Rewritable and Tunable Laser-Induced Optical Gratings in Phase-Change Material Films.
Rewritable and Tunable Laser-Induced Optical Gratings in Phase-Change Material Films.
复制标题
相变材料薄膜中的可重写和可调谐激光诱导光栅。
DOI：
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发表时间：
2021
影响因子：
9.5
通讯作者：
I. Sinev
中科院分区：
文献类型：
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作者：
P. I. Trofimov;I. Bessonova;P. Lazarenko;D. A. Kirilenko;N. Bert;S. Kozyukhin;I. Sinev
激光诱导周期性表面结构 (LIPSS) 几乎可以在所有类型的固体材料中制造，并在高效、可扩展地生产表面图案方面展现出巨大的前景，并应用于从光子学到工程的各个领域。虽然大多数 LIPSS 表现为表面浮雕的修改，但在特殊情况下，激光冲击也可能导致材料相状态的周期性调制。在这里，我们报告了在相变材料 Ge2Sb2Te5 (GST) 薄膜中制造高质量周期性结构的情况。由于晶态和非晶态 GST 的折射率具有相当大的对比度，所制造的结构提供了光学特性的强空间调制，这有利于它们的应用。通过改变激发激光波长，我们观察到光栅周期的缩放以及不同类型 LIPSS 形成之间的过渡。我们优化了激光曝光程序，以实现周期可控的大规模高质量相变光栅，并通过中间非晶化步骤证明了其可逆可调性。我们的研究结果揭示了快速、可重写制造光子学高质量周期性结构的前景，并且可以作为进一步开发基于相变材料的光学元件的指南。
Laser-induced periodic surface structures (LIPSS) can be fabricated in virtually all types of solid materials and show great promise for efficient and scalable production of surface patterns with applications in various fields from photonics to engineering. While the majority of LIPSS manifest as modifications of the surface relief, in special cases, laser impact can also lead to periodic modulation of the material phase state. Here, we report on the fabrication of high-quality periodic structures in the films of phase-change material Ge2Sb2Te5 (GST). Due to considerable contrast of the refractive index of GST in its crystalline and amorphous states, the fabricated structures provide strong spatial modulation of the optical properties, which facilitates their applications. By changing the excitation laser wavelength, we observe the scaling of the grating period as well as transition between formation of different types of LIPSS. We optimize the laser exposure routine to achieve large-scale high-quality phase-change gratings with controllable period and demonstrate their reversible tunability through intermediate amorphization steps. Our results reveal the prospects of fast and rewritable fabrication of high-quality periodic structures for photonics and can serve as a guideline for further development of phase-change material-based optical elements.