Publications by authors named "Shih-Hsiang Hsu"

In recent years, silicon-on-insulator substrates have been utilized for high-speed and low-power electronic components. Because of the high refractive index contrast of the silicon wire, its photonic device footprint can be significantly reduced. Moreover, the silicon photonic process is compatible with a complementary metal-oxide-semiconductor fabrication, which will benefit the high-density optoelectronic integrated circuits development.

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A chip-based spectral-domain optical coherence tomography (SD-OCT) system consists of a broadband source, interferometer, and spectrometer. The optical power divider flatness in the interferometer's wavelength is crucial to higher signal-to-noise ratios. A Mach-Zehnder directional coupler (MZDC) structure could be utilized to smoothly maximize the splitting ratio of 50:50 on a silicon platform, with a sub-micrometer of decoupler optical path difference insensitive to the process variation up to 20 nanometers.

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We design and compare the splitting ratio wavelength flatness of directional coupler (DC), Mach-Zehnder directional coupler (MZDC), and tandem MZDC. All coupler responses are analyzed, and tandem MZDC performance is the best in the wavelength insensitivity compared with the other two. An MZDC with any coupling ratio could be utilized to match the maximum flatness in a 40-nm wavelength range.

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The spectral linewidth from two cross-correlated fiber Bragg gratings (FBGs) are interrogated and characterized using a delayed self-homodyne method for fiber strain sensing. This approach employs a common higher frequency resolution instead of wavelength. A sensitivity and resolution of 166 MHz/με and 50 nε were demonstrated from 4 GHz spectral linewidth characterization on the electric spectrum analyzer.

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Various analytes can be verified by surface plasmon resonance, thus continuous improvement of this sensing technology is crucial for better sensing selection and higher sensitivity. The SPR sensitivity on the wavelength modulation is enhanced with increasing wavelengths. The telecommunication wavelength range was then utilized to detect Mycobacterium tuberculosis (MTB) deoxyribonucleic acid (DNA) under two situations, without immobilization and with 5'-thiol end labeled IS6100 DNA probes, for SPR sensitivity comparison.

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Optical low-coherence interferometry (OLCI) takes advantage of the variation in refractive index in silicon-wire microring resonator (MRR) effective lengths to perform glucose biosensing using MRR interferograms. The MRR quality factor (Q), proportional to the effective length, could be improved using the silicon-wire propagation loss and coupling ratio from the MRR coupler. Our study showed that multimode interference (MMI) performed well in broad band response, but the splitting ratio drifted to 75/25 due to the stress issue.

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A surface plasmon resonance sensor for Mycobacterium tuberculosis (MTB) deoxyribonucleic acid (DNA) is developed using repeatable telecommunication wavelength modulation based on optical fiber communications laser wavelength and stability. MTB DNA concentrations of 1 μg/mL and 10 μg/mL were successfully demonstrated to have the same spectral half-width in the dip for optimum coupling. The sensitivity was shown to be -0.

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The monitoring photodiode is the key building block for an optical triplexer at wavelengths of 1310, 1490, and 1550 nanometers. The InGaAs/InP photodetectors were proposed and fabricated to be monolithi-cally integrated with AlGaAs/GaAs optical waveguides using total internal reflection coupling. The metal coplanar waveguides on top of the polyimide planarization and passivation layer were then connected to illustrate the high speed monitoring functions.

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To fully utilize GaAs high drift mobility, techniques to monolithically integrate In0.53Ga0.47As p-i-n photodetectors with GaAs based optical waveguides using total internal reflection coupling are reviewed.

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A photodetector can be applied onto a silicon-wire waveguide tap to monitor light signals on waveguides. To meet the complexity of optical integrated circuits, the proposed photodetector would be positioned onto a wafer base instead of being employed and terminated at the edge end of an optical component. Because the silicon-wire-based optical directional coupler shows an undesirably high level of polarization-dependent loss on the tap port compared with the primary port, the complex refractive index of the reflective metal layer was proposed integrated into the direction-changing tap region, made using a 54.

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Six patients (three females and three males) were referred from their clinicians for evaluation with complaints of recurrent pain. A followup MRI showed fluid at the cemented vertebral bodies. Repeat percutaneous vertebroplasty (PV) was performed in these six patients at the cemented vertebrae.

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