  Experiments on Indium Tin Oxide (ITO) have revealed that a relatively broad
200THz pump pulse, roughly 30 cycles in width, can switch ITO from a
transparent to a reflecting state within one or two optical cycles, a few
Femtoseconds. So far the rapid switching has remained unexplained by theory.
Here a very simple bare bones theory explains the key experimental features in
terms of an avalanche model suggested by avalanche diodes.
