The rapid development of high-Q macroscopic mechanical resonators has enabled great advances in optomechanics. Further improvements could allow for quantum-limited or quantum-enhanced applications at ambient temperature. Some of the remaining challenges include the integration of high-Q structures on a chip, while simultaneously achieving large coupling strengths through an optical read-out. Here, we present a versatile fabrication method, which allows us to build fully integrated optomechanical structures. We place a photonic crystal cavity directly above a mechanical resonator with high-Q fundamental out-of-plane mode, separated by a small gap. The highly confined optical field has a large overlap with the mechanical mode, enabling strong optomechanical interaction strengths. Furthermore, we implement a novel photonic crystal design, which allows for a very large cavity photon number, a highly important feature for optomechanical experiments and sensor applications. Our versatile approach is not limited to our particular design but allows for integrating an out-of-plane optical read-out into almost any device layout. Additionally, it can be scaled to large arrays and paves the way to realizing quantum experiments and applications with mechanical resonators based on high-Q out-of-plane modes alike.
Telecom-Integrated Photonic Memory Operating Near the Mechanical Ground State
University of Electronic Science and Technology of China（电子科技大学）；Southwest Jiaotong University（西南交通大学）；Xihua University（西华大学）；Southwest Institute of Technical Physics（西南技术物理研究所）；University of Science and Technology of China（中国科学技术大学）；Hefei National Laboratory（合肥国家实验室）；Ministry of Education, University of Electronic Science and Technology of China（电子科技大学教育部量子物理与光量子信息重点实验室）；Institute of Electronics and Information Industry Technology of Kash（喀什电子信息产业技术研究所）
