A team of Foundry staff and users have fabricated a nanostructured GaAs/AlGaAs waveguide that enables record low-threshold lasing from an exciton-polariton condensate.
Significance and Impact
The new fabrication method substantially lowers the power needed to achieve a polariton condensate, making it a good candidate for thresholdless lasers which could be used in next-generation optical transitions or fast optical light switches.
- The research team fabricated the waveguide with a 90-nm-deep grating, along with a conformal passivating layer of Al2O3 deposited by ALD.
- ALD post-processing greatly reduces surface defects (which introduces nonradiative channels through which excitons can decay), increasing the polariton lifetime at the BIC and lowering the condensation threshold.