Characteristics of single defect laser modes in a two-dimensional square lattice photonic crystal slab

Square lattice photonic crystal single defect nanocavity structures are formed in free-standing slab InGaAsP materials emitting near 1.55 mum. Laser operations are achieved from two types of resonant modes, a degenerate dipole mode and a nondegenerate whispering-gallery-like mode. Each laser mode is identified by the measurement of mode shapes, quality factors, and polarization. The threshold absorbed pump power is estimated to be less than 0.2 mW for the whispering gallery mode. It is found, by rate equation analyses, that nonradiative surface recombination, which takes >60% of carrier recombination near threshold, is one of the main limiting factors for the low-threshold operation of photonic crystal single defect lasers. (C) 2003 American Institute of Physics.