Giant resonant enhancement of optical binding of dielectric disks

Abstract

Two-fold variation over the aspect ratio of each disk and distance between disks gives rise to numerous events of avoided crossing of resonances of individual disks. For these events, the hybridized anti-bonding resonant modes can acquire a morphology close to the Mie resonant mode with the high orbital momentum of an equivalent sphere. The Q factor of such resonance can exceed the Q factor of an isolated disk by two orders of magnitude. We show that dual incoherent counterpropagating coaxial Bessel beams with power 1 m W / µ m 2 with frequency resonant to such anti-bonding Mie-like modes result in unprecedented optical binding forces up to tens of nano-Newtons for silicon micrometer-sized disks. We show also that the magnitude and sign of optical forces depend strongly on the longitudinal wave vector of the Bessel beams.