Broadband Dielectric Metasurfaces Using Ceramic Stereolithography

A broadband half-wave plate is demonstrated based on cascaded alumina/air subwavelength gratings. Stacked subwavelength gratings can be well-approximated by homogeneous anistropic layers, permitting analysis by plane wave transfer matrix techniques and rapid design optimization. The example waveplate, fabricated using ceramic stereolithography, shows broadband phase performance and low loss over the K
a
frequency band (26.5 – 40 GHz). Analytic calculations show excellent agreement with measured reflection coefficients, validating the design approach.