This disclosure concerns devices such as DBRs, one example of which includes at least one first mirror layers having an oxidized region extending from an edge of the DBR to an oxide termination edge that is situated greater than a first distance from the edge of the DBR. The DBR also includes at least one second mirror layer having an oxidized region extending from the edge of the DBR to an oxide termination edge that is situated less than a second distance from the edge of the DBR, such that the first distance is greater than the second distance. Additionally, a first mirror layer includes an oxidizable material at a concentration that is higher than the concentration of the oxidizable material in any of the second mirror layers. Finally, a first mirror layer is doped with an impurity at a higher level than one of the second mirror layers.