Kuntman, E.; Kuntman, M. A.; Arteaga, O. Journal of the Optical Society of America A-Optics, Image, Science, and Vision Vol. 34, num. 1 DOI: 10.1364/JOSAA.34.000080 Publication date: 2017-12-31 Journal article
The optical activity of fabricated metallic nanostructures is investigated by complete polarimetry. While lattices decorated with nanoscale gammadia etched in thin metallic films have been described as two dimensional, planar nanostructures, they are better described as quasi-planar structures with some three dimensional character. We find that the optical activity of these structures arises not only from the dissymmetric backing by a substrate but, more importantly, from the selective rounding of the nanostructure edges. A true chiroptical response in the far-field is only allowed when the gammadia contain these non-planar features. This is demonstrated by polarimetric measurements in conjunction with electrodynamical simulations based on the discrete dipole approximation that consider non-ideal gammadia. It is also shown that subtle planar dissymmetries in gammadia are sufficient to generate asymmetric transmission of circular polarized light.
Nichols, S.; Arteaga, O.; Martin, A; Kahr, B Journal of the Optical Society of America A-Optics, Image, Science, and Vision Vol. 32, num. 11 DOI: 10.1364/JOSAA.32.002049 Publication date: 2015-12-31 Journal article
In this paper we describe a new Mueller matrix (MM) microscope that generalizes and makes quantitative the polarized light microscopy technique. In this instrument all the elements of the MU are simultaneously determined from the analysis in the frequency domain of the time-dependent intensity of the light beam at every pixel of the camera. The variations in intensity are created by the two compensators continuously rotating at different angular frequencies. A typical measurement is completed in a little over one minute and it can be applied to any visible wavelength. Some examples are presented to demonstrate the capabilities of the instrument.