Some errors and particular conclusions drawn in our Letter [Opt. Lett. 42, 5206 (2017) [CrossRef] ] are corrected.
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First, there is a typo in formula (4) of , the first part of which must read .
Second, the symmetry of the transfer matrix for the potential (12) is , which results in modified formula (13):1] and following Eq. (13) is invalid for potentials given by Eq. (12). In other words, the existence of self-dual spectral singularities a priori is not forbidden for complex potentials of this type.
Third, for potentials (14) of , the relation holds, but the conclusion on the absence of spectral singularities applies only if , provided that the localized function is chosen, such that potential in Eq. (14) is bounded, localized, and tends to constant limits at .
1. V. V. Konotop and D. A. Zezyulin, Opt. Lett. 42, 5206 (2017). [CrossRef]