**Experiment Techniques**

We have investigated the InxGa1-xAs/GaAs SLSs DFLs [32, 41]. As shown in **Figure 13a**,a1 μm two-step grown GaAs were grown on n-doped Si substrate (001) with 4° offcut towards <011> by using Molecular Beam Epitaxy (MBE) system, while the Si substrate was performed at 900°C for 30 minutes to deoxidize. Then three sets of DFLs were grown, while each DFL structure was composed of five periods of InxGa1-xAs/GaAs SLSs. On the top of DFL, an optimized InAs dot-in-awell (DWELL) structure was embedded between two 100 nm GaAs layers and 50 nm Al0.4Ga0.6As layers [42, 43]. A final 300 nm GaAs was deposited on the whole structure.
