CC BY 4.0Hendra, PatrickPatrickHendraLeon Torres, Josue RicardoJosue RicardoLeon TorresGili, Valerio FlavioValerio FlavioGiliGräfe, MarkusMarkusGräfe2025-09-152025-09-152025https://publica.fraunhofer.de/handle/publica/495207https://doi.org/10.24406/publica-541810.1364/JOSAB.56777510.24406/publica-54182-s2.0-105014942593We investigate the dual generation of type-0 and type-II spontaneous parametric down conversions (SPDCs) within a single periodically poled rubidium-doped (PPRKTP) waveguide. By coupling a 45° linearly polarized pump laser into the waveguide, both SPDC processes are concurrently excited: type-0 SPDC process is facilitated via third-order quasi-phase matching (QPM) utilizing the nonlinear coefficient , while type-II SPDC process employs first-order QPM with the nonlinear coefficient . This dual-SPDC scheme holds potential for applications in quantum communication protocols targeting the telecommunication wavelength.enfalsejournal article