Large area, ultra-thin membranes are useful as mechanical resonators whose mechanical degree of freedom can be easily controlled using light due to low spring constants and resonator mass. In this regard, there are advantages associated with using two dimensional materials like graphene and ultrathin silicon nitride. However, achieving large area suspended devices with high mechanical quality (Q) factors in these high surface-to-volume-ratio resonators has been a challenge. Recently it has been observed that the Q of these membranes can be significantly improved by a combination of tensile stress, resonator geometry and optimized fabrication techniques. Here we fabricate CVD grown, electrostatically tunable graphene drums of diameter up to 100 mm and measure high quality factors (up to 4000) at room temperature. We then use lasers to control the amplitude of mechanical vibrations using the back action provided by the photothermal effect. We can effectively cool (increase the effective damping) or heat (decrease the effective damping leading to self oscillation) the graphene membrane in a Fabry-Perot cavity formed by the membrane suspended over prefabricated trench, with cavity detuning provided by a highly reflective movable mirror. The strong optomechanical coupling1 observed in these membranes is due to the low mass and relatively strong absorption in the atomic monolayer.

1) Cavity Optomechanics with Graphene Resonators, R. A. Barton et al, Submitted.