Optical Levitation of Reflective Shells Using an LG01 Vortex Beam

The Gaussian beam is the most common choice of beam geometry for particle levitation but is limited to transmissive targets. To date, nano- and few micrometre sized targets have been successfully levitated, and with active-feedback systems to enhance trapping stability highly sensitive force sensing devices have been developed to search for dark matter [1] and gravitational wave detection [2]. Large reflective or thin-walled transmissive shell targets cannot be stably trapped by a static Gaussian beam. Instead, they require annular beams, such as the LG 01 vortex, which when reflected apply radiative pressure to drive the target towards the dark beam centre and an upwards force to counteract gravity.