A general overview of slow light waveguide structures made of negative metamaterials is presented. We discuss the conditions and the parameter space to achieve zero total energy flow and zero group velocity due to the degeneracy of forward and backward waves in waveguides cladded with single negative metamaterials. Absorptive loss plays a severely limiting role and can prevent achieving the zero group velocity condition. Gain can be introduced either in dielectric or negative metamaterials to restore the zero group velocity condition. This type of slow light waveguide has a large delay bandwidth product and is suitable for use in integrated optoelectronic circuits.
A general overview of slow light waveguide structures made of negative metamaterials is presented. We discuss the conditions and the parameter space to achieve zero total energy flow and zero group velocity due to the degeneracy of forward and backward waves in waveguides cladded with single negative metamaterials. Absorptive loss plays a severely limiting role and can prevent achieving the zero group velocity condition. Gain can be introduced either in dielectric or negative metamaterials to restore the zero group velocity condition. This type of slow light waveguide has a large delay bandwidth product and is suitable for use in integrated optoelectronic circuits.
Recently there has been a considerable interest in metamaterial waveguide structures capable of dramatically slowing down or, even, completely stopping light. Here, we shall explain in some detail the working principle behind the deceleration and/or stopping of light in metamaterial structures, and review the various, metamaterial-enabled, methods that have been proposed thus far towards achieving such a goal. Further, we will concisely describe how one can construct zero-loss metamaterials over a continuous and broad (but not infinite) range of frequencies, which is an essential prerequisite for any slow-light system. Moreover, it will be explained that inside such waveguide structures light can in principle be stopped (zero group velocity, vg = 0) even in the presence of losses. By nature, metamaterialenabled schemes for stopping/storing light invoke solid-state materials and, as such, are not subject to low-temperature or atomic coherence limitations. Furthermore, these methods simultaneously allow for broad bandwidth operation, since they do not rely on group index resonances; large delay-bandwidth products, since a wave packet can, in principle, be completely stopped and buffered indefinitely; and (for the case, in particular, where a negative-index metamaterial is used) high, almost 100%, in/out-coupling efficiencies. Thus, we conclude that these methods for trapping photons, which can be realised using existing technology, could open the way to a multitude of hybrid optoelectronic devices to be used in 'quantum information' processing, communication networks and signal processors and may conceivably herald a new realm of combined metamaterials and slow light research.
We introduce an efficient method for slowing and stopping/storing light, which is based on wave propagation along a slowly axially varying, adiabatically tapered, negative refractive index metamaterial heterostructure. We analytically show that the present method can, in principle, simultaneously allow for broad bandwidth operation (since it does not rely on group index resonances), large delay-bandwidth products (since a wave packet can be completely stopped and buffered indefinitely) and high, almost 100%, in/out-coupling efficiencies. Moreover, by nature, the presented scheme invokes solid-state materials and, as such, is not subject to low-temperature or atomic coherence limitations. This method for trapping photons conceivably opens the way to a multitude of hybrid, optoelectronic devices to be used in 'quantum information' processing, communication networks and signal processors, and may herald a new realm of combined metamaterials and slow light research.
Metamaterials, which are materials engineered to possess novel optical properties, have been increasingly studied. The ability to fabricate metamaterials has sparked an interest in determining possible applications. We investigate using a metamaterial for boundary engineering in waveguides. A metamaterial-clad cylindrical waveguide is used to provide confinement for an optical signal, thereby increasing the local electromagnetic energy density. We show that metamaterial-clad waveguides have unique optical properties, including new modes, which we call hybrid modes. These modes have properties of both ordinary guided modes and surface plasmon-polariton modes. We show that for certain metamaterial parameters, the surface plasmon-polariton modes of a metamaterial-clad waveguide have less propagation loss than those of a metal-clad guide with the same permittivity. This low-loss mode is exploited for all-optical control of weak fields. Embedding three-level Λ atoms in the dielectric core of a metamaterial-clad waveguide allows the use of electromagnetically induced transparency to control an optical signal. Adjusting the pump field alters the group velocity of the signal, thereby controllably delaying pulses. Using the low-loss surface mode of a metamaterial-clad guide reduces losses by 20% over a metal cladding without sacrificing the group velocity reduction or confinement. In addition, we show that losses can be reduced by as much as 40% with sufficient reduction of the magnetic damping constant of the metamaterial. As this work aims for applications, practical considerations for fabricating and testing metamaterial-clad waveguides are discussed. An overview of the benefits and drawbacks for two different dielectric core materials is given. Also, a short discussion of other modes that could be used is given.
A competent method for slowing and completely stopping light, based on wave propagation along an adiabatically tapered negative-refractive-index metamaterial heterostructure, is presented. It is analytically shown that, in principle, this method simultaneously allows for broad bandwidth operation (since it does not rely on group index resonances), large delay-bandwidth products (since a wave packet can be completely stopped and buffered indefinitely) and high, almost 100%, in/out-coupling efficiencies. Moreover, by nature, the presented scheme invokes solid-state materials and, as such, is not subject to low-temperature or atomic coherence limitations. A wave analysis, which demonstrates the halting of a monochromatic field component travelling along the heterostructure, is followed by a corresponding ray analysis that illustrates the trapping of the associated light-ray and the formation of a double light-ray cone ('optical clepsydra'). This method for trapping photons conceivably opens the way to a multitude of hybrid, optoelectronic devices to be used in 'quantum information' processing, communication networks and signal processors, and may herald a new realm of combined metamaterials and slow light research.
We demonstrate the deceleration of guided electromagnetic waves propagating along an adiabatically tapered negative-refractive-index metamaterial heterostructure and show that light can ideally be brought to a complete halt. It is analytically shown that, in principle, this method simultaneously allows for broad bandwidth operation (since it does not rely on group index resonances), large delay-bandwidth products (since a wave packet can be completely stopped and buffered indefinitely) and high, almost 100 % in/out-coupling efficiencies. The halting of a monochromatic field component travelling along the heterostructure is demonstrated on the basis of a wave analysis and confirmed in a pertinent ray analysis, which unmistakably illustrates the trapping of the associated light-ray and the formation of a double light-ray cone (optical clepsydra) at the point where the ray is trapped. This method for trapping photons conceivably opens the way to a multitude of hybrid optoelectronic devices to be used in quantum information processing, communication networks and signal processors and may herald a new realm of combined metamaterials and slow light research.