Vacuum pressure imaging solution based on fiber-optic Fabry-Pérot interferometer and optical barcode

Abstract

Slight variations in vacuum can have a huge impact on industrial, medical, and scientific applications. For sub-atmospheric pressure measurements, conventional demodulation methods for fiber-optic sensors based on the wavelength tracking or power interrogation of the single resonant peak encounter difficulties in the direct vacuum level detection, in addition to cost and sensitivity issues which are one of the key obstacles for further applications of sensing probes. Here we demonstrate a total solution based on a fiber-based Fabry-Pérot interferometer (FPI) and an optical barcode based on Fréchet distance. The vacuum sensing fiber tip based on FPI prepared using the fixed-length cutting and fiber-end grinding techniques address the need for low-cost, high-sensitivity sensing for potential applications. Optical barcoding technique provides direct vacuum information by monitoring the overall behavior of the spectral resonance peaks. This work lays the foundation for the development of a low-cost, compact vacuum pressure sensing solution with direct vacuum reading.