Abstract
Interactions of few-cycle terahertz pulses with the induced optical polarization in a quantum-well microcavity reveal that the lower and higher exciton-polariton modes together with the optically forbidden -exciton state form a unique -type three-level system. Pronounced nonlinearities are observed via time-resolved strong-terahertz and weak-optical excitation spectroscopy and explained with a fully microscopic theory. The results show that the terahertz pulses strongly couple the exciton-polariton states to the -exciton state while no resonant transition between the two polariton levels is observed.
- Received 9 December 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.267402
© 2012 American Physical Society