Fabrication of optical reflectors by using of elastomer with self-organized undulations

Back-surface diffusive reflectors have been widely applied in many optical systems to promote the efficiency used in system. In this work, we propose a novel way to fabricate a soft diffusive reflector by using of silicone (polydimethylsiloxane, PDMS). High-reflectance substrates were first fabricated by mixing nanoscaled TiO2 powders with PDMS polymers, and then microscale wave-like undulations were spontaneously developed after the substrates were dipped into H2SO4/HNO3 solutions. After optical examination, a TiO2/PDMS plate comprising microscale undulations, which can surely serve as a reflector, could reflect and diffuse light effectively. Besides, all fabrication processes can be executed in the ambient environment and at low temperature. This proposed method has a potential for mass production in the future.