热拉式多材料纤维光电子技术研究进展与展望

随着纺织工程和材料科学的快速发展,智能纤维与织物以其柔软、轻便、透气等优势成为可穿戴设备的首选载体。热拉式多材料光电子纤维有望通过热拉制工艺发展为具有多参量感知、温度调控、信息交互等功能的智能纤维。为使热拉式多材料光电子纤维可更好地服务于纺织行业,重点讨论了热拉式多材料纤维光电子技术的研究进展,总结了热拉纤维内微纳结构的调控机制,阐述了热拉式多材料纤维在传感、能源、生物、医疗等场景中的应用,并展望了热拉式多材料纤维光电子技术未来在材料选择及研发、纤维结构调控、纺织加工、多功能集成、人工智能5个方面的研究趋势。最后指出:热拉式多材料光电子纤维未来将从单一功能向多功能、力学性能改善、智能计算等方向发展,以便更好地与传统纺织加工技术结合,进一步提升织物的功能性、穿戴舒适性、场景普适性。

红外飞秒激光诱导Ce^(3+)掺杂闪烁晶体的上转换发光研究

本文研究了红外飞秒激光照射下Ce3+掺杂的YAP和LSO两种闪烁晶体的上转换发光现象。实验发现在飞秒激光泵浦下,这两种晶体的荧光均来自于Ce3+离子的5d-4f跃迁。荧光强度与泵浦光功率之间的依赖关系揭示了Ce3+:YAP和Ce3+:LSO晶体的上转换过程皆由三光子吸收过程所主导。分析表明,Ce3+:YAP和Ce3+:LSO晶体中的三光子吸收是三光子同时吸收。

铒镱共掺磷硅酸盐光纤的制备及其激光性能研究

利用改进化学气相沉积法(MCVD)的反向沉积工艺,结合无铝的溶液掺杂技术,制备了高性能掺磷石英基的铒镱共掺光纤.反向沉积技术表现出了在纤芯中大量沉积磷这类高温下极易蒸发成分上的优势.研究表明,这种光纤中,铒镱离子能量传递效率极高,掺磷的石英基质对于促进镱离子对铒离子的能量传递,抑制镱离子寄生荧光作用明显.最后,搭建了双包层铒镱共掺光纤激光器系统,在光纤长度为4 m时,获得了3.2 W的最大功率输出,斜率效率达30%.

面向海洋传感与探测的光纤传感器研究进展

调研了近几年光纤传感器在海洋探测方面的研究进展,主要包括测量海水温度、压力、盐度、叶绿素、pH值和溶解氧的相关光纤传感器以及光纤水听器。简要介绍了光纤传感器的基本原理、结构及性能,同时跟踪了国内外相关的最新研究进展,并与传统的测量方法进行了比较,分析得出光纤传感器是对现有传统海洋探测器的重要补充,并在一些探测领域具有独特的优势。文章最后,探讨了光纤传感技术的未来发展趋势,认为在海洋温度、压力、叶绿素、水听器等领域可能会率先突破技术瓶颈并实现商用,同时提出了未来海洋光纤探测技术新的研究方向。

A Novel Hollow-Core Holey Fibre with Random Hole Distributions in the Cladding

We provide a novel hollow-core holey fibre that owns a random distribution of air holes in the cladding. Our experiments demonstrate that many of the features previously attributed to photonic crystal fibres with perfect arrangement of air holes, in particular, photonic bandgap guidance, can also be obtained in the fibre. Additionally, this fibre exhibits a second guided mode with both the two-lobe patterns, and each pattern is in different colour.

Nd^(3+) Doped Silicate Glass Photonic Crystal Fiber with Random Hole Distributions

The fabrication of one kind of large core area Nd3 + doped silicate glass photonic crystal fiber, and demonstration of the fiber's waveguidence properties were reported. This fiber owns a random air hole distribution in the cladding. The measured minimum loss of this kind of fiber is 10 dB·m-1 at 660 nm. These fibers can sustain only a single mode at least over wavelength ranging from 660 nm to 980 nm.

Upconversion Luminescence of Ce^(3+) Doped BK7 Glass by Femtosecond Laser Irradiation

Near-infrared to visible upconversion luminescence was observed in a multicomponent silicate （BK7） glass containing Ce^3 ＋ ions under focused infrared femtosecond laser irradiation. The emission spectra show that the upconversion luminescence comes from the 4f-5d transition of the Ce^3 ＋ ions. The relationship between the intensity of the Ce^3 ＋ emission and the pump power reveals that a three-photon absorption predominates in the conversion process from the near-infrared into the blue luminescence. The analysis of the upconversion mechanism suggests that the upconversion luminescence may come from a three-photon simultaneous absorption that leads to a population of the 5d level in which the characteristic luminescence occurs.

High Quantum Efficiency and High Concentration Erbium-Doped Silica Glasses Fabricated by Sintering Nanoporous Glasses

A new method was used to prepare erbium-doped high silica （SiO2 % 〉 96 % ） glasses by sintering nanoporous glasses. The concentration of erbium ions in high silica glasses can be considerably more than that in silica glasses prepared by using conventional methods. The fluorescence of 1532 nm has an FWHM （Full Wave at Half Maximum） of 50 nm, wider than 35 nm of EDSFA （erbium-doped silica fiber amplifer）, and hence the glass possesses potential application in broadband fiber amplifiers. The Judd-Ofelt theoretical analysis reflects that the quantum efficiency of this erbium-doped glass is about 0.78, although the erbium concentration in this glass （6 × 10^3） is about twenty times higher than that in silica glass. These excellent characteristics of Er-doped high silica glass will be conducive to its usage in optical amplifiers and microchip lasers.

Transparent Ni^2＋-Doped MgO-Al2O3-SiO2 Glass Ceramics with Broadband Infrared Luminescence

We report on transparent Ni^2＋-doped MgO-Al2O3-SiO2 glass ceramics with broadband infrared luminescence. Ni^2＋-doped MgO-Al2O3-SiO2 glass is prepared by using the conventional method. After heat treatment at high temperature, MgAl2O4 crystallites are precipitated, and their average size is about 4.3 nm. No luminescence is detected in the as-prepared glass sample, while broadband infrared luminescence centred at around 1315 nm with full width at half maximum （FWHM） of about 300 nm is observed from the glass ceramics. The observed infrared emission could be attributed to the ^3T2g（^3F）→^3A2g（^3F） transition of octahedral Ni^2＋ ions in the MgAl2O4 crystallites of the transparent glass ceramics. The product of the fluorescence lifetime and the stimulated emission cross section is about 1.6×10^-24 s cm^2.

Photodarkening-Induced Absorption and Fluorescence Changes in Yb Fibers

We study the photodarkening effect in a double clad ytterbium-doped silica fiber fabricated by modified chemical vapor deposition and solution doping.A common measurement technology for photodarkening is used to study the photodarkening-induced absorption spectra.We present a fast and simple method to observe the PD effect by measurement of the fluorescence spectra.The method proposed here can be used to observe the influence for a short time,and thus reduces the requirements of system stability and heat management.It is obtained that under the condition of 45.5%Yb ion inversion level,photodarkening-induced excessive loss at an equilibrium state is above 4.5 dB/m and florescence intensity degradation is above 10%after 500 min pumping at 1041 nm for the home-made normal Yb/Al co-doped silica fiber.

Spectroscopic Properties of Nd^(3+)-Doped High Silica Glass Prepared by Sintering Porous Glass

A new kind of Nd^3＋-doped high silica glass （SiO2 〉 96% （mass fraction）） was obtained by sintering porous glass impregnated with Nd^3 ＋ ions. The absorption and luminescence properties of high silica glass doped with different Nd^3 ＋ concentrations were studied. The intensity parameters Ωt （t = 2, 4, 6）, spontaneous emission probability, fluorescence lifetime, radiative quantum efficiency, fluorescence branching ratio, and stimulated emission cross section were calculated using the Judd-Ofelt theory. The optimal Nd^3＋ concentration in high silica glass was 0.27% （mole fraction） because of its high quantum efficiency and emission intensity. By comparing the spectroscopic parameters with other Nd^3 ＋- doped oxide glasses and commercial silicate glasses, the Nd^3 ＋ -doped high silica glasses are likely to be a promising material used for high power and high repetition rate lasers.

Preparation and Fluorescent Property of Eu-Doped High Silica Glasses

A method to fabricate europium ions doped-high silica glass for transparent fluorescence materials based on the fabrication and sintering technique of nano-porous silica glass was reported. Glasses impregnated with Eu ions and sintered at above 1150℃in a reduction atmosphere show a very strong blue light from an emission band at about 430 nm due to the 4f65d→4f7(8S7/2) transition of the Eu2+ ions. On the other hand, the Eu-doped glass obtained by co-impregnated with Y3+ and V5+ ions and sintering in oxidation atmosphere behaves a very strong red emission band at about 615 nm with a UV excitation. An appearance of vanadate band in the excitation spectrum of Eu3+ , Y3+ .and V5+ ions co-doped high silica glass implies an effective energy transferring from VO43- to Eu3+ and effective excitation of Eu3+ by about 500 nm strong broad emission of VO43- .

Influence of Annealing Temperature on Structure, Optical Loss and Laser-Induced Damage Threshold of TiO2 Thin Films

TiO2 thin films are prepared on fused silica with conventional electron beam evaporation deposition. After annealed at different temperatures for 4h, the spectra and XRD patterns of the TiO2 thin film are obtained. Weak absorption of coatings is measured by the surface thermal lensing technique, and laser-induced damage threshold （LIDT） is determined. It is found that with the increasing annealing temperature, the transmittance of TiO2 films decreases. Especially when coatings are annealed at high temperature over 1173K, the optical loss is very serious. Weak absorption detection indicates that the absorption of coatings decreases firstly and then increases, and the absorption and defects play major roles in the LIDT of TiO2 thin films.

Controlling the Spectral Characteristics of Bismuth Doped Silicate Glass Based on the Reducing Reaction of Al Powder

Silicate glasses co-doped with Al metal powder and Bi2O3 are prepared.The effects of Al on spectral properties of samples are studied.It is found that the absorption intensity increases with increasing Al concentration in bismuth doped silicate glasses.The near-infrared(NIR)emission of the samples can be controlled by Al powder concentration no matter whether or not excited by 808 nm or 976 nm lasers.Furthermore,the influence of Al on formation of Bi-NIR active ions is discussed.The dependence relationship between the emission property of~416 nm and Al concentration is a way to investigate the NIR emission origin of bismuth doped glass.

磷硅酸盐发光玻璃及光纤研究进展

随着对发光材料在理论和技术方面的深入研究,发光材料已经被广泛应用于白光LED照明、光学成像、光存储、光通信、光纤激光等领域。近年来,研究发现引入磷元素作为共掺元素所制备的发光材料在光学性能方面展现出独特的优势,磷元素成为突破众多发光材料发光性能瓶颈的关键因素。本文对磷硅酸盐发光玻璃的制备方法及其光学特性进行了综述,介绍了几种主流的发光材料制备方法及其掺磷技术,以及各种发光离子在P^(5+)的配位环境下的光谱特性,展现出磷硅酸盐发光玻璃及光纤在光通信及光纤激光等领域极大的优势,最后对多种掺磷有源特种光纤的应用前景进行了展望。

光子晶体制备方法最新进展

光子晶体是一种介电常数随空间呈周期性变化的材料。具有光子带隙结构(Phtotonic Band Gap)的光子晶体,可以调制光子的状态模式,其潜在用途十分广泛。本文介绍了光子晶体的制备方法及其进展。

掺铒高硅氧玻璃光谱性质的研究

应用Judd-Oflet理论计算了新型掺铒高硅氧玻璃中铒离子的强度参量Ωt(t=2,4,6),Ω2=8·15×10-20,Ω4=1·43×10-20,Ω6=1·22×10-20,相比于其他氧化物玻璃,表现出较大的Ω2,6值,反映了铒离子周围的近邻结构不对称性和Er-O键的离子键成分较高.利用McCumber理论计算得到了能级4I13/2→4I15/2跃迁的受激发射截面为σc=0·51pm2.这种高硅氧玻璃掺铒离子浓度尽管高于石英光纤的掺杂浓度10倍左右,其荧光寿命和量子效率仍达到6·0ms和66·0%,有可能成为新的光学放大和微片激光材料.