“…Arecchi [1] proposed the 3-dimensional quadratic differential system ⎧ ⎪ ⎨ ⎪ ⎩Ė = −k E + g P, P = −γ ⊥ P + g EΔ, Δ = −γ (Δ − δ 0 ) − 4g P E, (1.1) called the Maxwell-Bloch system, where E is the coupling of the fundamental cavity mode, P is the collective atomic polarization, Δ represents the population inversion, k, γ ⊥ , γ are the loss rates of field, polarization and population respectively, g is a coupling constant (g = 0) and δ 0 is the population inversion which would be established by the pump mechanism in the atomic medium, in the absence of coupling. As indicated in [1,15,17], the Maxwell-Bloch system describes Type I laser (He-Ne), Type II laser (Ruby and CO 2 ) and Type III laser (far infrared) when γ ⊥ ≈ γ k, when γ ⊥ γ ≈ k and when Δ 0 is large enough, respectively. Numerical simulations [1] show that Type I laser and Type II laser are both stable but Type III laser is unstable.…”