Coherence Dynamics of the Exciton-Polariton System in GaAs Microcavities under Pulse Resonant Photoexcitation

It is found that exciton-polariton systems resonantly excited in GaAs semiconductor microcavities by coherent picosecond laser pulses inherit the high coherence of the laser beam and retain it for their lifetime (>100 ps), while the coherence-formation time in polariton systems resonantly excited by incoherent pulses without excitation of the exciton reservoir exceeds 200 ps.