Method of fabricating of diamond moth-eye surface

A method of forming a diamond moth eye surface on an optical material, comprising the steps of:

• providing a substrate;
• etching said substrate anisotropically to produce cavities in said substrate, said cavities forming a surface relief pattern having an etch profile comprising an inverse of said diamond moth eye surface;
• seeding said etched substrate with diamond particles;
• nucleating and growing a polycrystalline diamond film on said substrate, said diamond film covering said substrate and filling said cavities;
• bonding said optical material to said diamond film with a refractive index matched cohesive material;
• and
• removing said substrate from said diamond film to expose said diamond moth eye surface to the atmosphere, said moth eye surface having dimensions for providing an effective refractive index gradient between the atmosphere and said optical material bonded to said diamond film.

A method of forming a thick film polycrystalline diamond moth eye surface on an optical material, comprising the steps of:

• providing a substrate for supporting growth of said diamond film;
• etching said substrate anisotropically to produce cavities in said substrate, said cavities forming a surface relief pattern having an etch profile comprising an inverse of said diamond moth eye surface;
• seeding said etched substrate with sub-micron diamond particles;
• nucleating and growing said polycrystalline diamond film on said substrate, said diamond film covering said substrate and filling said cavities;
• bonding said optical material to said diamond film with a refractive index matched cohesive material;
• and
• removing said substrate from said diamond film to expose said diamond moth eye surface to the atmosphere, said moth eye surface having dimensions providing an effective refractive index gradient between the atmosphere and said optical material bonded to said diamond film.