Programa de Pós-Graduação em Ciências de Materiais, Universidade Federal de Pernambuco, Recife, 50670-901, PE, Brazil.
Pós-Graduação em Ciência dos Materiais, Universidade Federal do Vale do São Francisco, 48902-300, Juazeiro, BA, Brazil.
Sci Rep. 2019 Aug 13;9(1):11765. doi: 10.1038/s41598-019-48056-w.
We report an alternative random laser (RL) architecture based on a flexible and ZnO-enriched cellulose acetate (CA) fiber matrix prepared by electrospinning. The electrospun fibers, mechanically reinforced by polyethylene oxide and impregnated with zinc oxide powder, were applied as an adsorbent surface to incorporate plasmonic centers (silver nanoprisms). The resulting structures - prepared in the absence (CA-ZnO) and in the presence of silver nanoparticles (CA-ZnO-Ag) - were developed to support light excitation, guiding and scattering prototypes of a RL. Both materials were excited by a pulsed (5 Hz, 5 ns) source at 355 nm and their fluorescence emission monitored at 387 nm. The results suggest that the addition of silver nanoprisms to the ZnO- enriched fiber matrix allows large improvement of the RL performance due to the plasmon resonance of the silver nanoprisms, with ~80% reduction in threshold energy. Besides the intensity and spectral analysis, the RL characterization included its spectral and intensity angular dependences. Bending the flexible RL did not affect the spectral characteristics of the device. No degradation was observed in the random laser emission for more than 10,000 shots of the pump laser.
我们报告了一种基于灵活且富含氧化锌的醋酸纤维素 (CA) 纤维基质的替代随机激光 (RL) 架构，该纤维基质通过静电纺丝制备而成。通过静电纺丝制备的纤维由聚氧化乙烯机械增强，并浸渍氧化锌粉末，作为吸附剂表面来结合等离子体中心（银纳米棱镜）。所得到的结构 - 在没有（CA-ZnO）和存在银纳米粒子的情况下制备（CA-ZnO-Ag） - 被开发为支持 RL 的光激发、引导和散射原型。这两种材料均由 355nm 的脉冲（5Hz，5ns）源激发，并在 387nm 处监测荧光发射。结果表明，由于银纳米棱镜的等离子体共振，将银纳米棱镜添加到富含氧化锌的纤维基质中可以大大提高 RL 的性能，其阈值能量降低了约 80%。除了强度和光谱分析外，RL 的特征还包括其光谱和强度角依赖性。弯曲柔性 RL 不会影响器件的光谱特性。在泵浦激光的 10000 多次照射下，随机激光发射没有观察到任何退化。
