Two-color lasing in cold atoms

Elaborating versatile strategies for new lasing schemes is important for both fundamental research and realistic applications. By using atomic photonic crystals, two-color distributed feedback lasing can be shown to occur in a nonlinear regime of balanced optical gain. Within the context of a simple model based on coupled-wave theory and applied to alkali-metal-atom crystals, we find that the two-color lasing threshold in cold atoms is within state-of-the-art experimental reach.