In this paper, an integrated few-mode erbium-doped fiber amplifier (FM-EDFA), with high gain, low differential modal gain (DMG), and low gain flatness for multi-wavelength amplification, is constructed using homemade weakly-coupled ring-core few-mode erbium-doped fiber (FM-EDF) and low insertion-loss passive components. The gain characteristics of the FM-EDFA for multi-wavelength amplification are analyzed in detail and compared with single-wavelength amplification. The experimental results demonstrate that, although multi-wavelength amplification in different modes has an impact on the gain characteristics, through simple LP core pumping only, all guided modes can achieve a gain higher than 22.
View Article and Find Full Text PDFA high-efficiency and broadband tunable chalcogenide fiber Raman laser with the Fabry-Perot (F-P) cavity formed by the Fresnel reflection was established. A maximum average power slope efficiency of around 43 and a maximum output peak power of about 2.9 W at 2148 nm were demonstrated by using a 2 µm nanosecond pump source.
View Article and Find Full Text PDFOptical fiber humidity sensors have sparked enormous interests in many fields because of their excellent features. However, it remains a great challenge to balance sensitivity, humidity response, temperature crosstalk, and wet hysteresis for real-world application. To overcome this trade-off, an optical fiber humidity sensor is developed here by coating functional graphene oxide (GO)/polyelectrolyte nanocomposite film on the excessively tilted fiber grating (ex-TFG), in which GO/polyelectrolyte nanocomposite film is employed for enhancing the hydrophilicity and accelerating the adsorption/desorption of water molecule, while the ex-TFG is utilized for improving the sensitivity of refractive index and eliminating the crosstalk of temperature.
View Article and Find Full Text PDFThe catalysts employed in catalytic reactors greatly affect the reaction efficiency of the reaction system and the reactor’s performance. This work presents a rapid comparative study on three kinds of Fe-based materials integrated into an optofluidic Fenton reactor for water treatment. The Fe-based sheets (FeSiB, FeNbCuSiB, and FeNi) were respectively implanted into the reaction chamber to degrade the organic dyes with the assistance of H2O2.
View Article and Find Full Text PDFAlthough epitaxial strain imparted by lattice mismatch between a film and the underlying substrate has led to distinct structures and emergent functionalities, the discrete lattice parameters of limited substrates, combined with strain relaxations driven by film thickness, result in severe obstructions to subtly regulate electro-elastic coupling properties in perovskite ferroelectric films. Here a practical and universal method to achieve highly strained phases with large tetragonal distortions in Pb-based ferroelectric films through synergetic effects of moderately (≈1.0%) misfit strains and laser fluences during pulsed laser deposition process is demonstrated.
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