Materials Science Institute, Engineering Department, Lancaster University, Lancaster LA1 4YW, UK.
Nanotechnology. 2016 Oct 28;27(43):435703. doi: 10.1088/0957-4484/27/43/435703. Epub 2016 Sep 23.
Spherical silver nanoparticles (NPs) of 30 nm diameter embedded in soda-lime glass were uniformly reshaped (elongated) after irradiation by a linearly polarised 250 fs pulsed laser operating within the NPs' surface plasmon resonance band. We observed second harmonic generation (SHG) and multiphoton-absorption-induced luminescence (MAIL) in the embedded laser-reshaped NPs upon picosecond (10 ps) pulsed laser excitation at 1064 nm. A complementary study of SHG and MAIL was conducted in soda-lime glass containing embedded, mechanically-reshaped silver NPs of a similar elongation ratio (aspect ratio) to the laser-reshaped NPs. This supports the notion that the observed difference in SHG and MAIL in the studied nanocomposite systems is due to the shape modification mechanism. The discrete dipole approximation method was used to assess the absorption and scattering cross-sections of the reshaped NPs with different elongation ratios.
嵌入在钠钙玻璃中的 30nm 直径的球形银纳米粒子（NPs）在其表面等离子体共振带内的线性偏振 250fs 脉冲激光照射下均匀地被重塑（拉长）。我们在纳秒（10ps）1064nm 脉冲激光激发下观察到嵌入的激光重塑 NPs 中的二次谐波产生（SHG）和多光子吸收诱导发光（MAIL）。在含有嵌入的机械重塑银 NPs 的钠钙玻璃中进行了 SHG 和 MAIL 的补充研究，这些银 NPs 的拉长比（纵横比）与激光重塑的 NPs 相似。这支持了这样一种观点，即在研究的纳米复合材料系统中观察到的 SHG 和 MAIL 的差异是由于形状修改机制。离散偶极子近似法被用来评估具有不同伸长比的重塑 NPs 的吸收和散射截面。
