基于离子注入的玻璃结构调控对铋离子超宽带近红外发光特性影响及其机理研究

Since Bi-doped materials have outstanding performance with NIR ultra-broadband emission, they are promise for achieving ultra-broadband optical amplification in full communication band by a single wavelength pump. However, the practical application of these materials is restricted, because the origin for the ultra-broadband emission, and the effect on the NIR emission property caused by the glass structure have not been clarified. Ion implantation is a kind of surface modification technology which can achieve some new properties by changing material composition and structure. It is known that medium- and long-distance optical communication is by now well established, and the next development planar photonic integrated circuits are being developed to perform functions such as guiding, splitting, switching, wavelength multiplexing and amplification of light. This project will focus on important materials in planar optical amplifier with ultra-broadband. In this project, firstly, network former and network modifier in the glass matrix will be adjusted under ion implantation, and the relationship between glass micro-structure and the properties of ultra-broadband near infrared emission of bismuth ion under glass structure successive modulation will be discussed. Secondly, the influence law of broadband optical amplification on the structure environment, neighboured stuctrure and distribution condition around bismuth ions will be investigated, and the regulation method for the near infrared broadband emission in bismuth ion doped glasses and its internal physical mechanism will also be discussed. Thirdly, the relationship between microstructure of glass matrix and gain characteristic of bismuth near infrared optical amplification will be investigated, and the materials for planar waveguide optical amplifier will be explored by using ion implantation method. Finally, The implement of this project will be theoretically and practicality significant for enhancing the optical amplification gain of Bi ion-doped materials and developing new optical amplifier devices, and we demonstrate that by taking advantage of the known Bi-doped materials for effective bandwith of optical amplification can be made with extremely planar optical waveguides.

铋离子掺杂玻璃具有近红外超宽带发光特性，有望实现用单一波长泵浦实现全通讯波段的超宽带光放大，然而由于其发光的机制以及玻璃结构对其近红外发光性能的影响机制不完全清楚，一定程度上制约其实际应用。离子注入可以引起材料成分、结构的变化，获得某些新功能。本项目以开发新型超宽带平面波导光放大器用材料为主要研究目标，通过离子注入调节玻璃基质的网络形成体与网络修饰体成分实现对玻璃微结构的连续调控，研究铋离子掺杂玻璃近红外超宽带发光性能与玻璃微结构之间的关系；通过研究铋离子在玻璃中的赋存状态、近邻结构和分布形态对发光及光放大特性的影响规律，探讨铋离子掺杂玻璃的近红外宽带发光的外在调控方法和内在物理机制；通过玻璃基质微观结构与铋离子近红外光放大增益特性关系的研究，探索通过离子注入实现超宽带光放大的平面光波导材料和方法。本项目的实施对提高铋离子掺杂材料的有效光放大增益，开发新型光放大器件提供理论基础和技术支撑。

本项目以铋离子在离子注入玻璃结构调控下的超宽带近红外发光特性及发光机理为研究重点，通过注入离子种类的选择、化学态、注入剂量和能量的控制，对玻璃的微观结构以及铋离子的配位环境进行调控，系统开展离子注入结构调控下，注入离子对玻璃基质结构、结构变化对铋离子近红外发光性质的影响规律，以及铋离子掺杂材料近红外发光机理，从而达到有效提高铋离子超宽带近红外发光效率的目的。通过本项目的实施，得到以下结论：1、铋离子的近红外荧光受玻璃基质光学碱度影响，低的光学碱度有利于铋离子的近红外发光。2、铋离子的近红外荧光不仅受到玻璃基质光学碱度的影响，也受到玻璃网络结构的影响。随着离子注入后玻璃中CaO浓度的增加，[GeO4]-4元环向[GeO4]-3元环转变。由于[GeO4]-3元环网络空隙小，能更好的将铋离子近红外荧光中心分散开来，减少了铋离子近红外荧光中心之间的交叉弛豫等因素导致的荧光猝灭，使得铋离子近红外荧光增强。3、通过离子注入后的交换调整铋离子近红外荧光中心的周围环境而调整铋离子的近红外荧光。银和铜离子注入后，经过热处理离子交换后，主要以Ag+、Cu+的形式进入玻璃网络，占据Na+离子的位置。Ag+、Cu+离子电负性较大，在玻璃网络中占据较少O配位（2~3个），使得玻璃网络中出现富余的非桥氧键，即出现负电位置，处在这些位置附近的高价态铋离子（Bi3+离子）可以被还原为低价态铋离子包括铋离子近红外荧光中心，导致玻璃中铋离子近红外荧光中心增加。根据本研究的工作，当铋离子周围环境能够提供还原条件（光学碱度低、提供负电位置等）或者能更好的将铋离子发光中心分隔开（减少交叉弛豫等荧光猝灭机会），将有利于铋离子近红外发光的增强。共掺荧光中心能够调整铋离子近红外荧光，然而荧光中心之间无可避免的能量传递无法得到理想的平坦增益带宽，阻断铋离子与稀土离子之间的相互作用也许是一种可取的研究思路。本项目的实施对提高铋离子掺杂材料的光放大增益,开发新型光放大器件具有理论和现实意义。