Optical dephasing of excitonic polaritons in CuCl is directly measured for the first time in the picosecond time domain by means of time-resolved, nondegenerate four-wave mixing. Dephasing of the ω1 polariton pulse is probed by an interrogation ω2 polariton pulse whose group velocity is faster than that of the ω1 polariton pulse. It is found that the dephasing damping constant Γ2 of excitonic polaritons is of order of 0.01 meV and increases as ω1 approaches the exciton resonance energy from below.
ASJC Scopus subject areas
- General Physics and Astronomy