Jang, Juyeong Lee, Seunghwan Kim, Minju Woo, Sunwoo Kim, Inhong Kyhm, Jihoon Song, Jindong Taylor, Robert A. Kyhm, Kwangseuk 2024-01-19T16:03:22Z 2024-01-19T16:03:22Z 2021-09-02 2020-11-23 0003-6951 https://pubs.kist.re.kr/handle/201004/117828 We have employed a variable stripe length method in order to measure the optical gain of GaAs/AlGaAs quantum rings. Although the large lateral diameter of quantum rings ( similar to 50nm) with a few nm size distribution is expected to cause a small spectral inhomogeneity ( similar to 1 %), a broad gain width ( similar to 300meV) was observed. This result was attributed to a variation of the vertical heights and variations in localized states that exhibit crescent shaped wavefunctions, whereby the energy levels are distributed over a broad spectral range. When the excitation intensity is decreased, irregular peaks appear in the gain spectrum gradually. Similar phenomena were also observed as the temperature increased. We conclude that excited carriers in quantum rings are distributed stochastically at various localized states and that the population inversion is sensitive to both excitation intensity and temperature. English AMER INST PHYSICS SATURATION LASER Excitation and temperature dependence of the broad gain spectrum in GaAs/AlGaAs quantum rings Article 10.1063/5.0020890 1 APPLIED PHYSICS LETTERS, v.117, no.21 APPLIED PHYSICS LETTERS 117 21 scie scopus 000595660800001 2-s2.0-85096646989 Physics, Applied Physics Article SATURATION LASER GaAs droplet quantum dots