Electro-optical enhanced photonic crystal fiber-tip sensor based on LiNbO<inf>3</inf> for E-field detection

Abstract

Non-intrusive electric field sensing devices have recently attracted attention due to their capability to face the problem derived from the conventional sensing probes which present a large sensing area and are based on conductive materials, distorting the field to be measured. This constraint is solved by employing all optical and compact probes which rely on electro-optical materials. However, all the electro-optical sensing devices are limited to sensibilities of the order of mV. For high sensing applications, nanophotonics is needed in order to enhance the electro-optical effect. Recently, the “Lab-on-fiber” technology has emerged, leading to optical nanoprobes which offer a broad range of sensing applications such as biological and chemical sensing, acoustic detection and temperature sensing [1]. In this work, we have designed and fabricated an E-field fiber tip sensor based on a LiNbO 3 thin film with mV sensitivity. In [2], we demonstrate that combining the thin film with periodical structures, the pyroelectric effect presents a higher sensitivity than other configurations. Moreover, in [3] we perform an accurate theoretical sensitivity analysis for E-field sensing in similar structures which show up the Fano resonances, characteristic for its asymmetrical high aspect-ratio, estimating a theoretical sensitivity of 50uV/m.