Slowly varying envelope approximation in a laser with optical feedback - art. no. 033803

We examine the application of the slowly varying envelope approximation (SV EA) to the study of the laser with optical feedback, comparing the monochro matic modes obtained using a SVEA approximation with those emerging from a fall treatment of the Maxwell-Bloch equations in a coupled cavity formulati on of the laser with optical feedback [A. A. Duarte and H. G. Solari Phys. Rev. A 58, 614 (1998)]. While the SVEA approximation in the body of laser p roduces reliable results, the same approximation applied to the boundary co nditions completely distorts the metamorphosis of the spectrum present in t he original model, yet far from the transition region the SVEA gives accept able results. The failure of the SVEA at the metamorphosis is related to th e high sensitivity of the dispersion relations k(w) with respect to frequen cy changes.