High Q whispering gallery modes in GaAs/AlAs pillar microcavities.
We report the observation of whispering gallery modes (WGM) in high quality GaAs/AlAs pillar microcavities defined by electron-beam lithography and electron cyclotron resonance reactive ion etching. Photoluminescence experiments, conducted using InAs quantum dots as an internal probe, reveal a remarkably simple WGM spectrum, consisting of a single series of TE modes. For diameters ranging from 3 to 4 mum, Q-factors in excess of 15 000 were measured, allowing for WGM lasing. Noticeably, sub-micron diameter micropillars also display high Qs (~ 1000), close to the limit set by intrinsic radiative losses. These results open the way to the development of original microlasers and improved quantum-dot single photon sources.
Nowicki-Bringuier
Y-R
YR
Claudon
J
J
Böckler
C
C
Reitzenstein
S
S
Kamp
M
M
Morand
A
A
Forchel
A
A
Gérard
J M
JM