Fabrication of anti-reflective structures using hot embossing with a stainless steel template irradiated by femtosecond laser

Periodic nanostructures have played critical roles in key components for optical applications. Femtosecond laser-induced periodic surface structures (FLIPSS) in nano scale on many material surfaces have drawn much attention in recent years. However, the relatively low throughput of the direct inducing process limits its potential in regard to high volume manufacturing. In this study, fast replication of FLIPSS on Polycarbonate (PC) films by gas-assisted a hot embossing process is demonstrated. A selected surface area of a stainless steel thin plate is irradiated by femtosecond laser pulses to form a kind of periodic anti-reflective nanostructure with a period measuring 600–700 nm. The stainless plate was then used as a template for the hot embossing process. PC films with periodic nanostructures are then replicated quickly. Compared to the original PC film, at least up to 5% of the reflectivity of the fabricated PC films with nanostructures was reduced. It proves that the gas-assisted hot embossing could procure uniform transcription for anti-reflection PC film with stainless steel template that is irradiated by femtosecond laser pulses.

Using Gas-assisted hot-embossing to manufacture anti-reflective films from Femtosecond Laser mold.Figure optionsDownload as PowerPoint slideHighlights
► Femtosecond Laser to fabricate period anti-reflective structures on stainless steel.
► Let the SSL to become a mold and hot-embossing to PC substrate by gas-assisted.
► Try different parameters of hot-embossing and check the experiment results.
► Reflectivity of the PC films with structures reduced from 9% to 5% at 400–800 nm wavelength.