Optical self-excitation and detection for inertial MEMS Sensors

We report on the development of an optical self-excitation and detection method to allow for high stability operation of inertial MEMS sensors. A single constant amplitude laser beam is used to both drive and optically interrogate the resonant frequency of a MEMS resonator. A parametric study of x,y,z position of the laser spot location, laser power, and laser wavelength with respect to frequency stability of the MEMS sensor is presented. A frequency bias instability of 3 ppb at 1 s without any calibration and a frequency white noise of 2.4 ppb/√Hz for a MEMS resonator with resonant frequency of 68.28 kHz and quality factor of 4,600 have been measured.