Optomechanical Light-Matter Interface with Optical Wavelength Conversion

An optomechanical resonator features the unique property that an optically active mechanical mode can couple to any of the optical resonances in the resonator via radiation pressure. The main objective of this program is to exploit this unique property to develop a light-matter interface that can map quantum states between two different optical wavelengths. Using silica microspheres as a model optomechanical system, these studies have led to the experimental realization of coherent inter-conversion between optical and mechanical excitations and to the demonstration of mechanically-mediated coherent conversion between two optical modes. In addition, Bogoliubov mechanical mode, which is a precursor for entangled mechanical mode, has also been realized in a system, in which two mechanical modes couple a common optical mode via respective red and blue sideband coupling. A particular emphasis of this program is on overcoming the thermal mechanical motion in mechanically mediated optical state transfer or optical entanglement. The dark mode and the Sorensen-Molmer approaches have been proposed and analyzed theoretically. Both approaches aim to take advantage of mechanical degrees of freedom, while avoiding the detrimental effects of thermal mechanical motion.