Figure 20.
(a) Ray trajectory of light entering the spherical transformation space is guided smoothly around any object within the inner spherical region. Reproduced with permission.336 Copyright 2006, American Association for the Advancement of Science. (b) Calculated photon trapping by a photon black hole created by designing a spatial varying silicon-silica composite. Reproduced with permission.339 Copyright 2009, American Institute of Physics. (c) The photonic band diagram of a metallic double gyroid structure enabling negative refraction of light. The local energy flux vectors (the inset) of the negative refraction mode (thick red line in the band diagram) is in the opposite direction to the wavevector. Reproduced with permission.340 (d) SEM image of BCP derived gold gyroid network with a = 35 nm and filling fraction of 30%. Reproduced with permission.341