Light emitting device, method of manufacturing a light emitting device, and method of manufacturing a submount

A light emitting device comprising:

• a submount including:
• a graphite layer having an upper surface and a lower surface that extend along a first direction and a second direction which are orthogonal to each other, wherein the graphite layer includes a plurality of graphene structures that are layered in the first direction, each of the plurality of graphene structures extending in the second direction, and
• a support layer having an upper surface and a lower surface that extend in the first direction and the second direction, the support layer being thicker than the graphite layer, the upper surface of the support layer supporting the lower surface of the graphite layer;
• a semiconductor laser device configured to emit laser light through an end surface in the first direction, the semiconductor laser device including a waveguide that extends in the first direction and is supported by the upper surface of the graphite layer;
• and
• a base supporting the submount, wherein
• the graphite layer is provided on the entire upper surface of the support layer,
• the graphite layer includes a main portion having an upper surface and a lower surface and a flange portion around the main portion and having an upper surface and a lower surface,
• the upper surface of the main portion supports the semiconductor laser device,
• the lower surface of the main portion and the lower surface of the flange portion are flush with each other, and
• relative to the upper surface of the support layer, the upper surface of the flange portion is at a lower position than is the upper surface of the main portion.