Metamaterials subwavelength terahertz resonant cavities M. Al-Rubaiee, A. H. Al-Janabi, S. C. Fleming and A. Argyros J. Eur. Opt. Soc.-Rapid Publ., 17 1 (2021) 11 Published online: 16 June 2021 DOI: 10.1186/s41476-021-00157-8