Sir, NO heat or cooling involved ??

100 femtoseconds is a pretty fast switch time, but it is activated by temperature, changing which takes considerably longer. Heating is doable with a laser pulse. How fast would the particle heat up? Cooling sounds more difficult; the heat would need to radiate away somehow – a pretty slow process. The result is a kind of a "instant on – slow off" switch.

Materials are known to be able to retain optical switching properties and non volatile polarities to 3.8 nanometer cell sizes while being able to change binary dipole states at less than 160 picoseconds.