Performance of humidity sensor based on photonic crystal fiber interferometer

Abstract EN

Photonic Crystal Fiber Interferometers (PCFIs) are greatly used for sensing applications.

This work presents the fabrication and characterization of a relative humidity sensor based on Mach- Zehnder Interferometer (MZI), which operates in reflection mode.

The humidity sensor operation based on the adsorption and desorption of water vapour at the silica-air interface within the PCF.

The fabrication of this sensor is simple, it only includes splicing and cleaving the PCF with SMF.PCF (LMA-10) with a certain length spliced to SMF (Corning-28).

The spectrum of PCFI exhibits good sensitivity to humidity variations.

The PCFI response is observed for a range of humidity values from (27% RH to 85% RH), the position of the interference peaks is found to be shifted to longer wavelength with humidity increasing.

In this work, a different length of PCFs are used, and the maximum humidity sensitivity of (5.86 pm / %RH) is achieved with (4.5cm) PCF length, and the rise time of (8sec) is achieved.

This humidity sensor has distinguished features as that it does not require the use of a hygroscopic material, robust, compact size, immunity to electromagnetic interference, and it has potential applications for high humidity environments.