We consider the generation of photon pairs by spontaneous four-wave mixing in ring resonators, as described by Clemmen et al. in Opt. Express 17, 16558 (2009). We show that the theoretical limit predicted for the generation rate in their Erratum–Opt. Express 18, 14107 (2010)–is far too large due to an incorrect definition of a field enhancement factor.
Liscidini, M., Sipe, J. E., & Helt, L. G. (2016). Continuous wave photon pair generation in silicon-on-insultator waveguides and ring resonators and erratum: comment. Optics Express, 24(8), 9130-9131. https://doi.org/10.1364/OE.24.009130