Low-noise Kerr frequency comb generation with low temperature deuterated silicon nitride waveguides

We report very low-loss deuterated silicon nitride (SiN_x:D) micro-ring resonators fabricated by back-end CMOS compatible low-temperature plasma-enhanced chemical vapor deposition (PECVD) without annealing. Strong confinement micro-ring resonators with a quality factor of > 2 million are achieved, corresponding to a propagation loss in the 1460-1610 nm wavelength range of ∼ 0.17 dB/cm. We further report the generation of low-noise coherent Kerr microcomb states including different perfect soliton crystals (PSC) in PECVD SiN_x:D micro-ring resonators. These results manifest the promising potential of the back-end CMOS compatible SiN_x:D platform for linear and nonlinear photonic circuits that can be co-integrated with electronics.