Properties of sub-diffraction limited focusing by optical phase conjugation.

Recent work has demonstrated sub-diffraction limited focusing using time-reversal mirrors and sources in scattering media at microwave frequencies. We numerically investigate the possibility of observing analogous effects in the optical domain using small cylindrical scatterers of realistic dielectric materials combined with an enclosing optical phase conjugate mirror in two-dimensional geometries. Such focusing is possible but appears not to significantly exceed the focusing available from an equivalent homogenized material, and is highly sensitive to precise scatterer configuration.