Bai Jing, Cheng Guanghua, Long Xuewen, Wang Yishan, Zhao Wei, Chen Guofu, Stoian Razvan, Hui Rongqing
State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China.
Opt Express. 2012 Jul 2;20(14):15035-44. doi: 10.1364/OE.20.015035.
Ultrashort pulsed laser photoinscription of Ti:Sapphire crystals may result in the self-organization of nanoscale material redistribution regions in regular patterns within the laser trace and stress-induced birefringence around the laser trace. We report on the formation of anisotropic optical waveguides in Ti:Sapphire by a procedure that involves femtosecond laser inscription of adjacent nonguiding birefringent traces with nanopatterned crosssections and the accumulation of stress birefringence in the region between. Double parallel line structures with a separation of 25μm with vertical and horizontal nanoscale arrangements were written with a choice of orthogonal polarizations. Due to anisotropic light scattering on periodic nanostructures and stress-induced birefringence in the central zone, remarkable polarization dependent guiding effects were observed as a function of the microscopic geometry of the structures. Building on this polarization sensitivity, several structure such as 3 × 3 waveguide arrays, diamond and hexagon patterns are also investigated.
钛宝石晶体的超短脉冲激光光写入可能会导致纳米级材料再分布区域在激光轨迹内以规则图案自组织，并在激光轨迹周围产生应力诱导双折射。我们报道了通过一种方法在钛宝石中形成各向异性光波导，该方法包括用具有纳米图案横截面的相邻非导向双折射轨迹进行飞秒激光写入，以及在其间区域积累应力双折射。选择正交偏振，写入了间距为25μm、具有垂直和水平纳米级排列的双平行线结构。由于周期性纳米结构上的各向异性光散射以及中心区域的应力诱导双折射，观察到了与结构微观几何形状有关的显著偏振相关导光效应。基于这种偏振敏感性，还研究了几种结构，如3×3光波导阵列、菱形和六边形图案。
