Abstract
We describe time-integrated and spectrally resolved degenerate four-wave mixing (DFWM) on hexagonal GaN on sapphire for different laser energies and intensities. Our measured DFWM signal decays exhibit no contributions originating from polariton propagation effects in the 1- to 3-(Formula presented)m-thick bulk samples or from exciton/free-carrier scattering. At low temperatures and low excitation intensities the dephasing time of the (Formula presented) exciton is as long as 3 ps and is most likely due to scattering by defects. At excitation densities above (Formula presented) exciton-exciton scattering becomes the dominant dephasing mechanism and a fifth-order diffraction signal is observed above (Formula presented).
| Original language | English (US) |
|---|---|
| Pages (from-to) | R12718-R12721 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 56 |
| Issue number | 20 |
| DOIs | |
| State | Published - 1997 |
| Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics