Damage-induced spectral perturbations in multilongitudinal-mode semiconductor lasers

Mechanical stressing was applied to commercial Fabry-Perot semiconductor lasers to create damage at controlled locations along the optic axis. This damage induces spectral perturbations sinusoidal in wavelength space whose periods are inversely proportional to the distance from the damage to the nearest facet. Experimental and theoretical evidence is presented for a new spectrum-based analytical technique which can provide quantitative information on the location and relative absorption strength of damage sites within the active region. Applications and limitations of this new technique are discussed.>