Abstract

Indium Tin Oxide, ITO, is the workhorse of high speed switching of light. High intensity pulses switch ITO from a metallic to a transparent state within a few tens of femtoseconds by heating the conduction electrons. Recent experiments using multi-GW intensity pumps reveal previously unseen processes where very hot conduction electrons have enough energy to promote valence electrons into the conduction band via the Auger effect. This high intensity switching has different characteristics from the low intensity process and offers the possibility of even faster switching rates and of shaping the window of transparency. We construct a model which accurately reproduces the features seen in experiment..