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The work aims at understanding the changes in magnetic properties and the magnetoimpedance (MI) effect for the Fe84.5Zr4B8.5Nb2Cu1 (FZBNC) nanocrystalline alloys with the annealing temperature (Ta) from the microstructure point of view. The as-quenched FZBNC ribbons were annealed in a vacuum condition at selected temperatures for 20 min. The microstructures of the specimens were examined by the x-ray diffraction technique. The bcc a-Fe phase is identified from the XRD patterns. The mean grain size of the a-Fe phase (D1) at different annealing temperatures (Ta) was estimated using Scherrer's equation. The results show that D1 for the sample annealed at 575 °C is about 20 nm, which is the smallest value among all the samples. Measurements on the MI effect reveal that the FZBNC ribbon annealed at 575 °C exhibits the most drastic MI ratio of 756% at 600 kHz accompanied by the field sensitivity of 108% Oe[?]1, while a large MI effect is not observed in the sample annealed at other temperatures. The origin of the excellent MI effect is investigated in this paper. [ABSTRACT FROM AUTHOR]

We introduce a novel scheme which combines conventional Doppler dichroic atomic vapor laser lock (DAVLL) and nanofiber techniques for realizing frequency stabilization with sub-nanowatt laser power. The dependences of DAVLL signal on the total incident power of probe light and the quantification magnetic field amplitude indicate that the power for frequency stabilization could be minimized to only 15 pW. To evaluate the frequency stability of the locked laser, we calculate the Allan standard deviation, which shows that the relative frequency stability could reach 10−10 level at 10 s. This frequency stabilization scheme paves the road for future quantum optical device integration. [ABSTRACT FROM AUTHOR]

We theoretically study the properties of optical losses in a plasmonic multimer and find modes with lower radiative losses due to the cancellation of the dipole moment. High order plasmonic resonances, including electric quadrupole and magnetic dipole resonances, can be achieved by the reduction of symmetry in a multimer. Meanwhile, the dipole moment can be significantly reduced in these high order modes, and consequently, the radiative losses decrease efficiently. The low-loss modes can lead to a lower gain threshold in the gain-assisted nanosystem. In particular, compared with the electric dipolar mode in a single nanoshell, the gain threshold of the electric quadrupolar and magnetic dipolar modes in a multimer can drop by 57.66% and 59.22%, respectively. On the other hand, the gain threshold can reflect the extent of the optical losses of the plasmonic mode in a nanosystem. These findings may have potential applications in the design of a nanolaser, plasmon waveguide and photo-thermal device. [ABSTRACT FROM AUTHOR]