Using Bessel-Gaussian beam in optical trapping of nanoparticles for gensitive gravimetry

Over the past decade, researchers have developed very sensitive force detection techniques including yoctonewton (10−24 N) force measurement, yoctogram-scale mass sensitivity and femto-scale magnetic field sensing. However, the measurement of gravitational or inertial forces to such high precision still to date remains a scientific and technological challenge. Compact integrated room temperature inertial sensors capable of sensing ultra-small changes in inertial forces is still lacking.In this thesis, I propose an all-optically controlled novel design for performing sensitive gravimetry based on trapped and levitated nanoparticles using Bessel-Gaussian beams. I particularly focus on the characterization of Bessel-Gaussian beam and its challenges and application in optical trapping. Optical trapping in vacuum and air has near-complete mechanical isolation from the environment. Without the need for clamping mechanism and robust decoupling from surrounding environment, the all-optical trapping and cooling techniques will yield potentially ultrahigh Q-factor resulting in ultrasensitive force detection at room temperature.