三价稀土离子上转换发光有着一些很有价值的应用技术: 波导上转换及放大和激光、 上转换三维立体显示、 飞秒光谱应用、 激光控温、 三维成像与存储、 光学温度感应系统、 牙科等生物物理应用、 上转换荧光防伪、 上转换宽带光源、 和上转换红外显示片等。 因为受到太阳能电池发展需求的促进, 上转换研究再度呈现出澎湃的研究热潮。 目前, 利用金属表面等离子体共振的近场增强效应能够有效增强其表面附近的荧光物质的发光的特性, 有可能较大幅度的提高上转换发光的强度, 从而有可能进一步把上转换发光推向实用。 利用离子引入法, 在铋化物的发光玻璃中引入银颗粒。 研究结果表明银表面等离激元的表面等离子体共振吸收峰位于580～600 nm; 而且, 加热时间的延长导致了表面等离子体共振吸收峰的剧烈增强和稍微蓝移。 978 nm半导体激光能够导致531.0, 546.0和657.5 nm的三组Er3+的2H11/2→4I15/2, 4S3/2→4I15/2, 4F9/2→4I15/2的双光子上转换荧光, 978 nm激光激发掺铒铋化物发光玻璃的上转换发光的机理是第一步的4I15/2→4I11/2共振基态吸收和随后的第二步的4I11/2→4F7/2的共振激发态吸收; 纳米银的表面等离激元的引入促成铋化物发光玻璃中铒离子的978 nm激光激发的上转换发光最大增强了272.0%倍。 1 539 nm半导体激光能够导致波长为528.0, 547.0, 657.0和795.0 nm的四组Er3+的2H11/2→4I15/2, 4S3/2→4I15/2, 4F9/2→4I15/2和4I9/2→4I15/2的上转换荧光; 1539 nm激光导致的528.0 nm 2H11/2→4I15/2和547.0 nm 4S3/2→4I15/2上转换荧光的机理主要是1 539 nm激光的4I15/2→4I13/2, 4I13/2→4I9/2和4I9/2→2H11/2的三步光激发吸收跃迁过程, 1 539 nm激光导致的657.0 nm 4F9/2→4I15/2上转换荧光的机理主要是1 539 nm激光的4I15/2→4I13/2, 4I13/2→4I9/2和4I11/2→4F9/2的三步光激发吸收跃迁过程; 纳米银的表面等离激元的引入导致了铋化物发光玻璃中铒离子的1 539 nm激光激发的上转换发光最大增强160.3%倍。 显然, 靠近银表面等离激元共振吸收峰的978 nm激光上转换的增强效果比1 539 nm激光的要好。

Upconversion luminescence of trivalent rare-earth ions has some valuable application technologies: Waveguide upconversion and amplification and laser, Up-conversion three-dimensional display, Femtosecond spectral applications, Laser temperature control, Three-dimensional imaging and storage, Optical temperature sensing system, Dental and other biophysical applications, Up-conversion fluorescence anti-counterfeiting, Up-conversion broadband light source, and Up-conversion infrared display, etc.Promoted by the demand for solar cells, up-conversion research has once again shown a surging upsurge of research. Current, using the near field enhancement effect of metal surface Plasmon resonance can effectively enhance the luminescent properties of fluorescent substances near its surface. It is possible to increase the intensity of upconversion luminescence by a considerable margin. Thus, it is possible to promote up-conversion luminescence to practical use further. We use the ion introduction method to introduce silver particles into bismuth luminescent glass. Experimental results show that the surface Plasmon resonance absorption peak of silver surface Plasmon is positioned at about 580～600 nm. Moreover, the prolongation of heating time leads to a sharp enhancement and a slight blue shift of the surface Plasmon absorption peak. Subsequently, we find that three groups two-photon upconversion fluorescence of 531.0 nm 2H11/2→4I15/2, 546.0 nm 4S3/2→4I15/2, and 657.5 nm 4F9/2→4I15/2of Er3+ ions can be induced by the 978 nm laser. Upconversion luminescence mechanism, when erbium doped bismuth luminescent glass excited by 978 nm laser, is the first step 4I15/2→4I11/2resonance ground state absorption and the second step 4I11/2→4F7/2 resonance excited state absorption. The introduction of silver nano surface Plasmon facilitates that the maximum enhancement of upconversion luminescence is 272.0% times bigger in bismuth glass, when excited by 978 nm laser. Finally, the 1 539 nm laser can induce four groups upconversion fluorescence of 528.0 nm 2H11/2→4I15/2, 547.0 nm 4S3/2→4I15/2, 657.0 nm 4F9/2→4I15/2, and 795.0 nm 4I9/2→4I15/2 of Er3+ ion. The mechanism of 528.0 nm 2H11/2→4I15/2 and 547.0 nm 4S3/2→4I15/2 upconversion luminescence is mainly 4I15/2→4I13/2, 4I13/2→4I9/2, and 4I9/2→2H11/2three-step photo-excited absorption transition process of 1539 nm laser. The mechanism of 657.0 nm 4F9/2→4I15/2 upconversion fluorescence is mainly the 4I15/2→4I13/2, 4I13/2→4I9/2, and 4I11/2→4F9/2 three-step photo-excited absorption transition process of 1 539 nm laser. Furthermore, the introduction of silver nano surface Plasmon induces that the maximum enhancement of up-conversion luminescenceof Er3+ ionstimulated by 1 539 nm laser is 160.3% times bigger in bismuth glass. Obviously, the enhancement effect of 978 nm laser upconversion, which is near the resonance absorption peak of silver surface Plasmon, is better than that of 1 539 nm laser upconversion.