Spectrally selective coatings for optical surfaces

A method of fabricating a spectrally selective coating, comprising:

• producing, by a spark erosion process, nanoparticles that are oxidation resistant to air exposure at a temperature higher than 650° C.;
• forming a nanoparticle-dispersed solution including the nanoparticles contained within a solvent fluid including a dielectric material;
• depositing the nanoparticle-dispersed solution onto a surface of a light absorbing material;
• and
• drying or curing the nanoparticle-dispersed solution to form a coating having a particular spectral absorptivity and spectral emissivity, the coating formed of a composite material including the nanoparticles embedded in the dielectric material.