Mode selection in electrically driven quantum dot microring cavities

Abstract

Within this paper a novel method for selecting certain lasing modes from a whispering gallery mode (WGM) spectrum of electrically pumped microrings is presented. Selection is achieved by introducing sub-wavelength sized notches of about 50nm width and 500nm depth to the sidewalls of ring shaped quantum dot micro cavities with 80 mu m diameter and ridge widths below 2 mu m. It is shown that the notches act as scattering centers, suppressing modes that have maxima in intensity at the notch position. By a variation of the angle between the notches, different repetitive patterns of lasing modes and suppressed modes are conceivable. (C) 2013 Optical Society of America