Special CPM Seminar

Phase shifting, squeezing and non-Gaussian states in a strongly coupled opto-electromechanical resonator

Menno Poot

Yale University

Opto-electromechanical devices combine the very high position sensitivity of optical readout with strong electrostatic forces. Our on-chip device consists of a high-stress SiN resonator and integrated optical circuits. By placing two electrodes, one fixed and one movable, in close vicinity we obtain very strong electromechanical interactions: the resonance frequency can be tuned over an extremely large range using the electrostatic spring effect, and the nonlinearity of the resonator is varied all the way from a stiffening spring to a softening one by changing the applied voltage. The device can be used as an optomechanical phase shifter by applying static voltages. When an a.c. voltage at twice the resonance frequency is applied, the thermal motion of the resonator is squeezed. By measuring the phase-space trajectory of the resonator and adjusting the phase of the parametric drive in real-time we achieve a stationary reduction in both quadratures that is far beyond the 3dB limit that exists for such a parametric drive. Using tomography it is shown that this method can also be used to prepare the resonator in highly nonlinear states that are far from the regular Gaussian ones that can be achieved using normal optomechanical cooling.