Performance of Bloch-like Surface Wave Refractometers Based on Laterally Polished Photonic Crystal Fibers with Single-Layer Coatings: From Nanolayer to Nanostrip

Bloch-like surface waves (BLSWs) are electromagnetic waves generated at the interface between a dielectric medium and a photonic crystal. BLSWs has significant potential for sensing applications, since their electromagnetic fields are tightly confined near the interface, reaching comparable sensitivities to those of surface plasmon polariton (SPP)-based devices, but with higher figures of merit (FOM). This work explores a sensor based on BLSW at the interface formed by a TiO2 thin film deposited on the flat surface of a laterally polished photonic crystal fiber (PCF). The performance of the sensor is studied when the TiO2 film is partially removed, transforming the nanolayer into a nanostrip. The results of this study contribute to the optimization of the sensing performance of the proposed structure.