A high-sensitivity curvature sensor based on an up-taper-core-offset structure is proposed and demonstrated in this paper. Here two specially designed cascaded up-tapers with maximum diameters of 247 μm and 251 μm, ...A high-sensitivity curvature sensor based on an up-taper-core-offset structure is proposed and demonstrated in this paper. Here two specially designed cascaded up-tapers with maximum diameters of 247 μm and 251 μm, respectively, are used as a cladding mode exciting component. The excited cladding modes will propagate in the cladding and re-couplers with the core mode at the core-offset jointing point. When the curvature is changed, the dip wavelength of the sensor will shift to a blue wavelength and an average curvature sensitivity of more than -12.5 nm/m^-1 is achieved within the measured curvature intervals.展开更多
The valence band offsets of the strained and longitudinally relaxed diamond/cubic boron-nitride （c-BN） （110） superlattice are investigated by the plane wave density functional theory approach and using the on-site...The valence band offsets of the strained and longitudinally relaxed diamond/cubic boron-nitride （c-BN） （110） superlattice are investigated by the plane wave density functional theory approach and using the on-site core electron as a reference energy level. For the strained diamond/c-BN superlattice, the valence band offset of around 1.50 eV is in good agreement with those using all the electrons methods. As for the longitudinally relaxed superlattice, the valence band offset of around 1.28 eV is smaller than that of the strained superlattice. The reason for this is mainly due to the split of the valence band maximum caused by the anisotropic strain.展开更多
文摘A high-sensitivity curvature sensor based on an up-taper-core-offset structure is proposed and demonstrated in this paper. Here two specially designed cascaded up-tapers with maximum diameters of 247 μm and 251 μm, respectively, are used as a cladding mode exciting component. The excited cladding modes will propagate in the cladding and re-couplers with the core mode at the core-offset jointing point. When the curvature is changed, the dip wavelength of the sensor will shift to a blue wavelength and an average curvature sensitivity of more than -12.5 nm/m^-1 is achieved within the measured curvature intervals.
基金supported by the National Natural Science Foundation of China (Grant No.60877017)the Innovation Program of Shanghai Municipal Education Commission (Grant No.08YZ04)the Shanghai Leading Academic Discipline Project (Grant No.S30107)
文摘The valence band offsets of the strained and longitudinally relaxed diamond/cubic boron-nitride （c-BN） （110） superlattice are investigated by the plane wave density functional theory approach and using the on-site core electron as a reference energy level. For the strained diamond/c-BN superlattice, the valence band offset of around 1.50 eV is in good agreement with those using all the electrons methods. As for the longitudinally relaxed superlattice, the valence band offset of around 1.28 eV is smaller than that of the strained superlattice. The reason for this is mainly due to the split of the valence band maximum caused by the anisotropic strain.
