Publications by authors named "Qiuhua Nie"

Article Synopsis
  • The study explores using Er/Yb co-doped fluorotellurite glass fiber to tackle the capacity crisis in narrow-bandwidth C band applications by creating a broadband luminescence covering C + L bands.
  • Optimal doping levels of 1.5 mol% ErO and 3 mol% YbO were identified based on fluorescence performance metrics, along with a detailed examination of various optical properties and energy transfer mechanisms.
  • Additionally, a step-index fiber based on this glass showed an impressive bandwidth of ~112.5 nm for amplified spontaneous emission, making it a promising candidate for broadband amplifiers and tunable fiber lasers.
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Article Synopsis
  • - Multicore fiber (MCF) has a larger mode area than traditional single-core fiber, allowing for greater designs like a 19-core fiber made from chalcogenide glass with a mode area over 3000 µm.
  • - The newly created fiber exhibits a low transmission loss of 1.8 dB/m at 6.7 µm and demonstrates low bending loss (around 0.6 dB) when the bending radius exceeds 6 cm, aligning well with simulation data.
  • - The study analyzes the supermode characteristics of the fiber through both experimental and simulation methods, concluding that this multicore structure could advance high-power, bend-resistant fiber technology.
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Supercontinuum sources with high compactness are essential for applications such as optical sensing, airborne detection and communication systems. In the past decades, the adoption of bulky optical parametric amplifier to pump various chalcogenide glass waveguides are widely reported for on-chip mid-infrared supercontinuum generation, but this usually leads to a large volume of the whole system, and is not practical. Therefore, integrating advanced femtosecond fiber lasers with optical waveguides using nano-fabrication technology are highly desired.

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High-power laser delivery in the mid-infrared via hollow-core fibers is attractive, but it is too difficult to be fabricated using chalcogenide glasses. Here, we designed a mid-infrared hollow-core anti-resonant chalcogenide fiber (HC-ARCF) with a simplified Kagome cladding micro-structure for the first time. Then, the fiber was firstly fabricated through a precision mechanical drilling and pressured fiber drawing method.

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Nd-doped glasses are the most widely used laser gain media. However, Nd-doped non-silica microsphere lasers generally have lower quality (Q) factors due to the presence of non-radiative energy-loss impurities in traditional glass systems. In this work, we report the first, to the best of our knowledge, Nd-doped phosphate glass microsphere laser with the highest Q-factor of 1.

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The complete removal of the impurities like Se-H in Se-based chalcogenide glasses has been challenging in the development of highly transparent chalcogenide glass fiber. In this paper, several purification methods, including dynamic distillation, static distillation, and combined distillation method, were adopted with an aim of purifying arsenic selenide glass with ultra-low content of the impurities. The experimental results demonstrated that the Se-H can be completely eliminated in the arsenic selenide glass host and fiber without the introduction of any chloride.

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Objective: To explore the clinical effect of acupuncture combined with traditional Chinese medicine (TCM) application on the treatment of functional dyspepsia (FD) in children and the influence on serum 5-HT and NO levels.

Methods: 94 FD children admitted to the pediatric department of our hospital from March 2019 to March 2020 were selected as the research object and divided into the study group ( = 45) and reference group ( = 49) by the number table method. The routine Western medicine therapy was given to the reference group and the combination therapy of acupuncture and TCM application was given to the study group to analyze the effect of different therapies on FD children by detecting their serum 5-hydroxytryptamine (5-HT) and nitric oxide (NO) levels and electrogastrogram (EGG) before and after treatment.

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We demonstrate the tunable Raman femtosecond solitons generation with a record-breaking power of 1.2 W at 2.3 µm and an ever-reported highest Raman soliton energy conversion efficiency of 99% via precise seed-pulse management in the thulium-doped single-mode fiber amplifier.

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Chalcogenide glass possesses outstanding advantages, such as supercontinuum generation, but its nonlinear applications were limited by large zero-dispersion wavelength (ZDW). Traditional suspended-core fibers can shift the ZDW to near IR with a tiny core size of less than 5 µm but a large evanescent wave loss exists in these fibers. In this paper, we prepared a novel suspended-core fiber (SCF) based on chalcohalide glasses for the first time via the extrusion method, in which the ZDW of the fundamental mode in the fiber with a core size of larger than 30 µm was successfully shifted to 2.

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We demonstrate a thulium-doped mode-locked fiber laser with ultra-broadband wavelength tunability for micro-strain sensing based on the multimode interference (MMI) effect in single-mode-multimode-single-mode (SMS) fiber configuration. The homemade SMS device with high performance is fusion spliced in the laser cavity, and the developed dispersion precisely managed the all-fiber structured mode-locked picosecond laser with a record-breaking wavelength tuning range from 1976 to 1916 nm while exerting axial strain on this SMS device. We experimentally explored the regularity between the strain and the central-wavelength shift of the mode-locked pulse, and for the first time to the best of the authors' knowledge, achieved the precise in-line axial strain measurement from 0 to 5385 µɛ by using the tunable ultrafast-laser-based sensor, and sensitivity is up to -11.

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We demonstrate a watt-level mid-infrared supercontinuum source, with the spectrum covering the infrared region from 2 to 6.5 µm, in an all-fiber structured laser transmission system. To further improve the SC spectral bandwidth, power and system compactness in the follow-up AsS fiber, we theoretically and experimentally explored some knotty problems that would potentially result in the AsS fiber end-facet failure and low SC output power during the high-power butt-coupling process and proposed an optimal coupling distance on the premise of the safety of AsS fiber end face.

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A novel 2H-phase transition metal dichalcogenide (TMD)-tantalum selenide (TaSe) with metallic bandgap structure is a potential photoelectric material. A band structure simulation of TaSe via ab initio method indicated its metallic property. An effective multilayered TaSe saturable absorber (SA) was fabricated using liquid-phase exfoliation and optically driven deposition.

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A novel low-loss selenium-based chalcohalide fiber, with a low zero-dispersion wavelength, was prepared by an innovative preparation process. The composition optimized fiber has a wide transmission range of up to 11.5 μm, a lowest fundamental mode zero-dispersion wavelength of 4.

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We have prepared a well-structured tellurium chalcogenide (ChG) fiber with a specialized double cladding structure by an improved extrusion method, and experimentally demonstrated an ultra-flat mid-infrared (MIR) supercontinuum (SC) generation in such a fiber. The step-index fiber had an optical loss of <1 dB/m in a range from 7.4 to 9.

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ZnSbTe thin films have been deposited by magnetron co-sputtering of ZnTe and SbTe targets. The microstructure, phase-change speed, optical cycling stability, and crystallization kinetics have been investigated during thermal annealing and laser irradiation. The thermal-annealed and laser-irradiated films give a clear evidence of the coexistence of trigonal SbTe and cubic ZnTe phases, which are homogeneously distributed in a single alloy as confirmed by advanced scanning transmission electron microscopy.

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The well-known Swanepoel method was often used to obtain the refractive index (RI) of thin films at the wavenumber values corresponding to the extremes of the transmission interference fringes. But it is difficult to accurately obtain the RI of chalcogenide thin films, especially at an arbitrary wavenumber. So a regional approach method (RAM) was presented here to extend the Swanepoel method to an arbitrary wavenumber.

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We report on the observation of different pulse formation dynamics in a nonlinear polarization evolution (NPE)-based broadband erbium-doped fiber laser when the net cavity group-velocity dispersion (GVD) is managed to be close to zero. The fiber laser can generate pulses with a single wavelength or dual wavelengths by adjusting the waveplates. When the laser operates in dual-wavelength emission, the output pulses corresponding to the two wavelengths exhibit Gaussian- and parabolic-like waveforms, respectively, indicating that the laser can simultaneously operate in stretched-pulse and self-similar regimes.

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The structure evolution and crystallization processes of SbTe-TiO films have been investigated. The SbTe-rich nanocrystals, surrounded by TiO amorphous phases, are observed in the annealed SbTe-TiO composite films. The segregated domains exhibit obvious chalcogenide/TiO interfaces, which elevate crystallization temperature, impede the grain growth and increase crystalline resistance.

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In this study, the supercontinuum (SC) generation in a 1-m-long AsS fiber with a 200 μm core diameter was demonstrated experimentally. The high-purity AsS fiber we used exhibited very low optical loss with a background loss of approximately 0.1 dB/m at a wavelength of 2-5 μm.

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We have experimentally demonstrated midinfrared (MIR) supercontinuum (SC) generation in a low-loss Te-based chalcogenide (ChG) step-index fiber. The fiber, fabricated by an isolated extrusion method, has an optical loss of 2-3 dB/m at 6.2-10.

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Two series of chalcogenide glasses in Ge-Sb-S ternary system were synthesized with melt-quenching method. The phycochemical properties and spectral characteristic of glasses with different content of Ge and Sb were obtained with a series of measurements, and the systematic analysis on the change of optical properties was conducted in terms of microstructure of glasses combined with the Raman spectra. With constraint theory based on mean coordination number (Z), we described the variation trend of network structure directly.

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Two types of reverse pillar integrated chalcogenide glass (As₂S₃) waveguides are proposed in this study. These geometries exhibit an ultraflat and low dispersion profile with four zero dispersion wavelengths. Its low dispersion is approximately ±10  ps/nm/km over a 2240 nm bandwidth (for L waveguide) and ±13  ps/nm/km over a 2030 nm bandwidth (for F waveguide).

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CO2 molecule, one of the main molecules to create new life, should be probed accurately to detect the existence of life in exoplanets. The primary signature of CO2 molecule is approximately 15 μm, and traditional S- and Se-based glass fibers are unsuitable. Thus, Te-based glass is the only ideal candidate glass for far-infrared detection.

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Downconversion materials, which can convert one high-energy photon to two low-energy photons, have provided a promising avenue for the enhancement of solar cell efficiency. In this work, the Pr3+-Yb3+ codoped 25GeS2-35Ga2S3-40CsCl chalcohalide glasses were synthesized in a vacuumed silica ampoule by the melting-quenching technique. Under 474 nm excitation, the visible and near-IR emission spectra reveal the energy transfer from Pr3+ to Yb3+ ions, resulting in the intense 1008 nm near-IR emission for the c-Si solar cells.

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(ZnO)x(Sb2Te3)1-x materials with different ZnO contents have been systemically studied with an aim of finding the most suitable composition for phase change memory applications. It was found that ZnO-doping could improve thermal stability and electrical behavior of Sb2Te3 film. Sb2Te3-rich nanocrystals, surrounded by ZnO-rich amorphous phases, were observed in annealed ZnO-doped Sb2Te3 composite films, and the segregated domains exhibited a relatively uniform distribution.

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