Can anyone point me to a source for measurements of the third-order nonlinear electric susceptibilities $\chi^{(3)}$ of various metals? Specifically in relation to the AC Kerr effect, so measurements of the second-order index $n_2$ would do as well.
For example, Bloembergen published measurements in 1969 (Opt. Comm. 1(4), 195) of the $\chi^{(3)}$ of silver and gold determined using THG, but I'd like to know if there's any data for other metals, and whether they are any different when studying the Kerr effect.
