Homogeneous dielectric cylinders invisible at optical frequency

Abstract

We report invisible circular cylinders without any coating at optical frequency. The invisibility appears when the refractive index of the dielectric cylinder ranges from 2.7 to 3.8, which we can realize with natural materials. The possibility to perform an experimental demonstration on the invisibility is discussed. The calculation is based on the finite-difference time-domain method which revealed that the invisibility stems from the cancellation of the dipoles generated in the cylinder.