Patrick Kung

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Avalanche p-in photodiodes were fabricated on AlN templates for back illumination. Structures with different intrinsic layer thicknesses were tested. A critical electric field of 2.73 MV/ cm was estimated from the variation of the breakdown voltage with thickness. From the device response under back and front illumination and the consequent selective(More)
The authors report the Geiger-mode operation of back-illuminated GaN avalanche photodiodes. The devices were fabricated on transparent AlN templates specifically for back illumination in order to enhance hole-initiated multiplication. The spectral response in Geiger-mode operation was analyzed under low photon fluxes. Single photon detection capabilities(More)
Avalanche p-in photodiodes of various mesa areas were fabricated on AlN templates for back illumination for enhanced performance through hole-initiated multiplication, and the effects of increased area on device performance were studied. Avalanche multiplication was observed in mesa sizes up to 14 063 ␮m 2 under linear mode operation. Uniform gain and a(More)
As a classical analogue of electromagnetically induced transparency, plasmon induced transparency (PIT) has attracted great attention by mitigating otherwise cumbersome experimental implementation constraints. Here, through theoretical design, simulation and experimental validation, we present a novel approach to achieve and control PIT by hybridizing two(More)
Although ZnO has recently gained much interest as an alternative to the III-Nitride material system, the development of ZnO based optoelectonic devices is still in its infancy. Significant material breakthroughs in p-type doping of ZnO thin films and improvements in crystal growth techniques have recently been achieved, making the development of(More)
Manipulating the speed of light has never been more exciting since electromagnetic induced transparency and its classical analogs led to slow light. Here, we report the manipulation of light group velocity in a terahertz metamaterial without needing a dark resonator, but utilizing instead two concentric split-ring bright resonators (meta-atoms) exhibiting a(More)
Terahertz technologies have gained great amount of attention for biomedical imaging and tissue analysis. In this study, we utilize terahertz imaging to study the effects of hydrofluoric acid on both compact bone tissue and cartilage. We compare the differences observed in the exposure for formalin fixed and raw, dried, tissue as well as those resulting from(More)
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