Jaime Gómez Rivas

We present measurements of the transmission of terahertz radiation through periodic arrays of holes made in highly doped silicon wafers. The size of the holes, $70\ifmmode\times\else\texttimes\fi{}70\ensuremath{\mu}\mathrm{m},$ is significantly smaller than the radiation wavelength $\ensuremath{\lambda}\ensuremath{\simeq}500\ensuremath{\mu}\mathrm{m}.$ Sharp resonances and enhanced transmissions are observed. This unusual transmission is attributed to the resonant tunneling of surface-plasmon po

Photonic bound states in the continuum (BICs) are protected eigenstates in optical systems with infinite lifetimes. This unique property, which translates in infinite Q-factor resonances, makes BICs extremely interesting not only from a fundamental perspective but also for various applications such as lasing and sensing. General means to achieve robust BICs are, however, elusive. Here we demonstrate analytically that BICs emerge in metasurfaces formed by arrays of detuned resonant dipolar dimers

Light-emitting diodes (LEDs) are driving a shift toward energy-efficient illumination. Nonetheless, modifying the emission intensities, colors and directionalities of LEDs in specific ways remains a challenge often tackled by incorporating secondary optical components. Metallic nanostructures supporting plasmonic resonances are an interesting alternative to this approach due to their strong light–matter interaction, which facilitates control over light emission without requiring external seconda

We demonstrate the extraordinary transmission of terahertz THz radiation through gratings of subwavelength apertures structured in indium antimonide InSb. This transmission can be attributed to the tunneling of surface plasmons polaritons which are excited in semiconductors at THz frequencies. By thermally controlling the permittivity of the grating the transmittance increases by more than one order of magnitude. This increase might be associated to the larger the skin depth in InSb at low tempe

We present time-domain measurements of terahertz surface plasmon polaritons (SPPs) propagating on gratings structured on silicon surfaces. Using single-cycle pulses of terahertz radiation to excite SPPs in a broad frequency range, we observe that the efficient SPPs scattering on the semiconductor periodic structure introduces significant dispersion and modifies the SPPs propagation. A stop gap, or a frequency range where SPPs are Bragg reflected, is formed by the structure. This gap depends stro

A major challenge in the development of surface plasmon optics or plasmonics is the active control of the propagation of surface plasmon polaritons (SPPs). Here, we demonstrate the feasibility of low-frequency active plasmonics using semiconductors. We show experimentally that the Bragg scattering of terahertz SPPs on a semiconductor grating can be modified by thermal excitation of free carriers. The transmission of SPPs through the grating at certain frequencies can be switched completely by ch

The interaction between molecular electronic transitions and electromagnetic fields can be enlarged to the point where distinct hybrid light-matter states, polaritons, emerge. The photonic contribution to these states results in increased complexity as well as an opening to modify the photophysics and photochemistry beyond what normally can be seen in organic molecules. It is today evident that polaritons offer opportunities for molecular photochemistry and photophysics, which has caused an ever

Abstract Key in the application of plasmonics is the realization of low loss or high quality ( Q ) factor resonances. Nanoparticle arrays are systems capable of sustaining remarkably high Q ‐factor resonances through the hybridization of plasmonic and photonic modes, known as surface lattice resonances (SLRs). SLRs result from the coupling of localized surface plasmon resonances (LSPRs) to in‐plane orders of diffraction known as Rayleigh anomalies (RAs). To date, the highest Q ‐factors have been

We demonstrate the strong coupling of direct transition excitons in tungsten disulfide (WS2) with collective plasmonic resonances at room temperature. We use open plasmonic cavities formed by periodic arrays of metallic nanoparticles. We show clear anti-crossings with monolayer, bilayer, and thicker multilayer WS2 on top of the nanoparticle array. The Rabi energy of such hybrid system varies from 50 to 100 meV from monolayers to 16 layers, respectively, while it does not scale with the square ro

Abstract An enhanced emission of high quantum yield molecules coupled to dielectric metasurfaces formed by periodic arrays of polycrystalline silicon nanoparticles is demonstrated. Radiative coupling of the nanoparticles, mediated by in‐plane diffraction, leads to the formation of collective Mie scattering resonances or Mie surface lattice resonances (M‐SLRs), with remarkable narrow line widths. These narrow line widths and the intrinsic electric and magnetic dipole moments of the individual Si