Undesirable light scattering is an important fundamental cause for photon
loss in nanophotonics. Rayleigh backscattering can be particularly difficult to
avoid in wave-guiding systems and arises from both material defects and
geometric defects at the subwavelength scale. It has been previously shown that
systems with broken time-reversal symmetry (TRS) can naturally suppress
detrimental Rayleigh backscattering, but these approaches have never been
demonstrated in integrated photonics or through practical TRS-breaking
techniques. In this work, we show that it is possible to suppress
disorder-induced Rayleigh backscattering in integrated photonics via electrical
excitation, even when defects are clearly present. Our experiment is performed
in a lithium niobate on insulator (LNOI) integrated ring resonator at telecom
wavelength, in which TRS is strongly broken through an acousto-optic
interaction that is induced via radiofrequency input. We present evidence that
Rayleigh backscattering in the resonator is almost completely suppressed by
measuring both the optical density of states and through direct measurements of
the back-scattered light. We additionally provide an intuitive argument to show
that, in an appropriate frame of reference, the suppression of backscattering
can be readily understood as a form of topological protection