US Patent 11670497 Light emitting sealed body and light source device

A light emitting sealed body includes: a housing containing light-emitting gas in an internal space; a first window portion provided to the housing and on which first light that is laser light for maintaining a plasma generated in the light-emitting gas is incident; and a second window portion provided to the housing and from which second light that is light from the plasma is emitted. The second window portion includes a second window member made of a material containing diamond. A protective layer made of an inorganic material is formed at least on a surface of the second window member on a side of the internal space.