Surface-emitting microlaser combining two-dimensional photonic crystal membrane and vertical Bragg mirror

Abstract

We report on the design and fabrication of heterogeneous and compact surface-emitting microlasers, optically pumped and operating at 1.5 μ m at room-temperature. A very low threshold, below 15 μ W , is achieved. The devices consists of a top two-dimensional InP photonic crystal slab, including four InAsP quantum wells, a Si O 2 bonding layer, and a bottom high index contrast Si ∕ Si O 2 Bragg mirror deposited on a Si wafer. The graphitelike photonic crystal lattice is tailored for vertical emission. We theoretically and experimentally demonstrate that the Bragg reflector can strongly enhance the quality factor of the photonic crystal resonant mode, leading to a drastic decrease of the lasing threshold.