The strong transient optical absorption in n-InSb Raman Spin-flip laser device at 2°K was observed by Figueira, Cantrell, Rink and Forman. It was interpreted due to the laser generated hot conduction electrons. We present the main results of a theoretical microscopic calculations for this non-linear laser absorption. By assuming the time-dependent functions for electronic temperature and Fermi energy, the time evolution of the non-equilibrium hot electron distribution during the pulsed laser irradiation is calculated from first principle.