# Gradient metasurface reflector
Electromagnetic metamaterials and metasurfaces are artificially engineered structures made of subwavelength resonating unit cells. By utilizing various design principles, they have enabled fascinating electromagnetic phenomena and capabilities such as negative refraction, cloaking, high-NA focusing, and so on.
This example demonstrates a near-infrared metasurface reflector consisting of plasmonic antennas. First, we model the unit cell and extract the relationship between a geometric parameter and the corresponding complex reflection coefficient. Then, a super cell consisting of ten antennas is designed to exhibit a linear reflection phase such that the incident light can be diffracted to a particular angle efficiently. By a similar procedure, other beam shaping devices and metalenses can be designed according to different phase profiles.
This example is based on the landmark work Sun, S.; Yang, K.-Y.; Wang, C.-M.; Juan, T.-K.; Chen, W.T.; Liao, C.Y.; He, Q.; Xiao, S.; Kung, W.-T.; Guo, G.-Y.; et al. High-Efficiency Broadband Anomalous Reflection by Gradient Meta-Surfaces. Nano Lett. 2012, 12, 6223–6229 (opens new window).
To view the full example in Python, please click here (opens new window).
To view the example in our web GUI, please click here (opens new window).