Spatially selective modification of optical and magneto-optical properties in Fe- and Au-doped glasses irradiated with femtsecond-laser
Spatially selective modification of optical and magneto-optical properties in Fe- and Au-doped glasses irradiated with femtsecond-laser
复制标题
飞秒激光照射下铁和金掺杂玻璃的光学和磁光性质的空间选择性修饰
DOI：
10.1007/s00339-012-7150-9
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Kohki Mukai
中科院分区：
文献类型：
--
作者：
Seisuke Nakashima;Koji Sugioka;Katsumi Midorikawa;Kohki Mukai
采用红外飞秒激光辐照和退火的方法，对掺Fe ~（3+）和Au ~（3+）的透明玻璃进行了光学性质和磁光响应的空间选择性改性。该辐照过程不仅诱导磁性尖晶石型Fe-氧化物纳米颗粒的沉淀，而且诱导玻璃内部的Au纳米颗粒的沉淀，其在大于500 nm的波长处显示局部表面等离子体共振吸收。随着退火时间的延长和温度的升高，LSPR峰的位置发生红移，这是由于Au纳米颗粒的生长。测量了作为波长函数的法拉第旋转角，并且差谱显示出明显的正峰，表明由于Au纳米颗粒和基质玻璃的抗磁性之间的LSPR耦合是有效的。为了减少与抗磁性玻璃的耦合，在用fs-激光照射后进行两步退火过程（在450 °C下90分钟和在550 °C下30分钟）。在较低温度下的预退火有助于亚铁磁性磁铁矿纳米颗粒的沉淀。随后通过在550 °C下退火来生长Au纳米颗粒。在这种情况下，与单一退火过程相比，LSPR和亚铁磁性纳米颗粒之间的有效耦合显著抑制了法拉第光谱中的正峰的强度。
The optical property and the magneto-optical response were space-selectively modified in transparent Fe3+- and Au3+-doped glasses by using infrared femtosecond- (fs-) laser irradiation and subsequent annealing. This irradiation process induces the precipitation of not only magnetic spinel-type Fe-oxide nanoparticles but also Au nanoparticles inside the glasses, which shows localized surface plasmon resonance absorption at the wavelengths larger than 500 nm. As the annealing time and the temperature increases, the position of the LSPR peaks exhibits red shifts, which is due to the growth of Au nanoparticles. Faraday rotation angles as a function of wavelength were measured, and the difference spectra exhibit distinct positive peaks, indicating that the coupling between the LSPR due to the Au nanoparticles and the diamagnetism of the matrix glass is effective. To decrease the coupling with the diamagnetic glass, a two-step annealing process (at 450 °C for 90 min and at 550 °C for 30 min) was carried out after irradiation with fs-laser. The preliminary annealing at the lower temperature contributes to the precipitation of ferrimagnetic magnetite nanoparticles. Au nanoparticles were subsequently grown by annealing at 550 °C. In this case, effective coupling between the LSPR and ferrimagnetic nanoparticles has significantly suppressed the intensity of the positive peak in the Faraday spectra compared with the single annealing process.