Optical absorption measurement at 1550 nm on a highly-reflective Si/SiO2 coating stack
Optical absorption measurement at 1550 nm on a highly-reflective Si/SiO2 coating stack
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在高反射 Si/SiO2 涂层堆栈上进行 1550 nm 光吸收测量
DOI：
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
R. Schnabel
中科院分区：
文献类型：
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作者：
J. Steinlechner;A. Khalaidovski;R. Schnabel
未来的激光干涉引力波探测器（GWD）将可能采用来自晶体硅的测试质量镜和1550 nm的激光波长，这对应于硅带隙以下的光子能量。硅也可能是一种有吸引力的高折射率材料的介质镜涂层。然而，已经发现非晶硅（a-Si）的膜在1550 nm处比晶体硅（c-Si）明显更有吸收性。在这里，我们调查的光吸收的Si/SiO2电介质涂层与离子镀技术生产。离子镀技术不同于标准的现有技术的离子束溅射技术，因为其使用约250 °C的较高处理温度、较高粒子能量，并且通常导致沉积膜的较高折射率。我们的涂层堆叠被制造为对于1550 nm处的s偏振光和44°的入射角具有R = 99.95%的反射率。利用光热自相位调制技术测量了薄膜在s偏振和p偏振方向的吸收。αs coat =（1035±42）ppm？αp coat =（1428±97）ppm。这些结果对应于低于a-Si的文献值的吸收系数，a-Si的文献值从100 cm-1变化到2000 cm-1。然而，它仍然比c-Si的预期高几个数量级，因此对于GWD应用仍然太高。
Future laser-interferometric gravitational wave detectors (GWDs) will potentially employ test mass mirrors from crystalline silicon and a laser wavelength of 1550 nm, which corresponds to a photon energy below the silicon bandgap. Silicon might also be an attractive high-refractive index material for the dielectric mirror coatings. Films of amorphous silicon (a-Si), however, have been found to be significantly more absorptive at 1550 nm than crystalline silicon (c-Si). Here, we investigate the optical absorption of a Si/SiO2 dielectric coating produced with the ion plating technique. The ion plating technique is distinct from the standard state-of-the-art ion beam sputtering technique since it uses a higher processing temperature of about 250 °C, higher particle energies, and generally results in higher refractive indices of the deposited films. Our coating stack was fabricated for a reflectivity of R = 99.95% for s-polarized light at 1550 nm and for an angle of incidence of 44°. We used the photothermal self-phase modulation technique to measure the coating absorption in s-polarization and p-polarization. We obtained αs coat =(1035±42) ppm ?> and αp coat =(1428±97) ppm ?>. These results correspond to an absorption coefficient which is lower than literature values for a-Si which vary from 100 cm−1 up to 2000 cm−1. It is, however, still orders of magnitude higher than expected for c-Si and thus still too high for GWD applications.
1550 nm 晶体硅测试质量中主要表面吸收的指示
影响因子：
3.5
作者：
A. Khalaidovski;J. Steinlechner;R. Schnabel
通讯作者：
R. Schnabel
TiO2 掺杂单层 Ta2O5 低温机械耗散峰的测量
影响因子：
3.5
作者：
I. Martin;H. Armandula;C. Comtet;M. M. Fejer;A. Gretarsson;G. Harry;J. Hough;J. M. M. Mackowski;I. MacLaren;C. Michel;J. L. Montorio;N. Morgado;R. Nawrodt;S. Penn;S. Reid;A. Remillieux;R. Route;S. Rowan;C. Schwarz;P. Seidel;W. Vodel
通讯作者：
W. Vodel