Recently Petit
et al.published a paper devoted to a high-resolution spectroscopy study of the 0-0 laser band in the Second Positive System of molecular nitrogen and explaining the optical gain formation on its different branches.All the results by Petit
et al. are equivalent to those previously published by Massone
et al.and are in accordance with theoretical predictions reported by Tocho
et al.Summarizing, we would comment as follows....