AI 中文总结
该研究提出一种混合超表面-布拉格镜设计，结合多种结构并考虑加工效应，实现高反射率、低非反射功率与低热噪声，适配精密光学及引力波测试台需求。
AI 中文摘要
用于精密干涉测量的高反射率涂层必须同时最小化光学损耗和热驱动位移噪声。介质布拉格镜可提供稳定的高反射率，但依赖厚多层涂层；超表面镜虽兼具高反射率和低噪声，但对加工引起的偏差敏感。本文提出一种可加工混合镜概念，结合共振单层超表面、刻蚀停止层、反共振间隔层和简化布拉格反射镜，在光学设计中明确考虑几何容差和线边粗糙度等加工效应。将全波电磁模拟与截断高斯蒙特卡洛分析结合，确定假设加工条件下的性能分布：理想超表面设计反射率超99.999%；经粗糙度感知再优化后，95%加工良率下建模非反射功率低于2.88×10⁻⁴；针对低温ETpathfinder引力波测试台，3对布拉格层使完整堆叠的非反射功率降至约6.4ppm；100Hz处热位移噪声振幅谱密度估计为8.4×10⁻²¹ m·Hz⁻¹/²。该架构在单一设计框架内实现了加工稳健性、光学性能与热噪声降低的结合。
英文摘要
High-reflectivity coatings for precision interferometry must simultaneously minimize optical losses and thermally driven displacement noise. Dielectric Bragg mirrors provide robust high reflectance but rely on thick multilayer coatings, whereas metasurface mirrors provide high reflectance and low noise but are sensitive to fabrication-induced deviations. A fabrication-aware hybrid mirror concept is introduced that combines a resonant single-layer metasurface, an etch-stop layer, an antiresonant spacer, and a reduced Bragg reflector. Fabrication effects, including geometric tolerances and line-edge roughness, are explicitly considered in the optical design. Full-wave electromagnetic simulations are combined with a truncated-Gaussian Monte Carlo analysis to determine the performance distribution under the assumed fabrication conditions. The ideal metasurface design achieves a modeled non-reflected power of $1-R<10^{-5}$. After roughness-aware reoptimization, the modeled non-reflected power remains below $1.04\cdot10^{-4}$ at $80\%$ fabrication yield. For the cryogenic ETpathfinder gravitational-wave testbed, two Bragg layer pairs reduce the non-reflected power of the complete stack to approximately $6.6\,\mathrm{ppm}$. The estimated thermal displacement-noise amplitude spectral density is $1.97\cdot10^{-20}\,\mathrm{m/\sqrt{Hz}}$ at $100\,\mathrm{Hz}$. The architecture connects fabrication robustness, optical performance, and thermal-noise reduction within a single design framework.
Comments19 pages, 7 figures, 2 tables
