Low threshold, room-temperature microdisk lasers in the blue spectral   range
  InGaN-based active layers within microcavity resonators offer the potential of low threshold lasers in the blue spectral range. Here we demonstrate optically pumped, room temperature lasing in high quality factor GaN microdisk cavities containing InGaN quantum dots (QDs) with thresholds as low as 0.28 mJ/cm2. This work, the first demonstration of lasing action from GaN microdisk cavities with QDs in the active layer, provides a critical step for the nitrides in realizing low threshold photonic devices with efficient coupling between QDs and an optical cavity. 
Igor Aharonovich, Alexander Woolf, Kasey J. Russell, Tongtong Zhu,   Menno J. Kappers, Rachel A. Oliver and Evelyn L. Hu
cond-mat.mtrl-sci physics.optics