Computational Exploration of Anti-Reflective Nanostructures

Anti-reflective (AR) coatings and structures are a key part of many optical systems, providing increased transmission efficiency and reducing issues related to back-reflection and unwanted interference. However, the theory behind these devices means they often function best at specific wavelengths and incidence angles, leading to difficulties when reflection needs to be minimized over a broadband spectrum or wide angular range. This project uses the GD-Calc MATLAB package to computationally explore the design of AR nanostructures, periodic patterns of sub-wavelength structures designed to create a gradient in the effective refractive index. Baseline construction parameters are determined from previous work in the literature, manufacturing feasibility is considered when determining final structure parameters, and structure performance is evaluated based on overall transmittance as well as sensitivity to small parameter variations. We present the results of our exploration of structures such as cones, cylinders, and pyramids with manufacturing parameters optimized for 1550 nm light under a variety of incidence angles.