Double Resonance Self-induced Transparency

An analytic solution is found for SIT with two co-propagating pulses which are doubly resonant with two transitions sharing a common excited state. The pulse shapes are the usual hyperbolic secants, but the areas are not 2n. This solution satisfies the atomic equations exactly for all detunings and arbitrary relative amplitudes for the two pulses. The field equations, however, place extra restrictions on the detunings for perfect dispersionless propagation.