Sub-wavelength gratings fabricated on a light bar by roll-to-roll UV embossing process.

This research uses a roll-to-roll based ultraviolet (UV) resin process to make sub-wavelength gratings for display applications. Based on the rigorous coupling wave analysis (RCWA), we analyze the relationship between the first order transmission/reflection efficiency and the pitch of the grating for various shapes as rays pass through the sub-wavelength gratings, patterned with a backlight. The objective is to turn the R/G/B (620 nm, 520 nm, and 450 nm) incident rays into uniformly and normally output white light with high illuminance from the surface of a light guide.