Cryogenic optomechanic cavity in low mechanical loss material

Mechanical losses lower than 10−9 have been demonstrated on quartz crystal acoustic cavities at liquid helium temperature. In addition, such cavities could rather easily be adapted to be used as optical cavities. This paper addresses the optomechanic devices that could merge from, while highlighting the major assets of each option and showing some preliminary results, including tests on quartz and CaF2 samples. It is shown that the mechanical displacement can be actuated optically by radiation pressure according to proper designs.