Abstract
We present far-infrared (FIR) modulated photoluminescence measurements of self-assembled InAs/GaAs quantum dots. The sample was annealed to remove any indium profile roughness from within the quantum dots and thus from the inhomogeneous broadening. The annealed sample shows resonant FIR excitations just as the unannealed sample, but exhibits spectral hole burning unlike the unannealed sample. The results indicate that indium roughness is one of the primary inhomogeneous broadening mechanisms in self-assembled quantum dots.