Fast temperature sensing using changes in extraordinary optical transmission through an array of subwavelength apertures

Abstract

A fast, sensitive temperature sensor using changes in extraordinary optical transmission (EOT) through an array of nanoholes in a metallic film with a monochromatic collimated light source is analyzed and experimentally demonstrated. The device is composed of a dielectric material in contact with a metallic film with an array of nanoholes, (25 arrays per chip were treated as a single sensor), on a glass substrate. Although the present experiment used a volume of water in a test cell to demonstrate the phenomena, there are many configurations that implement this technology in a variety of applications. The fast response of the device is expected because it measures the average temperature of a thin layer of the dielectric material directly above the nanoholes, ~100 nm. The thermal response parameter of the nanohole array sensing region is ~108 times smaller and orders of magnitude faster than that of the reference thermistor. The increased speed and sensitivity of the nanohole array temperature sensor over the thermistor is observed in the reported data. The configuration of this temperature sensor was used for simplicity and to demonstrate that EOT effects can be used for temperature sensing.