The architecture shown in the schematic in Fig. 1 (a) demonstrates the multi-wavelength optomechanical architecture that allows control of the speed and tension of both the mask web and substrate web. This allows for deformation-free contact between the mask and the substrate to enable the best lithography conditions.

Approaching the challenge of creating a consistent exposure intensity across the entire web within the spatial constraints of a roller necessitated the use of a laser diode array over other optical beam expanding methods. An array of 19 laser diodes (LDs) of each wavelength allows the light source to reach the collimation, dosage level, and dosage homogeneity required for acceptable exposure conditions. The data shown in Fig. 2 (a) demonstrates optical simulation methods being taken to optimize a roll-to-roll holographic lithography prototype and demonstrate the exposure across the web.

Curing three dimensional structures into a thick photoresist layer also requires demonstrating that the proper collimation gives repeatable spatial interference to prevent pattern loss deeper into the photoresist. By leveraging a Talbot imaging algorithm, and couple wave simulation, it is possible to demonstrate the success that LDs are able to create the desired structures, as shown in Fig. 2 (b) A nal volumetric model of the three-dimensional volumetric intensity pro le produced by the mask is then generated using a nite-di erence time-domain (FDTD) simulation Fig 2 (c). The combination of these simulations supports and informs the design decisions behind the prototyping of this roll-to-roll system and sets the foundation for validating future experimental results. (a) (b)