Thursday, October 15, 2015
Abstract-Generation of Terahertz Surface Plasmon Polaritons Using Nondiffractive Bessel Beams with Orbital Angular Momentum
Bessel vortex beams with topological charges of and were produced in the terahertz spectral range from a free electron laser Gaussian beam () transformed using silicon binary diffractive optical elements. The spatial characteristics of the beams were obtained using a microbolometer array. A radius to path length ratio of was achieved for nondiffractive beams with the average power of 30 W. Surface plasmon polaritons (SPPs) on gold–zinc-sulphide–air interfaces were generated due to diffraction of vortex beams on a sample edge. A new effect, a dependence of the efficiency of SPP generation on the direction of the azimuthal component of incident-radiation Poynting vector, was revealed.