Fig. 2. Ladder diagrams of the circular dichroism signal. The left and right diagrams correspond to first and second term in eqn (9) respectively. The gray zone is the pump pulse with either a linearly polarized pulse or circularly polarized pulse. After the pump pulse, the polariton is excited and described by density matrix ρee′. A CD measurement is done with circularly polarized pump pulse at a later time.
