AlGaAs-on-insulator Waveguides for Highly Efficient Photon Pair Generation

Efficient photon pair sources that provide high generation rates are necessary for applications in secure non-classical communication, quantum teleportation, and quantum information processing. This motivated the development of diverse integrated photon pair sources based on silicon nitride [1] , As 2 S 3 [2] , and AlGaAs [3] . In particular, the fabrication of AlGaAs-on-insulator (AlGaAs-OI) waveguides allows for submicrometer modal confinement, which leads to the enhancement of the effective nonlinearity in a material platform with low propagation losses. In addition, the high second χ (2) and third order χ (3) nonlinearities of AlGaAs [4] , and the possibility to modify the Al concentration of the alloy to reduce two-photon absorption (TPA) at telecom wavelengths [3] , make AlGaAs-OI a very promising candidate for highly efficient photon-pair generation via spontaneous parametric down conversion (SPDC) and spontaneous four-wave mixing (SFWM) processes.