Using a hybrid ion implanted/selectively oxidized device structure, we repo
rt high-power single-mode operation of an 850-nm vertical-cavity laser. Und
er continuous-wave operation, > 4 mW of single-mode power with 45 dB of sid
e-mode suppression is achieved. The spectral behavior under pulsed modulati
on is determined to be influenced by thermal lensing. When biased to thresh
old, single-mode operation with > 35-dB side-mode suppression is obtained f
or large signal modulation.