Whispering gallery mode emission of low density InP/GaInP quantum dots

GaInP microdisks contained InP/GaInP quantum dots having lateral size ∼150 nm and 1-5 μm−2 were investigated with help of microphotoluminescence technique. Experiments carried out in confocal, time-resolved and low-temperature modes. Comparison of results allowed to conclude that overlap of quantum dot emission area with whispering gallery mode antinode results in faster luminescence lifetime (Purcell effect). Whispering gallery mode lasing was detected. Obtained threshold power values were following 6 µW (Q=4500, T=8.5 K) and 0.4 µW (Q=7400, T=80 K).