Multiple and colorful cone-shaped lasing induced by band-coupling in a 1D dual-periodic photonic crystal

We demonstrate multiple and colorful cone-shaped lasing from dual-periodic photonic crystal, indicating that coupling occurs between the photonic bands in a photonic crystal laser system. We propose a band-coupling model to estimate lasing wavelengths and emission-cone angles, which match well those from experimental observations from cone-shaped lasing. Band coupling may yield a high optical-conversion efficiency in photonic crystal laser systems, and be of interest in quantum optics communication.