Lerch, StefanStefanLerchBessire, BänzBänzBessireBernhard, ChristofChristofBernhardFeurer, ThomasThomasFeurerStefanov, AndréAndréStefanov0000-0002-5588-79862024-10-152024-10-152013-04-01https://boris-portal.unibe.ch/handle/20.500.12422/120106We study the tuning curve of entangled photons generated by type-0 spontaneous parametric down-conversion in a periodically poled potassium titanyl phosphate crystal. We demonstrate the X-shaped spatiotemporal structure of the spectrum by means of measurements and numerical simulations. Experiments for different pump waists, crystal temperatures, and crystal lengths are in good agreement with numerical simulations.en500 - Science::530 - Physicsarticle10.7892/boris.4984910.1364/JOSAB.30.000953