Exciton-photon coupling in a ZnSe based microcavity fabricated using epitaxial liftoff

Abstract

We report the observation of strong exciton-photon coupling in a ZnSe based microcavity fabricated using epitaxial liftoff. Molecular beam epitaxial grown ZnSe/Zn$_{0.9}$Cd$_{0.1}$Se quantum wells with a one wavelength optical length at the exciton emission were transferred to a SiO$_2$/Ta$_2$O$_5$ mirror with a reflectance of 96% to form finesse matched microcavities. Analysis of our angle resolved transmission spectra reveals key features of the strong coupling regime: anticrossing with a normal mode splitting of $23.6 meV$ at $20 K$; composite evolution of the lower and upper polaritons; and narrowing of the lower polariton linewidth near resonance. The heavy hole exciton oscillator strength per quantum well is also deduced to be $1.78 \times 10^{13} cm^{-2}$.