Hamamatsu-photonics K.k.

Yutaka Takagi

Takahiro Sugiyama

Masahiro Hitaka

A DFB laser element includes an active layerhaving a multiple quantum well structure including a plurality of well layersB having different thicknesses, a diffraction grating layerthat is optically coupled to the active layer, and a pair of cladding layers with the active layerand the diffraction grating layerinterposed therebetween. An effective refractive index of the diffraction grating layeris high, and a thickness of the well layerB increases as a distance from the diffraction grating layerincreases. In this structure, it is possible to reduce dependence on temperature when the DFB semiconductor laser element is miniaturized.

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Hamamatsu, Japan

Yutaka Takagi