Hybrid trap for levitated optomechanics of mesoscopic particles

<p dir="ltr">In this M.Phil thesis, a hybrid trap for optomechanical studies of mesoscopic particle is investigated. It uses a Planar Paul Trap (PPT) for electrical confinement and a parabolic mirror for optical confinement. The PPT is compatible with the printed circuit board (PCB) technology making it easier to integrate with the mirror trap. This compatibility also simplifies particle loading, enhances ground state cooling and improves optical interrogation within the trap. It can create various potential landscapes of a quartic potential, including double well or inverted harmonic, and is a potential tool for investigating macroscopic quantum superposition states. This planar geometry of the Paul trap allows large optical access required for optical confinement and detection of the particle. The parabolic mirror provides the benefits of virtually no chromatic aberration, high numerical aperture and functioning as an additional RF electrode of the hybrid trap. The work includes simulations and experiments to characterize the hybrid trap by analyzing the effective trapping potential. From the numerical simulations, the ratio of axial to radial secular frequencies of the trapped particle under the RF drive is = 0.98, implying the chosen parameters of the PPT + mirror RF trap has approximately the same stiffness and hence confinement in the axial and radial directions. It is also observed that the dynamics of a single particle under the RF drive is not affected by damping and random forces in a high vacuum (∼ 10^-6 mbar).</p>