Plasmonics for lasing action at the nanoscale

• Autores: Javier Cuerda Rodríguez
• Directores de la Tesis: Francisco J. García Vidal (dir. tes.), Jorge Bravo Abad (dir. tes.)
• Lectura: En la Universidad Autónoma de Madrid ( España ) en 2017
• Idioma: inglés
• Tribunal Calificador de la Tesis: Luisa E. Bausá (presid.), Esteban Moreno Soriano (secret.), María Ángeles Díaz García (voc.), Jaime Gómez Rivas (voc.), Alejandro José Martínez Abietar (voc.)
• Materias:
  • Física
    • Electromagnetismo
      • Interacción de ondas electromagnéticas con la materia
    • Óptica
      • Láseres
      • Óptica no lineal
• Enlaces
  • Tesis en acceso abierto en: Biblos-e Archivo
• Resumen

  • This thesis is devoted to the study of lasing action in plasmonic nanostructures. In order to treat the non-linear interaction of plasmonic resonances and active laser medium, we have developed a theoretical formalism based on a time-domain generalization of the finite element method. Within this framework, we analyze recent proposals of experimental designs of nanolasers in terms of the plasmonic modes that enable lasing action. This approach provides access to the full spatio-temporal dynamics of the electromagnetic fields and the population densities of the active medium.

    We start by analyzing recent proposals based on propagating surface modes in plasmonic waveguides. We show that, under coherent pumping, plasmonic waveguides can be used, together with a feedback mechanism, to achieve loss-compensation and laser self-sustained oscillations in this class of systems.

    Our theoretical formalism also enables us to analyze the lasing properties of periodic metallic nanostructures, so-called plasmonic crystals. Considering recent experiments, we show the role of non-radiative modes in the near-field laser emission, finding that there exists an optimal lasing regime with enhanced light-emission properties. Moreover, our results allow us to discuss the existence of an optimal set of geometrical parameters for this class of periodically nanostructured lasers.

    Finally, we analyze lasing action in core-shell metallic nanoparticles, focusing on how the laser properties evolve when going from a spherical geometry towards an elongated nanorod configuration. Discussion of these results in view of the current experimental paradigm, as well as physical insight based on a semianalytical approach, is finally provided.