DIFFUSION OF NANOPARTICLES INTO TRANSPARENT PLASTIC

A method of preparing an optical element made of a transparent plastic with embedded nanoparticles, the method comprising:a) activating the surface of the optical element by attaching sulfate groups to the surface, comprising immersing the optical element in an aqueous solution of sulfuric acid for a period of time at a maintained activation temperature range; andb) exposing the activated surface to nanoparticles, and allowing the nanoparticles to diffuse into the optical element; wherein a concentration of the sulfuric acid solution, the maintained activation temperature range, and the period of time are selected to:i) activate the surface sufficiently to at least double a diffusion rate of the nanoparticles into the optical element compared to a diffusion rate of the nanoparticles into the optical element using a same protocol but without activating its surface; andii) not cause visible damage to the optical quality of the optical element.