Quantenmechanische Behandlung des Lasers mit nichtresonanter Rückkopplung. III Berechnung des Frequenzspektrums



Neglecting intensity fluctuations of the radiation the mean photon number per mode, nλ, is calculated for a laser with nonresonant feedback in case of a homogenously as well as an inhomogenously broadened atomic line. The dependence of nλ on the frequency ωλ displays the frequency spectrum of the radiation which is found to be narrowed with respect to the spontaneous line. The linewidth, nevertheless, is much greater than in the case of a 1-mode-laser (with resonant feedback).