Electrically driven optical isolation through phonon-mediated photonic Autler–Townes splitting

Optical isolators are indispensible components in nearly all photonic systems as they help ensure unidirectionality and provide crucial protection from undesirable reflections. While commercial exclusively built on magneto-optic (MO) principles not readily implemented within integrated circuits due to the need for specialized materials. Importantly, MO effect is generally weak, especially at shorter wavelengths. These challenges a whole have motivated extensive research non-MO alternatives. To date, however, no alternative technology has managed simultaneously combine linearity (i.e. frequency shift), linear response input-output scaling), ultralow insertion loss, large directional contrast on-chip. Here we demonstrate an optical isolator design that leverages unbeatable transparency of short, high quality dielectric waveguide, with near-perfect attenuation critically-coupled absorber. Our concept using lithium niobate racetrack resonator which phonon mediated Autler-Townes splitting (ATS) breaks chiral symmetry resonant modes. We on-chip wavelengths one octave apart near 1550 nm 780 nm, fabricated same niobate-on-insulator wafer. Linear isolation demonstrated <1 dB >39 contrast, bandwidth wide mode used. results outperform current best-in-class both loss figures-of-merit, lithographically defined wavelength adaptability cannot yet be achieved any isolator.