一种二元整形元件激光直写方法的实验研究

为了实现具有复杂位相结构的二元光束整形元件，提出了采用方光点的激光直写系统来逐点光刻浮雕位相结构的方法，通过双远心投影缩微光路获得5-20 μm方点，光点尺寸对应于最小位相单元，从而获得了位相结构的高质量直写.分析了高斯光点和方光点位相单元结构对二元整形元件衍射效率的影响，方形两台阶二元整形元件的+1级衍射效率达到31%，给出了实验结果.     

Facile preparation of silver nanoparticles in bulk silicate glass by high-repetition-rate picosecond laser pulses

One-step precipitation of Ag nanoparticles in Ag+-doped silicate glasses was achieved through a focused picosecond laser with a high repetition rate. Absorption spectra and transmission electron microscopy(TEM) confirmed that metallic Ag nanoparticles were precipitated within glass samples in the laser-written domain. The surface plasmon absorbance fits well with the experimental absorption spectrum. The nonlinear absorption coefficient β is determined to be 2.47 × 10-14 m/W by fitting the open aperture Z-scan curve, which originated from the intraband transition in the s-p Ag band. The formation mechanism of Ag-glass nanocomposites is discussed as well.