Spectral manipulation in Fabry-Perot lasers: Perturbative inverse scattering approach

We present a method for tailoring the lasing spectrum of a Fabry-Perot laser through the introduction of a low density of weakly reflective features along the length of the optical cavity. Using a transfer-matrix approach, the positions of the features are obtained from a self-consistent solution of the corresponding inverse problem at first order in the effective index step introduced. Theoretical examples are given describing how a single-mode laser cavity and a two-color laser are designed. Experimental measurements show that the method enables the realization of single-mode semiconductor lasers with high spectral purity at a predetermined wavelength. We also demonstrate that cavities designed according to our first-order prescription are robust at larger values of the effective index step where effects at second order cannot be neglected.