In the past few years, optical
cooling and manipulating of macroscopic objects, such as micro-mirrors and
cantilevers has developed into an active field of research.
In mechanical systems, the oscillator is attached to its suspension,
a thermal contact that limits the motion isolation. On the other hand, when
these small objects are levitated using the radiation pressure force of lasers,
the excellent thermal isolation even at room temperatures helps produce
very sensitive force detectors, and eventually quantum transducers for quantum
computation purposes. These new techniques may have a variety of applications
for fundamental physics such as short distance tests of gravity and
gravitational wave detection at high frequencies. In addition, there are
several proposals suggesting that optically levitated dielectrics can be cooled
to the ground state of the center of mass motion, opening the exciting
possibility of creating macroscopic matter-wave interferometers.