Optical concentrator from a hyperbolic liquid-crystal metamaterial Frankbelson dos S. Azevedo, David Figueiredo, Fernando Moraes, Bertrand Berche and Sébastien Fumeron EPL, 124 3 (2018) 34006 Published online: 05 December 2018 DOI: 10.1209/0295-5075/124/34006