Fabrication of GaInAsP/InP photonic crystal lasers by ICP etching and control of resonant mode in point and line composite defects

We theoretically and experimentally investigated lasing and resonant characteristics in photonic crystal lasers with point defects and/or point and line composite defects. The finite-difference time domain simulation showed that various resonant modes can occur in arbitrary defect geometries. A GaInAsP airbridge photonic crystal slab with a lattice constant of similar to 0.42 mum, a hole diameter of similar to 0.25 mum, a sidewall angle of similar to 90degrees, and a sidewall roughness of similar to10 nm, was fabricated by Cl-2 / Xe inductively coupled plasma etching, in which ions and radicals were balanced by optimizing the gas pressure and the bias voltage. The room temperature pulsed lasing was observed with a threshold irradiated power of 1.4 mW by photopumping. The possibility of the continuous-wave (CW) lasing was also discussed with the estimation of the thermal resistance. The mode control in some composite defects was confirmed from resonant photoluminescence peaks under CW condition.