Extraordinary terahertz transmission through subwavelength spindle-like apertures in NbN filmExtraordinary terahertz transmission through subwavelength spindle-like apertures in NbN filmExtraordinary terahertz transmission through subwavelength spindle-like apertures in NbN filmExtraordinary terahertz transmission through subwavelength spindle-like apertures in NbN film

We studied numerically the temperature dependent extraordinary terahertz transmission through niobium nitride （NbN） film perforated with subwavelength spindle-like apertures. Both the resonant frequency and intensity of extraor- dinary terahertz transmission peaks can be greatly modified by the transition of NbN film from the normal state to the superconducting state. An enhancement of the （~1,0） NbN/magnesium oxide （MgO） peak intensity as high as 200% is demonstrated due to the combined contribution of both the superconducting transition and the excitation of localized surface plasmons （LSPs） around the apertures. The extraordinary terahertz transmission through spindle-fike hole arrays patterned on the NbN film can pave the way for us to explore novel active tuning devices.     

Temperature-dependent far-infrared properties of Bi12GeO20 single crystal

Far-infrared reflectivity spectra of bismuth germanium oxide (Bi12GeO20) single crystals are measured from room temperature down to 10 K. All the reflectivity spectra are fitted to a complex dielectric function ε(ω) in the factorised form. Phonon modes at low frequency are found to develop upon decreasing temperature and gain considerable spectrum weight below 150 K. The temperature-dependent static dielectric constants are obtained from the Lyddane-Sachs-Teller relation based on the obtained oscillator parameters. The dielectric constants are found to increase upon decreasing temperature, which is attributed to the charge transfer among the ions in the unit cell with the temperature varying.     

Extraordinary terahertz transmission through subwavelength spindle-like apertures in NbN film

We studied numerically the temperature dependent extraordinary terahertz transmission through niobium nitride(NbN) film perforated with subwavelength spindle-like apertures. Both the resonant frequency and intensity of extraordinary terahertz transmission peaks can be greatly modified by the transition of NbN film from the normal state to the superconducting state. An enhancement of the(±1, 0) NbN/magnesium oxide(MgO) peak intensity as high as 200% is demonstrated due to the combined contribution of both the superconducting transition and the excitation of localized surface plasmons(LSPs) around the apertures. The extraordinary terahertz transmission through spindle-like hole arrays patterned on the NbN film can pave the way for us to explore novel active tuning devices.     

铈铽共惨杂氟化镧纳米晶体的快速合成和荧光特性

用一种简单的方法快速合成了水溶性铈铽共惨杂氟化镧纳米晶体。这种荧光纳米晶体直径只有14 nm,具有很好的生物相容性,并且在活体干细胞中显示出很强的荧光。结果表明这种铈铽共惨杂氟化镧纳米晶体可作为一种有效的生物荧光标记材料。