  The topic of this thesis is the theoretical analysis of the optomechanical
coupling effects in a high-finesse optical cavity, and the experimental
realization of such a device. Radiation pressure exerted by light limits the
sensitivity of high precision optical measurements. In particular, the
sensitivity of interferometric measurements of gravitational wave is limited by
the so called standard quantum limit. cavity with a movable mirror. The
internal field stored in such cavity can be orders of magnitude greater than
the input field, and it's radiation pressure force can change the physical
length of the cavity. In turn, any change in the mirror's position changes the
phase of the out put field. This optomechanical coupling leads to an
intensity-dependent phase shift for the light equivalent to an optical Kerr
effect. Such a device can then be used for squeezing generation or quantum
nondemolition measurements. In our experiment, we send a laser beam in to a
high-finesse optical cavity with a movable mirror coated on a high Q-factor
mechanical resonator. Quantum effects of radiation pressure become therefore,
at low temperature, experimentally observable. However, we've shown that the
phase of the reflected field is very sensitive to small mirror displacements,
which indicate other possible applications of this type of device like high
precision displacements measurements. We've been able to observe the Brownian
motion of the moving mirror. We've also used an auxiliary intensity modulated
laser beam to optically excite the acoustic modes. We've finally obtained a
sensitivity of 2x10^(-19) m/sqrt(Hz), in agreement with theoretical prediction.
