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Fan-Ching Chien

Publications and source records attributed to Fan-Ching Chien.

3 recordsLinked to original sources

Precise determination of the dielectric constant and thickness of a nanolayer by use of surface plasmon resonance sensing and multiexperiment linear data analysis.

Surface plasmon resonance (SPR) sensing and an enhanced data analysis technique are used to obtain precise predictions of the dielectric constant and thickness of a nanolayer. In the proposed approach, a modified analytical method is used to obtain initial estimates of the dielectric constants and thicknesses of the metal film and a nanolayer on the sensing surface of a SPR sensor. A multiexperiment data analysis approach based on a two-solvent SPR method is then employed to improve the initial estimates by suppressing the noise in the measurement data. The proposed two-stage approach is employed to determine the dielectric constant and thickness of a molecular imprinting polymer nanolayer. It is found that the results are in good agreement with those obtained with an ellipsometer and a high-resolution scanning electron microscope.

Journal Article↗

Optical waveguide biosensors constructed with subwavelength gratings.

The reflection resonance spectrum of a subwavelength diffraction-grating-coupled waveguide is used to analyze biomolecular interactions in real time. By detecting this resonance wavelength shift, the optical waveguide biosensor provides the ability to identify the kinetics of the biomolecular interaction on an on-line basis without the need for extrinsic labeling of the biomolecules. A theoretical analysis of the subwavelength optical waveguide biosensor is performed. A biosensor with a narrow reflection resonance spectrum, and hence an enhanced detection resolution, is then designed and fabricated. Currently, the detection limit of the optical waveguide sensor is approximately 10(-5) refractive-index units. The biosensor is successfully applied to study of the dynamic response of an antibody interaction with protein G adsorbed on the sensing surface.

Biosensing Techniques↗

Angular-interrogation attenuated total reflection metrology system for plasmonic sensors.

We develop an angular-interrogation attenuated total reflection (ATR) metrology system for three different plasmonic sensors, namely, a conventional surface plasmon resonance (SPR) device, a coupled-waveguide SPR device, and a nanoparticle-enhanced SPR device. The proposed metrology system is capable of measuring the reflectivity spectra of the transverse magnetic mode and the transverse electric mode simultaneously. Through the optimal control of the fabrication process and use of sophisticated system instrumentation, the experimental results confirm that the developed ATR system is capable of measuring the resonant angle with an angular accuracy of 10(-4) deg.

Journal Article↗