Tailoring second-order harmonic generation with crystal antiphase domains in GaP/Si

International audience; GaP is a promising candidate for the development of integrated photonic functions on silicon, because of its quasi lattice‐matching with Si and its interesting χ(2) non‐linear properties. We present the realization of GaP‐based microdisks on Si substrates, and discuss their optical properties, especially the antiphase domains (APDs) impact on second‐order harmonic generation. We show that the relevant parameter is the average polarity of the crystal while the size of the APDs does not impact the non‐linear processes. The control of the APD annihilation with AlGaP markers is found to be a promising route towards nonlinearity engineering in Si‐integrated photonic devices.