Fernandez T Toney, Gross Simon, Arriola Alexander, Privat Karen, Withford Michael J
Opt Express. 2020 Mar 30;28(7):10153-10164. doi: 10.1364/OE.387790.
Alkali-free borosilicate glasses are one of the most used dielectric platforms for ultrafast laser inscribed integrated photonics. Femtosecond laser written waveguides in commercial Corning Eagle 2000, Corning Eagle XG and Schott AF32 glasses were analyzed. They were studied in depth to disclose the dynamics of waveguide formation. We believe that the findings presented in this paper will help bridge one of the major and important gaps in understanding the ultrafast light-matter interaction with alkali-free boroaluminosilicate glass. It was found that the waveguides are formed mainly due to structural and elemental reorganization upon laser inscription. Aluminum along with alkaline earth metals were found to be responsible for the densification and silicon being the exchanging element to form a rarefied zone. Strong affinity towards alkaline earth elements to form the densified zone for waveguides written with high feed rate (>200 mm/min) were identified and explained. Finally we propose a plausible solution to form positive refractive index change waveguides in different glasses based on current and previous reports.
无碱硼硅酸盐玻璃是超快激光写入集成光子学中最常用的介电平台之一。对飞秒激光写入商业康宁Eagle 2000、康宁Eagle XG和肖特AF32玻璃中的波导进行了分析。对它们进行了深入研究以揭示波导形成的动力学。我们相信本文所呈现的研究结果将有助于填补在理解超快光与无碱硼铝硅酸盐玻璃相互作用方面的一个主要且重要的空白。研究发现，波导的形成主要是由于激光写入时的结构和元素重组。发现铝与碱土金属共同导致了致密化，而硅是形成稀薄区域的交换元素。确定并解释了碱土元素对以高进给速度（>200 mm/min）写入的波导形成致密区域具有很强的亲和力。最后，基于当前和以往的报道，我们提出了一种在不同玻璃中形成正折射率变化波导的可行解决方案。
