Search

The performance of laser-based instruments heavily depends on the stability of their laser source. Some instruments, such as the Cs–4He magnetometer, even require the frequency stabilization and the power stabilization at the same time. In this work, we design a double-locking system with a fiber-coupled output on a small bread board and apply it to the pump laser of a Cs–4He magnetometer. By carefully choosing the stabilization methods, we significantly improve the long-term simultaneous stability of frequency and power of the pump laser. The laser frequency drifts in 2 h are reduced from 100 to 10 MHz. For 10 h continuous measurements, their Allan deviation obtains about two orders of magnitude improvement for the averaging time larger than 200 s and reaches σ( τ) = 1.57 × 10−9 with a 200 s averaging time. The laser power stability for 1.8 h also obtains two orders of magnitude improvement from 3.22% to 0.031%, and its power noise reaches a level that is very close to the electronic noise of the detector. Applying this stabilization system to the pump laser of a fiber-coupled Cs–4He magnetometer, its magnetic sensor noise is significantly reduced from 0.158 to 0.009 nT, which is a reasonable noise for magnetic field detection. With this on-board design of the laser stabilization system, it is more convenient to transform the magnetometer into an outdoor device.

Nanoceramics have a wide application in dielectric field due to their excellent dielectric properties. However, it is extremely difficult to fabricate densified BaTiO3 with nanometer scale crystalline. In this study, nanoscale BaTiO3 ceramics are successfully fabricated by deposition of a FeO layer onto BaTiO3 nanoparticle, and the structure and dielectric behavior of the BaTiO3@FeO nanoceramics are systematically investigated. The multilayer structure including 1) an inner tetragonal core, 2) a gradient lattice strain layer and 3) a surface insulating layer makes the dielectric constant peak tend to be rounded and broadened. Consequently, an excellent temperature/frequency stability met the X7R requirements and accompanied by the low dielectric loss are achieved in the BaTiO3@FeO nanoceramics.

Nanoceramics have a wide application in dielectric field due to their excellent dielectric properties.However, it is extremely difficult to fabricate densified BaTiO3with nanometer scale crystalline. In this study, nanoscaleBaTiO3 ceramics are successfully fabricated by deposition of a FeO layer onto BaTiO3 nanoparticle, and the structure and dielectric behavior of the BaTiO3@FeO nanoceramics are systematically investigated. The multilayer structure including 1) an inner tetragonal core, 2) a gradient lattice strain layer and 3) a surface insulating layer makes the dielectric constant peak tend to be rounded and broadened. Consequently, an excellent temperature/frequency stability met the X7R requirements and accompanied by the low dielectric loss are achieved in the BaTiO3@FeO nanoceramics.

We propose a feasible scheme to create macroscopically entangled atom-photon pairs by preparing an input optical superposition state. Several interesting non-classical quantum statistical effects like the atomic squeezed effects are clearly demonstrated. The making and manipulation of entangled atom-photon pairs are useful for, e.g., high-precision interferometry and quantum information science.