Efficient wavelength conversion with low operation power in a TaO-based micro-ring resonator.

The TaO-based micro-ring resonator with an unloaded quality factor of 182,000 has been demonstrated to realize efficient nonlinear wavelength generation. The propagation loss of the resonator is 0.5  cm, and the buildup factor of the ring resonator is estimated to be ∼50. With a high buildup factor of the ring structure, the four-wave-mixing (FWM) conversion efficiency of -30  dB is achieved in the resonator with a pump power of 6 mW. Based on power-dependent FWM results, the nonlinear refractive index of TaO is estimated to be 1.4×10  cm/W at a wavelength of ∼1550  nm. The demonstration of an enhanced FWM process in the TaO-based micro-ring cavity implies the possibility of realizing FWM-based optical parametric oscillation in a TaO-based micro-ring resonator.