A light emitter includes a substrate, a first mirror layer provided on the substrate, a columnar section including an active layer provided on a side of the first mirror layer that is the side opposite the substrate and a second mirror layer provided on a side of the active layer that is the side opposite the first mirror layer, a semi-insulating member provided on the side surface of the columnar section and having thermal conductivity higher than the thermal conductivity of the first mirror layer and the thermal conductivity of the second mirror layer, and a sub-mount which has a first surface bonded to the semi-insulating member and through which light produced in the active layer passes, and a second surface of the sub-mount that is the surface opposite the first surface is oriented in the direction in which the light produced in the active layer exits.