Frequency upconversion can be utilized as flexible broadband mode selector for engineered phase matching properties. We give a detailed spectral analysis of frequency upconversion in two different nonlinear waveguides, namely LiNbO3 and KTiOPO4.
We investigate the spectral correlations between input and output photon and derive conditions for their absence. By applying our analysis to the special scenario of upconverting a 1550 nm input photon, we find that for this scenario LiNbO3 is better suited than KTiOPO4. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)