Optical elements with subwavelength structures (SWSs) may function as anti-reflection layers, wave plates, or polarizers. In this study, the authors focus on a pair of two-beam interference lithography systems for fabricating SWS optical elements. These systems have different optical configurations for forming the interference fields required for exposure. The first lithography system described herein creates an interference field by splitting a laser beam with a half-mirror and then superimposing the two resulting beams on a substrate after they propagate through free space. A resist pattern with a period of 140 nm is formed across a 4-inch substrate using a 266-nm CW laser. The other lithography system employs a high-density holographic grating. The two diffracted light waves (0th order and 1st order) produced by the holographic grating generate an interference field in close proximity to the holographic grating, thus enabling a more compact exposure system and a stable lithography process. The desired nano-pattern is obtained by exposing the resist with the 266-nm CW laser using a 140-nm-pitched holographic grating. This research demonstrates the potential of two-beam interference lithography as a viable process for manufacturing SWS optical elements used with the visible spectrum.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.