A vertical cavity surface emitting laser with a mode-selective mirror. A
filter is formed on the top DBR stack of a VCSEL. The filter includes
semiconductor layers that are etch stops for immediately superior layers.
The filter is selectively etched to create a first region that is phase
matched to the top DBR stack and a second region that is phase mismatched
to the top DBR stack. The second region inhibits undesired modes and
provides additional absorption for the undesired modes. The first region
is formed using a wet-etch process whose etch depth is controlled because
the semiconductor layers are etch stops for immediately superior layers.