On the problem of virtual optical media: Controllable refractive index

The method of creation of a virtual optical medium with controllable refrac tive index is proposed and analyzed. The virtual medium is created by ampli fication of a scattered a probe light wave and scattering back an amplified one. The equation governing propagation of a probe field is derived. It is shown that the effective controllable susceptibility in the case of Raylei gh scattering can be obtained using a medium of suspended nanoballs and a c ylindrical or spherical geometry of an amplifier.