The scope of the present doctoral thesis has been the conception of a novel and efficient method for decelerating, over a range of frequencies, and completely 'stopping' light (zero group velocity, vg = 0) inside solid-state materials, at room temperature. To this end, we analytically show that an adiabatically tapered waveguide having a core of a lossless negative refractive index (NRI) metamaterial (MM) and claddings made of normal dielectrics can 'trap' a light pulse in such a way that each individual frequency component of the pulse is stopped at a different point along the waveguide, forming what we have called a 'trapped rainbow'. Crucially, it is shown that light can efficiently be in-coupled inside such a waveguide heterostructure from a normal dielectric waveguide, since with a suitable design one can achieve simultaneous thickness-, mode- and characteristic-impedance-matching between the two waveguides. A pertinent analysis reveals that the optical path length of a 'trapped' light ray (associated with a particular frequency component of the pulse), as well as the corresponding effective thickness of the NRI waveguide itself, become exactly zero. The ray circulates at the point where it is trapped in such a way that its trajectory forms what we have called (in view of its characteristic hourglass form) an 'optical clepsydra'. Furthermore, we introduce a novel methodology that allows for obtaining ultra- low- or zero-loss magnetic metamaterials over a continuous range of frequencies. We analytically prove that a higher-degrees-of-freedom MM design methodology based on equivalent electrical circuits with more than one mesh leads to metamaterial magnetism with either ultra-high figures-of-merit or with perfectly lossless performance over a broad range of frequencies. The so-obtained lossless metamaterial magnetism has a truly intrinsic character, and as such is scalable and can be implemented at any frequency regime, from the radio up to the optical domain.

Les enjeux majeurs des dispositifs hyperfréquences utilisés dans les systèmes de télécommunication modernes sont la montée en fréquence de fonctionnement, la miniaturisation des circuits et l’intégrabilité des composants.Grâce à l’émergence des métamatériaux et à la maîtrise des propriétés des ferrites, il est possible de développer nouveaux dispositifs répondant à ces nouvelles exigences de l’électronique embarquée.Cette thèse développe, à partir d’une ligne métamatériau HIW coplanaire basée sur un substrat de ferrite, un nouveau dispositif hyperfréquence non réciproque de faible encombrement, opérant à des fréquences situées entre 13 et 15 GHz.Les prototypes fabriqués et caractérisés sous de faibles valeurs de champ magnétique, présentent les performances caractéristiques d’un isolateur bande étroite: isolation supérieure à 30 dB, pertes d’insertion inférieures à 1 dB. / The main challenges of microwave devices used in modern telecommunication systems are the increase of the operating frequency, the circuit’s miniaturization and the integration of components.Thanks to the emergence of metamaterials and the control of the properties of ferrites, it is possible to develop new circuits that meet these new requirements for embedded electronics.This thesis investigates, from a coplanar HIW metamaterial line based on a ferrite substrate, a new non-reciprocal microwave device, operating in frequency range between 13 and 15 GHz.Prototypes were fabricated and characterized under low magnetic field. They achieved the characteristic performances of a narrow band isolator: isolation over 30 dB and insertion losses of less than 1 dB.