Browsing by Author "Liao, Shu-Wei"

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Circular Polarized Lasing Characteristics in Metal/GaN Double-Spiral Nanowire Cavity
(2017-01-01)
Yu, Cheng-Li
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Liao, Shu-Wei
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Hsiao, Yu-Hao
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Kuo, Hao-Chung
;
Shih, Min-Hsiung
Room temperature highly circular polarized laser was demonstrated with a compact metal/GaN double-spiral nanowire cavity. The lasing action was observed with a UV wavelength of 363 nm and a high dissymmetry factor of +1.05.
Optimized Spiral Metal-Gallium-Nitride Nanowire Cavity for Ultra-High Circular Dichroism Ultraviolet Lasing at Room Temperature
(2016-05-25)
Liao, Wei-Chun
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Liao, Shu-Wei
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Chen, Kuo-Ju
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Hsiao, Yu-Hao
;
Chang, Shu-Wei
Circularly polarized laser sources with small footprints and high efficiencies can possess advanced functionalities in optical communication and biophotonic integrated systems. However, the conventional lasers with additional circular-polarization converters are bulky and hardly compatible with nanophotonic circuits, and most active chiral plasmonic nanostructures nowadays exhibit broadband emission and low circular dichroism. In this work, with spirals of gallium nitride (GaN) nanowires (NWRs) covered by a metal layer, we demonstrated an ultrasmall semiconductor laser capable of emitting circularly-polarized photons. The left-and right-hand spiral metal nanowire cavities with varied periods were designed at ultraviolet wavelengths to achieve the high quality factor circular dichroism metastructures. The dissymmetry factors characterizing the degrees of circular polarizations of the left-and right-hand chiral lasers were 1.4 and -1.6 (+/- 2 if perfectly circular polarized), respectively. The results show that the chiral cavities with only 5 spiral periods can achieve lasing signals with the high degrees of circular polarizations.
Planar Metal-GaN Spiral Nanowire Cavities for High Circular Dichroism Lasing Action
(2016)
Hsiao, Yu-Hao
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Kao, Tsung Sheng
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Liao, Shu-Wei
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Liao, Wei-Chun
;
Chen, Kuo-Lu
The compact and energy-efficient planar metal-GaN spiral nanowire cavity lasing device has been demonstrated with high circularly polarized UV laser light at 364 nm and the circular dichroism performance enhanced to dissymmetry factor of + 1.4.
Room temperature lasing characteristics in metal-cavity GaN shallow grating and spiral structures
(2015)
Liao, Shu-Wei
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Liao, Wei-Chun
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Chen, Kuo-Ju
;
Shih, Min-Hsiung
;
Kuo, Hao-Chung
We demonstrated a metal-cavity GaN spiral structure lasing at room temperature with the threshold power density about 17 W/cm(2) under circularly polarized pumping condition. The emission wavelength is approximately 363 nm.
Room temperature lasing characteristics in metal-coated GaN spiral and grating structures
(2014)
Liao, Wei-Chun
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Liao, Shu-Wei
;
Chen, Kuo-Ju
;
Shih, Min-Hsiung
;
Kuo, Hao-Chung
We had investigated a metal-coated GaN spiral structure laser at room temperature. The lasing action was observed around 363 nm wavelength with a low threshold power density. We also compare the lasing characteristics from metal-coated GaN spiral and grating structures. The experiment results ensure the circular-polarized emission from the metal-coated GaN spiral laser.