Plasmonic Lattice Lasers

This project investigates the development and optimization of plasmonic nanolasers emitting around 600 nm, which combine an active polymeric thin film doped with a dye and a metasurface comprising an ordered two-dimensional array of metallic nanoparticles. These nanoparticles serve as an open feedback cavity, enabling room-temperature laser emission based on plasmonic devices. By designing and fabricating periodic metallic nanostructures that support surface plasmon resonances, we achieved coherent light emission under ambient conditions, overcoming significant challenges in plasmonic-based light sources. Our results demonstrate that plasmonic crystals fabricated via electron beam lithography (EBL) provide strong optical confinement and efficient feedback mechanisms, even in the presence of high intrinsic losses associated with metals. The observed emission characteristics, such as threshold behavior, spectral narrowing, and directional output, confirm the lasing nature of the phenomena. Additionally, the stability of the emission was closely tied to pump laser fluctuations, highlighting the importance of high stability for accurate characterization using nanoplasmonic devices. This work highlights the importance of a comprehensive description of the coupled photonic and plasmonic responses. It demonstrates the potential of plasmonic crystal lasers as compact, ultrafast, and tunable light sources. Future directions include enhancing the efficiency and tunability of such devices, exploring alternative materials, and integrating them into photonic circuits. The findings in this thesis provide both theoretical and experimental evidence for the viability of plasmonic lasers at room temperature, providing possible practical applications in on-chip optical communication, sensing, and quantum photonics.