Parasitic photon analysis in sum frequency generation using a bulk PPLN crystalFlora Segur, Sacha Welinski, Romain Demur, Arnaud Grisard, Loic Morvan and Perrine BergerJ. Eur. Opt. Society-Rapid Publ., 21 2 (2025) 46DOI: https://doi.org/10.1051/jeos/2025044