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arXiv · 2312.13851

Visible metalenses with high focusing efficiency fabricated using nanoimprint lithography

Andrew McClung·Mahsa Torfeh·Vincent J. Einck·James J. Watkins·Amir Arbabi
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Abstract

Metasurfaces enable precise control over the properties of light and hold promise for commercial applications. However, fabricating visible metasurfaces suitable for high-volume production is challenging and requires scalable processes. Nanoimprint lithography is a cost-effective and high-throughput technique that can meet this scalability requirement. This work presents a mask-templating nanoimprint lithography process for fabricating metasurfaces with varying fill factors and negligible wavefront aberrations using composite stamps. As a proof-of-concept, a 6 mm diameter metalens formed of silicon nitride nano-posts with a numerical aperture of 0.2 that operates at 550 nm is demonstrated. The nanoimprinted metalens achieves a peak focusing efficiency of ($81\pm1$)%, comparable to the control metalens made with electron beam lithography with a focusing efficiency of ($89\pm1$)%. Spatially resolved deflection efficiency and wavefront data, which informs design and process optimization, is also presented. These results highlight nanoimprint lithography as a cost-effective, scalable method for visible metasurface fabrication that has the potential for widespread adoption in consumer electronics and imaging systems.

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Andrew McClung, Mahsa Torfeh, Vincent J. Einck, James J. Watkins, Amir Arbabi. 2023-12-21. Visible metalenses with high focusing efficiency fabricated using nanoimprint lithography. https://doi.org/10.1002/adom.202301865

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