Analysis of a Plasmonic Slit Nanoantenna as a High Sensitivity Tilt Sensor

The emergence of nanotechnology allows the discovery of new phenomena, such as extraordinary optical transmission (EOT). In 1998, Ebbesen reported an unusual transmission in nanoantennas, however, only in 2004 Lallane and Hugonin presented results to prove that surface plasmon polaritons (SPPs) are the main agents of this phenomenon, at least in the visible and ultraviolet region. Thin metals can in certain conditions transmit radiation instead of reflecting it as predictable by classical theories. These conditions are imposed by the dielectric-metal interfaces of the designed devices. Then, the device response is going to change if the materials' properties vary. Consequently, excellent sensors may appear and the EOT effect can improve their specifications. A four-slit nanoantenna is going to be analyzed as a tilt sensor. A novel developed model is used to design the tilt sensor. This semiclassical model is based on wave-particle dualism. This research work aims to verify if an optical nanoantenna can act as a tilt sensor and if the EOT improves the sensor's response. By analyzing the output optical power, maxima sensitivities of 70 219 and 18 882 rad(-1) are obtained inside and outside the resonances, respectively. Also, sensibilities around 7 fs rad(-1) are determined when analyzing the time until obtaining results capable to have information about the tilt angle. Based on the results, it is possible to conclude that the analyzed device can detect variations of at least 0.5p/100 rad (0.9.) and that the EOT increases the sensors' sensitivity.