An in-and-quadrature phase (I/Q) heterodyne interferometer is developed as a feedback sensor of a servo system, and a synchronized counting method is proposed. The proposed measurement system can measure the accurate position of fast moving object with robustness to external sensing noise from actuator vibration. The developed servo stage will be applied to optic fiber device assembly system.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.3
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• pp.70-77
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• 2009

We proposed the method of avionics integrated architecture using high-speed fiber optic bus. Typically, data bus of aircraft consists of electronic and optic data transmission method. Avionics systems are difficult to operate the electronic data transmission method for the high speed data processing, synchronization and interconnection between flight control system and flight management system efficiently. In this paper, it is known to look into the problem of data bus and the advanced trend in avionics systems, and propose the appropriate data bus of the advanced avionics systems.

• YAKHAK HOEJI
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• v.46 no.5
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• pp.331-336
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• 2002

The purpose of this study is to develop a non-invasive blood glucose measurement method by a portable near infrared (NIR) system which was newly integrated by our lab. The portable NIR system includes a tungsten halogen lamp, a specialized reflectance fiber optic probe and a photo diode array type InGaAs detector; which was developed by a microchip technology based on the lithography. Reflectance NIR spectra of different parts of human body (finger tip, earlobe, and inner lip) were recorded by using a fiber optic probe. The spectra were collected over the spectral range 1100 ∼ 1740 nm. Partial least squares regression (PLSR) was applied for the calibration and validation for the determination of blood glucose. The calibration model from earlobe spectra presented better results, showing good correlation with a glucose oxidase method which is a mostly used standard method. This model predicted the glucose concentration for validation set with a SEP of 33 mg/dL. This study indicated the feasibility for non-invasive monitoring of blood glucose by a portable near infrared system.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.67.3-68
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• 2003

The purpose of this study is to improve repeatability of a non-invasive blood glucose measurement. The portable NIR system that was newly integrated by our lab includes a tungsten halogen lamp, a specialized reflectance fiber optic probe and a photo diode array type InGaAs detector, which was developed by a microchip technology based on the lithography. Reflectance NIR spectra of finger tip were recorded by using a fiber optic probe. The probe was fixed in the system and subjects put their finger on the probe head. (omitted)

• Current Optics and Photonics
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• v.8 no.1
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• pp.16-29
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• 2024

This paper presents a comprehensive review of metasurface technology, focusing on its significant role in extraordinary flat optic functionalities. Traditional optical components, though optimized, are bulky and less congruent with modern integrated electromagnetic and photonic systems. Metasurfaces, recognized as the 2D counterparts of bulk metamaterials, offer solutions with their planar, ultra-thin, and lightweight structures. Their meta-atoms are adept at introducing abrupt shifts in optical properties, paving the way for high-precision light manipulation. By introducing the key design principles of these meta-atoms, such as the magnetic dipole and Pancharatnam-Berry phase, various applications in wavefront shaping and beam forming with simple amplitude/phase manipulation and advanced applications including retroreflectors, Janus metasurfaces, multiplexing of optical wavefronts, data encryption, and metasurfaces for quantum applications are reviewed.