Microtapered long period gratings: Non-destructive fabrication, highly sensitive torsion sensing, and tunable broadband filtering

A Taper-in-Taper Structured Interferometric Optical Fiber Sensor for Cu2+ ion Detection

“…Such sensors have been widely applied in physical, chemical, and biological applications due to their unique properties (e.g., micro-size, lightweight, flexible, durable, biocompatibility, corrosion resistance, cost-effective, immune to electromagnetic interference) [ 6 , 7 , 8 , 9 ]. To date, several fiber-optic sensors with different structures have been developed, including photonic crystal fibers [ 10 , 11 ], FBGs [ 12 , 13 ], long-period fiber gratings [ 14 , 15 ], optical microfibers [ 16 ], and tapered optical fibers [ 17 , 18 ].…”

Switchable dual-wavelength erbium-doped fiber laser based on the broadband filtering performance of tapered long period fiber gratings

“…Recently, long-period fiber gratings (LPFGs), fabricated by periodically tapering single mode fibers, i.e., tapered-LPFGs (TLPFGs), have demonstrated their excellent performance as all-fiber optical sensors, owing to the fact that their attenuation bands or resonant wavelengths are highly sensitive to temperature, curvature, and the refractive index of the external medium [1][2][3][4][5][6][7][8][9][10]. In addition, the fabrication flexibility and repeatability of TLPFGs are now guaranteed by currently available fusion splicers and fiber processing machines, such as the CO2 laser-based glass processor or arc-electric Vytran machines, resulting in high quality and a high degree of sensitivity as compared with conventional LPFGs.…”