In this paper, we report an approach for tuning the surface morphology and phase of Ge2Sb2Te5 (GST) by using an ultrafast laser in a one-step process. Four surface micro/nanostructures with specific phase states were sequentially formed by changing the pulse energy: the modified ripple structure, the completely crystallized structure, the ablated nanodots, and the ablated ripple structure. A high correlation existed between the surface micro/nanostructures and their property. Through integrated property–structure modulation, multifunctional optical recording could be achieved by using modified ripples with specific crystallized phase states. The geometric grating morphology caused by the volume shrinkage effect during crystallization enabled modified ripples to exhibit a structural color based on the grating’s diffraction effect. Moreover, the considerable change in the reflectivity of the crystallized area enabled easy grayscale identification. On the basis of the spatially resolved phase-transition threshold effect, the integrated modulation of the geometric nanograting proportion and degree of crystallization was conducted in multilevel states. Notably, different from the fixed ablated surface structures, the printed modified surface structures could be erased and rewritten by controlling its phase state. This paper presents a promising method for producing dynamic tunable metasurfaces, conducting optical anticounterfeiting, and achieving information storage.

中文翻译：

---

用于多功能和多级可重写光学记录的 Ge2Sb2Te5 的超快激光诱导综合性质结构调制

在本文中，我们报告了一种调整 Ge 表面形态和相位的方法2锑2碲5(GST) 通过在一步工艺中使用超快激光。通过改变脉冲能量依次形成四种具有特定相态的表面微/纳米结构：改性波纹结构、完全结晶结构、烧蚀纳米点和烧蚀波纹结构。表面微/纳米结构与其性质之间存在高度相关性。通过集成的属性-结构调制，可以通过使用具有特定结晶相态的修改波纹来实现多功能光学记录。结晶过程中由体积收缩效应引起的几何光栅形貌使修改后的波纹呈现出基于光栅衍射效应的结构颜色。而且，结晶区域反射率的显着变化使灰度识别变得容易。在空间分辨相变阈值效应的基础上，对几何纳米光栅的比例和结晶度进行了多能级的综合调制。值得注意的是，与固定烧蚀表面结构不同，印刷的改性表面结构可以通过控制其相态来擦除和重写。本文提出了一种用于生产动态可调超表面、进行光学防伪和实现信息存储的有前景的方法。与固定的烧蚀表面结构不同，印刷的改性表面结构可以通过控制其相态进行擦除和重写。本文提出了一种用于生产动态可调超表面、进行光学防伪和实现信息存储的有前景的方法。与固定的烧蚀表面结构不同，印刷的改性表面结构可以通过控制其相态进行擦除和重写。本文提出了一种用于生产动态可调超表面、进行光学防伪和实现信息存储的有前景的方法。