Ultra-low-loss on-chip resonators with sub-milliwatt parametric oscillation threshold

On-chip optical resonators have the promise of revolutionizing numerous fields including metrology and sensing; however, their optical losses have always lagged behind their larger discrete resonator counterparts based on crystalline materials and flowable glass. Silicon nitride (Si3N4) ring resonators open up capabilities for optical routing, frequency comb generation, optical clocks and high precision sensing on an integrated platform. However, simultaneously achieving high quality factor and high confinement in Si3N4 (critical for nonlinear processes for example) remains a challenge. Here, we show that addressing surface roughness enables us to overcome the loss limitations and achieve high-confinement,…

• NS
  National Science Foundation

  Award: ECCS-1542081
• DA
  Defense Advanced Research Projects Agency

  Award: N66001-16-1-4052
• AF
  Air Force Office of Scientific Research

  Award: FA9550-15-1-0303