Surface relief waveguides with high refractive index resist

Abstract

The disclosure describes an improved drop-on-demand, controlled volume technique for dispensing resist onto a substrate, which is then imprinted to create a patterned optical device suitable for use in optical applications such as augmented reality and/or mixed reality systems. The technique enables the dispensation of drops of resist at precise locations on the substrate, with precisely controlled drop volume corresponding to an imprint template having different zones associated with different total resist volumes. Controlled drop size and placement also provides for substantially less variation in residual layer thickness across the surface of the substrate after imprinting, compared to previously available techniques. The technique employs resist having a refractive index closer to that of the substrate index, reducing optical artifacts in the device. To ensure reliable dispensing of the higher index and higher viscosity resist in smaller drop sizes, the dispensing system can continuously circulate the resist.