Direct observation of plasmonic index ellipsoids on a deep-subwavelength metallic grating

Liang Feng, Zhaowei Liu, Yeshaiahu Fainman
2011 Applied Optics  
We constructed a metallic grating on a deep-subwavelength scale and tested its plasmonic features in visible frequencies. The deep-subwavelength metallic grating effectively acts as an anisotropic homogeneous uniaxial form-birefringent metal, exhibiting different optical responses for polarizations along different optical axes. Therefore, this form-birefringent metal supports anisotropic surface plasmon polaritons that are characterized by directly imaging the generated plasmonic index
more » ... s in reciprocal space. The observed plasmonic index ellipsoids also show a rainbow effect, where different colors are dispersively distributed in reciprocal space.
doi:10.1364/ao.50.00g473 fatcat:6bymtjdkc5fovbufv74m3rh6ji