Controlling the Center of Mass Motion of Levitated Particles Using Structured Wavefronts

ABSTRACT

Optically levitated particles have great potential to form the basis of novel quantum‐enhanced sensors as the particles are isolated from the thermal environment at low pressure. However, the stability and harmonic confinement of these oscillators are always affected by the optical aberrations in the wavefront of the trapping laser. The effect of structured wavefronts on levitated particles has not been thoroughly studied. In this work, we present a theoretical model and experimental confirmation based on a complete basis of orthogonal polynomials (Zernike polynomials) to control and modulating spatial phase of the wavefront of trapping beam, which allows us to compare their impact on the quality of traps for optically levitated particles in vacuum. We observe that there is a trade‐off in the optimization of trapping frequencies. In particular, while Zernicke polynomials can be used to correct aberrations in an optical beam and increase the longitudinal trapping frequencies, this will be detrimental for the transversal ones. This has direct applications in quantum sensing and fundamental studies of quantum mechanics, as we present direct guidelines on how to produce stable levitation for a wide range of particles, while reducing the optical backaction and thermal decoherence of the particles.