The interaction of light with matter offers an invaluable tool to characterize the properties of materials and, at the same time, can be exploited for applications in optical communications, data storage, or sensing.
In our lab the focus is on the tailoring of the spectral response of electromagnetic waves in complex materials, including strongly correlated electron systems, photonic crystals and plasmon resonators. Our recent investigations have demonstrated the possibility of having customized magneto-optic spectral responsiveness, with magneto-optic enhancements at particular light wavelengths when coupled to photonic or plasmonic structures. A particular attention is also paid to the effect on light polarization when it interacts with media that present ordered electronic states, such as magnetic or ferroelectric compounds, that is exploited to carry out submicron domain imaging.
Our lab has different equipment to carry optic and magneto-optic characterization:
Magneto-optic spectroscopy lab.
Magneto-optic spectroscopy form UV to near IR (wavelength range ~ 300 – 1200 nm). Measurements of Kerr/Faraday rotation and ellipticity and magnetic circular dichroism from 8 K up to 320 K, and with magnetic fields up to ~ 2 Tesla.
Confocal microscopy lab.
High-resolution imaging (below the micron) based on confocal microscopy with polarized light contrast. It allows obtaining mappings of rotation/ellipticity and circular dichroism, as well as linear dichroism effects. These possibilities are exploited to perform magnetic as well as ferroelectric domain imaging.
Optical reflectance spectrometer.
Reflectance spectra in the visible range as a function of the angle of incidence. It allows obtaining reflectance contour maps for wavelength range l » 400 – 800 nm and angle of incidence within (–40º, +40º). From these plots we can obtain the dispersion relationship w– k (frequency versus wavector) of light interacting with media (plasmon reonators, gratings, photonic crystals, etc.)
Magneto-optical set up with remote-control rotor stage. It allows the study of magnetic anisotropy with high accuracy in azimuth angle.