Nonlinear Electromagnetics and Coherent Energy Transfer in Negative-Index metamaterials.

摘要

An understanding was advanced of nonlinear propagation properties of electromagnetic (EM) waves in double-domain negative/positive index metamaterials (MMs) with focus on the coherent nonlinear-optical (NLO) energy transfer between the ordinary and backward waves (BWs), i.e. the waves with contra-directed energy flux and phase velocity. A theory was developed and proof-of-principle computational studies were conducted of the outlined processes in the context of particular MMs and their unique potential applications to photonics. Numerical simulations were carried out of the multi-parametric dependences of the solutions to the set of partial differential wave equations accounting for the backwardness of one of the coupled waves. Frequency conversion, which stems from the NLO coupling of contra-propagating short pulses, was studied. A novel approach was proposed to engineering of the MMs, which support coexistence of phase-matched ordinary and BEM eigenmodes satisfying to three-wave mixing. It is based on negative spatial dispersion. A possibility to mimic the outlined extraordinary processes using stimulated Raman scattering on BW optical phonons was shown, which enables greatly enhanced amplification of ordinary Stokes signals.