Transformation-based spherical cloaks designed by an implicit transformation-independent method: theory and optimization

Based on the concept of the cloak generating function, we propose an implicit transformation-independent method for the required parameters of spherical cloaks without knowing the needed coordinate transformation beforehand. A non-ideal discrete model is used to calculate and optimize the total scattering cross-sections of different profiles of the generating function. A bell-shaped quadratic spherical cloak is found to be the best candidate, which is further optimized by controlling the design parameters involved. Such improved invisibility is steady even when the model is highly discretized. 5 Author to whom any correspondence should be addressed. New Journal of Physics 11 (2009) 113001 1367-2630/09/113001+16$30.00 © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft