Problem 2: (from Siegman Lasers section 6.2). 4-level laser inversion and saturation including degeneracies. Repeat the pumping and saturation calculations for a 4-level laser system given during the lecture (and also described in the section 6. 2 of the Siegman's book) assuming the same pumping rate Rp and relaxation rates yij as in the text, but taking into account the existence of degeneracies g and g2 of the lower and upper energy levels and their effect on the definitions of W12, W21, and AN21.