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Low-cost and high-precision fabrication of surface relief gratings on AR/VR waveguide combiners is one of the critical steps in realizing devices suitable for mass adoption. Displacement Talbot Lithography (DTL) has emerged as a viable technology that relies on the proven optical lithography approach of the semiconductor industry while offering a low-cost solution for large area printing of periodic structures of the kind required on waveguides. However, patterning with DTL differs from the common projection photolithography approaches in terms of the optical concepts used in printing an image in a photoresist layer. A key capability required for mass adoption is accurate simulation support for faster integration, process optimization, and mask design. Electronic Design Automation (EDA) tools are common for projection approaches and can now be used to understand DTL interactions with waveguide designs. This approach relies on three specific Synopsys modeling tools, namely S-Litho and RSoft Photonic Device Tools in conjunction with LightTools which are used for optimization of the photolithographic printing process (DTL) and the optical performance of the printed device (waveguide), respectively. A dedicated suite for modelling the DTL process within the S-Litho software was developed for this purpose. The model is calibrated and optimized using actual printing results in photoresist layers obtained through the DTL process. In this presentation we will show results of this new method that combines the optimization of DTL lithographic printing and optical performance of the resulting waveguide. The combination of the unique DTL solution and the comprehensive simulation capabilities holds great promise for accelerating the development and commercialization of AR devices.
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