Exploring the negative diffraction order in plasmonic crystals by refractive index engineering

In this paper an engineered dielectric material is used to introduce porosities which will change the plasmonic crystal´s (PCL) refractive index profile, its excitation conditions, electromagnetic (EM) characteristics and propagations. SPP excitation is moved from positive diffraction order (m=1) to negative diffraction order range (m=-1); hence the increment in wavelength will decrease the resonant angle. The m=-1 opens the possibility to control and manipulate the preferred excitation conditions of SPP for different purposes such as optical devices and sensors.