Gao Maodong, Yang Qi-Fan, Ji Qing-Xin, Wang Heming, Wu Lue, Shen Boqiang, Liu Junqiu, Huang Guanhao, Chang Lin, Xie Weiqiang, Yu Su-Peng, Papp Scott B, Bowers John E, Kippenberg Tobias J, Vahala Kerry J
T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, 91125, USA.
Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, CH-1015, Switzerland.
Nat Commun. 2022 Jun 9;13(1):3323. doi: 10.1038/s41467-022-30966-5.
Optical microresonators with high quality (Q) factors are essential to a wide range of integrated photonic devices. Steady efforts have been directed towards increasing microresonator Q factors across a variety of platforms. With success in reducing microfabrication process-related optical loss as a limitation of Q, the ultimate attainable Q, as determined solely by the constituent microresonator material absorption, has come into focus. Here, we report measurements of the material-limited Q factors in several photonic material platforms. High-Q microresonators are fabricated from thin films of SiO, SiN, AlGaAs, and TaO. By using cavity-enhanced photothermal spectroscopy, the material-limited Q is determined. The method simultaneously measures the Kerr nonlinearity in each material and reveals how material nonlinearity and ultimate Q vary in a complementary fashion across photonic materials. Besides guiding microresonator design and material development in four material platforms, the results help establish performance limits in future photonic integrated systems.
高品质（Q）因数的光学微谐振器对于广泛的集成光子器件至关重要。人们一直在不断努力提高各种平台上微谐振器的Q因数。随着成功减少与微加工工艺相关的光学损耗这一限制Q的因素，仅由构成微谐振器的材料吸收所决定的最终可达到的Q因数已成为关注焦点。在此，我们报告了几种光子材料平台中材料限制的Q因数的测量结果。高Q微谐振器由SiO、SiN、AlGaAs和TaO薄膜制成。通过使用腔增强光热光谱法，确定了材料限制的Q。该方法同时测量了每种材料中的克尔非线性，并揭示了材料非线性和最终Q如何在光子材料中以互补方式变化。除了指导四个材料平台中的微谐振器设计和材料开发外，这些结果有助于确定未来光子集成系统的性能极限。
