We demonstrate synchronization of laser-induced self-sustained vibrations of radio-
frequency micromechanical resonators by applying a small pilot signal either as an inertial
drive at the natural frequency of the resonator or by modulating the stiffness of the oscillator
at double the natural frequency. By sweeping the pilot signal frequency, we demonstrate that
the entrainment zone is hysteretic and can be as wide as 4% of the natural frequency of the
resonator, 400 times the 1/Q∼ 10− 4 half-width of the resonant peak. Possible applications …