  We demonstrate a microfabricated optomechanical accelerometer that is capable
of percent-level accuracy without external calibration. To achieve this
capability, we use a mechanical model of the device behavior that can be
characterized by the thermal noise response along with an optical frequency
comb readout method that enables high sensitivity, high bandwidth, high dynamic
range, and SI-traceable displacement measurements. The resulting intrinsic
accuracy was evaluated over a wide frequency range by comparing to a primary
vibration calibration system and local gravity. The average agreement was found
to be 2.1 % for the calibration system between 0.1 kHz and 15 kHz and better
than 0.2 % for the static acceleration. This capability has the potential to
replace costly external calibrations and improve the accuracy of inertial
guidance systems and remotely deployed accelerometers. Due to the fundamental
nature of the intrinsic accuracy approach, it could be extended to other
optomechanical transducers, including force and pressure sensors.
