A Chip‐Scale Oscillation‐Mode Optomechanical Inertial Sensor Near the Thermodynamical Limits

Abstract

Modern navigation systems integrate the global positioning system (GPS) with an inertial navigation system (INS), which complement each other for correct attitude and velocity determination. The core of the INS integrates accelerometers and gyroscopes used to measure forces and angular rate in the vehicular inertial reference frame. With the help of gyroscopes and by integrating the acceleration to compute velocity and distance, precision and compact accelerometers with sufficient accuracy can provide small-error location determination. Solid-state implementations, through coherent readout, can provide a platform for high performance acceleration detection. In contrast to prior accelerometers using piezoelectric or capacitive readout techniques, optical readout provides narrow-linewidth high-sensitivity laser detection along with low-noise resonant optomechanical transduction near the thermodynamical limits. Here an optomechanical inertial sensor with an 8.2 µg Hz −1/2 velocity random walk (VRW) at an acquisition rate of 100 Hz and 50.9 µg bias instability is demonstrated, suitable for applications, such as, inertial navigation, inclination sensing, platform stabilization, and/or wearable device motion detection. Driven into optomechanical sustained-oscillation, the slot photonic crystal cavity provides radio-frequency readout of the optically-driven transduction with an enhanced 625 µg Hz −1 sensitivity. Measuring the optomechanically-stiffened oscillation shift, instead of the optical transmission shift, provides a 220× VRW enhancement over pre-oscillation mode detection.

Power Spectral Density Analysis of Nanowire-Anchored Fluctuating Microbead Reveals a Double Lorentzian Distribution

“…In contrast, thermal noise represents the main disturbing and limiting factor in experiments that rely on highly sensitive mechanical and opto-mechanical systems. Examples are inertial sensors [12,13] as well as recently proposed gravitational-wave and dark matter sensors [14][15][16].…”

Opto-Mechanical Photonic Crystal Cavities for Sensing Application

“…However, considering practical engineering applications, one large obstacle that should not be underestimated is associated with a complete integration on-chip device. Significant studies and In a similar manner, another optomechanical inertial sensor based on a slot-type 2D photonic crystal cavity [143] was demonstrated in Figure 25a. One side of the slot cavity was anchored on the silicon top layer and the other suspended side was attached to a large proof mass of 5.6 ng for acceleration detection.…”

“…The proposed optomechanical accelerator exhibited a sensitivity of~0.1 µg/Hz 1/2 near the mechanical resonance frequency around 20 kHz. In a similar manner, another optomechanical inertial sensor based on a slot-type 2D photonic crystal cavity [143] was demonstrated in Figure 25a. One side of the slot cavity was anchored on the silicon top layer and the other suspended side was attached to a large proof mass of 5.6 ng for acceleration detection.…”

Quantum sensing with nanoparticles for gravimetry: when bigger is better

“…For some time, the optomechanics community has been prototyping classical accelerometers [61,84,85,[89][90][91][92]. Such sensors rarely require the level of environmental isolation needed for long-lived quantum state preparation.…”