Over the last years our investigation on polaronic, photonic and plasmonic crystals has revealed photonic / plasmon effects that increase the magneto-optic response [see, e.g., References 1-5 below]. Additionally, we have demonstrated the nonreciprocal propagation of plasmons in the presence of magnetic fields [5]. All this research is relevant to achieving unidirectional propagation of spatially confined electromagnetic waves, indispensable for the development of on-chip optical communications in photonic circuitry.
We pursue different approaches that aim towards creating actively controllable nanophotonic devices: (i) integration of electro- and magneto-optic materials into nanophotonic metasurfaces to enable using electric (magnetic) fields to control confined electromagnetic waves; (ii) special topologies designed in the wavevector space that enable helical edge propagation of modes that flow unimpeded by imperfections or back-reflections. The latter are akin to quantum spin Hall in fermionic systems, which have been demonstrated in honeycomb photonic dielectric lattices.
Among other methodologieswe exploit finite-difference time-domain (FDTD) simulations to design metasurfaces and topological photonic crystals and angle-resolved reflectance/transmission spectroscopy, which can resolve reciprocal space maps from near-IR to violet, with scanning beam sizes down to few microns. Beyond the more common real space imaging, this methodology enables the direct visualization of the photonic bands structure.
[1] JM. Caicedo et al., ACS Nano, 2011. DOI: 10.1021/nn1035872
[2] Rubio-Roy et al., Langmuir 2012. DOI: 10.1021/la301239x
[3] Vlasin et al., Physical Review Applied 2014. https://doi.org/10.1103/PhysRevApplied.2.054003
[4] Casals et al. Physical Review Letters 2016, https://doi.org/10.1103/PhysRevLett.117.026401
[5] R. Cichelero et al., Optics Express 26 34842-34852 (2018) https://doi.org/10.1364/OE.26.034842
Gervasi Herranz 