Negative-refraction-like behavior revealed by arrays of dielectric cylinders.

We investigate the electromagnetic propagation in two-dimensional photonic crystals, formed by parallel dielectric cylinders embedded in a uniform medium. The transmission of electromagnetic waves through prism structures is calculated by the standard multiple scattering theory. The results demonstrate that, in certain frequency regimes and when the propagation inside the scattering media is not considered, the transmission behavior mimics the negative refraction expected for a left-handed material. This feature may illusively lead to the conclusion that a negative refraction is observed and it obeys Snell's law of negative refraction. Possible implications for current experimental and theoretical studies of negative refraction are also discussed.