Negative refraction of light in Bragg mirrors made of porous silicon

In allowed photonic bands of one-dimensional photonic crystals (Bragg mirrors) light modes propagate with negative effective masses at certain frequencies. We demonstrate theoretically that this effect allows for the negative refraction of the visible light. We propose a structure made of two porous silicon Bragg mirrors with one rotated by 90° with respect to the other. This structure that may serve as a Veselago lens with a focal distance of the order of 10−5 m.