Wideband mechanical response of high-Q silicon Double Paddle Oscillator

We present experimental results of operation of a silicon double-paddle oscillator, namely the mechanical transfer function of the system and the quality factor of its resonant modes. We also describe the fabrication process, where efforts have been devoted to ensure strict dimensional tolerances for a proper functioning of the oscillator, and the setup used to drive the oscillation of the device and to detect its displacement with a sensitivity better that 10−12 m Hz−1/2 in the range 0.1–5 kHz. We observed mechanical quality factors higher than 105 in vacuum at room temperature for two specific resonant modes, while for all other modes the quality factor remains in the range 103–104. These values are in good agreement with the limit set by the thermoelastic dissipation in the device, evaluated by a finite element procedure, and demonstrate that our setup allows us to control losses coming from clamping and residual gas effects.