Grating waveguide structures (GWS) are reflective diffractive optical elements that operate based on the combination of sub-wavelength gratings (periodic microstructures) integrated with planar waveguides. They can be used for high-power laser applications for pulse compression, spectral stabilization, wavelength multiplexing, as well as polarization shaping. In this work, we investigate the laser-damage resistance of GWS based on Ta 2 O 5 /SiO 2 multilayers at pulse durations of 500 fs and wavelength of 1030 nm. We particularly study the influence of the material of the multilayer sequence, the designed grating structure, and the operational conditions (angle of incidence and polarization of the laser beam) on the laser-damage resistance of the GWS. Comparison of measurements to simulation of the electric-field distribution in the structure reveals a good correlation between laser-induced damage threshold (LIDT) values and electric-field enhancement in the structure. Based on this work, an optimized design has been defined to increase the LIDT of the GWS. An improvement of the LIDT of a factor 2 has been obtained.

中文翻译：

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亚皮秒脉冲对光栅波导结构的激光损伤研究

光栅波导结构 (GWS) 是基于与平面波导集成的亚波长光栅（周期性微结构）的组合工作的反射衍射光学元件。它们可用于脉冲压缩、光谱稳定、波长复用以及偏振整形的高功率激光应用。在这项工作中，我们研究了基于 Ta 2 O 5 /SiO 2 多层膜的 GWS 在 500 fs 的脉冲持续时间和 1030 nm 的波长下的抗激光损伤性。我们特别研究了多层序列的材料、设计的光栅结构和工作条件（激光束的入射角和偏振）对 GWS 抗激光损伤的影响。将测量值与结构中电场分布的模拟进行比较，揭示了激光诱导损伤阈值 (LIDT) 值与结构中的电场增强之间存在良好的相关性。基于这项工作，定义了优化设计以增加 GWS 的 LIDT。LIDT 提高了 2 倍。