Niobium-tantalum oxide as a material platform for linear and nonlinear integrated photonics

Here we realize the first reported integrated photonic devices fabricated using sputtered niobium-tantalum oxide films. Sputtered niobium-tantalum oxide films are highly promising for integrated photonics as they are scalable to high volume manufacturing, possess high refractive index, and are transparent in the ultraviolet through near infrared wavelength range. At a wavelength near 1550 nm, we observe propagation losses as low as 0.47 dB/cm in waveguides and ring resonators with resonator quality factors as high as 860,000. We also characterize the nonlinear performance of these films and find a Kerr coefficient (n₂) of 1.2 ( ± 0.2) × 10^-18 m²/W. With this high Kerr coefficient we demonstrate optical parametric oscillation in a ring resonator and supercontinuum generation in a waveguide.