Ni-rich LiNi Co Mn O (NCM+ + = 1, ≥ 0.8) layered oxide materials are considered the main cathode materials for high-energy-density Li-ion batteries. However, the endless cracking of polycrystalline NCM materials caused by stress accelerates the loss of active materials and electrolyte decomposition, limiting the cycle life.
View Article and Find Full Text PDFThe optical fiber distributed strain sensor based on the optical frequency domain reflectometer (OFDR) preserves its dominant position in short-distance measurement fields with high spatial resolution, such as biomedical treatment, soft robot, etc. However, owing to the weak intensity of the Rayleigh backscattered signal (RBS) in the single-mode fiber (SMF) and complex computation, the large strain changes cannot be precisely and rapidly demodulated by the traditional cross-correlation method. In this work, the OFDR with backscattering enhanced optical fiber (BEOF) is proposed and demonstrated for fast and large strain measurement.
View Article and Find Full Text PDFSilicon (Si) anode has attracted broad attention because of its high theoretical specific capacity and low working potential. However, the severe volumetric changes of Si particles during the lithiation process cause expansion and contraction of the electrodes, which induces a repeatedly repair of solid electrolyte interphase, resulting in an excessive consuming of electrolyte and rapid capacity decay. Clearly known the deformation and stress changing at µε resolution in the Si-based electrode during battery operation provides invaluable information for the battery research and development.
View Article and Find Full Text PDFA fiber Bragg grating (FBG) displacement sensor based on synchronous sensing is developed for real-time monitoring of a tunnel lining. The sensing principle and mechanical structure of the proposed sensor are analyzed and simulated, and its sensitization effectiveness and temperature compensation are verified. Equivalent model tests show that the sensor has a good linear sensitivity of 19.
View Article and Find Full Text PDFThis publisher's note contains corrections to Opt. Lett.47, 4937 (2022)10.
View Article and Find Full Text PDFMode-locked lasers with ultra-narrow spectral widths and durations of hundreds of picoseconds can be versatile light sources for a variety of newly emergent applications. However, less attention seems to be given to mode-locked lasers that generate narrow spectral bandwidths. We demonstrate a passively mode-locked erbium-doped fiber laser (EDFL) system that relies on a standard fiber Bragg grating (FBG) and the nonlinear polarization rotation (NPR) effect.
View Article and Find Full Text PDFWe have numerically and experimentally presented the diffraction characteristics of radiated tilted fiber grating (RTFG) in terms of the spectrum, bandwidth, degree of polarization, angular dispersion, and temperature crosstalk. The theoretical and experimental results have shown that the polarization property, bandwidth, and dispersion of RTFG highly depended on the tilt angle of RTFG, and the RTFG has ultra-low temperature crosstalk. We have simulated the transmission spectrum of the RTFG with different tilt angles (25°, 31°, 38°, 45°, and 54°), in which the results show that the larger tilt angle has the wider bandwidth.
View Article and Find Full Text PDFIn this Letter, we have proposed an in-fiber duplex optical antenna based on a 45° radiated titled fiber grating (RTFG), in which the 45° RTFG not only radiates the light from the fiber core to the free space, but also harvests the light from the free space back into the fiber core. Using the finite difference time domain method, we have theoretically analyzed the light recoupling efficiency of the RTFG. The simulated results have shown that the RTFG-based optical antennas have a maximum coupling efficiency of 10%.
View Article and Find Full Text PDFWith zero excess lithium, anode-free lithium metal batteries (AFLMBs) can deliver much higher energy density than that of traditional lithium metal batteries. However, AFLMBs are prone to suffer from rapid capacity loss and short life. Monitoring and analyzing the capacity decay of AFLMBs are of great importance for their future applications.
View Article and Find Full Text PDFUltrafast fiber lasers have been serving as an ideal playground for spreading the extensive industrial applications and exploring the optics nonlinear dynamics. Here, we report a bidirectional fiber laser scheme for validating the possibility of a multiplexed laser system, which is passively mode-locked by the nonlinear polarization rotation (NPR) technique. In particular, the proposed fiber laser consists of one main cavity and two counter-propagating branches with different dispersion distributions.
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