Mapping multiple surface-plasmon-polariton-wave modes at the interface of a metal and a chiral sculptured thin film

We charted multiple surface-plasmon-polariton (SPP)-wave modes at the planar interface between a metal and a chiral sculptured thin film (STF) in terms of the period, vapor flux angle, and orientation angle of the latter material. Two distinct scenarios were considered: one based on a canonical boundary-value problem involving half-spaces filled with the metal and the chiral STF and another based upon a modified Kretschmann configuration for ease of implementation. Calculations using empirical data for the constitutive relations of both partnering materials show that the number and nature of the SPP-wave modes are highly dependent on all three parameters.