Did you even read the article? It explicitly states the cloak bandwidth includes red, green, and blue optical frequencies. Calcite's dispersion relation gives s

Did you even read the article? It explicitly states the cloak bandwidth includes red, green, and blue optical frequencies. Calcite's dispersion relation gives slightly different shifts for each frequency, but this is nevertheless a huge step forward. http://arxiv4.library.cornell.edu/abs/1012.2238 http://arxiv4.library.cornell.edu/abs/1012.2238 http://arxiv4.library.cornell.edu/abs/1012.2783v1 http://arxiv4.library.cornell.edu/abs/1012.2783v1