Quantum-Enhanced Optomechanical Accelerometers

University Of Arizona, Tucson AZ

Investigators

Abstract

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.