Temperature sensor based on a liquid crystal plasmonic wire grating

In this work, a novel liquid crystal (LC) temperature sensor, based on a Silver (Ag) wire grating, is proposed and theoretically analyzed. The structure is composed of several Ag nanowires distributed in a parallel configuration (see Fig. 1). These wires can be deposited onto a silica glass or plastic substrate. Another substrate positioned on it is separated by spacers of 1.2 μm. The resulting cavity is filled with an E7 LC. The high thermo-optic coefficient of the LC is used to modify the plasmonic resonance of the wire grating. The structure is simple and easily scalable. The application of a 420 nm laser allows an output power ratio sensitivity of 16.7·10^-2 dB/°C with a high linearity. This is ten times more than other related temperature sensors based on light intensity variation.