Resonator device

A method of fabricating a resonator device, the method comprising:

• providing wafers comprising a diaphragm wafer, a resonator wafer and a cap wafer;
• forming an optical cavity between an inside surface of the cap wafer and the resonator wafer;
• bonding the wafers together to form a hermetically sealed package with the resonator wafer enclosed by the diaphragm wafer and the cap wafer;
• arranging the hermetically sealed package to apply an electromagnetic radiation to the hermetically sealed package;
• and
• positioning a target on a surface of the resonator to receive the electromagnetic radiation, wherein a diameter of the target is larger than a diameter of a fibre which is used to apply the electromagnetic radiation.

A resonator device for a transducer, the resonator device comprising:

• a resonator positioned on a diaphragm, and
• a cap enclosing the resonator to form an optical cavity between an inside surface of the cap and the resonator,
• wherein the resonator is arranged to be excited by applying an electromagnetic radiation, and
• wherein an electromagnetic signal, having a different wavelength than the electromagnetic radiation, is applied into the optical cavity to derive a frequency change of the resonator.