FIG. 5: Comparison of our nanophotonic spectral translation efficiency with state-of-the-art results.

We compare our results with other state-of-the-art devices in terms of translation efficiency vs. pump power. Solid/dashed lines show the scaling in ${\chi }^{(2)}$ LiNbO₃ (blue) and ${\chi }^{(3)}$ Si₃N₄ (red) resonators/waveguides, respectively, which agree with theoretical estimates in that ${\chi }^{(2)}$ and ${\chi }^{(3)}$ processes have linear and quadratic power scaling, respectively (Ref. 23 is distinguished from others due to its cavity frequency mismatch.). Through resonance enhancement and careful mode engineering, our ${\chi }^{(3)}$ device is projected to reach a translation efficiency of (274 ± 28) % at 1 mW, which is comparable to that of the best ${\chi }^{(2)}$ device. This represents a many order of magnitude improvement relative to the waveguide case, where the ${\chi }^{(3)}$ process is over 50 dB smaller in efficiency than the ${\chi }^{(2)}$ case at 10 mW, μ: micro. wg: waveguide.