Fan et al. raised technical concerns about our study regarding the Lorentz reciprocity theorem, with which we completely agree. Unfortunately, we incorrectly used the term "nonreciprocal"to describe the behavior of electromagnetic propagation in our devices. In our paper, this term does not refer to Lorentz reciprocity but to the asymmetric mode conversion that is experimentally demonstrated.
Feng, L., Ayache, M., Huang, J., Xu, Y. L., Lu, M. H., Chen, Y. F., … Scherer, A. (2012, January 6). Response to comment on “nonreciprocal light propagation in a silicon photonic circuit.” Science. American Association for the Advancement of Science. https://doi.org/10.1126/science.1213954