The photonic spin Hall effect(PSHE),characterized by two splitting beams with opposite spins,has great potential applications in nano-photonic devices,optical sensing fields,and precision metrology.We present the sign...The photonic spin Hall effect(PSHE),characterized by two splitting beams with opposite spins,has great potential applications in nano-photonic devices,optical sensing fields,and precision metrology.We present the significant enhancement of terahertz(THz)PSHE by taking advantage of the optical Tamm state(OTS)in In Sb-distributed Bragg reflector(DBR)structure.The spin shift of reflected light can be dynamically tuned by the structural parameters(e.g.the thickness)of the InSb-DBR structure as well as the temperature,and the maximum spin shift for a horizontally polarized incident beam at 1.1 THz can reach up to 11.15 mm.Moreover,we propose a THz gas sensing device based on the enhanced PSHE via the strong excitation of OTS for the InSb-DBR structure with a superior intensity sensitivity of 5.873×10^(4)mm/RIU and good stability.This sensor exhibits two orders of magnitude improvement compared with the similar PSHE sensor based on In Sb-supported THz long-range surface plasmon resonance.These findings may provide an alternative way for the enhanced PSHE and offer the opportunity for developing new optical sensing devices.展开更多
The garnet type phosphors of Eu^(3+)doped Ca_(3)Ga_(2)Ge_(3)O_(12)were synthesized via conventional solid statereaction techniques.The phase purity and luminescence properties of the fabricated phosphors werecharacter...The garnet type phosphors of Eu^(3+)doped Ca_(3)Ga_(2)Ge_(3)O_(12)were synthesized via conventional solid statereaction techniques.The phase purity and luminescence properties of the fabricated phosphors werecharacterized by X-ray powder diffraction,photoluminescence excitation and emission spectra,temperaturedependent emission spectra as well as luminescence decay curves.The phosphors show enhancedred emission from a^(5)D_(0)→^(7)F_(4)transition of Eu^(3+)under the excitation of 394 nm.The unusual^(5)D_(0)→^(7)F_(4)intensity was explained by structural analysis.The emission intensity of the phosphors increases with theconcentration of Eu^(3+)until the quenching concentration of 10 mol%.Excited by a pulsed laser of wavelength610.8 nm,the emission intensity of the^(5)D_(0)→^(7)F_(4)transition increases monotonously as the temperatureincreases in the range of 160–360 K.The temperature dependent fluorescence behavior wasinvestigated.The relative sensitivity reaches the maximum value of 3.66%K−1 at 160 K and reaches 1.04%K^(−1)at 300 K.The results show that the garnet type Ca_(3)Ga_(2)Ge_(3)O_(12):Eu^(3+)phosphor is a promising materialfor the application of optical thermometry.展开更多
With the increasing demand for non-contact temperature sensing, the development of an optical thermometer with excellent performance is more and more compelling. A Cr^(3+)-doped InTaO4 phosphor was prepared for the im...With the increasing demand for non-contact temperature sensing, the development of an optical thermometer with excellent performance is more and more compelling. A Cr^(3+)-doped InTaO4 phosphor was prepared for the implementation of multi-mode high-sensitivity optical temperature sensing. Its temperature-dependent fluorescence intensity and fluorescence lifetime in the temperature range from 240 to 420 K were investigated in detail for achieving two different temperature sensing modes. At 347 K, the optimal relative temperature sensitivities are 2.50% K^(−1) for the fluorescence intensity mode and 2.27% K^(−1) for the fluorescence lifetime mode, respectively. Moreover, due to the rapid decrease of the fluorescence lifetime of Cr^(3+), another temperature sensing scheme based on a time-resolved technique was also presented. Here, the fluorescence intensities of Cr^(3+) in two different time windows during its decay process were captured with an intensified charge-coupled device (ICCD), and the temperature dependence of the ratio of fluorescence intensities in these two-time windows was calculated and calibrated. An optimal relative sensitivity of 5.03% K^(−1) at 388 K was achieved in this scheme with a temperature resolution of about 0.3 K. Combined with fluorescence microscopy and the use of the ICCD, the temperature imaging of an operating printed circuit board with high spatial resolution was demonstrated by employing the temperature sensing scheme based on the time-resolved technique. The above results reveal that the InTaO4:Cr^(3+) phosphor is very promising for applications in multi-mode high-sensitivity optical thermometry and temperature imaging.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12175107 and 12004194)the Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant No.NY220030)
文摘The photonic spin Hall effect(PSHE),characterized by two splitting beams with opposite spins,has great potential applications in nano-photonic devices,optical sensing fields,and precision metrology.We present the significant enhancement of terahertz(THz)PSHE by taking advantage of the optical Tamm state(OTS)in In Sb-distributed Bragg reflector(DBR)structure.The spin shift of reflected light can be dynamically tuned by the structural parameters(e.g.the thickness)of the InSb-DBR structure as well as the temperature,and the maximum spin shift for a horizontally polarized incident beam at 1.1 THz can reach up to 11.15 mm.Moreover,we propose a THz gas sensing device based on the enhanced PSHE via the strong excitation of OTS for the InSb-DBR structure with a superior intensity sensitivity of 5.873×10^(4)mm/RIU and good stability.This sensor exhibits two orders of magnitude improvement compared with the similar PSHE sensor based on In Sb-supported THz long-range surface plasmon resonance.These findings may provide an alternative way for the enhanced PSHE and offer the opportunity for developing new optical sensing devices.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFB0701001)the National Natural Science Foundation of China(Grant No.11574298 and 61635012).
文摘The garnet type phosphors of Eu^(3+)doped Ca_(3)Ga_(2)Ge_(3)O_(12)were synthesized via conventional solid statereaction techniques.The phase purity and luminescence properties of the fabricated phosphors werecharacterized by X-ray powder diffraction,photoluminescence excitation and emission spectra,temperaturedependent emission spectra as well as luminescence decay curves.The phosphors show enhancedred emission from a^(5)D_(0)→^(7)F_(4)transition of Eu^(3+)under the excitation of 394 nm.The unusual^(5)D_(0)→^(7)F_(4)intensity was explained by structural analysis.The emission intensity of the phosphors increases with theconcentration of Eu^(3+)until the quenching concentration of 10 mol%.Excited by a pulsed laser of wavelength610.8 nm,the emission intensity of the^(5)D_(0)→^(7)F_(4)transition increases monotonously as the temperatureincreases in the range of 160–360 K.The temperature dependent fluorescence behavior wasinvestigated.The relative sensitivity reaches the maximum value of 3.66%K−1 at 160 K and reaches 1.04%K^(−1)at 300 K.The results show that the garnet type Ca_(3)Ga_(2)Ge_(3)O_(12):Eu^(3+)phosphor is a promising materialfor the application of optical thermometry.
基金supported by the National Natural Science Foundation of China(No.11974338)the Natural Science Foundation of Anhui Province(No.2008085MA21)+1 种基金the Natural Science Foundation of Jiangsu Province[No.BK20190725]NUPTSF[Grant No.NY219139].
文摘With the increasing demand for non-contact temperature sensing, the development of an optical thermometer with excellent performance is more and more compelling. A Cr^(3+)-doped InTaO4 phosphor was prepared for the implementation of multi-mode high-sensitivity optical temperature sensing. Its temperature-dependent fluorescence intensity and fluorescence lifetime in the temperature range from 240 to 420 K were investigated in detail for achieving two different temperature sensing modes. At 347 K, the optimal relative temperature sensitivities are 2.50% K^(−1) for the fluorescence intensity mode and 2.27% K^(−1) for the fluorescence lifetime mode, respectively. Moreover, due to the rapid decrease of the fluorescence lifetime of Cr^(3+), another temperature sensing scheme based on a time-resolved technique was also presented. Here, the fluorescence intensities of Cr^(3+) in two different time windows during its decay process were captured with an intensified charge-coupled device (ICCD), and the temperature dependence of the ratio of fluorescence intensities in these two-time windows was calculated and calibrated. An optimal relative sensitivity of 5.03% K^(−1) at 388 K was achieved in this scheme with a temperature resolution of about 0.3 K. Combined with fluorescence microscopy and the use of the ICCD, the temperature imaging of an operating printed circuit board with high spatial resolution was demonstrated by employing the temperature sensing scheme based on the time-resolved technique. The above results reveal that the InTaO4:Cr^(3+) phosphor is very promising for applications in multi-mode high-sensitivity optical thermometry and temperature imaging.
