Stability analysis for bad cavity lasers using inhomogeneously broadened spin-1/2 atoms as gain medium

摘要

Bad cavity lasers are experiencing renewed interest in the context of activeoptical frequency standards, due to their enhanced robustness againstfluctuations of the laser cavity. The gain medium would consist ofnarrow-linewidth atoms, either trapped inside the cavity or intersecting thecavity mode dynamically. A series of effects like the atoms finite velocitydistribution, atomic interactions, or interactions of realistic multilevelatoms with auxiliary or stray fields can lead to an inhomogeneous broadening ofthe atomic gain profile. This causes the emergence of instable regimes of laseroperation, characterized by complex temporal patterns of the field amplitude.We study the steady-state solutions and their stability for themetrology-relevant case of a bad cavity laser with spin-1/2 atoms, such asYb-171, interacting with an external magnetic field. For the stabilityanalysis, we present a new and efficient method, that can be applied to a broadclass of single-mode bad cavity lasers with inhomogeneously broadenedmultilevel atoms acting as gain medium.