Probing material absorption and optical nonlinearity of integrated photonic materials
Abstract
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 SiO2, Si3N4, Al0.2Ga0.8As, and Ta2O5. 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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 09, 2022
- Source ID
- 10.1038/s41467-022-30966-5
Entities
People
- Boqiang Shen
- Guanhao Huang
- Heming Wang
- John E. Bowers
- Junqiu Liu
- Kerry Vahala
- Lin Chang
- Lue Wu
- Maodong Gao
- Qi-Fan Yang
- Qing-Xin Ji
- Scott B. Papp
- Su-Peng Yu
- Tobias Kippenberg
- Weiqiang Xie
Organizations
- United States Department of Defense