Abstract: A dielectric grating apparatus comprises a substrate; a grating layer, disposed above the substrate; a first interference layer, disposed above the substrate; and a second interference layer, adjacent to the first interference layer, wherein a refractive index of a material of the second interference layer is greater than a refractive index of a material of the first interference layer.

Abstract: A golf club head including a main body and a physical vapor deposition layer is provided. The physical vapor deposition layer is formed on a curved surface of the main body and has a laser engraved structure. The disclosure further discloses a manufacturing method of the golf club head. According to the golf club head and the manufacturing method thereof, the physical vapor deposition layer is formed on the curved surface, so the curved surface appears to have a natural metallic luster and texture. Furthermore, the laser engraved structure is formed on the physical vapor deposition layer by using the laser engraving technology, so the curved surface further appears to have a stereoscopic texture. In addition, the laser engraved structure is filled with a dye layer, so the laser engraved structure appears to have a color different from that of the physical vapor deposition layer.