Herein, finite‐element analysis is used to optimize the performance of mid‐infrared (MIR) (7.7–13.7 μm) waveguides by selecting optimal waveguide and substrate materials, waveguide size, and boundary field. The results show that a diamond waveguide has a substantially higher sensitivity than Si‐ or Ge‐based waveguides owing to its higher boundary evanescent field at the same depth. Furthermore, it is found that AlN substrates have better optical stabilities than SiO₂ and Si₃N₄ substrates, because AlN substrates do not have apparent absorption characteristics in the MIR range (7.7–13.7 μm). Geometry of diamond waveguide on AlN substrate is optimized, and a section length of 45 μm is chosen for optimal signal transmission quality. The calculations of the infrared attenuated total reflection (ATR) of the diamond waveguide applied to water, alcohol, and diisopropyl methyl phosphate are highly consistent with the actual infrared absorption spectrum. This proves the feasibility of applying AlN/diamond waveguides in MIR ATR detection, which is of great significance for the preparation of high‐sensitivity MIR detectors.

中文翻译：

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基于金刚石的中红外传感器的设计和性能

在此，通过选择最佳波导和基板材料，波导尺寸和边界场，使用有限元分析来优化中红外（MIR）（7.7-13.7μm）波导的性能。结果表明，由于在相同深度具有更高的边界渐逝场，金刚石波导比基于硅或锗的波导具有更高的灵敏度。此外，发现AlN衬底具有比SiO ₂和Si ₃ N ₄更好的光学稳定性。因为AlN衬底在MIR范围（7.7-13.7μm）中没有明显的吸收特性，因此不适合使用。优化了AlN衬底上金刚石波导的几何形状，并选择了45μm的截面长度以实现最佳信号传输质量。应用于水，酒精和磷酸二异丙酯甲酯的金刚石波导的红外衰减全反射（ATR）的计算与实际的红外吸收光谱高度一致。这证明了将AlN /金刚石波导应用于MIR ATR检测的可行性，这对制备高灵敏度MIR检测器具有重要意义。