"Cavity optomechanics has over the past years emerged as a new research field in which basic concepts of quantum measurement theory such as quantum limited displacement sensing or backaction evading measurements as well as highly sensitive force measurements may be realized by virtue of radiation pressure optomechanical coupling to nano- and micro-mechanical oscillators. The objective of this research area is to achieve quantum limited detection of mechanical motion and ground state cooling of a mechanical oscillator. Analogous to the success of quantum limited photon detectors in the field of quantum optics, it is likely that quantum limited motion transducers will continue to lead to new advances in both fundamental science and technology. The significance of the research program lies in experimentally approaching the fundamental quantum limits of motion transduction and demonstrating quantum phenomena of a mechanical oscillator; the most tangible harmonic oscillator. This research will directly build on the recognized contributions of the participating Swiss research group, which is the Laboratoy of Photonics and Quantum Measurements of Dr. Tobias J. Kippenberg at the EPFL. The research group has over the past 4 years made many seminal and widely recognized contributions to the field of cavity optomechanics. The applicant is a French scientists who obtained his PhD at ENS in Paris in the labatory of the world renowned Quantum Physics pioneer Serge Haroche. His work has been pioneering and has been published in leading journals (including two publications in Nature). The proposed research activities are at the forefront of the rapidly developing field of cavity optomechanics - which has sparked widespread contemporary interest in Physics - , and will place the applicant in an excellent position to launch into a carreer in science. Moreover the applicant will be exposed within the Laboratory of Photonics and Quantum Measurements to complementary research projects."