Gaas laser (a) the degenerate occupation of the conduction and valence bands with electrons and holes to maintain the laser requirement that emission must overcome absorption. explain how the degeneracy prevents band-to-band absorption at the emission wavelength of 867 nm (b) assuming equal electron and hole concentrations, and same effective masses for electrons and holes, calculate the minimum carrier concentration n -p for population inversion in gaas at 300 k. the intrinsic carrier concentration at 300 k in gaas is 1x106 cm3, the gap energy is 1.43 ev.