Anomalous absorption of p-polarised laser on metallic surface ingrained with noble-metal nanotubes in the presence of external magnetic field

A theoretical study has been proposed where a p-polarised laser is irradiating a metallic surface topped with nanotubes at oblique incidence in the presence of static magnetic field. Interaction between incident laser and metallic surface stimulates the electrons of the nanotubes, causing them to excite and resonate at the plasma frequency. Incorporating external magnetic field with the system of nanotubes significantly enhances the absorption phenomenon. The absorption coefficient thus obtained is found to have direct dependence on the transmission coefficient of the incident laser as well as on dimensions of the nanotubes. Increasing the magnetic field strength along with the angle of incidence is found to produce more sharp absorption peaks. The result was also carried out for different materials. Due to their large surface-to-volume ratio of nanotubes, the carried-out study has a straight relevance in various biomedical applications like DNA sensor, immunosensors among other sensors, electrochemical sensors due to their excellent catalytic properties, in photothermal therapy and in photoacoustic imaging.