Fabrication of a nano/micro hybrid lens using gas-assisted hot embossing with an anodic aluminum oxide (AAO) template

This paper reports a novel and effective method for the fabrication of a polymeric nano/micro hybrid lens array. The nanostructure and microlens arrays are fabricated on the same polycarbonate ( PC) substrate by hot embossing in sequence. First, an anti-reflection PC film with sub-wavelength nanostructures is fabricated using an anodic aluminum oxide (AAO) template. The anti-reflection characteristic of nanostructures on the PC film is evaluated. Then an array of convex microlenses is formed from the nanostructured PC film using a stainless steel mold with a microhole array. Both processes employ gas-assisted hot embossing to perform the partial protrusion of the film into nano-sized or micro-sized holes in the AAO template and steel mold. The optical property of the microlens has been verified. This proposed technique has proven its potential for effectively fabricating a nano/micro hybrid lens array on a polymeric substrate.