The quantum dots have added great benefits to the photonic activity, among them the decoupling between the lattice parameter of the substrate and the dot has opened the way to enlarge the spectral windows which can be accessible on different substrates. For example on a GaAs substrate a long wavelength laser emission of 1.46 µm has been demonstrated at room temperature. The specific properties like: large material gain, large spectral bandwidth, high speed carrier dynamics, have improved device performances. The minimum threshold current densities of laser devices, the large spectral bandwidth of semiconductor optical amplifiers and the very high repetition rate and very short pulse width on mode locked lasers are other benefits.