Optical absorption measurements from single semiconductor quantum dots

Summary form only given. Size fluctuations in ensembles of semiconductor quantum dots lead to inhomogeneous broadening, which mask the intrinsic properties of individual quantum dots. In recent years, many research groups have chosen photoluminescence (PL) to optically probe individual quantum dots due to the sensitivity and simplicity of PL. However, the amount of information extracted from PL is limited. Absorption measurements can complement PL studies and provide important quantitative information such as dipole moments and dephasing rates without any complications arising from spectral and spatial diffusion. The interface fluctuation quantum dots formed in a 6.2 nm GaAs/Al/sub 0.3/Ga/sub 0.7/As quantum well are probed with high spatial resolution through submicron apertures in a 100 nm thick Al mask on the sample surface.