Lasing from a circular Bragg nanocavity with an ultrasmall modal volume

We demonstrate single-mode lasing at telecommunication wavelengths from a circular nanocavity employing a radial Bragg reflector. Ultrasmall modal volumes and submilliwatt pump thresholds level are observed for lasers with InGaAsP quantum well active membrane. The electromagnetic field is shown to be tightly confined within the 300 nm central pillar of the cavity. The quality factors of the resonator modal fields are estimated to be on the order of a few thousands.microcavity lasers; nanotechnology; distributed Bragg reflector lasers; optical pumping; indium compounds; gallium arsenide; gallium compounds; III-V semiconductors; semiconductor epitaxial layers; quantum well lasers; Q-factor; laser mode