Nanotechnology Department, Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover, Germany.
Nat Commun. 2014 Mar 4;5:3402. doi: 10.1038/ncomms4402.
Silicon nanoparticles with sizes of a few hundred nanometres exhibit unique optical properties due to their strong electric and magnetic dipole responses in the visible range. Here we demonstrate a novel laser printing technique for the controlled fabrication and precise deposition of silicon nanoparticles. Using femtosecond laser pulses it is possible to vary the size of Si nanoparticles and their crystallographic phase. Si nanoparticles produced by femtosecond laser printing are initially in an amorphous phase (a-Si). They can be converted into the crystalline phase (c-Si) by irradiating them with a second femtosecond laser pulse. The resonance-scattering spectrum of c-Si nanoparticles, compared with that of a-Si nanoparticles, is blue shifted and its peak intensity is about three times higher. Resonant optical responses of dielectric nanoparticles are characterized by accumulation of electromagnetic energy in the excited modes, which can be used for the realization of nanoantennas, nanolasers and metamaterials.
由于在可见光谱范围内具有强烈的电偶极子和磁偶极子响应，尺寸为数百纳米的硅纳米粒子表现出独特的光学性质。在这里，我们展示了一种用于控制制造和精确沉积硅纳米粒子的新型激光打印技术。使用飞秒激光脉冲，可以改变 Si 纳米粒子的尺寸及其晶相。飞秒激光打印产生的 Si 纳米粒子最初处于非晶相（a-Si）。通过用第二束飞秒激光脉冲照射它们，可以将它们转化为晶相（c-Si）。与 a-Si 纳米粒子相比，c-Si 纳米粒子的共振散射光谱蓝移，其峰值强度约高三倍。介电纳米粒子的共振光学响应的特征在于在激发模式中积累电磁能，这可用于实现纳米天线、纳米激光器和超材料。
