Multi-functional light emitter based on band-edge modes near Γ-Point in honeycomb photonic crystal

In this report, we demonstrate multi-functional light emitter based on band-edge modes near Γ-point in a two-dimensional honeycomb photonic crystal slab. Different band-edge modes near Γ-point are identified, including the monopole (Γ₂), dipole (Γ_4,5), and quadrupole (Γ_6,7) modes. The monopole and quadrupole modes lasing are observed with high side-mode suppression-ratio of 35 dB and high index sensitivity of 375 nm per refractive index unit, which shows their potential in optical micro-laser and index sensor applications. Over five-fold photoluminescence enhancement with broad band-width of 100 nm from the dipole mode is also observed at room temperature, which shows the advantage of honeycomb lattice structure for designing high brightness light emitting diodes.