Microelectromechanical systems (MEMS) have been applied to many measurement problems in physics, chemistry, biology and medicine. In parallel, cavity optomechanical systems have achieved quantum-limited displacement sensitivity and ground state cooling of nanoscale objects. Here, we integrate these technologies into a MEMS sensing platform enabled by cavity optomechanics, featuring high quality factor interferometric readout, MEMS-tunable optomechanical coupling, and mechanical transfer function adjustable via feedback. Cold-damping of the fundamental mechanical mode by >3 orders of magnitude and broadening of mechanical bandwidth to above twice the fundamental frequency are achieved. We demonstrate displacement sensitivity of 4.6 fm/Hz1/2 and force sensitivity of 53 aN/Hz1/2 with only 250 nW optical power launched into the sensor. Sensitivity approaching the standard quantum limit is combined with MEMS actuation in a fully integrated, compact, low power, stable system compatible with Si batch fabrication and electronics integration. The platform separates optical and mechanical components, allowing flexible customization for specific scientific and commercial applications.
Citation: New Journal of Physics
Pub Type: Journals
MEMS, Optomechanics, Sensors