Toward achieving a low energy state of a gram-scale mirror oscillator

We report on use of a radiation pressure induced restoring force, the optical spring effect, to optically cool a 1 gram mirror. In the present experiment the oscillator mode reaches a minimum temperature of 6.9 mK, a factor of ~100 lower than previously reported for this technique. A further advantage of the optical spring effect, not previously discussed, is that it can increase the number of oscillations before decoherence by several orders of magnitude. In the present experiment we infer an increase in the dynamical lifetime of the state by a factor of ~200. We describe an experimental path, using existing technologies, that should culminate in low energy quantum states, thereby exposing quantum effects in gram-scale objects with $10^{22}$ atoms.