Harmonic Generation in GaP/Si and GaP/AlP Superlattice-Based Waveguides

We present a theoretical investigation, based on the tight-binding Hamiltonian, of efficient second harmonic generation (SHG) in the lattice-matched N-doped (GaP)(N) / (Si-2)(M) short-period superlattice integrated in a strip waveguide in the silicon-on-insulator platform. The X-(2) spectrum has been simulated as a function of the number of the monolayers for the "non-relaxed" heterointerfaces. For TM pumps at 5.05 mu m a X-(2) value of 1.25x10(4) pm/V has been calculated for the (GaP)(1) / (Si-2)(2) superlattice giving a maximum conversion efficiency around 1.14%/W, where the waveguide coherence length was 3.37 mu m and the waveguide width was 2 mu m. Moreover the (GaP)(3) / (AlP)(3) superlattice is proposed for SHG with surface incidence, operating in the mid infrared with X-(2) value of 1.8x10(4) pm/V. Finally, the X-(2) spectrum for difference frequency generation is reported for (GaP)(5) / (Si-2)(1) and (GaP)(4) / (Si-2)(2).