Hydrogen-Induced Ultralow Optical Absorption and Mechanical Loss in Amorphous Silicon for Gravitational-Wave Detectors
Hydrogen-Induced Ultralow Optical Absorption and Mechanical Loss in Amorphous Silicon for Gravitational-Wave Detectors
复制标题
用于引力波探测器的非晶硅中氢致超低光吸收和机械损耗
DOI：
10.1103/physrevlett.131.256902
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发表时间：
2023
影响因子：
8.6
通讯作者：
Hellman, F.
中科院分区：
文献类型：
--
作者：
Molina-Ruiz, M.;Markosyan, A.;Bassiri, R.;Fejer, M. M.;Abernathy, M.;Metcalf, T. H.;Liu, X.;Vajente, G.;Ananyeva, A.;Hellman, F.
引力波探测器的灵敏度受到探测器反射镜非晶涂层相关机械损耗的限制。非晶硅比目前的高折射率涂层具有更高的折射率和更低的机械损耗，但目前其在探测器所用波长处的光吸收很大。在非晶硅网络中添加氢可降低在所有测量波长和温度下在一系列条件下制备的薄膜的光学吸收和机械损失，这对在室温下生长的薄膜影响特别大。在室温下生长的薄膜中氢的吸收量最大，但仍低于 1.5 at.% H，这表明在 2000 nm 处测量 500 nm 厚的薄膜具有超低光学吸收（低于 10 ppm）。这些结果表明，氢化是减少非晶硅光学吸收和机械损失的一种有前景的策略，并且可以为引力波探测器制造镜面涂层，提高灵敏度。
The sensitivity of gravitational-wave detectors is limited by the mechanical loss associated with the amorphous coatings of the detectors’ mirrors. Amorphous silicon has higher refraction index and lower mechanical loss than current high-index coatings, but its optical absorption at the wavelength used for the detectors is at present large. The addition of hydrogen to the amorphous silicon network reduces both optical absorption and mechanical loss for films prepared under a range of conditions at all measured wavelengths and temperatures, with a particularly large effect on films grown at room temperature. The uptake of hydrogen is greatest in the films grown at room temperature, but still below 1.5 at.% H, which show an ultralow optical absorption (below 10 ppm) measured at 2000 nm for 500-nm-thick films. These results show that hydrogenation is a promising strategy to reduce both optical absorption and mechanical loss in amorphous silicon, and may enable fabrication of mirror coatings for gravitational-wave detectors with improved sensitivity.