A high-aspect-ratio microstructure in polycrystalline Zinc selenide (ZnSe) is important for waveguides and photonic crystals application. In this work, we demonstrated a successful approach for fabricating microstructure with Bessel beam inscription and etching using a mixed solution of hydrogen peroxide (H₂O₂) and ammonia hydroxide (NH₄OH). The microstructure inscribed using the femtosecond laser back-side fabrication and selective etching, has a longitudinal length of 140 μm and a width of 12 μm. The aspect ratio of microstructures is ∼ 11.2. To showcase the potential of this technique, a rib waveguide with a longitudinal length and width of 60 μm was prepared and the rib waveguides supported a well confined mode at 1.55 μm. This process makes it possible to produce three-dimensional microstructures inside polycrystalline ZnSe, and thus offers a pathway for expanding the photonic crystal structure to the mid-to-far infrared field.

多晶硒化锌 (ZnSe) 中的高纵横比微结构对于波导和光子晶体应用很重要。在这项工作中，我们展示了一种使用过氧化氢 (H ₂ O ₂ ) 和氢氧化氨 (NH ₄哦）。使用飞秒激光背面制造和选择性蚀刻内切的微结构，纵向长度为 140 μm，宽度为 12 μm。微结构的纵横比为～11.2。为了展示该技术的潜力，制备了纵向长度和宽度为 60 μm 的肋形波导，并且肋形波导支持 1.55 μm 的良好限制模式。该过程使得在多晶 ZnSe 内部产生三维微结构成为可能，从而为将光子晶体结构扩展到中远红外领域提供了途径。