Title: Sub-Hertz Optomechanically-Induced Transparency Show Chinese title

Title: 亚赫兹光机诱导透明度

Abstract: Optical interferometers with suspended mirrors are the archetype of all current audio-frequency gravitational-wave detectors. The radiation pressure interaction between the motion of the mirror and the circulating optical field in such interferometers represents a pristine form of light-matter coupling, largely due to 30 years of effort in developing high quality optical materials with low mechanical dissipation. However, in all current suspended interferometers, the radiation pressure interaction is too weak to be useful as a resource, and too strong to be neglected. Here, we demonstrate a meter-long interferometer with suspended mirrors, of effective mass $~ 125$ g, where the radiation pressure interaction is enhanced by strong optical pumping to realize a cooperativity of $50$. We probe this regime by observing optomechanically-induced transparency of a weak on-resonant probe. The low resonant frequency and high-Q of the mechanical oscillator allows us to demonstrate transparency windows barely $100$ mHz wide at room temperature. Together with a near-unity ($\sim 99.9\%$) out-coupling efficiency, our system saturates the theoretical delay-bandwidth product, rendering it an optical buffer capable of seconds-long storage times. Show Chinese abstract

Abstract: 以悬挂镜面为特色的光学干涉仪是所有当前音频频率引力波探测器的典范。这种干涉仪中镜面运动与循环光学场之间的辐射压力相互作用代表了一种纯净的光-物质耦合形式，这在很大程度上归功于30年来在开发低机械耗散的高质量光学材料方面的努力。然而，在所有当前的悬挂干涉仪中，辐射压力相互作用太弱，无法作为资源使用，又太强，不能被忽略。在这里，我们展示了一个带有悬挂镜面的米级干涉仪，有效质量为$~ 125$克，其中通过强光泵浦增强辐射压力相互作用，实现了 $50$的协同性。我们通过观察弱共振探测器的光机诱导透明度来研究这一区域。机械振荡器的低共振频率和高-Q值使我们能够在室温下演示仅 $100$ mHz 宽的透明窗口。结合接近单位（$\sim 99.9\%$）的出射耦合效率，我们的系统达到了理论上的延迟带宽乘积，使其成为一个能够实现秒级存储时间的光学缓冲器。