Coherent backscattering of electromagnetic waves in random media

Abstract

The single and multiple scattering regimes of electromagnetic waves in a disordered system with fluctuating permittivity are studied by numerical simulations of Maxwell's equations. For an array of emitters and receivers in front of a medium with randomly varying dielectric constant, we calculate the backscattering matrix from the signal responses at all receiver points j to electromagnetic pulses generated at each emitter point i. We show that the statistical properties of the backscattering matrix are in agreement with the recent experimental results for ultrasonic waves (Aubry A. and Derode A.,

Symmetry constraints for vector scattering and transfer matrices containing evanescent components: energy conservation, reciprocity and time reversal

“…Knowledge of these matrices and their statistical properties has revealed the existence of highly transmitting 'open eigenchannels', even for optically thick systems [12][13][14], and has greatly enhanced the prospect of imaging through multiple scattering media, such as biological tissue, through careful wavefront control and the exploitation of scattered field correlations, such as the memory effect [15][16][17][18][19][20][21]. Scattering matrices have also been employed in theoretical studies of random laser modes [22], information transfer through random media [23], coherent backscattering [24] and Anderson localization [25].…”

Phase conjugation of ultrasound waves in comparison with backscattering in disordered medium

“…Coherent multiple scattering in disordered media still belongs to the hot topics in various branches of the fundamental wave physics: acoustics, optics, electrodynamics [1][2][3][4][5][6]. Time reversal transformation of acoustic and electromagnetic waves under multiple scattering was proposed as a mean for achievement of super-resolution over the diffraction limit [7][8][9].…”