Subsurface probing of terahertz particle plasmons

Here, the authors exploit the potential barrier at the interface between dissimilar metals to probe frequency dependent subsurface charge induction on metallic microparticles excited with terahertz radiation. The authors' experimental data and model show that terahertz electromagnetic charge induction on the microparticles occurs over a distance comparable to the skin depth. This work provides a technique to probe subsurface terahertz charge induction in subwavelength metallic structures and may open research avenues of low-frequency plasmonic behavior. (c) 2007 American Institute of Physics.