Abstract: An emitter adapted to emit a first radiation, said emitter having a substrate, and a mesa made of a first semiconductor material having a first bandgap value. The mesa has a superior side and a lateral side. A covering layer has one or several radiation-emitting layer(s) made of a second semiconductor material having a second bandgap value strictly inferior to the first bandgap value. Each radiation-emitting layer has a first portion corresponding to the superior side and a second portion corresponding to the lateral side. A first thickness is defined for the first portion and a second thickness is defined for the second portion, the second thickness being strictly inferior to the first thickness.