  The nowadays notable development of all the modern technology, fundamental
for the progress and well being of world society, imposes a great deal of
stress in the realm of basic Physics, more precisely on Thermo-Mechanical
Statistics. In electronics and optoelectronics we face situations involving
physical-chemical systems far-removed-from equilibrium, where ultrafast (in
pico- and femto-second scale) and non-linear processes are present. Here we
describe in an extended overview the question of ultrafast relaxation processes
in the excited plasma in semiconductors.
