| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser element which can be used for a long period, even when the output of the element is increased by lowering the oscillation threshold of the element. SOLUTION: In a nitride semiconductor element having an active layer 8 between an n-type nitride semiconductor layer and a p-type nitride semiconductor layer, a superlattice layer formed by laminating a first nitride semiconductor layer containing Al and a second nitride semiconductor layer having a different composition from that of the first layer upon another is provided to at least one of the n- and p-type nitride semiconductor layers and the Al content in the first layer is adjusted so that the content may become lower as going toward the active layer 8. In addition, the content of the impurity contained in the superlattice layer to decide the conductivity is also adjusted so that the content may become lower as going toward the active layer 8. Since light rays tend to concentrate to the active layer 8 due to the GRIN structure composed of the superlattice, the oscillation threshold of the nitride semiconductor element is reduced. |
