Lasing of whispering‐gallery modes in GaInP waveguide micro‐discs and rings with InP quantum dots

Whispering-gallery-mode (WGM) GaInP micro-disc (MD) and micro-ring (MR) resonators (diameters D=1-3 mm, quality factors Q up to 5×103) with embedded InP quantum dots (size/density ∼100 nm/∼109cm-2, emission range 720-770 nm) have been fabricated using a wet oxidation technique. Ultralow (sub-nanoWatt) lasing thresholds for a single InP quantum dot have been demonstrated for these resonators at 15 K under optical pumping. Observed thresholds are two orders of magnitude lower than for single InAs QD lasing (M. Nomura et al., Opt. Express 17, 15975 (2009) [1]). (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)