Negative Photoconductivity Induced by Surface Plasmon Polaritons in the Kretschmann Configuration

Prism coupling in the Kretschmann configuration is a well-known method for the excitation of surface plasmon polaritons (SPPs) in thin films bounded from one side by a prism and from the other side by air. Based on the Kretschmann configuration, we experimentally study the transport properties of a silver thin film with a thickness of 55 nm and a width of 500 µm undergoing total internal reflection. We observe considerable negative photoconductivity in the film induced by the SPPs excited in this configuration and find that both SPP-electron interactions and SPP-induced heating have contributions to the negative photoconductivity. We believe that the new phenomena, which result from the combination of photonics and electronics, will be useful in relative technical applications and scientific research.