Terbium scandium aluminum garnet(TSAG) crystals have been widely used in magneto-optical systems. We investigate the complex refractive index of the TSAG crystal in the terahertz frequency range using terahertz(THz) t...Terbium scandium aluminum garnet(TSAG) crystals have been widely used in magneto-optical systems. We investigate the complex refractive index of the TSAG crystal in the terahertz frequency range using terahertz(THz) time-domain spectroscopy in the temperature range 100–300 K. It is observed that the refractive index and the absorption coefficient increase with the THz frequency. The refractive index increases with the temperature.We measure the temperature coefficient of the refractive index of the TSAG crystal in the frequency range 0.4–1.4 THz. Furthermore, the loss tangent, i.e., the ratio of experimental values of the imaginary and real part of the dielectric permittivity, is found to be almost independent of frequency. TSAG is very promising for applications in THz optoelectronics because it has a high dielectric constant, low loss, and low thermal coefficient of the dielectric constant.展开更多
Since the 1990s, the progress of nanofabrication technologies has resulted in increasing interests in the study of superconducting properties of mesoscopic samples. A mesoscopic sample has a size comparable to the coh...Since the 1990s, the progress of nanofabrication technologies has resulted in increasing interests in the study of superconducting properties of mesoscopic samples. A mesoscopic sample has a size comparable to the coherence length ξ and penetration depth λ. Properties of mesoscopic systems are considerably influenced by confinement effects. Therefore, the vortex state depends on the size and geometry of the sample.展开更多
基金the National Natural Science Foundation of China under Grant Nos 11604202,11674213,61735010 and 51572275the Shanghai Rising-Star Program under Grant No 18QA1401700+2 种基金the ‘Chen Guang’ Project under Grant No 16CG45the Shanghai Municipal Education Commissionthe Shanghai Education Development Foundation
文摘Terbium scandium aluminum garnet(TSAG) crystals have been widely used in magneto-optical systems. We investigate the complex refractive index of the TSAG crystal in the terahertz frequency range using terahertz(THz) time-domain spectroscopy in the temperature range 100–300 K. It is observed that the refractive index and the absorption coefficient increase with the THz frequency. The refractive index increases with the temperature.We measure the temperature coefficient of the refractive index of the TSAG crystal in the frequency range 0.4–1.4 THz. Furthermore, the loss tangent, i.e., the ratio of experimental values of the imaginary and real part of the dielectric permittivity, is found to be almost independent of frequency. TSAG is very promising for applications in THz optoelectronics because it has a high dielectric constant, low loss, and low thermal coefficient of the dielectric constant.
文摘Since the 1990s, the progress of nanofabrication technologies has resulted in increasing interests in the study of superconducting properties of mesoscopic samples. A mesoscopic sample has a size comparable to the coherence length ξ and penetration depth λ. Properties of mesoscopic systems are considerably influenced by confinement effects. Therefore, the vortex state depends on the size and geometry of the sample.
