First Measurement of the Non-instantaneous Response Time of a χ(3) Nonlinear Optical EffectSusanta K. Das, M. Bock, R. Grunwald, B. Borchers, J. Hyyti, G. Steinmeyer, D. Ristau, A. Harth, T. Vockerodt, T. Nagy and U. MorgnerEPJ Web of Conferences, 41 (2013) 12005DOI: https://doi.org/10.1051/epjconf/20134112005