Laser-Based Trace Gas Detection inside Hollow-Core Fibers: A Review

• Main Author: Michal Nikodem
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Materials
• Subjects: hollow-core fiber (HCF); negative curvature hollow-core fiber (NC HCF); photonic band-gap hollow-core fiber (PBG HCF); anti-resonant hollow-core fiber; Kagome hollow-core fiber; laser spectroscopy
• Online Access: https://www.mdpi.com/1996-1944/13/18/3983

Thanks to the guidance of an optical wave in air, hollow-core fibers may serve as sampling cells in an optical spectroscopic system. This paper reviews applications of hollow-core optical fibers to laser-based gas sensing. Three types of hollow-core fibers are discussed: Hollow capillary waveguides, photonic band-gap fibers, and negative curvature fibers. Their advantages and drawbacks when used for laser-based trace gas detection are analyzed. Various examples of experimental sensing systems demonstrated in the literature over the past 20 years are discussed.