Photo‐Curing Vis‐IR Hybrid Fresnel Lenses with High Refractive Index

Abstract

AbstractConventional IR lenses, typically refractive lenses, composed of inorganic semiconductors or chalcogenide glasses, are usually bulky, heavy, and difficult processable. Here, a one‐step photo‐curing imprinting strategy is presented to fabricate lightweight, compact, and high refractive index (HRI) hybrid Fresnel lenses for optical devices based on thiol‐ene/‐yne reactions. The hybrid Fresnel lenses consist of two layers: the silicon/quartz as the support substrate and HRI polymer films as functional layer which are synthesized by thiol‐ene/‐yne reactions with high sulfur‐content comonomers 2,3‐bis((2‐mercaptoethyl)thio)‐1‐propanethiol (BMETP) and its derivatives. The as‐prepared photopolymer films exhibit excellent transparency properties and HRI above 1.62 both in the visible and infrared regions, resulting from the large ratio of sulfur element with high molar refraction. A series of images captured by vis‐IR hybrid Fresnel lenses are demonstrated to confirm the applicability in the area of the optical imaging technique. This strategy, based on the one‐step photo‐curing imprinting, integrating the advantages of the easy processability of organic polymers and high dimensional stability of the inorganic substrate materials, provides a facile, processable, and highly efficient process for fabricating lightweight optical lenses.