Abstract: During the three years of this grant, conclusions were reached that are important for the future of semiconductor cavity QED utilizing photonic crystal nanocavities. A new way was found to scan the cavity mode by condensation of xenon or nitrogen while keeping the quantum dot cold to minimize dephasing. Absorption was shown to reduce the cavity Q when the dot density is 400 per square micron. Lasing with a soft threshold was observed using several quantum dots. Almost 30 samples were grown and characterized for the 900-1000 nm range; ten were grown with an AlGaAs sacrificial layer and GaAs slab for nanocavity fabrication at Caltech. Desirable characteristics were measured: peak wavelengths of the ensemble photoluminescence between 915 and 1020 nm, dot densities from 200 down to just a few per square micron, ensemble radiative lifetimes around 700 ps, and strong Purcell cavity enhanced emission exhibiting anti-bunched photon statistics. However, after at least five years of trying, only one of the best etching groups in the world achieved a Q exceeding 10,000 in the 900-1000 nm range using a GaAs slab; this strongly points to fabricating nanocavities for 1500 nm where scattering losses are smaller.
| Limitations: |
 APPROVED FOR PUBLIC RELEASE |
| Description: |
Final rept. 1 Sep 2005-31 Jul 2008 |
| Pages: |
10 |
| Report Date: |
Aug-2008 |
| Contract Number: |
FA9550-05-1-0455 FA95500510455 |
| Report Number: |
A383005 |
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