Single-mode operation in the slow-light regime using oscillatory waves in generalized left-handed heterostructures

The authors present an exact, analytic study of oscillatory modes guided by generalized asymmetric two-dimensional planar heterostructures with negative refractive index in either the core or the cladding. It is shown that, in sharp contrast to normal dielectric configurations, these waveguides always possess a frequency region where the second-order oscillatory mode may exist alone and allow for attaining zero group velocity under weak guidance conditions. In addition the mode has a field distribution that renders it excitable with an end-fire approach, making such structures attractive for applications requiring slow light. Advantages compared to previous methods of slowing or stopping light are discussed.