Quantum-Enhanced Optomechanical Accelerometers

利用光来测量和操纵机械物体最近在量子光力学领域取得了巨大的进步。现在可以利用光腔内的辐射压力将宏观机械谐振器冷却到接近绝对零度。相反，通过将激光场反射到低损耗的机械谐振器上，有可能将其统计涨落压缩到超出经典极限，为量子增强干涉测量提供资源。该项目将结合这两种技术来开发下一代光学机械惯性传感器，在该传感器中，光被用来探测机械谐振器在加速参考坐标系下的位移。除了空间重力测量和惯性导航等精密应用外，该项目还将为基础实验打开大门，如低于标准量子极限的加速度法和将加速度校准为基本常量。长期视觉是一种新型的场可展开、微型化的量子技术。该项目的具体目标是(1)展示第一个芯片级的具有纳米g灵敏度的光机械加速度计(以紧凑的外形尺寸实现诸如惯性导航和重力测量等精密应用)；(2)通过在声频腔光机械系统中实现有质运动光压缩来展示压缩增强型光机械加速度计；(3)利用辐射压力散粒噪声将光机械加速度计校准为基本常数；以及(4)利用高保真相干和基于测量的反馈冷却技术来稳定光机械加速度计。为了实现这些目标，研究人员将改进两种先进的传感器设计，它们代表了PI和co-PI的互补专业知识：(1)集成在法布里-珀罗腔中的厘米级高应力氮化硅薄膜，以及(2)与光纤腔集成的块状熔融二氧化硅光学机械谐振器。作为一种使能工具，PI/COPI还将开发一种紧凑型激光光源，能够在声音频率下进行散粒噪声限制操作。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The use of light to measure and manipulate mechanical objects has recently seen dramatic advances in the field of quantum optomechanics. It is now possible to cool a macroscopic mechanical resonator to near absolute zero using radiation pressure inside an optical cavity. Conversely, by reflecting a laser field off a low-loss mechanical resonator, it is possible to “squeeze” its statistical fluctuations beyond classical limits, providing a resource for quantum-enhanced interferometric measurements. This project will combine both techniques to develop next-generation optomechanical inertial sensors, in which light is used to probe the displacement of a mechanical resonator in response to accelerating reference frame. In addition to precision applications such as space-based gravimetry and inertial navigation, the project will open the door to fundamental experiments such as accelerometry below the standard quantum limit and calibration of acceleration to fundamental constants. The long-term vision is a new class of field-deployable, miniaturized quantum technology.Specific goals of the project are (1) demonstrate the first chip-scale optomechanical accelerometer with nano-g sensitivity (enabling precision applications such as inertial navigation and gravimetry in a compact form factor), (2) demonstrate a squeezing-enhanced optomechanical accelerometer by realizing ponderomotive light squeezing in an acoustic frequency cavity optomechanical system; (3) use radiation pressure shot noise to calibrate an optomechanical accelerometer to fundamental constants; and (4) use radiation pressure to stabilize an optomechanical accelerometer, by harnessing high fidelity coherent and measurement-based feedback cooling techniques. To accomplish these goals, the researchers will refine two advanced sensor designs representing complementary expertise of the PI and co-PI: (1) a centimeter-scale high stress silicon nitride membrane integrated in a Fabry-Perot cavity and (2) a bulk fused-silica optomechanical resonator integrated with a fiber cavity. As an enabling tool, the PI/CoPI will also develop a compact laser source capable of shot-noise-limited operation at acoustic frequencies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.